To learn about electronics in a different and very effective way, check out my Patreon page. Many of my designs are released there as well. Click this Link: www.patreon.com/MrCarlsonsLab
@HalfSpeedMastering -- In this particular case it certainly is same, since the FET in question has a pure and very brief pop-suppression function and is otherwise pretty close to a piece of wire in the signal chain. I would trust Paul 100 percent to avoid degrading or otherwise altering the audio performance of any gear he works on.
Gotta love this old school equipment. Very stylish scientific look to the dials, markings, and solid cabinetry. Reliable circuitry, and easy to work on. 🎛🎚🎚🎚🎚 👌😙
Quick question where did you get you desoldering tool. And or what is the brand name/ what is it called. Thank you for your time and have yourself a grate day. 😁
As an industrial electrician, that spent literally weeks fault finding and eventually repairing a marantz vintage amplifier, as a hobby at home, this was very humbling to watch and follow. Thankyou sir !
Same, I'm an industrial electrician and don't know as much about electronics as I should mainly because my PA system has 10, 15 band eq's and 2, 31 band eq's. Atleast one of them has an issue in rotation.
Wow, freakin' awesome video. My first equalizer was an ADC Sound Shaper Two (with the VU meter) in 1978. Worked great but with three tape decks I eventually wanted a dubbing feature on the EQ. So in 1982 I purchased this model ($213). With bidirectional dubbing, large LED meters, a good subsonic filter (18dB/oct@15hz), THD and IM of 0.02% and great layout of controls I was pleased. My original EQ was given to my brother-in-law and he still uses it today. That's over forty years. My SS2 IC still functions perfectly and is used every time the hifi is on. Not bad for thirty six years old. Some folks just don't understand how useful an equalizer can be. This video is very interesting and a definite keeper. The SS2 IC is an excellent EQ, functional and pleasing to the eye with that "industrial" look. Remember their first EQ?? The ADC 500??? Well worth an hour of my time to view this. Nicely done, sir.
Love your channel! You are an incredible tech. I used to calibrate analog aircraft instruments mostly rate of climbs and altimeters and we used to call it technician proximity syndrome. I haven't commented yet but have been binge watching your channel. I am also a ham. 67 yrs old and been a ham for 35 yrs. You have more knowledge about things than most people have forgotten. You and Nicola Tesla would have been the team to change the world. 73 de KB7ICI.
Respected sir, I have seen lots of audio repairs uploads on TH-cam. BUT your upload is top of all those .In my opinion you well described, relaxed,well speech,through, well repaired videos.
@@sferg9582 Still have my ~40 year old one, a SS110 Mk. II, that I had given to me back when I was 14. That was in 1991. Just fixed it today, now it works right :)
We used to sell and service SoundShaper equaliser back i n The early 70' and this one you repaired is so simpler than the first ones they designed! The had the power supply completely shielded from the rest of the circuitry and used at the first models germanium transistors, but I see their basic or original design hasn't changed to much. Keep videos like these coming , they are a pleasure to watch for a retired old engineer like me! :)
My Soundcraftsmen PE2217 Preamp-Equalizer is due for an overhaul. Time to get my hands in there and have some fun. Sliders have gotten sticky, and some electrolytic caps are on their last leg and thus are affecting the bandwidth at the low end.
I'm not an electronics tech by any stretch of the imagination, but you explain things so well that I was able to follow along without any problems whatsoever. Great presentation and quality I might add.
So cool to watch you diagnose and repair this graphic equalizer ! You are quite the expert and I thank you for sharing your outstanding skills for others to learn from and enjoy on TH-cam.
its funny you might be right. i put on mr carleson to relax and go on adventures into vintage troubleshooting land. youre right. its an awesome quality and i hope he never changes. im gonna subscribe to his patreon i think
I appreciate you making these videos with a high megapixel camera. That way we can really see what's going on with the circuitry and individual components.
What an excellent example and tutorial on the most useful devices for quick repairs! Many thanks Paul, for taking the time going along the schematics with us step by step. You're an awesome teacher!
I don't really understand a lot of what he talks about, but I still very much enjoy watching this channel because even if I don't understand most of the things he is doing, I do slowly pick up on things that make sense to me, so I still gain knowledge about how these things work that I didn't have before.
I have what is probably a previous version of that very EQ. It is simply called Sound Shaper Two and it has analog/mech level indicators. Aside from some of the switches needing cleaning, I use it to this day and and after around 40 years, I still like it! Glad to see with very little effort, they can be repaired! Thanks!
@@BruceNitroxpro Ha! I would if I could figure out a way to recap my ears! Sadly I can't hear any highs anymore! But along those lines, I do have a couple old Heath Kit amps and pre-amps that I used as a stereo years ago that definitely need recapping. No idea what kind to use though.
Paul - You did it again. The equalizer has come back to life! I appreciate the enlarged schematic. Many times they are too small to read. This time it was much better. Thanks
So many of your fans have old scopes. One of the most common scopes over the decades was the Tektronix 465B. I think this would be a worthy work horse to go over as a general "what to look out for" and common problems specifically pertaining to this aging scope. I built mine from scraps of others that were beyond ECONOMICAL repair. Nothing is irreparable with your keen skill!
Check the DC restorer diodes going to the grid. Also, check if the Z intensity control input has any effect. After that, ebay for the transformer, or a dead 465b for parts. Check your local tyrannical government electronics redistribution center. I have seen them sell for $20 working!
I had an Apple tech brake tabs off and leave pry bar marks on an Apple IIc computer because he did not know the proper way to open the case. It really got my goat. I love the channel. Keep up the great work. Wish I knew one tenth as much as you about electronics. I learned just enough to get a ham licence. Love the old equipment (boat anchors).
Amen brother. Don't know how many times someone sent in a radio saying xxx was wrong with it and the instant it got set on my bench it started to work again. Having been a heavy truck mechanic also many years ago I speak from experience when I say they suffer from the same problem to.
@@Mariano.Bernacki For me the opposite happens. I test the damn computers for 2-3hours and the next day the client calls me that the thing stopped working.
The effect also happens with desktop support. Arriving at customers desk will sometimes solve the problem. I always used to say I was so good my mere presence solved the problem.
Truck driver to Radio tech: "It's the finals". Truck driver to Mechanic: "It's the EGR". -Former, recovering truck driver turn technician. Other favorites: "No, I bought it brand new! Nobody has ever been in there!(Covered in pry marks, stripped screw heads, missing screws, splatter-box, solder balls rolling around, cut diodes, over-sized caps...). "It just needs caps". (Burnt PCB around through holes, smoked resistors, some weird residue all over, is that a bobby pin? What is that smell? Is...is that urine? How the hell...). "I'll be back Thursday".(11 months later..)
Exemplary details, focus, patience, organization… I admire the thoroughness of this video. Thank you! P.S. I usually trace signal path on schematic with color marker to make it easier to follow as I go back and forth between the unit and the schematic.
Paul, I really appreciate your discussion on J-fets and how to test them. Back when I was in electronics school they hadn’t been invented yet, so I had only a rudimentary idea of how they worked. Your clear explanation answered many questions I had. I joined Patreon a few months ago after finding your channel and I have rediscovered my love of electronics again.
I know nothing about electronics, half the stuff you talk about totally confuses me, but it is fascinating watching how you troubleshoot this sort of thing :)
Hi Paul, I am very excited to see your first repair video of the New Year. Nice to see you use the SuperProbe and the 224. I love both very much I have a Mod 222 which I think is very useful, yet not as useful as the SuperProbe I built using your brilliant design. Thanks again for all that you do and sharing your bottomless knowledge, along with your ingenious electronic inventions with us! Take care my friend and please never stop sharing your vast and practical knowledge with the electronics repair community. "Why be a rockstar when you can be a god?" applies to Mr. Carlson's Lab. It's funny, you have the youthful appearance of someone in their late 30's or early 40's and yet you posses 125 years worth of electronics knowledge and experience.
We can se that you are a great engineer. Congratulations for that wonderful scenario. People like you make the world a better place. Wish I had 1% of your capabilities. Thank you for your videos.
I'd like to know how Paul got so heavily into vintage as his specialty. It's really what sets this channel apart because much of the knowledge he presents is no longer taught and is slowly being lost. And yet, he doesn't come off as some nostalgic curmudgeon but rather he makes everything seem timely and relevant. They say with everything being so digital today, it's often the analog aspects of a circuit that are most half-assed and overlooked. This is where the tricks of the past could serve us well.
Great job! Once again, making it look all too easy! And once again thinking I need to build that Super Probe. I built a probe(with an actual germanium diode) and it works well, but the idea of a non-contact probe where one can just wave it close to the board and not having to locate and contact an emitter at some absurd angle is blissful. Curve tracer first, though. Op Amps are coming in from Digi-key as we speak. Your Patreon page has been the single best tool on my bench. I have been using your transistor tester, matching, biasing circuit for a while now and it never fails. I just let your videos play while I work and always learn something new, even if I have heard the video a couple of times.
man im so keen on making a carelson super probe now. and a curve tracer. ive been obsessed with clipping & saturation shapes recently and i cant believe i didnt know what a curve tracer was. its such a straight forward bit of gear too, but it tells you so much. and the super probe is genius. non-coupled signal sniffing. what a ripper idea. thanks mate you do an amazing job.
Loved playing with my equalizer when I was young . Usually when tuning it to a song I was playing to make it sound good the song was almost over . Then played the song again at just the right tone . Half the fun was playing with it !
@@devilsoffspring5519not always. I have some older tapes that have poor sound at higher frequencies and things like that, and the equalizer allows me to make the recording sound good again. But year, when I was a 15 year old I loved pushing the sliders around, distorting the sound in horrible ways... But I learned a lot at the same time.
Thanks Paul. More invaluable coaching and instruction. I also agree with others in that you should bring the SuperProbe to market either in DIY kit form or finished product.
All thanks and credit to you Paul and 1/2 dozen excellent guys like w2aew, AA5R, Afrotech, Andreas, Andy Davis & a few other subject matter experts, who constantly share your wealth of knowledge and experiences with us.
I feel as if I've learned more watching your videos than I did during the handful of mandatory EE courses I had to take at uni (I studied SE). Wonderful content.
What jerk would give this video a thumbs down? Someone sharing their valuable knowledge like this does not deserve a dislike. Anyway, thanks Paul as always for sharing with us. Good stuff pal.
I love seeing the retro test equipment I learned on back in the late 70’s! Still more useful than the modern stuff if you understand their functionality and how to use them! We used the Huntron tracker regularly!
I have the same exact model equalizer which is still fortunately working. But I will save this video in case it develops a problem and needs to be fixed. Thank you very much
Another wonderful video. Almost root against you solving the problem because that's where it concludes. All of what was presented was fantastic but how much fun and learning it would have been had we made it into the equalizer sections? I don't think anyone could explain it better! Thanks for taking the time to make it I enjoyed every second.
Thank you for uploading extremely informative videos that inspire, help, motivate, and bring pleasure to people all over, and in a professional, calmly hypnotic manner. You deserve a lot more subs!
love that huge mid scoop they have going on on this unit. i have a late 80s 100 band eq/amp thats needing some repairs. each band has leds on the sliders, some have died , and hard to find 12v square type leds, without paying an arm and a leg. it also needs a re-cap which isnt to difficult once you dig into the unit. Thanks for sharing this beast!
Love this video Paul just the way you pursue a problem and solve it is just incredible I have to say this but you are so young but you have acquired so much knowledge and the equipment you have is just wonderful It's always a pleasure to watch you solve a problem and in such detail repair it
Wow, what a treat! There's always something cooking at Mr Carlson's Lab, but today you coincidentally covered the same model of equalizer my dad gave me which has a similar problem! I can't wait to work on it after seeing this video. I like the curve tracer you were using and the Super Probe was pretty cool. Your channel is an inspiration to me, the way you explain things make electronics fun and less daunting to learn. As always, keep posting awesome repair videos :)
I worked at a job troubleshooting printer PCBs years ago. I miss the Huntron Tracker (dual trace curve tracer). Great tool. Very necessary as the manufacters would not release schematics to our company. Info on a lot of the printers was still confidential.
Great video, man I have to build the super probe and curve tracer asap. Thanks Mr Carlson. Love your channel and being a patreon is a must! Best money I spend every month
We had an audio "sniffer" when I worked in the network/cellular industry. We connected the audio generator to one end of the RJ45 cable and used the probe to find the other end when we heard the test tone. It was a necessary tool when dealing with cabling that nobody thought to label, especially when going from one end of a building to the other.
Thanks again Paul for another great video and for your Patreon course. I have learned a great deal and have been able to understand how different parts work together.
I don’t know how it is that they get better and better. I am only half way through and I can already say this is the best video yet Don’t ask me to pin point why. It just is.
Absolutely amazing troubleshooting Mr Paul. This is the first I saw testing jfets, how great the curve tracer see inside the device. Wow, I really enjoyed. Best of the best video only in this channel👈👏👏👏👍👍
I would have to agree,you are the man when it comes to the tiny cities of electronics, I like listening to your comical jokes that sometimes not every body get's,cheers to you Mr Carlson's Lab..
Awesome video Mr. Carlson! Really appreciate the time you take to spread your knowledge. Watched the entire video with immense interest. Learn a lot. Looking forward to taking your course very soon. Cheers!
I’m sure this is going to be another great video and I’m looking forward to enjoying it over the next hour. It looks like nice unit, and these things could be useful in the right hands. Unfortunately, back in the day equalizers seemed to attract those that wanted overly-booming bass and overly-sizzling highs and not those that wanted to subtly correct for a room aberration or poor recording. I wish they had been designed with only +/- 4 dB of gain and not the typical 12. That’s more than enough, really, and would have kept people from destroying the careful sound that engineers take time to mix, while also saving amps, speakers and ears from damage. I can’t tell you how many times I got in a car back in the 80s and 90s, and was tempted to zero-out a friend’s equalizer. Nowadays, I’m still tempted, but the equalizer is buried in ten layers of GUI!
I don't think a lot of people understand the proper use of an EQ also. I use it more to remove frequencies rather than boost. Most people boost the crap out of it!
Another excellent troubleshooting video, perfect for the new technicians out there. There is an "official" name for the technique you used to divide the schematic near the beginning of the process - it's called "the half split method" - dividing the block at the middle and checking for signal. It works really well for very complex systems.
Thanks Paul! Nice work! That opening shot never gets boring! I am almost ready to start making boards. If I can't find a scope this month for my curve tracer, I will start on a more simple device that I already have most of the components for. Or I might just start making boards and set them aside until later.
I used to do with cameras what you do with electronics, but had what we called "Japanese Magic" -- if it was going to malfunction, it would do so for me! A very handy talent when you back your work with your word.
Thank you Mr. Carlson .. This vid just inspired my next fish can project - so named because I have a collection of sardine and the like cans with matching perfboard "covers" that I've been trying to come up with small one and two evening projects in which to utilize them. A curve tracer! No reason that I can't spin off a rudimentary battery powered 4 chip tracer with miniature 5x7 LED matrices (arranged 10 rows, 14 columns) as the display. 3/4 of a quad comparator to generate the probe sine, square it up for a pair of 4017's to do sweep, and level translate the other probe to center an LM3914 vertical input. Should be cute as a button, and the relatively low resolution shouldn't be an issue.
You can determine R and L channel on the schematics starting from the S.L.M. Jack. Tip is the left channel, so the right channel is the lower one in the schematics.
At min 24: HP taught that was the "half/split method." I was a technician for 38 years at Raytheon and then an engineer for up to year 50 and it worked for me
Great vid. Love your non-intrusive test tools. With regards to which channel is which, there are a few conventions that can help people make good educated guesses. they all follow the convention left comes first, then right; - the channel drawn on the top is usually Left - if all the component numbers are odd numbers (eg TR101, R113), and the other even (TR102, R114) then the odd channel is usually Left. - if the channel component numbers all differ by a hundred (eg TR511, R512, C518 one side) vs (TR611, R612, C618 the other) then the lower hundred series is usually Left - if only one channel has signal path, component values, voltages all drawn in, and the other doesn't, the channel with the extra info is usually Left - if only one channel is fully drawn (and the other is only partially drawn, if at all), the channel drawn properly is usually Left. Awesome vid. Really enjoyed.
A practical approach to audio or video equipment troubleshooting/repair: I think the determination of a (the) faulty channel could be done much quicker by a simple "audio in and out" setup. With a cheap mp3/music player, a powered speaker (I have one on my bench always ready to rumble) and a set of RCA cables this would take literally 20 seconds. No need to disassemble anything. From there the search could go on. Or you could determine a properly working EQ, with the only defect a faulty VU meter. It IS "audio" so it can be prechecked audibly :-). I recommend also to changes the state of all of the switches and sliders while testing (aka listening to the test sound/music), so a "rotten" switch or bad contact can be traced immediately. And what I missed in your video was a final check of audio. Only after that step, I would do a thumbs up, not before :-)
I learned alot from this video here. I learned how to divide a schematic to break it down to areas of concern. Also about Jfets and what the signals mean. I'm headed over to the pahtheon page to check it out. Thanks again.
To say Bravo, great job, is redundant. You know, I know you are brilliant! It's the be brave to open the cover and troubleshoot the problem and don't give up creed! If you follow the signal, you will find where it starts and where it stops you will find the faulty component. Happy 2019, a great video to start the new year. Thanxz
I used to have the earlier model of that EQ. However in the late 80's I converted it to balanced inputs and outputs and to use a higher line level to make it compatible with professional sound mixers. What made that easily possible compared to most consumer grade graphic EQs is they used a solid push-pull transistor stage in the outputs which most consumer gear didn't use. Another difference was the older model I had used inductors for the 1st three bands but they were later dropped to cut costs plus capacitor technology got better and high value tight tolerance capacitors became more affordable but even so the center frequency in the lower bands tends to be a bit sloppy as compared to using inductors but good enough for consumer devices
As an electronic technician hobbiest and formerly licensed fire alarm technician, your troubleshooting was very good but missing a few things that I would have done. 1) Test the output of the channels at the back panel as I start. This tells me if the issue is an actual dead circuit versus a dead led driver. Since this is easily done by using a cheap speaker hooked up to each channel (with an amplifier to make the speaker loud enough) it would be a part of my audio testing toolkit. A bonus to this testing is you find out which jack is lacking output which helps to trace the channel circuitry. 2) Following on from step 1, I would trace the circuit from the jack wiring backwards to the input wiring. (This is personal preference but it helps when you can't find a circuit diagram.) 3) 'Tone' out the circuitry. (Here is where a 'fox and hound' comes into play. Tone generator and probe used in phone line testing but handy in other areas.) Basically this is the super probe methodology but using the tools I have in my toolkit (and you can find in some stores like Harbor Freight, Home Depot, and Lowe's). Once you'd found your bad part, replace it (and companion for stereo components).
You're forgetting, this is a video. The whole idea is to show different troubleshooting techniques, not to go right to the problem. This video would be 5 Minutes long if I did that, and people wouldn't see a path to the issue.
Absolutely amazing stuff as always, Paul! I've been a patron for a while but haven't gotten around to building the Carlson Super Probe. Having watched this, I just HAVE to build it. Obviously, the time it will save me is a multiple of the time it takes to build it. Thanks so much!
Is it possible for this whole "porn" nonsense to be dropped, when referring to an area of interest which one likes? It sounds SO crude and ignorant, not to mention that it's just... unoriginal in the utmost. Maybe...?
I agree with unlokia, there is nothing pornographic about this. To be frank Penfold8, I would like to quote Inigo Montoya, "I don't think that word means what you think it means." This is pure electronics nerdvana, not something dirty at all and I would kindly ask that you refrain from referring to it as something it is not.
The chances of me ever having to repair any kind of amplifier to component level are about the same as me winning the lottery - but this held my interest completely and now I know what makes a good schematic diagram and what depletion means...
Great video, Paul. Thank you very much! About addressing the L-R, 1-2 part on the schematic; Firstly if the manufacturer doesn't label this on the front plate, it doesn't help much if they label it on the schematic. A possible explanation can be that in a professional environment, "a stereo" EQ most of the time isn't used on the stereo output chain. Perhaps one EQ is inserted on the console channel 16 before recording and the second EQ is used on return 4 to the vocalist's headphone, as this often is a dual mono signal. Nevertheless, you are right, for troubleshooting it is unacceptable not to address the two parts especially if these aren't electronically identical. Heck, name it Anne & Rose if L-R, 1-2 can be confusing.
To learn about electronics in a different and very effective way, check out my Patreon page. Many of my designs are released there as well. Click this Link: www.patreon.com/MrCarlsonsLab
@HalfSpeedMastering -- In this particular case it certainly is same, since the FET in question has a pure and very brief pop-suppression function and is otherwise pretty close to a piece of wire in the signal chain. I would trust Paul 100 percent to avoid degrading or otherwise altering the audio performance of any gear he works on.
Gotta love this old school equipment. Very stylish scientific look to the dials, markings, and solid cabinetry. Reliable circuitry, and easy to work on. 🎛🎚🎚🎚🎚 👌😙
Could you help or enlighten me with component VSHPS1437_040050680, your help will be highly appreciated sir....thanks
May you should make a video about the carlson super probe instead, if it is so easy to use.
Quick question where did you get you desoldering tool. And or what is the brand name/ what is it called.
Thank you for your time and have yourself a grate day. 😁
I am completely naive to the world of electronics but you present in such a way that makes it easy to understand.
As an industrial electrician, that spent literally weeks fault finding and eventually repairing a marantz vintage amplifier, as a hobby at home, this was very humbling to watch and follow. Thankyou sir !
Same, I'm an industrial electrician and don't know as much about electronics as I should mainly because my PA system has 10, 15 band eq's and 2, 31 band eq's. Atleast one of them has an issue in rotation.
A super probe on a super channel.........Beautiful explained and implemented, simply the best tech/designer/teacher on TH-cam .
Wow, freakin' awesome video. My first equalizer was an ADC Sound Shaper Two (with the VU meter) in 1978. Worked great but with three tape decks I eventually wanted a dubbing feature on the EQ. So in 1982 I purchased this model ($213). With bidirectional dubbing, large LED meters, a good subsonic filter (18dB/oct@15hz), THD and IM of 0.02% and great layout of controls I was pleased. My original EQ was given to my brother-in-law and he still uses it today. That's over forty years. My SS2 IC still functions perfectly and is used every time the hifi is on. Not bad for thirty six years old.
Some folks just don't understand how useful an equalizer can be. This video is very interesting and a definite keeper. The SS2 IC is an excellent EQ, functional and pleasing to the eye with that "industrial" look. Remember their first EQ?? The ADC 500??? Well worth an hour of my time to view this. Nicely done, sir.
Love your channel! You are an incredible tech. I used to calibrate analog aircraft instruments mostly rate of climbs and altimeters and we used to call it technician proximity syndrome. I haven't commented yet but have been binge watching your channel. I am also a ham. 67 yrs old and been a ham for 35 yrs. You have more knowledge about things than most people have forgotten. You and Nicola Tesla would have been the team to change the world. 73 de KB7ICI.
Respected sir, I have seen lots of audio repairs uploads on TH-cam. BUT your upload is top of all those .In my opinion you well described, relaxed,well speech,through, well repaired videos.
Wow, I have the same ADC Equalizer that I bought in the mid 80's. still works great. Thanks for the video.
Me too. Love it.
@@sferg9582 Still have my ~40 year old one, a SS110 Mk. II, that I had given to me back when I was 14. That was in 1991.
Just fixed it today, now it works right :)
The sliders on mine does light up and no sound it hasn't been used in years
We used to sell and service SoundShaper equaliser back i n The early 70' and this one you repaired is so simpler than the first ones they designed! The had the power supply completely shielded from the rest of the circuitry and used at the first models germanium transistors, but I see their basic or original design hasn't changed to much. Keep videos like these coming , they are a pleasure to watch for a retired old engineer like me! :)
Thanks for sharing your story!
My Soundcraftsmen PE2217 Preamp-Equalizer is due for an overhaul. Time to get my hands in there and have some fun.
Sliders have gotten sticky, and some electrolytic caps are on their last leg and thus are affecting the bandwidth at the low end.
I appreciate you showing us how we can fix ourselves these otherwise difficult equipment we thought could not be fix by us. Thank You very mucho!!!!!!
The modest demeanor is incredible. Awesome work!
I'm not an electronics tech by any stretch of the imagination, but you explain things so well that I was able to follow along without any problems whatsoever. Great presentation and quality I might add.
So cool to watch you diagnose and repair this graphic equalizer ! You are quite the expert and I thank you for sharing your outstanding skills for others to learn from and enjoy on TH-cam.
This guy is the Bob Ross of the electronic world... "Let's put a happy little TRIAC right here."
:) lol
Interestingly, his voice is also similar...
@@Rob2 you are right, had to listen again. Very much like Bob. lol
@@Rob2 The voice of interminable patience.
its funny you might be right. i put on mr carleson to relax and go on adventures into vintage troubleshooting land. youre right. its an awesome quality and i hope he never changes. im gonna subscribe to his patreon i think
I appreciate you making these videos with a high megapixel camera. That way we can really see what's going on with the circuitry and individual components.
Great job Mr. Carlson. Old school gear lives on. I've had a smaller version ADC EQ forever and it still works.
What an excellent example and tutorial on the most useful devices for quick repairs! Many thanks Paul, for taking the time going along the schematics with us step by step. You're an awesome teacher!
Thanks for your kind comment Ralf!
ADC one of the best sounding EQ ever made !
I don't really understand a lot of what he talks about, but I still very much enjoy watching this channel because even if I don't understand most of the things he is doing, I do slowly pick up on things that make sense to me, so I still gain knowledge about how these things work that I didn't have before.
I have what is probably a previous version of that very EQ. It is simply called Sound Shaper Two and it has analog/mech level indicators.
Aside from some of the switches needing cleaning, I use it to this day and and after around 40 years, I still like it!
Glad to see with very little effort, they can be repaired!
Thanks!
Throw Me Back, You may consider recapping it, also. That is a circuit long in the tooth.
@@BruceNitroxpro Ha! I would if I could figure out a way to recap my ears! Sadly I can't hear any highs anymore! But along those lines, I do have a couple old Heath Kit amps and pre-amps that I used as a stereo years ago that definitely need recapping. No idea what kind to use though.
this is amazing. World Radio Repair Championships are needed
Your channel is a great gift to the restoration and understanding of vintage electronics.
Paul - You did it again. The equalizer has come back to life! I appreciate the enlarged schematic. Many times they are too small to read. This time it was much better. Thanks
You are truly gifted in electronics. I'm envious. Thank you for all of your videos.
You are very welcome!
So many of your fans have old scopes. One of the most common scopes over the decades was the Tektronix 465B. I think this would be a worthy work horse to go over as a general "what to look out for" and common problems specifically pertaining to this aging scope. I built mine from scraps of others that were beyond ECONOMICAL repair. Nothing is irreparable with your keen skill!
Check the DC restorer diodes going to the grid. Also, check if the Z intensity control input has any effect. After that, ebay for the transformer, or a dead 465b for parts. Check your local tyrannical government electronics redistribution center. I have seen them sell for $20 working!
I had an Apple tech brake tabs off and leave pry bar marks on an Apple IIc computer because he did not know the proper way to open the case. It really got my goat. I love the channel. Keep up the great work. Wish I knew one tenth as much as you about electronics. I learned just enough to get a ham licence. Love the old equipment (boat anchors).
Amen brother. Don't know how many times someone sent in a radio saying xxx was wrong with it and the instant it got set on my bench it started to work again. Having been a heavy truck mechanic also many years ago I speak from experience when I say they suffer from the same problem to.
Ditto for computers and electrical installations.
@@Mariano.Bernacki For me the opposite happens. I test the damn computers for 2-3hours and the next day the client calls me that the thing stopped working.
The effect also happens with desktop support. Arriving at customers desk will sometimes solve the problem. I always used to say I was so good my mere presence solved the problem.
Truck driver to Radio tech: "It's the finals". Truck driver to Mechanic: "It's the EGR". -Former, recovering truck driver turn technician. Other favorites: "No, I bought it brand new! Nobody has ever been in there!(Covered in pry marks, stripped screw heads, missing screws, splatter-box, solder balls rolling around, cut diodes, over-sized caps...). "It just needs caps". (Burnt PCB around through holes, smoked resistors, some weird residue all over, is that a bobby pin? What is that smell? Is...is that urine? How the hell...). "I'll be back Thursday".(11 months later..)
@@sobolanul96, you mean the client failed to tell you that the computer was being used in a sauna? LOL
A pleasure to see a master at work.
Thanks for sharing another electronic tutorial Paul. That was fun to watch.
Exemplary details, focus, patience, organization… I admire the thoroughness of this video. Thank you! P.S. I usually trace signal path on schematic with color marker to make it easier to follow as I go back and forth between the unit and the schematic.
Paul, I really appreciate your discussion on J-fets and how to test them. Back when I was in electronics school they hadn’t been invented yet, so I had only a rudimentary idea of how they worked. Your clear explanation answered many questions I had. I joined Patreon a few months ago after finding your channel and I have rediscovered my love of electronics again.
I know nothing about electronics, half the stuff you talk about totally confuses me, but it is fascinating watching how you troubleshoot this sort of thing :)
Hi Paul, I am very excited to see your first repair video of the New Year. Nice to see you use the SuperProbe and the 224. I love both very much I have a Mod 222 which I think is very useful, yet not as useful as the SuperProbe I built using your brilliant design. Thanks again for all that you do and sharing your bottomless knowledge, along with your ingenious electronic inventions with us! Take care my friend and please never stop sharing your vast and practical knowledge with the electronics repair community. "Why be a rockstar when you can be a god?" applies to Mr. Carlson's Lab. It's funny, you have the youthful appearance of someone in their late 30's or early 40's and yet you posses 125 years worth of electronics knowledge and experience.
Wow - I had that model in 1983. I loved the way the slider LED's looked with the room lights turned off.
Fun to see this.
We can se that you are a great engineer. Congratulations for that wonderful scenario. People like you make the world a better place. Wish I had 1% of your capabilities. Thank you for your videos.
Mr. Carlson, the audio on your channel is outstanding, damn near the best on you tube.
I was just thinking that myself. Would love to see an episode where you give a tour of your audio video recording setup.
@@HarvardBob Good idea! I think he uses a Zoom H2 from memory for Audio
I'd like to know how Paul got so heavily into vintage as his specialty. It's really what sets this channel apart because much of the knowledge he presents is no longer taught and is slowly being lost. And yet, he doesn't come off as some nostalgic curmudgeon but rather he makes everything seem timely and relevant. They say with everything being so digital today, it's often the analog aspects of a circuit that are most half-assed and overlooked. This is where the tricks of the past could serve us well.
Near the best? No, Mr, Carlson is the best! Give me your superior reference.
Great job! Once again, making it look all too easy! And once again thinking I need to build that Super Probe. I built a probe(with an actual germanium diode) and it works well, but the idea of a non-contact probe where one can just wave it close to the board and not having to locate and contact an emitter at some absurd angle is blissful. Curve tracer first, though. Op Amps are coming in from Digi-key as we speak. Your Patreon page has been the single best tool on my bench. I have been using your transistor tester, matching, biasing circuit for a while now and it never fails. I just let your videos play while I work and always learn something new, even if I have heard the video a couple of times.
man im so keen on making a carelson super probe now. and a curve tracer. ive been obsessed with clipping & saturation shapes recently and i cant believe i didnt know what a curve tracer was. its such a straight forward bit of gear too, but it tells you so much. and the super probe is genius. non-coupled signal sniffing. what a ripper idea. thanks mate you do an amazing job.
the super probe we already have in electrical installations ..we call it a fuse finder..
Love to see these two tools used in ham radio repair, perhaps in circuits other than audio chains. Thanks again for another great video Paul.
Outstanding video....dozens of tips, techniques, and bits of information in a single video....bravo.
Loved playing with my equalizer when I was young . Usually when tuning it to a song I was playing to make it sound good the song was almost over . Then played the song again at just the right tone . Half the fun was playing with it !
Equalizers are more useful for their own entertainment value than they are for correcting a system's frequency response :)
@@devilsoffspring5519not always. I have some older tapes that have poor sound at higher frequencies and things like that, and the equalizer allows me to make the recording sound good again.
But year, when I was a 15 year old I loved pushing the sliders around, distorting the sound in horrible ways... But I learned a lot at the same time.
Thanks Paul. More invaluable coaching and instruction. I also agree with others in that you should bring the SuperProbe to market either in DIY kit form or finished product.
Thanks for your input!
All thanks and credit to you Paul and 1/2 dozen excellent guys like w2aew, AA5R, Afrotech, Andreas, Andy Davis & a few other subject matter experts, who constantly share your wealth of knowledge and experiences with us.
You make, troubleshooting and finding the issue look like Pre-K stuff. I'm so glad I found your channel!!!
Welcome aboard!
Very methodical and reassuring how Mr. Carlson approaches troubleshooting!
Wait, I have this exact EQ in my basement right now... I’m definitely glad I saw this video, thank you for posting it!
I feel as if I've learned more watching your videos than I did during the handful of mandatory EE courses I had to take at uni (I studied SE). Wonderful content.
Great to hear!
Your intro to "Repair-man syndrome" gave me chills... intermittent issues suck so much
I had the same EQ back in the day. I miss those component systems.
Superbly efficient troubleshooting, very informative narration, and excellent video/audio clarity -- IOW, A+++! Thanks very much.
What jerk would give this video a thumbs down? Someone sharing their valuable knowledge like this does not deserve a dislike.
Anyway, thanks Paul as always for sharing with us. Good stuff pal.
The people who designed it.
haters be hatin'
"No cats?! Thumbs down!" LOL
@@TheHermitHacker, FUNNY you were thinking exactly what I was thinking! LOL
and i thought i got alot of thumbs down, just for my channel name,lol, Carlson seems like one of the smartest electronic guys on YT !!!!!
I love seeing the retro test equipment I learned on back in the late 70’s! Still more useful than the modern stuff if you understand their functionality and how to use them! We used the Huntron tracker regularly!
I have the same exact model equalizer which is still fortunately working. But I will save this video in case it develops a problem and needs to be fixed. Thank you very much
Another wonderful video. Almost root against you solving the problem because that's where it concludes. All of what was presented was fantastic but how much fun and learning it would have been had we made it into the equalizer sections? I don't think anyone could explain it better! Thanks for taking the time to make it I enjoyed every second.
In the 80s, I had *Mr. Wizard's World.* Today, I have *Mr Carlson's Lab.* Life is good! 🤗🎙️📻
Thank you for uploading extremely informative videos that inspire, help, motivate, and bring pleasure to people all over, and in a professional, calmly hypnotic manner. You deserve a lot more subs!
I just love engineers, not only do they know how it works but also why.
love that huge mid scoop they have going on on this unit. i have a late 80s 100 band eq/amp thats needing some repairs. each band has leds on the sliders, some have died , and hard to find 12v square type leds, without paying an arm and a leg. it also needs a re-cap which isnt to difficult once you dig into the unit. Thanks for sharing this beast!
Love this video Paul just the way you pursue a problem and solve it is just incredible I have to say this but you are so young but you have acquired so much knowledge and the equipment you have is just wonderful It's always a pleasure to watch you solve a problem and in such detail repair it
Wow, what a treat! There's always something cooking at Mr Carlson's Lab, but today you coincidentally covered the same model of equalizer my dad gave me which has a similar problem! I can't wait to work on it after seeing this video. I like the curve tracer you were using and the Super Probe was pretty cool. Your channel is an inspiration to me, the way you explain things make electronics fun and less daunting to learn. As always, keep posting awesome repair videos :)
I worked at a job troubleshooting printer PCBs years ago. I miss the Huntron Tracker (dual trace curve tracer). Great tool. Very necessary as the manufacters would not release schematics to our company. Info on a lot of the printers was still confidential.
Great video, man I have to build the super probe and curve tracer asap. Thanks Mr Carlson. Love your channel and being a patreon is a must! Best money I spend every month
One of the best channels on TH-cam! Thanks for a great video!
We had an audio "sniffer" when I worked in the network/cellular industry. We connected the audio generator to one end of the RJ45 cable and used the probe to find the other end when we heard the test tone. It was a necessary tool when dealing with cabling that nobody thought to label, especially when going from one end of a building to the other.
Thanks again Paul for another great video and for your Patreon course. I have learned a great deal and have been able to understand how different parts work together.
I don’t know how it is that they get better and better. I am only half way through and I can already say this is the best video yet
Don’t ask me to pin point why.
It just is.
I don't understand any of this, but dang, I love this channel!
The Super Probe is incredible. Thanks for making this video.
Absolutely amazing troubleshooting Mr Paul. This is the first I saw testing jfets, how great the curve tracer see inside the device. Wow, I really enjoyed. Best of the best video only in this channel👈👏👏👏👍👍
Thanks Roy!
I would have to agree,you are the man when it comes to the tiny cities of electronics, I like listening to your comical jokes that sometimes not every body get's,cheers to you Mr Carlson's Lab..
Awesome video Mr. Carlson! Really appreciate the time you take to spread your knowledge. Watched the entire video with immense interest. Learn a lot. Looking forward to taking your course very soon. Cheers!
I’m sure this is going to be another great video and I’m looking forward to enjoying it over the next hour. It looks like nice unit, and these things could be useful in the right hands. Unfortunately, back in the day equalizers seemed to attract those that wanted overly-booming bass and overly-sizzling highs and not those that wanted to subtly correct for a room aberration or poor recording. I wish they had been designed with only +/- 4 dB of gain and not the typical 12. That’s more than enough, really, and would have kept people from destroying the careful sound that engineers take time to mix, while also saving amps, speakers and ears from damage. I can’t tell you how many times I got in a car back in the 80s and 90s, and was tempted to zero-out a friend’s equalizer. Nowadays, I’m still tempted, but the equalizer is buried in ten layers of GUI!
I don't think a lot of people understand the proper use of an EQ also. I use it more to remove frequencies rather than boost. Most people boost the crap out of it!
Flux Condenser, I have one with built in Spectrum Analyzer, which makes the unit a hoot to use.
I don't find it tedious watching you take screws out because you always talk about interesting things while you do it!
You are a great instructor and do an excellent job producing your videos, keep up the great work.
With these kind of devices repairs are piece of cake i love your videos so clearly explained everything thank you for sharing this video
Another excellent troubleshooting video, perfect for the new technicians out there. There is an "official" name for the technique you used to divide the schematic near the beginning of the process - it's called "the half split method" - dividing the block at the middle and checking for signal. It works really well for very complex systems.
binary search in programming lingo
Thanks Paul! Nice work! That opening shot never gets boring! I am almost ready to start making boards. If I can't find a scope this month for my curve tracer, I will start on a more simple device that I already have most of the components for. Or I might just start making boards and set them aside until later.
Thanks!! I've learned soo much from watching your videos!! The lil workflow tricks you do are freakin rad!!! nobody gets that in school!
Wow! Talk about deja vu, I had the exact EQ. Brings back memories! After this EQ I bought a parabolic EQ , much better!
I used to do with cameras what you do with electronics, but had what we called "Japanese Magic" -- if it was going to malfunction, it would do so for me! A very handy talent when you back your work with your word.
Thank you Mr. Carlson .. This vid just inspired my next fish can project - so named because I have a collection of sardine and the like cans with matching perfboard "covers" that I've been trying to come up with small one and two evening projects in which to utilize them. A curve tracer! No reason that I can't spin off a rudimentary battery powered 4 chip tracer with miniature 5x7 LED matrices (arranged 10 rows, 14 columns) as the display. 3/4 of a quad comparator to generate the probe sine, square it up for a pair of 4017's to do sweep, and level translate the other probe to center an LM3914 vertical input. Should be cute as a button, and the relatively low resolution shouldn't be an issue.
Mr. carlson's.. the easy way to take us to the trouble shooting with less efforts is amazing..!
Mr Catlson's , what a great electrónic technicion,with increadable tools...
You can determine R and L channel on the schematics starting from the S.L.M. Jack. Tip is the left channel, so the right channel is the lower one in the schematics.
Mr Csrlson, great job! I enjoy your verbose explanations. Test equipment is very much useful. Cheers
At min 24: HP taught that was the "half/split method." I was a technician for 38 years at Raytheon and then an engineer for up to year 50 and it worked for me
Your proximity probe working well and made light work of that diagnostic :)
Great vid. Love your non-intrusive test tools.
With regards to which channel is which, there are a few conventions that can help people make good educated guesses. they all follow the convention left comes first, then right;
- the channel drawn on the top is usually Left
- if all the component numbers are odd numbers (eg TR101, R113), and the other even (TR102, R114) then the odd channel is usually Left.
- if the channel component numbers all differ by a hundred (eg TR511, R512, C518 one side) vs (TR611, R612, C618 the other) then the lower hundred series is usually Left
- if only one channel has signal path, component values, voltages all drawn in, and the other doesn't, the channel with the extra info is usually Left
- if only one channel is fully drawn (and the other is only partially drawn, if at all), the channel drawn properly is usually Left.
Awesome vid. Really enjoyed.
A practical approach to audio or video equipment troubleshooting/repair: I think the determination of a (the) faulty channel could be done much quicker by a simple "audio in and out" setup. With a cheap mp3/music player, a powered speaker (I have one on my bench always ready to rumble) and a set of RCA cables this would take literally 20 seconds. No need to disassemble anything. From there the search could go on. Or you could determine a properly working EQ, with the only defect a faulty VU meter. It IS "audio" so it can be prechecked audibly :-). I recommend also to changes the state of all of the switches and sliders while testing (aka listening to the test sound/music), so a "rotten" switch or bad contact can be traced immediately. And what I missed in your video was a final check of audio. Only after that step, I would do a thumbs up, not before :-)
I learned alot from this video here. I learned how to divide a schematic to break it down to areas of concern. Also about Jfets and what the signals mean. I'm headed over to the pahtheon page to check it out. Thanks again.
your voice is a buttery smooth soothing chill synth voice...god
Just in time for me! I'm about to dig into a similar unit for a friend, so again a big thumb up Paul 👍
To say Bravo, great job, is redundant. You know, I know you are brilliant! It's the be brave to open the cover and troubleshoot the problem and don't give up creed! If you follow the signal, you will find where it starts and where it stops you will find the faulty component. Happy 2019, a great video to start the new year. Thanxz
I used to have the earlier model of that EQ. However in the late 80's I converted it to balanced inputs and outputs and to use a higher line level to make it compatible with professional sound mixers. What made that easily possible compared to most consumer grade graphic EQs is they used a solid push-pull transistor stage in the outputs which most consumer gear didn't use. Another difference was the older model I had used inductors for the 1st three bands but they were later dropped to cut costs plus capacitor technology got better and high value tight tolerance capacitors became more affordable but even so the center frequency in the lower bands tends to be a bit sloppy as compared to using inductors but good enough for consumer devices
As an electronic technician hobbiest and formerly licensed fire alarm technician, your troubleshooting was very good but missing a few things that I would have done.
1) Test the output of the channels at the back panel as I start. This tells me if the issue is an actual dead circuit versus a dead led driver. Since this is easily done by using a cheap speaker hooked up to each channel (with an amplifier to make the speaker loud enough) it would be a part of my audio testing toolkit.
A bonus to this testing is you find out which jack is lacking output which helps to trace the channel circuitry.
2) Following on from step 1, I would trace the circuit from the jack wiring backwards to the input wiring. (This is personal preference but it helps when you can't find a circuit diagram.)
3) 'Tone' out the circuitry. (Here is where a 'fox and hound' comes into play. Tone generator and probe used in phone line testing but handy in other areas.) Basically this is the super probe methodology but using the tools I have in my toolkit (and you can find in some stores like Harbor Freight, Home Depot, and Lowe's).
Once you'd found your bad part, replace it (and companion for stereo components).
You're forgetting, this is a video. The whole idea is to show different troubleshooting techniques, not to go right to the problem. This video would be 5 Minutes long if I did that, and people wouldn't see a path to the issue.
Absolutely amazing stuff as always, Paul! I've been a patron for a while but haven't gotten around to building the Carlson Super Probe. Having watched this, I just HAVE to build it. Obviously, the time it will save me is a multiple of the time it takes to build it. Thanks so much!
This channel is one of my favorite YT channels. I love the vintage electronics porn.
Is it possible for this whole "porn" nonsense to be dropped, when referring to an area of interest which one likes? It sounds SO crude and ignorant, not to mention that it's just... unoriginal in the utmost.
Maybe...?
unlokia I agree 100%!
I agree with unlokia, there is nothing pornographic about this. To be frank Penfold8, I would like to quote Inigo Montoya, "I don't think that word means what you think it means."
This is pure electronics nerdvana, not something dirty at all and I would kindly ask that you refrain from referring to it as something it is not.
How about obscene or titillating or sexy? That okay Mom?
penfold8 - did you trigger somebody? bad penfold8.
Very watchable, educational and inspiring vid - as usual. Thanks.
The chances of me ever having to repair any kind of amplifier to component level are about the same as me winning the lottery - but this held my interest completely and now I know what makes a good schematic diagram and what depletion means...
Merci pour cette belle recherche de panne !
Tout çà très bien expliqué !
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Thank you for this beautiful search failure !
All very well explained !
Great video, Paul. Thank you very much! About addressing the L-R, 1-2 part on the schematic; Firstly if the manufacturer doesn't label this on the front plate, it doesn't help much if they label it on the schematic. A possible explanation can be that in a professional environment, "a stereo" EQ most of the time isn't used on the stereo output chain. Perhaps one EQ is inserted on the console channel 16 before recording and the second EQ is used on return 4 to the vocalist's headphone, as this often is a dual mono signal. Nevertheless, you are right, for troubleshooting it is unacceptable not to address the two parts especially if these aren't electronically identical. Heck, name it Anne & Rose if L-R, 1-2 can be confusing.