For tube rattle I’ve had great luck with the tube dampers from Eurotubes. They’re a bit softer and have a lot more mass than the standard o-ring style type, and seem to be more effective in difficult situations like high-power combos amps.
This the only Amp builder who's awesome enough to put himself out there to help people, answer questions, and really help people. Thank you Dr.Z Great amps and a great guy.love you!
I have been around vacuum tubes since 1967. I have recovered a few failing amps for myself and others, i have noticed the voltage deviations for myself without anyone to explain to me. But im a trained electronics tech (afl-cio). I recommend that users of vacuum tubes pay Close attention to anything dr. Z had to say. Seriously. This was all true, clearly stated, And in the interest of sharing. Thank you sir. Lbk
I performed this mod on my own JETTA combo. What a difference! Before tube rattle was noticeable on any ringing E note, even with dampers on the tubes alone. Now with the new retainers it is quiet as a church mouse. Only took me about 10 minutes to get this done and less than $10 in parts. Loved the amp before, love it even more now. DR Z's customer support is unmatched in this industry as far as I am concerned.
I just learned more in 15 minutes than I’ve ever known about tube amps and I have played tube amps for over 40 years. Thank you Dr. Z! Someday I will own one of your combo’s. 👍
This is a man who knows what to say and says it.The man is a wealth of knowledge about the dreaded tubes. Thanks for info...always a joy listening to someone who knows what hes talking about.
Your a really fantastic PERSON. Not thinking about yourself, or money or your business,. You truly care about what is going on in the world and your tips and tricks are helping people like me. I own a studio and several tube amps, Preamps and the like. I have been nervous as of late but you quality fixes has helped me a lot, so thank you. At this time we need to pray for Ukraine and the world, but posts like this go a long way to show your love of music, and I applaud you for it. My next amp purchase is a Dr Z, I put my money where my heart is!!! Or really, where your heart is.
Dr Z, I really enjoyed the write up about you on the Reverb Platform. That brought a smile inside for sure. It's no wonder that you have such good advice for us regarding our cherished tube amp. Regardless of where they came from. I knew when I saw you and your video the first time, that was going to be important. I would have loved to sit next to you for the Hell Freezes Over Tour to see your friend Joe Walsh jammin' out on your gear. Magnifico indeed. Thanks again for sharing as you do. I understand you
First-time listener and now a subscriber I have never owned a tube amp but this explains a lot of what happened to a buddy of mine if I purchase a tube amp, i probably will look at your inventory first
Cool video, I'm glad to hear someone else talking about the importance of clean power at the right voltages. I have not only a Brown Box to reduce the voltage for my '67 Deluxe Reverb and my '76 Marshall JMP 2203, but a voltage regulator to stabilize my wall voltage and filter the power as well before it goes to the Brown Box. All this was more to protect the transformers, but the tubes as well.
Thank you for this, Dr. Z. It seems to be something I can easily adopt into my amateur amp building. Also, you have a glow about you in this vid, you seem very happy.
What a brilliant video. This guy makes me want to binge watch all his content! Knowledgeable and passionate and has that genuine care for musos and gear. I couldn’t help but think that if Dr Z swore in his videos he’d sound like Lewis Black. 😉
Thank you for all the helpful info Dr Z. I am currently restoring / modding a 1963 Ampeg J-12-A with 6SL7 preamp tubes and 7591 output tubes. I had read that 6SL7 tubes are delicate when it comes to microphonics, etc. Because I did not want to leave anything to chance, I bought all new sockets. That means I can do some dampening like what you showed. There are some that state a rubber grommet can be used under each screw, but those cannot take a lot of heat. There is a company that sells high temp silicone grommets. But that causes a gap between the chassis and the socket which would cause heat to go up into the chassis. [ Those tubes hang down ... ] I have silicone dampener rings, so I may be using your fix in place of the high temp grommets. I'd like to get the Brown Box to adjust line voltage, but for now I have two thermistors (CL80) before the fuse, and on the HV CT to ground, I am putting in a 200 ohm 20 watt resistor to bring down the B+. [ I have 300 ohm and 400 ohm in case 200 is not enough. ] My understanding is that 7591 tubes should see about 450VDC on plates and 400VDC on screens ideally. But I've read conflicting numbers on that. I've also read that screen voltage should be closer to plate voltage for best sound. So I am shooting for 430VDC on plates and 400VDC on screens. Biasing at 70% like you talked about should cause the used 7591 tubes that came with the amp to last longer, and from what I gather, the chosen voltages can work for either used, NOS, or new production 7591A tubes. I have EH 7591A tubes that I had purchased some time ago. From what I've learned, Tung Sol 7591A tubes are the best new production. Thanks again for all the helpful info!
Now you have me looking for a Brown Box for my 1957 Silvertone Model 1392 with 6v6 tubes. Great information insight on Vacuum tubes & Amplifier Voltage sensitivity ❤️
Excellent stuff, sir! I already use a variac, always careful to never crank it. In the studio, it’s practical. A Brown Box is definitely the way to go for any sort of gigging.
Terrific. I've had a Brown Box for a long time at the studio using it with vintage amps but I can see the reasoning to have one for the newer amps too. We get very different voltage from the wall at times. Liked the MacGyver also.
Cool! Glad you’ve found an answer to the this tube shortage situation we find ourselves in. It’s also good to see you sharing knowledge with regards to ways to extend tube life. Nicely done! Tubes are magic… but very few know the correct incantations required for maximum filament specters transfer from the planets of origin. Sigh…
Dr. Z, I thank you for sharing your knowledge. I've learned some important things from your videos the last couple years. Knowledge should be shared. It makes us all better. Thank you for making us all better.
Absolutely correct on this and also weather impacts the sound of most tube amps. When I first met Kenny Fischer from Train Wreck, he explained to me about weather and magnetic pull. When I got into making my own amps it was 100% aluminum chassis for some of the theories Kenny explained to me early on.
Thanks so much Dr. Z for this video. I was going to buy a Brown Box a few years ago but never did. After watching this video I will now! I miss your weekly videos. Stay well! 😊👏🏻
For discharging the filter caps it actually does not matter if the speaker is connected to the chassis, as the output transformer separates the speaker in any case from the DC circuit in which the caps discharge. If not discharging them manually with a high wattage/low Ohm resistor, heated up tubes are necessary for the DC circuit being closed via tube and output transfo.
Great thing my father was in Vietnam in the 1960s and I currently have 6 cases of USN 30s to 60s Amp tubes all nos he always said they would be worth money one day
I got a NOS 6G6g in a tube lot. It is a lower power Pentode with the same pinout as a 6V6gt. They are rated for a lower voltage and in a 6v6 amp they don't last but 1/2 the time due to the abuse but boy did it sound great. I intend on trying to build an amp with the proper voltage to see what this tube sounds like in a guitar amp circuit designed for this tube. Playing with different NOS tubes is fun, produces unique tones and usually they are cheap. I like octal Preamp tubes, to me they have a really rich sound. I am building a SE amp with 1930's 2 digit tubes which I can't wait to hear. Tube compliment is 77,75, and 42 with an 80 rectifier.
I’ve been using 50/60 + year old Mullard & Brimar’s in my old Vox, Marshall’s & brown Fender’s. I have a couple of good tube testers( one being a Orange VT-1000’s another is a Vacuum Tube Valley tester) . I have a Brown Box too! It’s an excellent piece of kit!
It amazes my that most amps don't have a decent input voltage regulator circuit to begin with. Hell, even most consumer electronics these days have a high speed switching power supply....Not guitar amps. Clubs have notoriously crappy power but NOTHING is as bad as the outdoor "Festival" type venues that are generally run on generator!!!! Voltage sags and spikes gallor....let alone just overall dirty power. I've been recommending the little APC line conditioner for some time and it makes a world of difference cleaning up the input power, but it's not adjustable. It's usually around $100 and is pretty fool-proof. Great content!! Thanks for sharing!!!
Unfortunately switching power supplies don't typically provide the voltages needed for higher output power tubes. Also, input regulation requires a stepping transformer/auto transformer, which can be an expensive additional cost, on top of the space needed inside the amp.
You are str8 dope Thanks for sharing There’s no questioning your passion and affinity and knowledge Your clear explanations are much appreciated Thoroughly enjoy listening to you and for what you pass on 🤘
Amazing for you to share this with us! I have a Dr Z Cure which suffers from tube rattle exactly as the Doc describes, at the tale end of a single on the fretboard. Doesn't even happen if I play the same note on a different string. Having a solution other than an expensive and otherwise unnecessary tube swap is amazing. Thanks Doc!
Thank you for sharing your wisdom. I just bought a used (mint) BrownBox for $200 shipped. I've tried to contact the manufacturer on 3 separate occasions phone, YTube & email and he's never once provided assistance or help. I have no faith in their customer service at this point (all I did is ask for a manual). Nice product though. Rock on Z!
The Brown Box company has changed ownership . The originator of the product is no longer associated . Are you sure you are contacting the currant owners ?
@@mikezaite1335 thanks for the heads up. I will give them another try. Maybe I got them during transition? Who knows? That gives me hope! I've got many vintage amplifiers (two handwired JMP marshals, two MKII MV's and a 58 champ). I wanted to ensure that I'm doing everything properly. I'm pretty sure I've figured it all out at this juncture but support manuals would still be nice. I never want to assume anything. Thank you so much. I'd given up but I'l give em another try.
Just finished this on my amp- just a tip order the 28mm rings. I had 30mm and I had to trim them a little bit. It worked fine but def would have been a cleaner job with the 28mm.
One other thing that a power regulator box of any kind helps with in combination with you running your pedal board off of a battery pack is you get rid of ground loops. Raise your hand if you ever plugged in your amp, your board, and maybe a mic and had hum you had to deal with in some crappy theater or room somewhere. (the entire room raises their hand). DC wall warts plugged into an outlet strip and half-dead batteries are much hair pulled out over the years as well. My friend has a large 12V (recommended since you can easily regulate it down to a clean 9v for many devices) battery pack running his entire setup attached with velcro to the back of his amp. Then also a DC to DC regulator box tied to it (basically a Brown Box but for DC), and the cords all neatly wrapped up. Because pedals also have this same power regulation problem. 9V batteries *quickly* drop to 7-8V. The amp looks a little odd on the back side with several re-usable cable ties, things attached to it, and the two power regulators and power brick, but it's all there. The input to the amp and power to the pedal board are tied together, so just one combined cable from the amp to the board, essentially, thanks to connectors and a little soldering of jacks to make the extension cables work. So all he has to do is roll his amp/speaker combo into the room, plug in the main regulator box to any power cord, pull the pedal board out of his backpack, plug the pedal board into the loop and power it up. Basically 3 30-45 second steps, position the pedal board where it's comfortable, then relax and wait after at most 3-5 minutes of getting things ready. Yes, he's the bass player ;) And he always sounds the same and never has to chance a battery or rely on whatever power is there.
First of all, thank you so much for taking time to share your knowledge with everyone. Things like this make me a proud Dr. Z owner! I wanted to do this to my Dr. Z plus. Should I make this modification to the rectifier tube as well as the power tubes?
I bought a "Tone Preserver" after checking my wall voltage on a Saturday afternoon and seeing 128 volts at the wall. It also had a positive effect on my tone with my tweed based circuits.
Considering that I've got a pretty strong preference for solidstate amps, I'm surprised at how fascinating you managed to make this topic, even if I won't ever need to apply it.
@@DrZAmplification I'll have to, they sound great. Sadly there's no real chance I can buy any big amp in the foreseeable future (regardless of cost). My usual rig right now consists of an EQ pedal with two outs, one source of distortion for each channel (distortion pedals, the preamp from my Crate GX, an SLO preamp clone, etc), a Mooer Radar on each channel and a really cheap mixer to blend them back together, so it's really the Z-Drive that catches my eye, at least as something I'd want to own. Whether tube or transistor based, a preamp based on one of your amp designs would be a killer product for players who need to rely on headphone setups or pedal board rigs. Either as an entry level product or even simply for the convenience.
I built two amps - clones of a Fender 5C1 and a 5C3. I found some rubber washers that fit under the tube sockets. (Actually, over the tube sockets, because the tubes hang down in the combos).
You can also discharge the caps by turning the amp on for 5 mins then turning it off. The hot plates will still conduct and thus discharge the caps. If you just turn the amp on then off, the tubes will be cold and the caps will be fully charged!! The tubes must be hot for this to work. I also discharge the caps via a 1K resistor across the caps. Nice to see the only viable use for a standby switch is to discharge the caps, as it serves no other use on “receiver” amplifiers :)
You can use what is called a "variac" which is a fully adjustable AC transformer to adjust the line voltage to your amp as well. The other advantage of using a variac is that if you have an old amp that's been sitting many years and you don't trust it, you can very slowly bring up the voltage and catch problems before it catches fire or does damage to expensive transformers. It's a valuable tool for servicing tube amps as well as adjusting line voltage to whatever you require. These are about the same money as the brown box and do a lot more.
Yes, but they also allow you to overvoltage the amp. We are trying to offer a "dummy proof" solution, in a small portable package. Just be careful using a Variac.
I’ve found that modern amp building has pushed output tubes beyond their design spec. Plate voltages are always higher than the tube data sheet recommend. In some cases bias is also set either way too high or way too low. JTM30 I recently fixed had bias set to 130% via the zener diodes that Marshall fitted. I bought a brand new Supro 1623 and it was replating out of the box. Smoking hot. Laney Lionheart LT20 is great. Much lower plate voltages, bias set reasonably low. Getting a respectful 20W out of 4 EL84 tubes. Definitely worth getting some form of power regulation as you’re right, most clubs have horrible power.
How best to power on/off your tube amps? Is it better to leave power on and turn into standby for upwards of a hour or so, or power on and off fully between breaks?
Dr Z you are a Diamond. I find some power amp valves wobble in their sockets, they don't fit snugg like the older Valves. I have to make a mggyver spring tension holder outvof a shampagne cork wire stopper to keep em in place. Thanks for sharing, you are a Generous Rocknroller.Just a thought, you could design an adjustable valve base with little tension screws/slugs to tighten the valve in its base?
Looks like a simple and effective fix,thanks...btw,I have a Brown Box and besides protecting the amp's components,all my amps (mostly 60's-70's) sound better at lower voltages...they like it in the 114-117 volt range
At home, my wall voltage is 125v. I would probably set the variac at a voltage that would allow the heater filaments to reach spec voltage ie. 6.3 volts, etc. If the heater voltage is lower than spec then the cathode will be starved of electrons quicker leading to shorter life.
The Brown Box doesn’t regulate the voltage it attenuates the mains voltage. If the mains voltage goes down so will the voltage from the brown box. EL-84’s are generally subjected to too much voltage in most guitar amps. The Trainwreck Rocket has a 300vdc rail which was perfect for EL-84’s. The 100 ohm screen resistor value is too small to offer protection for the 2 watt screen grid. The air from the speaker is hitting the valve. There will be vibration from speaker cab too. I wouldn’t put the silicone washer in unless I had tried everything and this was my last resort. The pins of the valves will be closer to earth/chassis with this mod. The washer can’t be too compressed for it to work, should the washer compress a pin MIGHT come in contact with the chassis. If you’re happy with that possibility, that’s fine, but I’m cautious.
The older amps were designed to run on 110 volts . That is why I use a Varied with my 2 museum quality Gibson EH125s, and my Noble Victor from the 50s .
Blissful generosity of truth Thx. Dr. Z! …i have become familiar with The Brown Box, in fact i’ve reached out to them, super nice team over there in Nashville. How about veriacs, almost same thing, similar, problems for equipment, didn’t/doesn’t Ry Cooder use a veriac?
a variac would work, it's just typically larger, less compact, and you can accidentally OVERvoltage your amp if someone futz with it without you knowing.
The only reason I change my preamp tubes is because of the values. I prefer a 5751 in the V1 position and sometimes change the V2 or V3 for a 12at7 or 12ay7 depending on what sounds better. 🤷♂️
Hey Doc, great video! Quick question, do I have To bias my amp to whatever voltage you’ll be setting the brown box to? Or just plug it in not worry about that? ✌️ **update** Bought the brown box after … works great. Had my tech bias my amp to 117 volts on my blackface amps and set the brown box to 117 volts. Thanks for the great advice again Doc! Jason
at my house in the summer during a hot day I get 107 - 110 volts and at night I get 118-121 volts. In the winter all day and night long I get 120-122 volts
For tube rattle I’ve had great luck with the tube dampers from Eurotubes. They’re a bit softer and have a lot more mass than the standard o-ring style type, and seem to be more effective in difficult situations like high-power combos amps.
I have those, too. Great product.
Agree with the Eurotubes dampers recommendation. WAY more mass than standard silicone rings. Eliminated 99% of my tube rattling issues (Fender HRDv).
It was just enjoyable listening and watching you teach...you know how to keep people interested and I'm sure it's helping many...✌️
This the only Amp builder who's awesome enough to put himself out there to help people, answer questions, and really help people.
Thank you Dr.Z
Great amps and a great guy.love you!
I love that Dr Z broke the fourth wall and admitted that poor electrical current will make your amp sound like "shit"....LOVE Dr. Z!
I have been around vacuum tubes since 1967.
I have recovered a few failing amps for myself and others, i have noticed the voltage deviations for myself without anyone to explain to me.
But im a trained electronics tech (afl-cio).
I recommend that users of vacuum tubes pay
Close attention to anything dr. Z had to say.
Seriously. This was all true, clearly stated,
And in the interest of sharing.
Thank you sir.
Lbk
I performed this mod on my own JETTA combo. What a difference! Before tube rattle was noticeable on any ringing E note, even with dampers on the tubes alone. Now with the new retainers it is quiet as a church mouse. Only took me about 10 minutes to get this done and less than $10 in parts. Loved the amp before, love it even more now. DR Z's customer support is unmatched in this industry as far as I am concerned.
I just learned more in 15 minutes than I’ve ever known about tube amps and I have played tube amps for over 40 years. Thank you Dr. Z! Someday I will own one of your combo’s. 👍
This is a man who knows what to say and says it.The man is a wealth of knowledge about the dreaded tubes. Thanks for info...always a joy listening to someone who knows what hes talking about.
Your a really fantastic PERSON. Not thinking about yourself, or money or your business,. You truly care about what is going on in the world and your tips and tricks are helping people like me. I own a studio and several tube amps, Preamps and the like. I have been nervous as of late but you quality fixes has helped me a lot, so thank you. At this time we need to pray for Ukraine and the world, but posts like this go a long way to show your love of music, and I applaud you for it. My next amp purchase is a Dr Z, I put my money where my heart is!!! Or really, where your heart is.
This may be the best video on TH-cam
Dr Z, I really enjoyed the write up about you on the Reverb Platform. That brought a smile inside for sure. It's no wonder that you have such good advice for us regarding our cherished tube amp. Regardless of where they came from. I knew when I saw you and your video the first time, that was going to be important. I would have loved to sit next to you for the Hell Freezes Over Tour to see your friend Joe Walsh jammin' out on your gear. Magnifico indeed. Thanks again for sharing as you do. I understand you
First-time listener and now a subscriber I have never owned a tube amp but this explains a lot of what happened to a buddy of mine if I purchase a tube amp, i probably will look at your inventory first
Cool video, I'm glad to hear someone else talking about the importance of clean power at the right voltages.
I have not only a Brown Box to reduce the voltage for my '67 Deluxe Reverb and my '76 Marshall JMP 2203, but a voltage regulator to stabilize my wall voltage and filter the power as well before it goes to the Brown Box. All this was more to protect the transformers, but the tubes as well.
Thank you for this, Dr. Z. It seems to be something I can easily adopt into my amateur amp building. Also, you have a glow about you in this vid, you seem very happy.
What a brilliant video. This guy makes me want to binge watch all his content! Knowledgeable and passionate and has that genuine care for musos and gear. I couldn’t help but think that if Dr Z swore in his videos he’d sound like Lewis Black. 😉
thanks for watching our "back catalog!"
👍👍👍👍👍
Thanks Doc! Glad to hear that Dr. Z Amps will be safe from tube shortage!
Dr. z great to have you guys back sharing more good vibes and solid knowledge.
Thank you for all the helpful info Dr Z. I am currently restoring / modding a 1963 Ampeg J-12-A with 6SL7 preamp tubes and 7591 output tubes. I had read that 6SL7 tubes are delicate when it comes to microphonics, etc. Because I did not want to leave anything to chance, I bought all new sockets. That means I can do some dampening like what you showed. There are some that state a rubber grommet can be used under each screw, but those cannot take a lot of heat. There is a company that sells high temp silicone grommets. But that causes a gap between the chassis and the socket which would
cause heat to go up into the chassis. [ Those tubes hang down ... ] I have silicone dampener rings, so I may be using your fix in place of the high temp grommets. I'd like to get the Brown Box to adjust line voltage, but for now I have two thermistors (CL80) before the fuse, and on the HV CT to ground, I am putting in a 200 ohm 20 watt resistor to bring down the B+. [ I have 300 ohm and 400 ohm in case 200 is not enough. ] My understanding is that 7591 tubes should see about 450VDC on plates and 400VDC on screens ideally. But I've read conflicting numbers on that. I've also read that screen voltage should be closer to plate voltage for best sound. So I am shooting for 430VDC on plates and 400VDC on screens. Biasing at 70% like you talked about should cause the used 7591 tubes that came with the amp to last longer, and from what I gather, the chosen voltages can work for either used, NOS, or new production 7591A tubes. I have EH 7591A tubes that I had purchased some time ago. From what I've learned, Tung Sol 7591A tubes are the best new production. Thanks again for all the helpful info!
Check out the new Octal Six for the implementation of 6SL7 and 6SN7 tubes with a pair of 7591s!
adjusting bias 11:28 - Peak output X 0.7 = wattage at idle
Now you have me looking for a Brown Box for my 1957 Silvertone Model 1392 with 6v6 tubes. Great information insight on Vacuum tubes & Amplifier Voltage sensitivity ❤️
Love this!
The Amp Maniac is another good alternative to the brown box. Cheaper too
Thanks for a voice of reason during a time when tubes rival toilet paper! Good stuff!
Good to see you again, Doc! Loving my new Z Master!
Excellent stuff, sir! I already use a variac, always careful to never crank it. In the studio, it’s practical. A Brown Box is definitely the way to go for any sort of gigging.
Terrific. I've had a Brown Box for a long time at the studio using it with vintage amps but I can see the reasoning to have one for the newer amps too. We get very different voltage from the wall at times. Liked the MacGyver also.
Bought another one for my home setup after sending a couple friends to this video. Juice from my wall in home is 124-126! Brown Box Rx
I’ve been doing this to any ef86 amp I build that’s higher than 5 watts. Very easy and effective way to cut down on microphonics. Thanx for the tip!
Super informative, clearly explained, by a cat who is obviously passionate about his craft. Well done, Doc👏
Cool! Glad you’ve found an answer to the this tube shortage situation we find ourselves in. It’s also good to see you sharing knowledge with regards to ways to extend tube life. Nicely done!
Tubes are magic… but very few know the correct incantations required for maximum filament specters transfer from the planets of origin. Sigh…
Dr Z AMA are always fantastic! Thanks Doc.
Thank you for your love of the community, and congratulations on your new source! Mucho appreciado
Dr. Z, I thank you for sharing your knowledge. I've learned some important things from your videos the last couple years. Knowledge should be shared. It makes us all better. Thank you for making us all better.
Wow Doc thx so much for the great info!!!!
I watch intently your AMA’s!!!
Such a great series, you sir are a god send! ❤
Absolutely correct on this and also weather impacts the sound of most tube amps. When I first met Kenny Fischer from Train Wreck, he explained to me about weather and magnetic pull. When I got into making my own amps it was 100% aluminum chassis for some of the theories Kenny explained to me early on.
Thanks so much Dr. Z for this video. I was going to buy a Brown Box a few years ago but never did. After watching this video I will now! I miss your weekly videos. Stay well! 😊👏🏻
For discharging the filter caps it actually does not matter if the speaker is connected to the chassis, as the output transformer separates the speaker in any case from the DC circuit in which the caps discharge. If not discharging them manually with a high wattage/low Ohm resistor, heated up tubes are necessary for the DC circuit being closed via tube and output transfo.
Great thing my father was in Vietnam in the 1960s and I currently have 6 cases of USN 30s to 60s Amp tubes all nos he always said they would be worth money one day
I’ve played through several of your amps over the years. One day, I’m going to own one.
I got a NOS 6G6g in a tube lot. It is a lower power Pentode with the same pinout as a 6V6gt. They are rated for a lower voltage and in a 6v6 amp they don't last but 1/2 the time due to the abuse but boy did it sound great. I intend on trying to build an amp with the proper voltage to see what this tube sounds like in a guitar amp circuit designed for this tube. Playing with different NOS tubes is fun, produces unique tones and usually they are cheap. I like octal Preamp tubes, to me they have a really rich sound. I am building a SE amp with 1930's 2 digit tubes which I can't wait to hear. Tube compliment is 77,75, and 42 with an 80 rectifier.
I never knew you could drain your filter caps with just the speaker load! Thanks for the awesome tip.
This fix should be a mandatory consideration for amp manufacturers from now on. ; )
Thank you man I could listen to you talk valves and amps all day ,...greeti gs from Oz !
I’ve been using 50/60 + year old Mullard & Brimar’s in my old Vox, Marshall’s & brown Fender’s. I have a couple of good tube testers( one being a Orange VT-1000’s another is a Vacuum Tube Valley tester) . I have a Brown Box too! It’s an excellent piece of kit!
Good to see you again Doc
It amazes my that most amps don't have a decent input voltage regulator circuit to begin with. Hell, even most consumer electronics these days have a high speed switching power supply....Not guitar amps.
Clubs have notoriously crappy power but NOTHING is as bad as the outdoor "Festival" type venues that are generally run on generator!!!! Voltage sags and spikes gallor....let alone just overall dirty power.
I've been recommending the little APC line conditioner for some time and it makes a world of difference cleaning up the input power, but it's not adjustable. It's usually around $100 and is pretty fool-proof.
Great content!!
Thanks for sharing!!!
Unfortunately switching power supplies don't typically provide the voltages needed for higher output power tubes. Also, input regulation requires a stepping transformer/auto transformer, which can be an expensive additional cost, on top of the space needed inside the amp.
You are str8 dope
Thanks for sharing
There’s no questioning your passion and affinity and knowledge
Your clear explanations are much appreciated
Thoroughly enjoy listening to you and for what you pass on
🤘
Thank you for your generosity in sharing this expert perspective!
Great AMA as usual! I hope this recent “Tubepocalypse” ends soon.
Amazing for you to share this with us! I have a Dr Z Cure which suffers from tube rattle exactly as the Doc describes, at the tale end of a single on the fretboard. Doesn't even happen if I play the same note on a different string. Having a solution other than an expensive and otherwise unnecessary tube swap is amazing. Thanks Doc!
That is a wealth of knowledge given for free! Thanks Doc! ❤
Thanks so much Dr Z!!!
Thank you for sharing your wisdom. I just bought a used (mint) BrownBox for $200 shipped. I've tried to contact the manufacturer on 3 separate occasions phone, YTube & email and he's never once provided assistance or help. I have no faith in their customer service at this point (all I did is ask for a manual). Nice product though. Rock on Z!
The Brown Box company has changed ownership . The originator of the product is no longer associated . Are you sure you are contacting the currant owners ?
@@mikezaite1335 thanks for the heads up. I will give them another try. Maybe I got them during transition? Who knows? That gives me hope! I've got many vintage amplifiers (two handwired JMP marshals, two MKII MV's and a 58 champ). I wanted to ensure that I'm doing everything properly. I'm pretty sure I've figured it all out at this juncture but support manuals would still be nice. I never want to assume anything. Thank you so much. I'd given up but I'l give em another try.
Thanks Dr. Z for the great information! Always enjoy your AMA's.
Just finished this on my amp- just a tip order the 28mm rings. I had 30mm and I had to trim them a little bit. It worked fine but def would have been a cleaner job with the 28mm.
One other thing that a power regulator box of any kind helps with in combination with you running your pedal board off of a battery pack is you get rid of ground loops. Raise your hand if you ever plugged in your amp, your board, and maybe a mic and had hum you had to deal with in some crappy theater or room somewhere. (the entire room raises their hand). DC wall warts plugged into an outlet strip and half-dead batteries are much hair pulled out over the years as well.
My friend has a large 12V (recommended since you can easily regulate it down to a clean 9v for many devices) battery pack running his entire setup attached with velcro to the back of his amp. Then also a DC to DC regulator box tied to it (basically a Brown Box but for DC), and the cords all neatly wrapped up. Because pedals also have this same power regulation problem. 9V batteries *quickly* drop to 7-8V.
The amp looks a little odd on the back side with several re-usable cable ties, things attached to it, and the two power regulators and power brick, but it's all there. The input to the amp and power to the pedal board are tied together, so just one combined cable from the amp to the board, essentially, thanks to connectors and a little soldering of jacks to make the extension cables work.
So all he has to do is roll his amp/speaker combo into the room, plug in the main regulator box to any power cord, pull the pedal board out of his backpack, plug the pedal board into the loop and power it up. Basically 3 30-45 second steps, position the pedal board where it's comfortable, then relax and wait after at most 3-5 minutes of getting things ready. Yes, he's the bass player ;) And he always sounds the same and never has to chance a battery or rely on whatever power is there.
Thanks Z! Also for the brown box info!
First of all, thank you so much for taking time to share your knowledge with everyone. Things like this make me a proud Dr. Z owner! I wanted to do this to my Dr. Z plus. Should I make this modification to the rectifier tube as well as the power tubes?
the rectifier is not necessary as it's not an amplifier of sound
DR Z! Thank you!!! several looong standing mysteries of my musical life have been explained''''
I bought a "Tone Preserver" after checking my wall voltage on a Saturday afternoon and seeing 128 volts at the wall.
It also had a positive effect on my tone with my tweed based circuits.
dr Z is on fire🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥
Considering that I've got a pretty strong preference for solidstate amps, I'm surprised at how fascinating you managed to make this topic, even if I won't ever need to apply it.
thanks for watching, and maybe give one of our amps a spin
@@DrZAmplification
I'll have to, they sound great. Sadly there's no real chance I can buy any big amp in the foreseeable future (regardless of cost).
My usual rig right now consists of an EQ pedal with two outs, one source of distortion for each channel (distortion pedals, the preamp from my Crate GX, an SLO preamp clone, etc), a Mooer Radar on each channel and a really cheap mixer to blend them back together, so it's really the Z-Drive that catches my eye, at least as something I'd want to own.
Whether tube or transistor based, a preamp based on one of your amp designs would be a killer product for players who need to rely on headphone setups or pedal board rigs. Either as an entry level product or even simply for the convenience.
Yes Sir, this video did help. As a matter of fact, it helped a lot. Will most definitely follow your good advice. Thanks Again
Thanks for sharing that, Dr. Z. That was a very tidy mod with the split compression ring.
You’re the man, Dr Z.
I built two amps - clones of a Fender 5C1 and a 5C3. I found some rubber washers that fit under the tube sockets. (Actually, over the tube sockets, because the tubes hang down in the combos).
You can also discharge the caps by turning the amp on for 5 mins then turning it off. The hot plates will still conduct and thus discharge the caps. If you just turn the amp on then off, the tubes will be cold and the caps will be fully charged!! The tubes must be hot for this to work. I also discharge the caps via a 1K resistor across the caps. Nice to see the only viable use for a standby switch is to discharge the caps, as it serves no other use on “receiver” amplifiers :)
This is awesome when I buy tube amps out will be dr.z's way to just be flat out helpful.
You can use what is called a "variac" which is a fully adjustable AC transformer to adjust the line voltage to your amp as well. The other advantage of using a variac is that if you have an old amp that's been sitting many years and you don't trust it, you can very slowly bring up the voltage and catch problems before it catches fire or does damage to expensive transformers. It's a valuable tool for servicing tube amps as well as adjusting line voltage to whatever you require. These are about the same money as the brown box and do a lot more.
Yes, but they also allow you to overvoltage the amp. We are trying to offer a "dummy proof" solution, in a small portable package. Just be careful using a Variac.
I’ve found that modern amp building has pushed output tubes beyond their design spec. Plate voltages are always higher than the tube data sheet recommend. In some cases bias is also set either way too high or way too low.
JTM30 I recently fixed had bias set to 130% via the zener diodes that Marshall fitted. I bought a brand new Supro 1623 and it was replating out of the box. Smoking hot.
Laney Lionheart LT20 is great. Much lower plate voltages, bias set reasonably low. Getting a respectful 20W out of 4 EL84 tubes.
Definitely worth getting some form of power regulation as you’re right, most clubs have horrible power.
You the man, doc! Great to hear from ya again.
How best to power on/off your tube amps? Is it better to leave power on and turn into standby for upwards of a hour or so, or power on and off fully between breaks?
turn it off for extended periods
Power scaling is a good way to preserve output tubes and to get overdriven tone at low volumes.
Dr Z you are a Diamond. I find some power amp valves wobble in their sockets, they don't fit snugg like the older Valves. I have to make a mggyver spring tension holder outvof a shampagne cork wire stopper to keep em in place. Thanks for sharing, you are a Generous Rocknroller.Just a thought, you could design an adjustable valve base with little tension screws/slugs to tighten the valve in its base?
Looks like a simple and effective fix,thanks...btw,I have a Brown Box and besides protecting the amp's components,all my amps (mostly 60's-70's) sound better at lower voltages...they like it in the 114-117 volt range
Dr. Z ROCKS!
At home, my wall voltage is 125v. I would probably set the variac at a voltage that would allow the heater filaments to reach spec voltage ie. 6.3 volts, etc. If the heater voltage is lower than spec then the cathode will be starved of electrons quicker leading to shorter life.
The Brown Box doesn’t regulate the voltage it attenuates the mains voltage. If the mains voltage goes down so will the voltage from the brown box.
EL-84’s are generally subjected to too much voltage in most guitar amps. The Trainwreck Rocket has a 300vdc rail which was perfect for EL-84’s.
The 100 ohm screen resistor value is too small to offer protection for the 2 watt screen grid.
The air from the speaker is hitting the valve. There will be vibration from speaker cab too. I wouldn’t put the silicone washer in unless I had tried everything and this was my last resort.
The pins of the valves will be closer to earth/chassis with this mod. The washer can’t be too compressed for it to work, should the washer compress a pin MIGHT come in contact with the chassis.
If you’re happy with that possibility, that’s fine, but I’m cautious.
Сравнение радиоламп 6П14П ЕВ, 6П15П, 6П43П Е, EL84 TESLA, EL84 TELAM th-cam.com/video/XV4MEBqWqPI/w-d-xo.htmlsi=CBIdGIxr4vW7lOkl
The older amps were designed to run on 110 volts . That is why I use a Varied with my 2 museum quality Gibson EH125s, and my Noble Victor from the 50s .
VARIAC !
Great to see you posting again.
Excellent video. Thanks for the info on the tube rattle . That’s a great upgrade .
Love your voice! I think you could do some voice overs or cartoons! Love it😂
Wonderful video. You rock.
Helpful as always ...!! Many thanks to you Dr Z ....
Thanks Dr. Z! Just switched V1 and V3 and rattle is gone.
Thanks Doc for a great lesson.
Great information and well explained. Nice job🙂
Very much appreciate your presentation, knowledge and sharing. Great job, Fun stuff!
Blissful generosity of truth Thx. Dr. Z!
…i have become familiar with The Brown Box, in fact i’ve reached out to them, super nice team over there in Nashville. How about veriacs, almost same thing, similar, problems for equipment, didn’t/doesn’t Ry Cooder use a veriac?
a variac would work, it's just typically larger, less compact, and you can accidentally OVERvoltage your amp if someone futz with it without you knowing.
Great video! Very informative and the close ups were on point.
Thank You, Dr. Z!
Thoroughly enjoyed and learned something new.
Subscribed
12-26-24
👍😊👍
I got 2 of those Brown Boxes. They are great.
Thanks Mike! As always very good advice!
Mike's Pages . Decades worth of tube wisdom in 12 minutes . And that McGiver fella , he ain't gettin the tone that you do .
Outstanding Idea Dr. Z
Great video, thanks for sharing your knowledge!
The only reason I change my preamp tubes is because of the values. I prefer a 5751 in the V1 position and sometimes change the V2 or V3 for a 12at7 or 12ay7 depending on what sounds better. 🤷♂️
Generally correct, except that tolerances (in size and spacing of tube internal parts) don't cause rattle!
Audiophile here. Thanks for the tips and advice!🤜🤛🍻
Hey Doc, great video! Quick question, do I have To bias my amp to whatever voltage you’ll be setting the brown box to? Or just plug it in not worry about that? ✌️
**update**
Bought the brown box after … works great. Had my tech bias my amp to 117 volts on my blackface amps and set the brown box to 117 volts.
Thanks for the great advice again Doc!
Jason
Preach, amen, Dr. Z! (Great video!)
at my house in the summer during a hot day I get 107 - 110 volts and at night I get 118-121 volts. In the winter all day and night long I get 120-122 volts