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Duality Repair
United States
เข้าร่วมเมื่อ 26 มี.ค. 2019
Need some work done? Email me at:
nick@duality-er.com
Want to support the channel? Donate via PayPal here:
dualityer@gmail.com
Location: MN, USA (55129)
nick@duality-er.com
Want to support the channel? Donate via PayPal here:
dualityer@gmail.com
Location: MN, USA (55129)
DR #56 - ‘90s Receiver Repair - Fixing a Carver HR-742 With No Display and No Audio
This Carver HR-742 receiver has no display and no audio output. In this video, I document the troubleshooting and repair required to get it going again.
มุมมอง: 1 474
วีดีโอ
DR #55 - Restoring the Bass on an Adcom GFA 5500 Power Amplifier
มุมมอง 10Kหลายเดือนก่อน
This Adcom GFA 5500 is suffering from a common problem: weak bass. This video documents how I restore the bass, as well as the theory behind why it was lost.
DR #54 - Audio Amplifier Repair - Carver TFM-15CB
มุมมอง 2.8K2 หลายเดือนก่อน
This dead Carver TFM-15CB amplifier was sent in by a viewer. Follow along as I repair, upgrade, and test it. Parts Used: Lamp Replacement www.ebay.com/itm/125400378382?_trkparms=amclksrc=ITM&aid=777008&algo=PERSONAL.TOPIC&ao=1&asc=20240131095853&meid=e42b5c687fb14db4b6ead048c4322821&pid=101949&rk=1&rkt=1&itm=125400378382&pmt=1&noa=1&pg=4375194&algv=RecentlyViewedItemsV2&brand=Carver&_trksid=p43...
DR #53 - Yamaha M2 - Minor Service and Testing
มุมมอง 2.2K6 หลายเดือนก่อน
This amp wouldn't power off and the speaker set B light was not working. Parts Used: White LED - DigiKey - 1516-QBL7IW60D-WW-ND 470 Ohm Resistor - DigiKey - 541-CMF55470R00FKR6CT-ND
DR #52 - Speaker Amplifier Repair - Definitive Technology CS-8080HD
มุมมอง 4.4K10 หลายเดือนก่อน
I was sent 3 Definitive Technology speaker amplifiers for repair. In this video, I repair the CS-8080HD center speaker amp. Most of this video is centered around investigating and repairing the amplifier's switching power supply. You'll see troubleshooting using a multi-meter and self-made block diagram, parts replaced, and final testing using a signal generator and an oscilloscope.
DR #51 - Pure Electronic Troubleshooting with an NAD 3240PE Stereo Amplifier
มุมมอง 34Kปีที่แล้ว
How do I troubleshoot an electronic issue? - Define the problem (details, details, details) - Localize the problem (eliminate what's working) - Execute (replace the faulty component/s) This video reviews some basic electronic troubleshooting techniques. I use these techniques to repair a broken NAD 3240PE stereo amplifier.
DR #50 - Unique Audio Equipment - Phase Linear 1000 Service - Part 2
มุมมอง 1.9Kปีที่แล้ว
In this video, I finish servicing the interesting Phase Linear 1000 unit. There are 5 boards that make up the autocorrelator noise reduction circuitry: log amp, bandpass 1, bandpass 2, and 2 correlators. I give an overview of each board's circuitry and then perform some basic testing to see how the noise reduction system performs.
DR #49 - Unique Audio Equipment - Phase Linear 1000 Service - Part 1
มุมมอง 3Kปีที่แล้ว
In part 1, I document the initial service of this Phase Linear 1000, which includes servicing and testing the main PCB and the peak unlimiter PCB.
DR #48 - Quality Power Amplifier Service - NAD 2200 Recap / Relay Replacement / Setup & Testing
มุมมอง 9Kปีที่แล้ว
This is a short follow-up video to DR #47. In this video, I finish servicing and testing the NAD 2200 power amplifier. This includes a nearly complete re-cap, a relay replacement (with slight modifications), idle current and DC off-set adjustment, and testing. This was a very satisfying service.
DR #47 - Amplifier Stuck in Protection - Fixing an NAD 2200
มุมมอง 19Kปีที่แล้ว
This is a very short video documenting the repair of an NAD 2200 power amplifier stuck in protection mode. This can apply to many other audio amplifiers.
DR #46 - Pioneer SX 1980 Classic Audio Receiver Restoration - Chapter 3
มุมมอง 9Kปีที่แล้ว
In this video, I complete a few more modifications to the amplifier boards, pull and re-work all boards from the front end, restore the front-end cosmetically, perform some basic testing, and ask for much needed help from the viewers!
DR #45 - NAD 1155 Audio Preamplifier Repair, Service, and Testing
มุมมอง 13Kปีที่แล้ว
- Resolved intermittent output issue - Replaced both power supply transistors - Replaced all electrolytic capacitors - Verified power supply and preamp functionality
DR #44 - Pioneer SX 1980 Classic Audio Receiver Restoration - Chapter 2
มุมมอง 7Kปีที่แล้ว
In this video, I continue my restoration of the Pioneer SX-1980. I replace the bulk electrolytic capacitors, install an upgraded power supply board, power up the receiver, troubleshoot and re-work both amplifier boards, and perform some initial testing. A lot of work done, a lot more to go. Power Supply - Populated: www.ebay.com/itm/224649092473?hash=item344e211d79:g:6I0AAOSwP6JkNsti&amdata=enc...
DR #43 - B&K E200-D RF Generator Service, Modification, and Testing
มุมมอง 1.8Kปีที่แล้ว
This is my first experience with an RF generator. In this video, I complete some minor service and modifications and perform general testing & alignment.
DR #42 - Pioneer SX 1980 Classic Audio Receiver Restoration - Chapter 1
มุมมอง 7Kปีที่แล้ว
In chapter 1, I go over the basic layout of this Pioneer SX-1980. I service both amplifier boards and complete a modification for the unobtainable output transistors.
DR #41 - Carver C4000 Preamplifier Service, Testing, and Circuit Analysis
มุมมอง 8Kปีที่แล้ว
DR #41 - Carver C4000 Preamplifier Service, Testing, and Circuit Analysis
DR #40 - ART SLA 2 - Quick Audio Amplifier Repair
มุมมอง 3.3Kปีที่แล้ว
DR #40 - ART SLA 2 - Quick Audio Amplifier Repair
DR #39 - Carver Integrated Amplifier Repair - Resurrecting a CM-1090
มุมมอง 7K3 ปีที่แล้ว
DR #39 - Carver Integrated Amplifier Repair - Resurrecting a CM-1090
DR #38 - Repairing Audio Gear - Rotel RB-1080 Blowing Fuses
มุมมอง 26K3 ปีที่แล้ว
DR #38 - Repairing Audio Gear - Rotel RB-1080 Blowing Fuses
DR #36 - Multimeter Review - Kaiweets HT118A
มุมมอง 2.2K3 ปีที่แล้ว
DR #36 - Multimeter Review - Kaiweets HT118A
DR #35 - Carver CM-1090 Integrated Amplifier Repair
มุมมอง 8K3 ปีที่แล้ว
DR #35 - Carver CM-1090 Integrated Amplifier Repair
DR #31 - Audio Amplifier Repair - Parasound HCA-500
มุมมอง 7K4 ปีที่แล้ว
DR #31 - Audio Amplifier Repair - Parasound HCA-500
DR #27 - Tektronix 2213A Oscilloscope CRT Replacement & Tune-Up
มุมมอง 4.8K4 ปีที่แล้ว
DR #27 - Tektronix 2213A Oscilloscope CRT Replacement & Tune-Up
So may i ask what type /brand of capacitor did you use at C601 ??
Thànkyou. I just learned so much good information.
hi nick...i have yamaha m2 amp...my spendor s100 has 3 inputs on back of speakers...low , mid , high...so i had yamaha m2 high and lows on channel A and lows on channel B...never any problems sounded great... now today i go to hook up a Rel sub high level red to right A+ channel Yellow to B+ channel and black to right negative A-...all of a sudden no sound from channel B...on the back I turn the left volume gain control and it workd but the right volume gain and nothing...I thought maybe the Rel sub shorted out a fuse...i took gront pannel off and can' see any of those fuses out...is there another place i don't see where a fuse may be blown out❓
Great presentation Sir. I am going to buy the meter you used to measure the capacitance. Thank you for the wonderful demonstration
Awesome video, very clear explanations of the repair. Will you be releasing a video of the 8080st amp repair? I have the same issues with bad plate amps, they are a known issue with these DT speakers.
The sonic hologram is so clever. I wonder why the inverted signal doesn’t mess with the original ear (in your example, the left) where it arrives a fraction of a second after hitting the right, again locating the speaker.
I have a orange light on the right side what's could cost that problem thanks for your time
2:25 One more option: Not a fault in the regulator, rather a short on the +18V bus dragging it down...
I was a 16 year old drummer in 1882 playing with a guitarist much older than me, who sold high end audio. He demoed the Carver Holographic Generator for me and the shop he worked at, and it blew my doors off. Unbelievable. Bucket brigade chips are commonly used in all sorts of chorus and echo stompboxes. I had no idea that was the secret behind these.
1982, actually.
great ad fine job
After watching Mend it Mark vids, TH-cam sent me to your channel which I’m really enjoying. As a non-technical person could someone please explain to me why it’s necessary to replace the electrolytic caps? Is it because they have a limited lifespan or will new caps actually improve the performance of the amp even if the caps themselves have not yet gone bad? Thanks in advance for any explanation!
Good question. Electrolytic caps do have a life-span, usually much more so than other components. They have an electrolyte liquid / paste inside that dries out over time. As it dries, the capacitors performance degrades.
@@dualityrepair4770 thanks for your reply, that answers my question perfectly.
What a super explanation! Subscribed.
Wow! That thing is a Marantz inside! '90s Marantz Japan. (MJI) Basically an SR-63 with the added Carver board.
I really appreciate you posting the part replacements. Hope you’re busy, I’m booked out about 8 months at the moment. Would you mind in the future posting the device number pulled along with the replacement? The outputs can be read in the video, but I was curious what the TO92 package was. Thank you.
Ah good call. Will do Dan.
Nice to see a great unit like this given more life. Thanks.
Really well presented video, a joy to watch. Thank you
Thanks midmod
Outstanding informative video and a Great job!!!
Nice job Nick, as always.
That was awesome. The explanation and commentary made all the difference. Great job on the repair.
Thanks Frankie
Thanks Nick! Wonderful to see you at work and staying busy.
Thanks John. This one was a battle. Probably 10 hours of work for a 10 minute video. I learned a few things along the way.
Well done Sir...
Do a Carver m-400t cube amp.
I did the plain M-400. DR #37.
Replacing those single-turn quiescent current- and DC offset pots with multi-turn ones would let you dial in the precise numbers called for.
Helo i have changed the two 6.8 ohm resistors still short again why??
I knew all this stuff 30 years ago when I graduated from NEI. Thanks to your videos I want to learn it all over again. We have a throw away society, nobody wants to fix anything any longer but I'm going to give it shot on my 8060 that doesn't work any longer. Thanks!
Glad to hear it and good luck!
One of the things that I think technicians like you don't take into account is that a manufacturer will use certain capacitors to get a certain sound that he is aiming for. That means he may have tried many types of capacitors with many hours of listening until he decided what to put. And just because you put something with the same values and the wave looks good on the oscilloscope doesn't mean it sounds the same. This is audio equipment not a TV or a refrigerator. Therefore, when you decide to put something that has the same similar values but is produced by a different manufacturer, you should understand that it can affect the character of the sound.
That may be true, but 45 year old caps should be replaced if you want a piece of equipment to last another 45 years. And I can only use the components I have available to me.
@@dualityrepair4770 It is okay to make the equipment more stable and durable for years to come But if a certain component such as a capacitor or diode is measured properly I think it's better to leave them as they are. Especially if they are related to the audio signal. Because if you start replacing everything like this, you might change the original design of the device. And it can damage the magic of the sound that the designer aimed for. Even if from an electronic point of view everything is measured according to the electircal schem. In terms of sound, this could be a change for the worse.
i disagree, all electrolytic should be changed. He isn't changing the type of capacitors, just replacing them with modern equivalent. I would argue you that the sound after the recap is more inline with the sound when it was brand new - the sound it have currently isn't what it sounded in the 80's. It's often a debate with old resistors too, i can assure you that old crackling carbon resistor "warm" sound weren't a thing when new. He isn't changing elecytolytics for..say.. ceramics or playing with values; so it's fine. My old system sounded "clean" and reactive when new; over time it sounded more "bass" and vibrant with music. I liked it a lot, but a recap brought back it's original "snappy" sound. There will be a difference of course but even if you like it, the morph in the sound is because of components failing.
TH-cam shoved this video in my face but i didn't want to look at amp videos yet Next minute, i end up with an amp with no bass. Had to try and remember the name lol
Wow what timing
I have the other two amps one is failed I am interested in having You repair them.
Hi, I've got a similar issue on my Mission Cyrus one. Did you measure the output voltage under a resistive load?
Yes, the amp was connected to 8 ohm - 500 watt resistors.
@@dualityrepair4770 Thanks!
Your video is very useful and gave me the notion that the ayre mxr i owned has a similar issue. I always felt that the ayre lacks bass weight and resembles little to the reviews i have read. Would you think the ayre would have something like a "c3" lurking in the unit that is hindering the bass performance. Your insights is appreciated. Thanks
Yes it could very well have a “C3.” Unfortunately I can’t find a schematic anywhere to help point you at a specific component or area.
No worries...when I find a schematic I will come consult you again. Thanks
5:32 That little power board, did you have to squeeze the white plastic clips to remove it, or were there screws on the other side?
No screws. Just squeeze the plastic tips on the top of the board.
Great video. I also love the little Dynascan era BK scopes. Especially the round crt models like the 1470. Sexy! See if you can score a little 1405. So fun!
Thanks. The 1405 does look neat.
Wow, brilliant repair!
Thank you Mike!!
Has adcom ever been good?!
My Adcom GFA 5500 is nearly 30 years old. Works great and sounds great. 👍
It's always a treat when a new Duality video appears in my subscription feed!
If you add flux to your de-soldering wick, it pulls the solder easier, and leaves a clean pad. Great video.
From experience. I hate Adcom. I never like their sound. But then again I don't like half the amplifier's I went through other than , Spendor class a amplifier and Mackintosh 252
Then WHY are you here??? Weird
Why did Adcom use an electrolytic c3in the signal chain?
very good video. thank you for the explanation!!!☺
Random question, how difficult would it be to convert this to a dual monoblock? Is there space for a second toroidal there, or is there a smaller option available which can be placed side by side? Just curious.
Cool repair. Nice amp. Enough power and very high damping. 700!
I would look at using a Tantalum capacitor in that application as it will last a lot longer.
Cool! I have this amp and its 3-channel brother used perhaps 100 hours total. I bought them new and have been in the box since. I should sell.
I am a bit confused by the feedback resistor being so high at 10K ohm wirmth the other 50K ohm that would make the overall gain only X 6 or have i missed something.
Good eye.. and you're right.. a gain of 6 is ridiculous. It turns out that the schematic isn't completely correct. The feedback resistor is indeed a 49.9K, but the resistor to ground is not 10K.. it's 1.82K, making the gain ~28. Thanks for bringing this up.
The old schematic documentatio error problem . That is why we hone our fault finding skills to give us the tools to overcome these obstacles. Dealing with lack of or conflicting information. Maybe that would be a good subject for one of your future videos. @dualityrepair4770
Very Informative video. You must be from Texas your arm shows a map of the state.
Minnesota actually. Thanks for the comment.
Just found the channel today. Subscribed. 😊
Magnepans made in Minnesota 😊 Great tutorial 👌 thx for sharing 👍
Nice walkthrough and demonstration of the problem, along with solution.
Thanks!
Its easy to know why caps failed like that, its caused by heat you can see discolored pcbs in almost all Nelson, Adcom and Nakamichi top end amplifiers he likes to design time bombs deliverately, that amplifier also has a small heatsink in the differential pair that almost all the times (have seen that small metal thing missing in almost all of that model amplifier) and if it didnt went missing it will short ccircuit some transistor or something after the glue fail under the heat...... the same heat that caused the video capacitor fail 😅
This isn't Nelson Pass's fault, he only provides the circuit design. Adcom did all the actual board design, including decisions on heatsinking.
This failure is likely caused by heat. The input mosfets run super hot, which causes eventual failure of the capacitor. You can tell how hot the board gets by how browned it is in that area. There is usually a copper heat-spreader bar installed across the two mosfets, meant to keep them thermally tracking, and dissipate some heat. It looks like yours either fell off, or it wasn't included in that particular production run. What I do is install a DIP-16 heatsink across the two of them, with thermal heatsink epoxy, and that dissipates heat better than the original copper bar, as well as thermally coupling them. Also, the heat cycling eventually cracks the solder joints, resulting in a crackling sound, a common issue with this amp. The solder joints just need a touch-up.