[CADCAM]

what caused the failure? (assuming the repair is done) power supply? Just curious.

Never heard from the repair guy so I called him maybe a month or more ago, he said it was the power supply and he had ordered a new one from China. After 40 days of waiting he said he cancelled the order and got his money back. He still has the unit and says he is looking into options to repair it so I'm just waiting. Not sure if I'll ever hear anything though...too bad as I loved the way this thing looked!

 

[AudioCats]

Maybe the factory switching HV supply could not handle the high temp (heat generated by the tubes) and died. If the factory module is not available, I suppose you can always use conventional transformers. Transformers will not fit into the slim aluminum enclosure though, it will end up being a two-chassis amp. Might as well upgrade all capacitors while you are at it.

The circuit seems to be pretty simple, according to the schematic posted by evonimos
https://www.diyaudio.com/forums/hea...mp-kit-using-5670-6080-tubes-suggestions.html

 

[CADCAM]

Maybe the factory switching HV supply could not handle the high temp (heat generated by the tubes) and died. If the factory module is not available, I suppose you can always use conventional transformers. Transformers will not fit into the slim aluminum enclosure though, it will end up being a two-chassis amp. Might as well upgrade all capacitors while you are at it.

The circuit seems to be pretty simple, according to the schematic posted by evonimos
https://www.diyaudio.com/forums/hea...mp-kit-using-5670-6080-tubes-suggestions.html

Maybe I should grab the amp from him and have someone else take a crack at it.
Anyone in the community here that repair tube amps like this. My guy has had the amp since 2020 and nothing yet...

 

[AudioCats]

the main challenge here is the slim enclosure, it pretty much dictates the use of a switching supply. I'd guess, to do it right, the HV module will need to be at least 10w rated, probably around $100 (assuming such part is available from Mouser or Digikey), and the module should be housed outside the aluminum box. (say, you add a "bulge" in the area behind the 6080 tube).

The "2-chassis transformer" route might be less but not by much. The cheapest route (and might end up looking like $#!&) will still require >$50 of parts, just to get the proper power supply voltages.

What I am trying to get at..... it will be more of a "build" instead of just a "repair". Even if the factory HV module is available, you probably shouldn't just pop a new one into the same location, it will likely fail the same way in about the same amount of time. Maybe your repair guy is fully aware of all these, therefore not moving forward.

 

[AudioCats]

ran across the PCBA on ebay,
https://www.ebay.com/itm/274286928614?_trkparms=ispr=1&amdata=enc:1VA-DkJdISfylp_S0UgVqHQ10&chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=274286928614&targetid=1262843335129&device=c&mktype=pla&googleloc=1014485&poi=&campaignid=12873833227&mkgroupid=120757694159&rlsatarget=pla-1262843335129&abcId=9300536&merchantid=101700969&gclid=EAIaIQobChMIqaCoua7X8QIVEwutBh2lVQHzEAYYASABEgJtMPD_BwE

judging from the parts arrangement shown in the PCBA pictures, the output stage resistors (the green ones) are very close to the output electrolytic capacitors (the green ones). The heat generated by the resistors (about 5w each) will kill these caps over time and then the leakage current might kill the phones. So it probably was a good thing that the power supply died first.

Both the power supply and the amp board should be redone. Probably a good base amp for project purpose.

 

[AudioCats]

Here is a supply that can provide the high voltage, and the main 6.3v supply (for 6080). They offer a "custom voltage" option, maybe they can do a 200v version for you. 5"x3.3"x1.5".
https://www.ebay.com/itm/154411572865?hash=item23f3a59e81:g:j3wAAOSwCXdgc-tj

 

[CADCAM]

Spoke to the repair guy today and he did indeed order a new power supply, I told him about not wanting the same type of failure to happen to the amp in the future and he agreed that there needed to be some modifications to assure another similar failure didn't happen. We talked about mounting the ps in an external chassis and he agreed that would be a good idea. I would like to hear and see the amp again as I bought it basically based on looks! I think it's just a nice looking piece. I have a Monoprice Monolith headphone amp that uses the same tubes so tube rolling wouldn't be an issue as I have many options.
Maybe this amp has a future after all!

 

[AudioCats]

Don't forget to post pictures of the final result, will be interesting to see.

 

[AudioCats]

new P7 are on aliexpress. Maybe they will be on amazon soon.

 

[CADCAM]

new P7 are on aliexpress. Maybe they will be on amazon soon.

Don't see it...link?

 

[AudioCats]

try searching " P7 tube amplifier " on aliexpress.
Multiple sellers. Large qty (100, 569, 888 etc)

 

[AudioCats]

I didn't realize it has always have a fan inside..... where did they put the fan?

 

[AudioCats]

this might be the transformer version of the same thing, on ebay. The description doesn't mention a fan. Price is a bit higher though.

https://www.ebay.com/itm/265082127184?_trkparms=ispr=1&hash=item3db8204350:g:79YAAOSw1O9gRzBr&amdata=enc:AQAGAAACkPYe5NmHp%2B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsStdebXPz4ZTXCT8FI9kPBh7uNQWeJFIJ9yDDyy9G6DPBgPxs6sMjDTTlB1ZnQD6qZfMP%2BhxqBqpJaGP1CD4XiFP0nf%2Bfy1grT73oqI8zoC5MS8%2Br5H8rl4%2B0LOeBPYfPJY5lKeq66hsHL%2B3bD6x2YzTveWwadl1Rgr%2BuAc5pNf6QbbkjXUDK3%2Bg6QQTi9g35emDU1i3aCKUdAgxK6R4YKiinO3In93eH%2BfKs8NsYb5%2BHk42q7do4qockewDyniamPKHtvAMinvM9tJeXxZG0GSec3%2FjgqjIMRfBuNSG3eoPIO7HT6QNyM%2B20RJMPikqJUIktcQxR4nRSdGWdGZyGwhYKKnsz8I1GgOndLLLZ7V92pBt1E9mA2s94xpZQCxyBKaP%2BvtX6z%2B%2FBK6DzRdB39NaEYSb%2B60rWc2wYrhMlo0%2BZ1nO2gXxN%2BfXerQp7g%2BRy9%2B0DCXF%2FNBnbnB7f32qIiZHZJ6scXm7hnCEKynSGsgNk4fXwOOWhol08GzakR8P98NQD7iRMfzBY%2FlN10Ch9dVvHy9sWa2yIzey9fdGf%2B5anFvf8dRGWMGpPd310DbwZiivO2grf%2BO6%2BcIgGgIZhdhT%2BMqRX3n9FFOaNIpgnGunKzrF4mw6DpPQky1DBbcacgZIwEUu%2BYdhpRM7jUsBDuszYzq6Zu2ix9R8nY69%2B0OzQcbJ1kJFGlPJPpYt9HQx7n0YNLW6nWeYiLeX1oIjSUsBl9upHfALF2TZ1b0dbwWmAN9ZYRrSLKRO6q%2F%2BbuAMNZ6lsFVDu6P9Y9TUZ56NP7yldureFmVW1g4z3D6yO%2FOwPH5z9L%2BgKIbn7ztsgl%2B31K|ampidL_CLK|clp:2334524

edit: similar PCB but not the same. The PCBA in the photo has alps blue volume pot ($20 upgrade).

 

[CADCAM]

this might be the transformer version of the same thing, on ebay. The description doesn't mention a fan. Price is a bit higher though.

https://www.ebay.com/itm/265082127184?_trkparms=ispr=1&hash=item3db8204350:g:79YAAOSw1O9gRzBr&amdata=enc:AQAGAAACkPYe5NmHp%2B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsStdebXPz4ZTXCT8FI9kPBh7uNQWeJFIJ9yDDyy9G6DPBgPxs6sMjDTTlB1ZnQD6qZfMP%2BhxqBqpJaGP1CD4XiFP0nf%2Bfy1grT73oqI8zoC5MS8%2Br5H8rl4%2B0LOeBPYfPJY5lKeq66hsHL%2B3bD6x2YzTveWwadl1Rgr%2BuAc5pNf6QbbkjXUDK3%2Bg6QQTi9g35emDU1i3aCKUdAgxK6R4YKiinO3In93eH%2BfKs8NsYb5%2BHk42q7do4qockewDyniamPKHtvAMinvM9tJeXxZG0GSec3%2FjgqjIMRfBuNSG3eoPIO7HT6QNyM%2B20RJMPikqJUIktcQxR4nRSdGWdGZyGwhYKKnsz8I1GgOndLLLZ7V92pBt1E9mA2s94xpZQCxyBKaP%2BvtX6z%2B%2FBK6DzRdB39NaEYSb%2B60rWc2wYrhMlo0%2BZ1nO2gXxN%2BfXerQp7g%2BRy9%2B0DCXF%2FNBnbnB7f32qIiZHZJ6scXm7hnCEKynSGsgNk4fXwOOWhol08GzakR8P98NQD7iRMfzBY%2FlN10Ch9dVvHy9sWa2yIzey9fdGf%2B5anFvf8dRGWMGpPd310DbwZiivO2grf%2BO6%2BcIgGgIZhdhT%2BMqRX3n9FFOaNIpgnGunKzrF4mw6DpPQky1DBbcacgZIwEUu%2BYdhpRM7jUsBDuszYzq6Zu2ix9R8nY69%2B0OzQcbJ1kJFGlPJPpYt9HQx7n0YNLW6nWeYiLeX1oIjSUsBl9upHfALF2TZ1b0dbwWmAN9ZYRrSLKRO6q%2F%2BbuAMNZ6lsFVDu6P9Y9TUZ56NP7yldureFmVW1g4z3D6yO%2FOwPH5z9L%2BgKIbn7ztsgl%2B31K|ampidL_CLK|clp:2334524

edit: similar PCB but not the same. The PCBA in the photo has alps blue volume pot ($20 upgrade).

Still don't see it on Ali but that's fine as I would never purchase anything from Douk Audio again. They knowingly continued selling a product with serious design flaws that caused it to fail on most if not all customers who purchased the P7 amp.
I'm just one of the lucky ones that bought mine from Amazon and when Douk Audio never responded back when mine failed Amazon refunded my purchase and said keep the amp. Amazon then took the amp down off their site. Douk Audio changed the name of the amp slightly and continued selling it on feebay! Who's to say the companies QC dept did their job this time?

 

[AudioCats]

really, it doesn't show up in your search? Product photo shows different back panel style:

24v DC version
https://www.aliexpress.com/item/328...exp_id=de0275f1-b690-4598-acac-8d0e130ddebb-2

110v AC (IEC input) version)
https://www.aliexpress.com/item/100...exp_id=de0275f1-b690-4598-acac-8d0e130ddebb-6

however the descriptions all said "... with 24V switching power supply, 4A".