HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

Below you can see the warped/cracked single input amp Richard sold for low money a few years ago.





I took the opportunity of working at home now for a year and getting more and more bored to transform that amp into an four input dual mono copying the AP70 design. I had heat-sink elements from a wracked Dual amp I attached with thermal glue to an 5mm aluminum plate, ordered two 25V 150VA transformers from Toroidy, Vishay caps, an Alps poti and a lot of small stuff like speaker- and cinch sockets, tinned copper wire, cobs and so on, took the boards from the warped one and put all into a wooden box for three bottles of wine I bought a the local wine shop, sprayed it black and here is the result (a nice sounding amp):







Tomasz, I know you'll complain about the missing isolation of the headphone socket leads. I forgot to order heat-shrink tubing and the bit I had left was needed for the transformers. I'll complete it when shops are open again.

You could get acrylic for forty quid.

Did you notice any difference with the vishay caps?

Daniel Quinn wrote: ↑Mon Mar 22, 2021 10:53 am You could get acrylic for forty quid.

Did you notice any difference with the vishay caps?

Thank you, I'll think about acrylic when boredome comes up again (the wooden box was 5 Euros). It's now up for two days. Till now I don't hear any difference to the AP70, maybe after running in for a longer period. It's a bit hard to compare for me. When I unplug one amp, switch on the other and wait till it has reached it's temperature I already forgot how the other one sounded and am just happy with a good sounding amp.

For me , the uf of the capacitor had a greater impact than the make.

I took them because they should last much longer than the standard ones.

I love the idea of a wooden box with hinged lid for access Well done.

karatestu wrote: ↑Mon Mar 22, 2021 2:28 pm I love the idea of a wooden box with hinged lid for access Well done.

Thank you, I like it, too.

Nice work, Hannes.

There is always the extra satisfaction whenever you use if, of thinking ' I made that!' .

Thank you, Fretless. And it's true, I'm looking at it very often feeling a bit proud. But nonetheless it's a copy of a NVA design. So the applause has to go to Richard and regarding the transformers and caps to the new NVA.

Really impressed - I love the recycled nature of it.