Leaderboard

I wasn't sure where to put this but this is a PS Audio Perfect Wave DAC so might as well be here. Found this thing dirt cheap in Japan, clearly modded and thought... why not. Might be fun... but boy ohh boy this is utter insanity. It was showed as up and running by the seller so I needed to go in and see how I could change the voltage on it. I didn't snap any pics of it when it arrived but here is one once the felt strips had been pulled off... yeah felt strips: That's the bottom so it was covered in these strips. Now I dug deeper: So there was this layer of aluminum tape that was painted and sealed on the edges with this rather coarse paint, almost like the stuff you'd use to make chalkboard finish. Then underneath there was come copper tape and the adhesive on this was nasty shit. I attacked it with IPA, acetone and adhesive cleaner (mineral spirit) and now it is mostly off the outside. I had to use plastic scrapers to get it off and machine polish the top over (due to all the small scratches from cleaning it) but it looks okey. Now I had yet to open it as the top cover is pushed up through the bottom and you need 4-40# screws to do that... something that is impossible to get here. Two weeks ago I found myself in Chicago on my annual visit and Kevin hooked me up with some that did the trick and here is what I found: Now one starts to wonder about sanity and what hose clamps have to do with audio quality but yeah... this is the most insane shit I've ever seen. This is the top cover and here is this paint the whole unit is covered in. No idea what it is but it is rather inert and I had to scrape it off the top and bottom panels. Seriously... hose clamps. This is so retarded it isn't even funny. A few things to note, see those felt strips, same as were on the outside of the unit and those ferrite beads and rods are all over it. Now to switch things up a bit, here is what looks like a brillo pad around the transformer. It's not steel wool and it was around it all. Here is another shot of the steel what ever and those rods glued to the bottom of the chassis. Also see the silver bits attached to the cables... yeah more on that later. Here it is with the cotton? pulled out of it showing what I've stepped into. How many hours did this take? Our lovely hose clamps again but look at that transformer. It is wound in aluminum tape, then the felt, then some rod, then more aluminum tape... Then those rods on the bottom of the chassis... I've started to peel stuff off and it is like an onion Main transformer and in the bottom right hand corner are all the cable ties holding those silver bits on the cables. Yeah, that is about 10 layers of aluminum plus some small ferrites and rods... Why? Fuck knows... Main transformer peeking through the madness as I need to get to it and read its markings to covert it to 230V. I'll have to do some more cleaning but this was just too good not to post...

Someone had a massive snake oil OD... good god. Must be a vibration damping freak.

I really like this album. The song selection... the way she plays. I've listened to it twice in two days. Good morning coffee music. She got a new fan. ex.

When your audiophile OCD has OCD?

Schematics auto switching. Not sure it's accurate, but that's what I've done. New Grid Voltage Control boards. One trimmer for offset and the other for balance so, both sides are controlled simultaneously. Two jumpers. For 300B/2A3, EL34 and EML 20B-V4. Works al right, quite easy to use. The -510V is achieved with help from GRHV 110V supply. Here is one with Hammond 2VA trafo on board - 2.75in x 2in. New idea - servo controlled grid voltage. Okey, I've tried servo controlled Megatron (with solid state CCS) before and that failed...

highly similar to hev70 sennheiser amp. and by that i mean n-channel fet as current source into another n-channel fet with grounded gate drive. sennheiser amp single high voltage + 600v. this amp +/-400v (initial guess on current way off) output device is infineon imw120r350m1 which has input capacitance of 3460pf. kind of high. there are better parts to use. like this one. C3M0900170D which has input capacitance of 202 pf. calculated output current is about 12.5ma and about 5 watts per heatsink. going to get fairly hot. mc33078 opamps perform very differently inverting and non-inverting. koss esp950 uses the same part in a very different way. much better ways of doing the unbalanced to balanced conversion. power supply about as basic and cheap as possible. the chinese will do this for less than $500. which means that this is infinitely better than the topping eha5. likely sounds better too.

Another great one gone....RIP John Lodge. What a voice (EDIT: along with Justin)! https://www.the-independent.com/arts-entertainment/music/news/john-lodge-moody-blues-justin-hayward-b2843232.html