GeorgeP

Yup, that’s it.

Kevin commented on how to ground the amp, at the end of this post. The picture doesn’t work any longer but there was a short wire going from the terminal block ground to the board stand-off hole. Make sure to remove some anodizing from the chassis so there is continuity among all the pieces, that particular standoff and the IEC. The chassis ground from the amp section would then go directly to the IEC ground tab.

Try getting your 190v closer to 200v if possible. And then readjust after 30min or or as the value will change until the temps stabilize. If your offsets are still problematic then adjust as required (30ish volts or lower is good) but it might suggest an issue somewhere.

As discussed in PM, all three toroids are miswired. Someone has tinkered with the PSU and re-wired the toroids incorrectly. This amp was built in 2016 with Houlden's transformers, which are what I have in my T2. Toroidy may be the cheapest option for you given you are in Australia. Alternatively Primrose/Sumr can supply the required transformer. Hopefully your only issue the transformer.

1000%. I have seen people do this with unfortunate results. Even what some consider to be drop in replacements for the el34, like kt77, should not be used.

It’s even easier for the ones not mounted on the heatsink. 😉

The 2sa1486 from little diode are 100% fake. They are pretty scummy.

Where did you buy them? Most 2sa1486 being sold at the moment are fakes.

If the 2sc3381 and 2sk246 are the ones you got from me, then they are real. That said, I have seen fake 2sc3381.

use 1156 on the heatsinks, 1486 (if you have them) everywhere else.

Oof! So something has also gone in the psu *and* some resistors in the amp sparked (to ground or just blew?)? Sounds like you have a bit of work to do, obviously fix the psu first.

Ooof - then it sounds like you have some work ahead of you...

So you only have one properly working side then?

Sounds like current limiting in the power supply if only one side is powered up at a time and it powers up normally - 30r resistor to 25r or 20r will fix that. What happened though to cause you to start replacing parts in the amp section first - there may be something else afoot?

I don't think so. He actually has a picture of a train and a picture of a bicycle side-by-side, and then goes on to state that they are not the same thing. I found that illustration particularly compelling. Though I think he might have had the arrows from the amplifiers pointing the wrong way...

Only thing I learned from Fang's latest post is that a bicycle is not a train...

Russian Mullards? Maybe you messed up the balance/offset process.

Sounds like your tubes are the issue. If your tubes are within spec, you probably shouldn't have had to rebias at all. What were they measuring at before you rebiased?

Well one thing in the earshock guy's favour is that Hifiman wasn't able to get him to be one of their shills - that's got to be worth something.

But smoke and mirrors work wonderfully on their audience.

It is just a link to a tutorial on caps : https://www.electronics-tutorials.ws/capacitor/cap_7.html (so you can better edumacate yourself, of course...), and the following Pf calculation: MOSFET C1=65 Pf Transistor C2=6 PfCtotal=C1*C2/(C1+C2)Ctotal=5.49 Pf

The Board error is an easy fix - a missing trace if I recall. There are some posts on it in this thread. I seem to recall G600 had this issue. Why not post some pics of the sand (2sk216, 2sj79, 2sc3675 and 2sa1486) - sometimes it is easy to tell from a visual.

Have a couple of these I've been meaning to get to. Wish I got in on the parts group buy as I just can't get motivated now.

yeah but the rk50 is all gold-like and purdy lookn.

First, it would be hard to prove (and to what end, now, 4 years later). Second, you would not have known, so you shouldn't have any guilt on your part. I corresponded with him back in 2015 about the Lil Knight T2 boards he was selling and he indicated that "Last time I heard from him was 8-9 months. At that time, he was in hospital, probably in a coma. He was a big help to me back then, not sure what happening until now." Maybe it is true. If so, prior to going into a coma Lil Knight gave this guy all his partially completed amp builds, audio parts, T2 boards and chassis parts to sell on Head-fi...