Smeggy

I also need to find a big board of sexy wood for the amp top. That's gonna be expensive..

well the bolt/washer is like 3" across, so big fucking hole I'll come up with a plan involving a big hole... and some wood It's an ugly box anyway and could do with a pretty wood lid.

Hmm, didn't know that. It's not touching the top plate but only just. Is it ok to use a sheet of something over the bolt/washer to prevent metal contact? Sticky back vinyl damping sheet for nstance just as a layer of safety?

Thankee kindly dear sir Just looked, seems we (you) got it right first time That big-ass toroid only just squeezed in that case, it's a very tight fit. One more mm and I wouldn't be able to close the lid!

Yeah, it's all going to be headphones but a number of them require speaker power. It will not be used with actual speakers. Front panel normal phones, hi-power XLR and two 'stat transformers. I don't see any reason the XLRs wouldn't be fine for this but wanted to be sure I wasn't missing something like I have before.

We are in your pot making noise

heh, I have no idea why they failed aside from me maybe tweaking the trimpots wrongly and cooking something so rinse/repeat is all I can think of right now. On another matter of the Beta, If I wanted to route the speaker signal to a couple of different devices internally (stax, sony transfo boxes and XLR for K1000) can I use 4 pin XLRs to swap speaker outputs? So.. Binding post bananas to XLR male > Fem XLR 1,2,3 on the back > Stax, Sony and Front panel XLR phones or are XLRs not rated for the 18wpc these dish out.

I was gonna ask about that but have no idea what I might potentially need.

thanks, will get the orderved post-haste.. with spares

Cheers guys! I have the sigma out of the cast for testing and repairs, should I order a matching set of 4 resistors? I don't know what brand the blown ones are. I don't suppose it matters too much but I'd prefer to remove as few components as I can.

Further testing, with the sigma powered by itself I'm reading 1.6V +/- R12 and R13 are reading 41V one side, 1.6V the other. R14 and 15 are reading -1.6V at both ends of the resistors. The LED is glowing faintly, but glowing. many of the checkpoint voltages on the board seem fine, others not so.

Cheers Beefy, you identified a couple of bits already

see above, I wrote C5 instead of D5. The zener reads .759 on my diode setting looks like R12 and 13 are popped, 14 and 15 are reading 0.4

Hah, D5 is looking suspicious... and it was in the right area. It's the smallest whatever on the board and it's giving an add reading. Meter set to 200Kohms it's constantly rising from a -48kohms??? What the hell is that thing? *runs off to check ambs site again... *EDIT* D5 not C5 Ok, looks like it's a 12V zener diode, and a very important one. I don't know how to test it, any clues?

only if I can figure out what's blown... I have no idea what to even check.

heh, looking at the sigma shows no obvious signs of toast which is a pity because at least I'd have something obvious to replace Everything looks perfect.

It's the sigma that got smoked, not the boards, it's only outputting 0.3V now.

yep, 30v ac in, 30v dc out

the outputs to the boards, and the input, input had a smidgen more volts. It was like 30.xx in and 29.xx going out I think I had my 65mv, my 4.5v, my 0 dc offset and was just resetting offset after the 10 minute thermal drift period.

Indeed! Pars, how would I know if the sigma was made for 24 or 30V? I was measuring 30 at the terminals

yeah, got 30V coming in... 0.3V going out of the sigma. *sigh*

Well it didn't last long, I gave it the 10 minute warm up before final tweaking then smelled some faint smoke... switched it off, reset the trimpots to zero on the board I was working on and now nothing lights up I killed it.

Yeah, everything measures fine, just no led lighting up on two boards, everything else seems fine. I messed up first time because I had trimpot 2 and 3 mixed up, I thought they'd be in order

Ack! I wouldn't know where to even begin. I'm just trying to finish it up, the boards were already built.