kevin gilmore

1 ) yes 2) yes 3) the 4 tubes in the middle can either float or tie to -vcc yes the front end tubes are 6.3v, so 1.2 amps

no on the 3 terminal regulators. each output tube is 1.5 amps so that is 4 x 1.5 amp windings and 1 x 6 amp winding all the input tubes are in parallel, so 12V at 600ma

228.0 x 228.0

that looks a fair bit different than the first units

why no one tell me I got the wrong hole size... updated goldenreference6d file.

probably close to 50 milli ohms with a voltage gain of 10

highly unlikely the board is bad maybe you are connecting the transformer to the wrong place, center tap of transformer goes to the middle pin and for single bridge the other 2 wires go next to the center pin if there is no raw dc voltage on either of the main power caps, the bridge is toast or not the correct type for this board

joamat did this on a T2

OH boy is he taken!

I have never tried to get it to work that low, highly likely you have to use the 7V reference chip. Then it should work

i don't remember ever picking elna caps, definitely did pick the wima caps will look when i get home

I have seen ground loops do the 50(60) and 100(120) bumps, but never that amount of wideband noise. a missing ground wire between the pot and board ground could do it.

very noisy input fets or fakes, and volume pot of too high impedance. original was 10k pot.

i was wondering how you were going to do 3 layers in your kitchen, now i know

Definitely return it if you can otherwise get a scope and see if you get clock to the d/a outputs both before and after the opto isolators then see if you get any data etc.. My guess is that the input board is in trouble and I can't imagine anyone actually be willing to troubleshoot something that old filled with obsolete parts. check the +/-15 at each d/a board, same thing with the 5v

this definitely looks like NoNoNoNoNoNo class work. I have a few of his dead attempts in the basement, Jacob will remember. better question would be why you would want to put any more money into this in an attempt to fix it

warning: DO NOT DO THIS Mikhail did this with his "high voltage option" and zapped a number of people if you really must switch secondaries, use high voltage relays rated for 1kv or more isolation and even then, the inrush current might weld the contacts shut.

Outstanding

where did you get the delay board?

I bought one from headroom the first day they went on sale and it was $1399

soren also wanted buffers and a place for the attenuator on the board, which makes the board a fair bit bigger, and thus more expensive. if people think that is a good idea, or have other ideas i am certainly willing to modify. But i think that the smaller board is a better idea

Don't remember if there is a 100 ohm input series resistor on that board. the ss design need lowish input resistors because of the offset currents in the that 340 and the gain resistor is calculated from there

well if you are craig, you wire a 2 gang pot as parallel shunt with 2 resistors because that is moar better. unlikely this was wired that way. also requires a reverse log pot.

if you are going to get a tube amp, get a tube amp. if you are going to get a solid state amp, then get that. but a pair of tubes driven in parallel by a crappy opamp, with lots of feedback and garbage transformers modified to do both 32 ohms and high voltage at the same time seems like a really bad idea.

the mjf are plastic parts, so you can use metal screws, you still need a thermal isolator the mje parts are exposed tab, so you need to use insulators on the screws