Is this the 93 or 96 based board Ali?Ali Tait wrote:Ok, I will, thanks Nick. Listening further with the new board it is indeed still distorting with full output from the Touch.
Could the valves have drifted and caused a DC offset on the output TX?
Anyway, here's some useful news, I got mine going
I didn't add the supplied bridge rectifier chips as I intend to build another set of off-board regulators and shove DC directly in. I am current running off bench supplies, one set of +15v/-15v DC and the other +12v DC, it seems OK heat-wise; I'll get the temp probe out later on.
Just for the record the +15v side draws 55mA the -15v draw 15mA and the 12v supply doesn't even register on the supply's meter which is not sensitive enough @ 100mA per div. I can put a meter in line, if anyone is interested and will probably do that so I can size the supply accordingly. Since I'm doing this I may take the +12v supply via a reg off the +15v as a reg chip is cheaper (and smaller) than a separate TX.
I will measure the DAC at the weekend, but it sounds very good, better, or at least as good as the SB3, even with the stock op amp in and doesn't seem to be distorting.
One little foible I noticed is it seems picky which supply comes up first, one way around sweet music, the other it just pops and whistles. I think the 9v reg has to come up first but I'd need to check this to be sure.
I changes the reg chips for better ones, upgraded the caps around the op amp and on on the receiver and used PRP resistors for the low pass filter and IV stage, otherwise its stock. I used the LPF for the 96 as per the spec sheet.
That's about it.
Andrew