OK>>>> pretend I said TRIAC.... ugh... sorry
I've done a fair amount of work on this, and did the complete MKII upgrade and attempted to set the bias and voltage, but the supply voltage came on at about 60v and then started to decline... I pushed the main voltage reostadt just a little and the transformer started to hum a bit... so it was troubleshooting time...
As per the instructions, I disconnected everything from the outputs that could take down the voltage and then gave it another try and same voltage problem.
I am a tech, but as of yet, haven't bought a variac or scope, but I tested is like this, using a 10vac guitar pedal power supply I shorted the variac, as shown in the troubleshooting section, and instead of the 30v recommended, I used the 10vac and extrapolated the results... and I seem to have the same voltage from the supply coming from test point 5 and 6... and no ripple (not surprising since I just replaced the entire supply of E-caps)... so according to the troubleshooting, the variac is the prime suspect. i checked the 12v regulators and they were reading about 6 volts, which i still think is about right, given i was only hitting it with 10vac. Any dissenting voices? Also I checked for ripple using a small expendable powered speaker, grounding it to chassis and using a coupling cap as a probe to "listen" for ripple... and heard none. I've done that before, and fixed several quartz lock units using the "listening" technique, instead of a scope... not sure if anyone else has tried this, but i personally like it... and it's CHEAP... sure, I kill a 10 dollar speaker a few times a year... but they get a proper burial... Anyway... any input is appreciated... going to buy a variac, I guess... which I've never done... and don't know what i'm doing... lol
I've done a fair amount of work on this, and did the complete MKII upgrade and attempted to set the bias and voltage, but the supply voltage came on at about 60v and then started to decline... I pushed the main voltage reostadt just a little and the transformer started to hum a bit... so it was troubleshooting time...
As per the instructions, I disconnected everything from the outputs that could take down the voltage and then gave it another try and same voltage problem.
I am a tech, but as of yet, haven't bought a variac or scope, but I tested is like this, using a 10vac guitar pedal power supply I shorted the variac, as shown in the troubleshooting section, and instead of the 30v recommended, I used the 10vac and extrapolated the results... and I seem to have the same voltage from the supply coming from test point 5 and 6... and no ripple (not surprising since I just replaced the entire supply of E-caps)... so according to the troubleshooting, the variac is the prime suspect. i checked the 12v regulators and they were reading about 6 volts, which i still think is about right, given i was only hitting it with 10vac. Any dissenting voices? Also I checked for ripple using a small expendable powered speaker, grounding it to chassis and using a coupling cap as a probe to "listen" for ripple... and heard none. I've done that before, and fixed several quartz lock units using the "listening" technique, instead of a scope... not sure if anyone else has tried this, but i personally like it... and it's CHEAP... sure, I kill a 10 dollar speaker a few times a year... but they get a proper burial... Anyway... any input is appreciated... going to buy a variac, I guess... which I've never done... and don't know what i'm doing... lol
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