| Author | Message | ||
| Matt Sutton (matt_sutton) Username: matt_sutton Registered: 10-2006 |
Hi folks, I've almost got it working, but it's still not useful enough to tour with. I got a few 2N4091's from Mouser, and a couple of em worked (fairchild, and generic Korean), or at least oscillated. But no matter how I adjust the pot on the board (following the MM service bulletin), the effect is seeming way out of range. At full "intensity" setting the the oscillation collapses. At low "speed" setting the the effect also falls apart, and can even be "turned off" by playing a loud chord. Many other phenomena, harder to describe: a weird "sag"or delay as the speed is brought up from zero, and the rate even at the lowest speed corresponds to around the 4-5 setting before the tremelo went down. Any ideas? I can borrow a pedal for the month, but it seems crazy when the fault is a couple of $1.50 transistors. Amp info: 210 Sixty-Five 2275-65 Chassis 12AX7 Phase inverter. Thanks in advance, Matt Sutton | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
It sounds like you have a leaky cap in the trem circuit. I'd look around c29,c30, and c33 just for grins because if the short they could screw up your voltages drastically. | ||
| Matt Sutton (matt_sutton) Username: matt_sutton Registered: 10-2006 |
Thanks for the direction, Mike! I did find a capacitor that seemed to be behaving very differently from the others. Not sure whether it's designated C29 or C30, but the listed values are the same. No reliable capacitance meter here, but it was extremely slow to charge, and seemed to top out at 165K ohms. The others climbed steadily toward higher resistance. What kind of Cap is this, anyway. Doesn't seem like an electrolytic, doesn't look like a ceramic.. just yellow "INDCO INT., .22 250v. If I match the values will I be in the clear? Thanks for your quick reply, I'd just about washed my hands of the problem. -Matt | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Those are just regular capacitors that MM probably got a deal on. Get mallory, xicon,panasonic, etc., and you'll be fine. Just make sure the voltage rating is the same OR higher. |
Tue, 03/25/2014 - 09:29
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