On Tue, Aug 3, 2010 at 13:28, Altitude <[email protected]> wrote: > Correct me if I am wrong but the VCF trimmer is for upper range no?
Nope, the trimmer is some sort of offset it would seem. So the size of the range stays the same, but both top and bottom move together and get shifted up or down. I have turned it all the way down to get nice bass, but would like to get highs as well. Thanks for the tip Colin, maybe I should just put a 3k3 resistor across what ever is there already, this should give me a 3k08 resistor in the end. I'll check out the R61 mod too. Cheers, D. On Tue, Aug 3, 2010 at 13:28, Altitude <[email protected]> wrote: > Correct me if I am wrong but the VCF trimmer is for upper range no? > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of cheater cheater > Sent: Tuesday, August 03, 2010 3:07 AM > To: Amos > Cc: list 313; Analogue Heaven; synth-diy > Subject: Re: [sdiy] [AH] TB-303 Problems and Questions > > Thanks for the input guys! > > So far I have only tried with the 303 on batteries, I don't have a PSU > handy (which begs the question of whether there's one easy to buy here > in Germany where I will be for the next few months) > > I'm fairly sure the periodic buzz on the output comes from some sort > of led driver circuit. It might also have to do with the clock > circuit, as someone suggested. > > I'll check for broken traces around the output. That could be it, the > output is completely dead, but the schematic shows both headphone and > line outputs are driven by the same circuitry, so if the parts driving > the line output were dead, the headphone output would be silent also I > understand. > > I will try shorting out R47 to see what happens to the range. Would I > have to change the vcf range trimpot too? Currently it's at nearly the > lowest setting. > > Cheers, > D. > > On Tue, Aug 3, 2010 at 03:58, Amos <[email protected]> wrote: >> you might start by measuring continuity from component to component. >> 303s get cracked traces often; their circuit boards are made of flimsy >> stuff. >> As for various mods go to the x0xb0x wiki or forum and you'll find plenty. >> >> On Mon, Aug 2, 2010 at 9:51 AM, cheater cheater <[email protected]> > wrote: >>> Hi guys, >>> my TB-303 has some problems and I thought I would ask around if anyone >>> knows how to fix them :) >>> >>> 1. line output not working >>> yup :( no output. There is "perfect" output from the headphones output. >>> >>> 2. headphone output has a faint sound of digital buzz >>> When the LEDs are blinking, I can hear a buzz when the LED is on. This >>> might be the way it worked out of the box - but if so I would like to >>> fix it with some mods. The sound is fairly prominent and can be heard >>> when the synth is playing as well, making it useless for what I want >>> to do (i.e. put the 303 stems in a mix not obscured by a lot of other >>> sounds. I understand you wouldn't hear that in a very busy mix) >>> >>> 3. power-on thump >>> I assume this needs some replacement of the electrolytic caps, but not >>> sure which ones exactly. I wouldn't want to just go wild on it and >>> replace everything >>> >>> 4. decay knob doesn't do anything >>> No idea why. This started recently. >>> >>> 5. (hopefully a mod exists for this) the filter cutoff range is too >>> small. I know you can change the range around a bit with one of the >>> trimpots, but that doesn't give me the needed range. I would like to >>> go from around 30 Hz to 30k if possible. >>> >>> 6. Potentiometers are noisy and slow, i.e. difficult to drag: >>> the resonance knob is especially slow! The others feel a bit wonky too >>> and are probably quite worn. Is there a good replacement? >>> >>> 7. Waveform switch is wonky and sometimes doesn't close contact properly >>> is there a direct replacement part - or do I need to open it up and >>> recondition it? I would really like to avoid that :X >>> >>> BTW, is there a mod to change patterns in write mode? >>> >>> Thanks a lot, >>> D. >>> >> > _______________________________________________ > Synth-diy mailing list > [email protected] > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy > >
