Search results

Where did you buy your charge pump (IC7) from? Normally, to determine if it is a bad charge pump whine you would remove IC7 and work off of 9V. However, this design derives its Rref and IC power return from pin 5 of the IC, so if you remove the charge pump it won't work at all. Charge pump...

Thank you. Your FET voltages indicate shorted or near shorted FETs, perhaps from overheating when soldering or you received a bad batch. They should be something around: D = 8 VDC G= 4 VDC (mid-way between D & S, for symmetrical clipping) S = 0,6 VDC (all voltages depend on the bias trim...

Are your FET voltage measurements in relation to ground? As in, common probe to ground (black) and hot probe (red0 taking the measurements?

A friend of mine has been on a quest for the tone of a loud Fender Black panel amp, at about 70dB of real volume. Think of a Vibroverb or Super Reverb on '4' to '7'. We have tried pedals, master volume mods, speakers, expensive attenuators and various amps. Nothing got close to the nuance of a...

A couple of thoughts, based on my experience: - If a charge pump is suspected (typically a 'whining' sound), remove it and the pedal will now be operating on 9V. If the problem is resolved, try another charge pump. If the problem is still there, reinstall the charge pump. - In painted...

I do not believe here is room for the Transcendence Boost PCB and the original Wha circuits inside a standard Crybaby. You could gut it and swap in a 3DPT, to have a volume pedal and a switchable boost and volume pedal. You would have to swap the 100K wah potentiometer for a 1M to 500K audio...

It is always the weirdest things, like a wire with no continuity, that keep you on your toes. On the bright side, it sharpens your troubleshooting skills.

Check your potentiometer sweepers (lug 2) for continuity (bad pot check). Also check C12 + R16 values (15Khz high pass bleed). Check all the values in the tone stack.

Correct - omit C4, otherwise the pedal is only usable on dark amps.

I agree with @gonzo that the pickups are good. I am guessing: pickup heights, or got the wiring out of phase, or other wiring error,or switch malfunction.

I watched a video about Tom's Bukovac (Nashville studio session player / sideman), and really liked how he uses the Vertex Boost with an expression pedal as a volume / boost. So, I borrowed one from a local music store that I repair for, tried it and liked it. I could not hear any difference...

Have you measured the ohms of the neck pickup with a DMM?

I owned a Sabbra Cadabra and its cousin, the Gallello, - both were noisy due to the built-in treble booster.

Hey Patrick - reviving an older post. When you mention 'patches', does a builder need an EPROM programmer?

I built this Marble Drive in 2022, which is based on the 'Marvel Drive', to which I call mine 'Prodigy'. It was built to the schematic and bias values people cited, which is pretty much a Marshall model 1987 / 1959 (50w / 100w), except using J-201 FETS instead of tubes. It was really hard to...

IMHO, the artifacts of a decent regulated and filtered supply, rarely present themselves as audible noise floor. I could see a logical argument for it affecting linearity of amplification of an effect (clarity and evenness), which would be quite overcome by a boost or dirt pedal. I build my own...

With the toggle in the middle 'off' position, using a DMM check for continuity (1 Ohm 'beep') between the legs of C1 and the solder pin 2 of the switch. It should have continuity in all switch positions, including 'off'. Next check pin 2 to the base pin of Q1, with the 2nd pin of the switch...

Looks like spaghetti. All that wire makes for a great antenna to pull in RFI and create oscillations. I too recommend reducing the wire.

^ This. From the look of it, it appears to be a small value in the picofarads. From what we know of Bonamassa (he dislikes brittle trebles and prefers thick, dark tones), that is a 100pF ish cap to take out the RF (Radio Frequencies) and shrill highs.