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Vintage threads from the first ten years

Stellan's Tremolo

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3/1/2000 4:02 PM
Kent S.	Stellan's Tremolo Has anyone out there made the trem pedal from Stellan's sight? I've traced mine a thousand times and can't find any errors on my routing or parts yet I've got a couple problems. I'm wondering if the schematic is correct. Thanks all, Kent S.

3/1/2000 8:26 PM
Anders Westerberg	What's the problem? No sound at all? No effect? Try to replace the LED-side of the VTL5C3 with a regular LED and see if it flashes. If it does, the LFO (the lower half of the schematic) is OK.

3/2/2000 4:17 PM

Unfortunately it's deeper than that. I have found two problems. One is that the output buffer is showing about 7.5v DC before it goes to the last cap. This seems to me to be way high and could be the reason there's pleny o' distortion at some settings (a bad thing). Two is that the oscillator is working (looks good on a scope and yes the pedal makes the lovely trem sound) and the speed control is doing it's job but the depth sounds like it's at full bore all the time. If you change the depth control it eases back on the depth for a moment then kicks in again like a cap is filling up. What gets me is that it does this whether you turn the depth up or down. If you could lend some advice I would go from "knows enough to be dangerous" to just "threatening".

Thanks,
Kent S.

3/6/2000 3:00 AM

Suggestions for a community standard

RE: The posted tremolo schematic

This is not the first time that posted schematics by well-intentioned generous folks have turned up with a possible glitch. There are some things that are easy to reverse engineer, and others that get a little bit tricky in the 40 minutes of flipping the board back and forth before the owner starts getting nervous and wants it back.

Is it possible for this broader group to adopt a standard for posted schematics that will verify that the schematic is either:
a) a manufacturer original (for servicing)
b) a retouched original (e.g., more legible component values or series issue variations in component values)
c) an original design that works as is.
d) a redrawing that has been verified by a builder (i.e., someone who worked only from the posted schematic)
e) an unverified schematic (e.g., a drawing from a friend of a friend)
f) an incomplete schematic.

This is not a complaint as such, merely a suggestion to help out those whose savvy is not enough for them to spot the errors or gaps in the schematic. It also means that if a corrected or verified version shows up somewhere, the user will be able to distinguish between the two on the basis of a formal indication (e.g., "Verified by 2nd party builder, 1999").

Nothing fancy. But if you are posting schematics and are able to "stamp" a standard message in the corner of the GIF or JPG, with any sort of phrasing that lets the lurker know where they stand, that would be appreciated by all, and most especially by the recent converts to the DIY cult.

Thanks,
Mark
Ottawa, Canada

3/6/2000 4:16 PM
Kent S.	Mark, Hear, Hear! This is a great idea and I hope it doesn't get lost in this little blurb about a tremelo. When I think of all the guys out there making stuff from these sights which have unverified schematics it would certainly be a great help. Kent S. (p.s. the damn box still ain't working)

3/6/2000 5:38 PM

That's a great idea, Mark. As usual, you have a rather clear view of things. Knowing the condition of a schematic before you start allows for better use of precious time, and more pleasure when the thing works the first time. I like to check out a circuit's validity before I start building, so I can limit the amount of wasted time. Some guys dive right in, build it, then spend a huge amount of time trying to find where they went wrong, only to find out much later (usually with Ampage help) that the schematic has a wrong/missing component, a wire missing, etc.

3/6/2000 5:58 PM
Gus	Mark I try to do that on my hand drawn schematics. That expandora I did was a pain, hard on the eyes tracing that one.

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