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edit: derp, wrong thread!

I'll get some voltages off my build tomorrow morning and dig into this a bit more.

Some of these issues may resolve once boxed up, but it would be bet if we can eliminate them as much as possible before-hand.

Thanks for the clarification.

This is pretty much how Rick does the supply for his his mini-tube amps. I think he uses a heat sink, too.

NOTE: this illustrates a potentially lethal voltage output. No kidding. It's for illustration purposes only!



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R3 and R15 are both 510k. C4 is 51pF. You can use 47pF there without any noticeable tonal changes.

I see that I did list R15 as corrected to 150k under the errata section. I've seen both values equally listed on many different schematics. The Tube Screamer is 510k in that position. Basically, it provides some current limiting to the reference voltage supplied to the base of Q2, which it a buffer before the output. Either value should work in this case without a change in tone or output impedance. The actual value is not critical.

The "Quadrovibe" is 99% done! And it's smokin'!



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The Fuzz control works by reducing the resistance between C3 and ground. I haven't run into the problem you are describing, but it should be easy enough to fix.

If you have an extra pot, try subbing that first, just in case the wafer is damaged on the one you currently have hooked up. If that doesn't fix the problem, put a small resistor between lugs 3&2 of the Fuzz pot. This will prevent C3 from being connected directly to ground and should stop the squeal. I would try something like 100R or 47R.

Let us know what happens.

Also, what type of cap are you using for C3? I mean, brand and voltage rating? Just curious.

12v can potentially damage a MAX1044/TC1044. They are rated at 10v, I believe. However, frequencycentral uses a 12v input into these for his mini-tube amp projects without issue.

Alternatively, you can use an LT1054 which takes up to 15v, IIRC. One thing: use a socket and remove the leg for pin1 if using an LT1054. On the RR, pins 1&8 are connected on the PCB to use the frequency multiplier in the MAX/TC which boosts the oscillator frequency out of the audio range. The LT doesn't have this feature, or at least doesn't do it through connecting those two pins.

Terrific work....and a fun game, too! I should play that one again.

Sorry, I meant R2 as 1M, not R3.

Can we have a pic of the top and bottom of the build?

I would check to see that you are getting the correct bias voltage throughout the circuit. Remove IC1 and IC2. Confirm that R25, R26 are both 27k and that their junction point produces approx. 4.5v. Next confirm that R3 is 1M. Check pins 3 and 5 of the sockets (or pads) on IC1 and take voltage readings there. What do you get?

A smoking component would indicate incorrect voltage going someplace it shouldn't or possibly a backwards diode.

magnatone vibey sort of thing ?

Hmm...Optical Compressor?! 

-Kaleb

Nope.


In the meantime....PREPARE FOR BATTLE!


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This teaser may postpone my cosmo order which is ok considering I have a boneyard to build.  What effect category does the surprise fall under?

It has a lamp, but it's not a Univibe. That's all I'm sayin! I'm shooting to have it done by Sunday,

The LaVache and Cosmopolitan projects have been released!

http://www.madbeanpedals.com/projects/index.html

There may be one more project released this weekend. Something really cool....something I haven't even mentioned....something.....

Hi Brain !

I hope you are feeling better I'm so excited about the Les Lius modded launch... It is expected for today isn't it?

THanks, I'm doing better. Ankle is stiff as all hell, though.

Anyway, yup, it's ready. Just finishing the last part of the documentation right now. It is a really nice sounding OD...esp. with the couple of mods I put in. My Vox loves it.