Tube Amp Archive

That circuit should have that resistor so why was it left off of your build? The reason that the amp did not go silent, what happened is that the osscilation got up to such a high frequency and to such a strong level that (1) you could not hear it any more because the speaker could not reproduce it...

Had a weird thing happen today that I've never had happen before. I'm working on a Princeton style reverb circuit and I've got a super bad oscillation in the reverb circuit when I boost the preamp. As I turned up the volume higher and higher the squeal got worst of course and then the amp fell compl...

I'm curious to know something about local negative feedback. In Dumbles you often see: --|0.047uf|--*--22M-- going from the plate to the grid of the triode. In the same amp you could also see: --10M--*--|0.047uf|--*--10M-- What is the difference? The only thing I can think of is that you could use a...

You guys ever play with diode limiters? I'm messing with my Princeton reverb clone and when I bypass the tone stack for a boost I can at times get out of control osciallations out of my reverb section because I am jamming so much signal into it. I know I can always just lower the input impedance on ...

Magnetic Components in Chicago makes them if that helps at all.

xtian wrote:Um, nope. That would be a nifty magic trick, though!

Oh well. Had to ask!

If we can use a reverse biased zener to lower B+ with connected to the CT of the B+ winding, is the inverse true that we can use a positive biased zener to RAISE the B+ voltage?

I have a PT that puts out 400V and I need 450V that's why I ask.

I have a 70W amp that I'm playing with. The amp works great with a 350-0-350 @ 300mA winding with a full wave rectifier (two diodes) and is dead quiet. I get about 470V B+ under load and all is right with the world. So I want to try another PT: http://www.classictone.net/40-18084.pdf Obviously I nee...

I can't see that your goal is possible. The pot mods are in regard of their voltage output. The impact of the mods on the use of the pots as variable resistors is different. I think your best way forward would be to swap the pot tracks for the values you want, using donor pots of an identical type....

I'm trying to make a 1ML pot a 100kA pot by way of using tapering resistors found here: http://www.diystompboxes.com/analogalchemy/emh/emh.html I tried the values for the 20% taper and it flat out doesn't work. I don't really even need the pot to be a pot; just a variable resistor with a log taper t...

On the Dumble SSS SN: 002, is there any reason why the LOW filter couldn't just be a 1M pot with a 12k resistor from lug 3 to ground? Seems to me that would be a great deal easier to implement and cheaper. What am I missing here guys? You could do that, but then it wouldn't go click, click, click.....

On the Dumble SSS SN: 002, is there any reason why the LOW filter couldn't just be a 1M pot with a 12k resistor from lug 3 to ground? Seems to me that would be a great deal easier to implement and cheaper.

What am I missing here guys?

@MarshallPlexi: you can go with the 002 schematic. The Volume pot is 1M, not 100k (measures 100k with the Rock/Jazz switch engaged, that is where the mistake comes from). IMHO the ground tail resistor on V1b should be 100Ohms, not 1k, but I have not tried the 1k. You can use mhartmans Layout and ge...

Hey guys! I've been looking to build a SSS for years now and my schedule at work has finally opened up so I have the time to now. I've been reading on this forum for about 8 hours today and studying the various schematics for the SSS amps and while I see a lot of updates on the 001 and 002 serial nu...

SE or PP? your sketch shows SE primary windings. Keeping a common secondary winding and winding 2 primaries, one having roughly 1.75 times the number of winding turns than the other is not the best idea IMO. The winding with fewer number of turns will have 3x lower inductance resulting in 3x higher...