Tube Amp Archive

It'd be nice to find some libraries specifically for amp/pedal stuff. Like at the Hoffman site they've got all kinds of stuff for ExpressSCH and ExpressPCB. Unfortunately, those don't work with LT spice.

The scope seems to look a lot like what is shown on the second page of this article from way back: http://ken-gilbert.com/images/pdf/fixbias.pdf In the article it's positive feedback. Its a cathode biased amp. Fig. 2 (The circuit if Fig. 2 does not show biasing arrangements, because the action depi...

The scope seems to look a lot like what is shown on the second page of this article from way back:

http://ken-gilbert.com/images/pdf/fixbias.pdf

In the article it's positive feedback.

Technically, regarding temperature stability, leakage, tolerance, etc., mica caps are better than most other cap types. If the value is right, then i would use it. I have a couple mica caps on the 6 position rotary tone switch on my 18W EF86 amp.

Nice work. What did you use for that bus bar?

Weird, as it turns out, i have a 1N2824B sitting on my desk.

I think it's a 50W 33V stud mount zener.

If you strike out with Surplus Sales let me know.

There's a couple of places (non-Mouser) I have bought high power stud mount zeners from, if you are having problems. I have no idea why they wouldn't ship an NTE part to the UK. These 2 places will have something you can use. www.expediters.com You need to have a part number to find things at Expedi...

I am planning to get my nephew a decent ukelele later this year. He's going on 3. I don't think it will be one of those situations where he loses interest in it and never picks it up again. Whenever he comes over he makes a beeline for my guitar cases and won't give up until i take one out. Then he'...

Firestone hit the nail on the head. That's exactly what I read (about the screen supply/PI/preamp grounds).

I still can't remember where i saw this, though.

The location of the ground connections. Again, If my memory is not completely shot, it was that one of the filter caps further down the line was grounded at the same spot as the reservoir filter cap.

I remember seeing this problem discussed somewhere...maybe one of my books. If i remember correctly, the problem's root cause was the grounding of the filter caps, or rather where the caps were grounded.

If you take that squared off wave and do a fourier transform on it, i believe you will see the harmonics separately from the sine wave.

I've got all my stuff at work. My office is in an engineering lab so it's just easier to build amps and just leave them there. On weekends I am always cranking them up when there's nobody else working. Our next door neighbor is the police station. I guess there's no residential neighbors to complain...

I did exactly what you are trying to do (drop from 380 to 350).

I used the zener route.

I used the pink 1/2 watt takmans in my 2204. I like them fine, though I am not sure they make a noticable difference in sound.