The Amp Garage

I use Merlin's website all the time and even bought his recent book on Preamp design "Designing Tube Preamps for Guitar and Bass". It's well worth the money. He has a lot of great stuff on his site. I like the idea of using a DPDT switch on the AC feeds to the rectifier. You are switching lower volt...

Structo, thanks for the input. I have put caps on the recto diodes to no avail. You are correct I think, it doesn't sound like switching noise as you describe it. It is 60 or 120 Hz hum sounding. Not meaning to hijack the thread so I'll keep it short or start a new one. I will try upping the V1 filt...

I haven't investigated it that thoroughly since it just works for me, but since the current must flow through either one diode and then the other, the currents and voltages should be symmetrical unless I'm missing something, I haven't noticed any additional noise when using these. I haven't tried it...

I should have read your post more carefully. You should put in all the tubes and measure across the two feed wires With them all lit up you may be much closer to the correct voltage than the way you described measuring them. Usually fils under too high voltage will visibly be too bright and older, w...

When I run into this, (the 115V,117V primary PTs are prone to this) I usually try 2 1N4007s parallel forward and reversed (opposite directions) in one line of the filament wire off the supply. This should drop about .7V and get you back to a safe range, yours is unusually high, it may need more drop...

HiFi guys are using LED biasing on preamp tubes. A red one provides about 1.6volts and no cap is needed. They run a few in series when more bias voltage is needed, or a different color. Those guys are adverse to caps in general so they know how to avoid them. If you don't want the drawbacks of a ca...

So... pretty much I have to drill through the chassis? (Since there are no holes in the area the tagboard sits) :roll: ARGHHHHHHHHHHH! :x Get a step bit from 1/8" to 1/2". Get the titanium nitride coated or pro quality step bit like electricians use, it is about the handiest tool you can have.

I have just built a 6L6 amp based on the Epi Galaxie 10. I added another 12AX7 up front with both triodes in parallel like in a Matchless Lightning. Then I put in two gain pots. It's easy to build and experiment with and you can get incredible amount of gain from 3 or 4 preamp stages. Different bypa...

OK, I guess that really clears it up. I guess not all the old hands are so valuable after all, especiall if they go throwing out your prized vintage components. My only other real thinking on it was that the O'scope can be a valuable tool in conjunction with other methods. I'm a little surprised tha...

I was just joking when I said I almost electrocuted myself. I ALWAYS...ALWAYS drain caps before doing ANY work on an amp and if it has to be on, I ALWAYS use ONE hand. I can do repairs if the problem is visibly obvious like a burnt resistor or a bad cap or something. I've done capjobs on some of my...

Machine shop? Pretty much, I have mini mill, mini lathe, 2 bandsaws, 3 drill presses, a 48 inch box and pan brake, a light duty brake, table saw, numerous hand held power tools, 2 table routers, another hand held router, etc, etc . I make many of my own parts, all my own chassis, cabinets, brackets,...

What is the downside of 1N5408s? They are cheap, plentiful, and have good power and voltage ratings. I've used them quite a bit, am I tone deaf and don't know it? I thought they worked fine, maybe I'm missing something. I hear guys say, the Sovtek 5Y3 sounds like crap next to an old USA 5Y3GT. I hav...

I couldn't find the "Stix all" but I found "Ultra Stix all" also by Elmer's. It seems to stick OK, I hope. It seems to be very slow drying though, not so sure if I like it yet because of that. Maybe the regular "stix all" is faster drying. I guess it would be the thing to use before quitting and all...

Nothing wrong with perfboard. I fell into some nice old silver and gold plated turret boards, so I just use them. They are nice though, I'd have to say I'm spoiled and prejudiced toward the double barrel turreted boards of the good ol' days. I believe Keystone still makes and sells these things, tur...

This one really hits home. I started out by building one kit. I thought I could get into the amp building biz and make a few bucks. The first thing I learned is that while most guitarists would love to have your handwired amp, the stereotype of the "starving musician" is pretty much right on. Most c...