Tube Amp Archive

I am considering building a 3 or 4 way digital footswitch to select clean, OD and OD + PAB or OD + midboost. Has anyone done this? Marhsall has a 5 switch foot controller that could serve as the platform. It is called the 5 way TSL controller. Don't have the scematic but I think it uses a couple of ...

Yes thanks.

good job posting the pages from the text.

Alex

I don't have the ability to post a schematic right now, but here is a description the circuit: A .01 mF and and 15 M ohm as local feedback from anode. Then this plate has a 100K resistor, which is coupled to the output via a .05 mF cap to a 100K pot. The .05/100K node is connected (fedback) to the g...

Hey guys check out my post about this. I started a new thread about as I didn't realize this was here. Interesting stuff.

alex

I have been checking out the NFB applied locally on the second stage (non HRM). The 22M and .05 mF circuit. It is interesting to note that this technique was used in the 1940's and 1950's in phono preamps to get rid of turntable rumble. (Ryhmes with Dumble!...sorry). Anyway if anyone is interested i...

OK, funk, I'll take you up on this. Thanks so much.
Funny how one detail like this can really make something as simple as mounting the chassis very easy.

Alex

Does anyone know where to get those cool t-nuts used in the chassis mounting scheme. I must admit that I can't find these and they do seem to solve alot of mounting screw headaches.

Alex

The 100 ohm resistor in this application, seems to me an effort to avoid any noise induced through the audio ground. Often this is done to break a gound loop. I am guessing that since the small board with the trimmers was added after the main preamp board was populated, the best ground point may hav...

I am thinking of building an HRM Bluesmaster. Just considering using a 12VDC heater supply. From my experience with other desigins noise performance is of course improved greatly, but have never seen a HAD design incorporating DC on the heaters. Anyone have any ideas? I appreciate all input. This si...

Thanks for the info guys. It is very informative. I am now getting back to designing and tinkering after a 4 year break from the industry. I was the head designer and engineer at a major bass amp company, then for various reasons stepped away. It is nice to get a feel again and see what is going on....

Hey all! I am new here, but not new to amps and tube gear. If anyone knows which version Robben Ford is using now I would appreciate it. Also, at the risk of sounding stupid, I am assuming that HRM indicates an ODS with the mods that incorporate a post OD tone stack. Is that the correct nomenclature...