Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on July 17, 2010, 05:45:56 am
-
Hi Guys,I've heard a lot about the Princeton/champ amps so i thought i'd give one ago.Please feel free to add any thoughts. Thanks
-
I think that will be a nice amp. One of my favorite & most used mods has been a center off spdt switch where I'd parallel caps and/or resistors to the cathode cap & resistor.
Having said that, I don't use it very much anymore. I tend to be more set and forget more when playing. So in light of that, I don't know if I'd use a rotary switch for the second gain stage cathode. A center off spdt will give you three choices alone. And you might find that you only use one or two of them.
Math wise ............... 2 three position switches gives you 9 different tones. How many different tones do you need with a Champ?
With respect, Tubenit
-
Thanks for the feedback tubenit,As you well know not all amps sound the same.So having the different settings may allow me to get close to the sound i am looking for.I have heard sound clips of stock champs and was sold on the sound. The mods are bits ands pieces of posted amps that could mounted on a rotary switch and may tweaked with other values .Thanks
-
Nice job setting that up.
I've built a bunch of Camps and instead of all those switches which after about a week you will never touch again, add tone controls. Check out my Desktop Studio Champ Schematic... All the tone control you could ever need!
http://www.el34world.com/Forum/index.php?topic=9594.0
-
I like a tone stack with a mid control 10-50KL. By changing the value of the mid control a lot of different sounds can be gotten. That switch for changing the value of the cathode resistor/cap combinations is a good idea if you gig the amp a lot as the room can do strange things to your sound. It also helps with guitar changes, if you use one guitar you probably will never use the switch. But if you have a few different guitars with different outputs it could work really well dialing in a consistent sound from the amp. For instance a strat could use a bit more gain and less bass output then a tele depending on your pickups. The neck pickup of a strat can get these strange woofy sounds that I never had from a tele type of setup. So you might want to have a 1K/1mfd for a strat and a 1.5K/4.7-10mfd for a tele.
It's all about experimentation and in different rooms the amp will work differently. Many things can also be done with NFB or the removal of it too.
-
I'm with you bigdaddy. If I add a switch on the cathode of the first gain stage I'll switch between 1uf and 5uf. I don't switch the cathode resistor because it always makes a noise (even with a 100k resistor across the switch)... It's the "anti woof" control.
Got to say tho', I usually stick with the 1uf regardless of the axe.
-
In another post http://www.el34world.com/Forum/index.php?topic=9662.0 The make before break rotary switch is good.I do have three guitars Les Paul, Strat, LP Jr.the pickups requiring different settups. Once built and played the tweaking can be done (The rotary switch can be changed to many combinations) Can anyone tell me if the Cathode Resistor on the 6L6 is to high as i might inter change with 6V6. Thanks