• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Sure, copy an amp. . . It'd work but I'm looking for something different.

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Basically, The way my pre-amp system works is different. Instead of having one amp with one channel but different inputs for a *well, basically fake* pair of channels. i want to have two completely seperate pre-amps, each with Gain/level/EQ/etc with just one input feeding both pre-amps, then them both feeding out to the one power amp chip. They'd be selected with a 2 way latching push button switch mounted in a footswitch box, connected by a 1/4" jack lead. Get it? So to design my own gain and level circuits, because I've never actually seen an amp with controls like a DS-1 ;) I'm going to have to scratch design my own pre-amp. I've been looking at
MARSHALL: 3 different 1959s, JTM45, JCM2000, JMP-1
MESA: Dual Rectifier,
a STACK IN A BOX,
a KBAPPS pre-amp and a random MOSfet circuit for installing in a guitar.

Basically, I need to duplicate a one channel Pre-amp and add the extra controls and thats all. But I need to modify the designs to do it. Which is why I cant just do a copy. All I was wondering was If I needed the huge power, Because I think I'm going to kill myself. lol oh well, Another teenager out the way! Anyone know a mail order site in the UK, which accepts solo/switch and has the 2 suitable transformers? one for the 300VAC and one for I think +-10 to 42 Vcc. . . And can someone explain to me what that is?
Cheers, Phoenix
 
diyAudio Senior Member
Joined 2002
Hi,

Just noticed that the stack in the box schematic has no transformers on-board, and has one 12Ax7 (same as an ECC83) but only runs on 12vAC.

12VAC is the heater supply only and that has got to come from somewhere too....
Unless you have a pair of mice in that box pushing a dynamo or something!??

Seriously now, what exactly is it you want to do?

Cheers,;)
 
Not really sure what your ? is. Two channels are easy too combine into one amp. Just be sure that each side has the same amount of inverting/non-inverting stages so that the phase comes out the same. That way you can blend both channels for a third. Pretty cool if it works out. Combining one input into several channels is not difficult. Check the Bogner Triple X Giant for a great example of how this can be done. Soldano has an excellent preamp with 3 channels you may look at, the X88R. It splits the signal after the first stages coupling cap. You can also split the signal before the grid stopper resistor of the first stage. Use one stopper for each channel. Everything before this is like one channel and everything after is two seperate channels. Switching can be done by a number of methods. Ground shunt would be the easiest but this only allow A or A+B. Relays maybe the most widely used and are not too difficult. Good luck and try maybe to make your ?s more concise or to the point.
 
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