Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Leevi on October 15, 2014, 09:16:36 am
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Has anyone a tip for a good stereo amp schematic that could also be used for guitar and mic.
Some specs:
- 30-50W power
- big headroom
- line In/OUT
- Microphone/Guitar inputs
/Leevi
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Doug has a stereo amp in the Library Section.
Not enough info provided. E.g., the old fender 2 channel amps enabled a player to use a mic & an instrument through the same amp. These amps were 2 channel but not stereo. Also they assumed the use of hi-impedance mics, but today's mic's are usually lo-impedance, except for harp mics.
Please specify: vocal or harp mic; electric or acoustic guitar.
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Doug has a stereo amp in the Library Section.
What brand?
Please specify: vocal or harp mic; electric or acoustic guitar.
The amp will be mainly used as power amp for line level signals coming from computer, mixer, players etc.
But it could also be used as a guitar amp for electric guitars. And maybe more seldom for acoustic microphones
in some events.
/Leevi
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Here is the link to Doug's Stereo Amp
http://el34world.com/projects/StereoPreAmp1.htm (http://el34world.com/projects/StereoPreAmp1.htm)
I doubt it can be used for mic without mod, it is a guitar amp (a good guitar amp)
K
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Has anyone a tip for a good stereo amp schematic that could also be used for guitar and mic.
Some specs:
- 30-50W power
- big headroom
- line In/OUT
- Microphone/Guitar inputs
/Leevi
Here's a potential candidate:
http://el34world.com/charts/Schematics/files/gibson/Gibson_GA-78.pdf (http://el34world.com/charts/Schematics/files/gibson/Gibson_GA-78.pdf)
A good sounding amp, but I would run the heater wires in a separate shielded harness, if building from scratch. My 78RV has one harness with the Line In AC, heaters, and B+ all inside. It has a hum that I'm satisfied is coming from this arrangement. Power supply is mounted in the bottom of the cab, and the amp chassis in the top.
I experimented with it only one time, with the volume reduced. MP3 player into the stereo jack on the front end. Old record player, with it's own pre-amp, to the RCA jacks. 10" speakers.
Jack
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I just did this build for someone looking for about what you're asking, it's a 2 channel preamp board wired to a 70Wrms SSamp. I gained both preamp gain and tone pots so I had essentially 2 identical channels, one goes to the SS amp for the guitar, the other to a line out XLR jack, which I need to finalize but the amps 200miles away getting played.
pre is a M7C SRPP, the PA a VM100
fwiw