Need help with JCM800 preamp

Tube or solid-state, this section goes to eleven!
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login721
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Post by login721 »

Hello , i want to make a mini ~1w tube amp based on jcm800 schematic. Power amp stage use 12au7 and Fender reverb driver transformer.

I made a little change in original JCM800 schematic . This is my first tube project , im not sure if the output stage are correct or not .Can someone give me some advice please!
Thanks in advance ! and sorry for my bad English.
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modded jcm800.png

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sinner
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Post by sinner »

What's your aim with PI done like that? Why PI in preamp design in first instance? It's wrong on many levels.

Just stop after MV

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sinner
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Post by sinner »

Make sure to use closed type jacks for inputs!!

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petey the pitbull
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Post by petey the pitbull »

maybe install two ef86 pentodes after the phase invertor to drive the ot, or omit the phase n drive it single ended.

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sinner
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Post by sinner »

Shit, right, so it's 1w amp, not stand alone preamp unit. My bad, just read the topic title

Forget the phase inverter and go single ended in triode mode. Or switchable 1w-5w in pentode mode with el84 or 6v6

On Valve Wizard's website you will find lots of cool articles including one dedicated to SE amp designs.

Alternatively google JCM800 single ended and I'm sure shit load of projects will be there

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