Peavey Triple XXX crunch & ultra channel de-gain mod help

[philbinator1]

Hi guys,

My main rig is a Triple XXX head, hugely powerful with heaps of options, great head i'm mostly really happy with it.  The clean channel is great, very sparkly, but..the "Crunch" (overdrive) and "Ultra" (distortion) channels are just too gainey for me; my usual settings are crunch: barely even on, and ultra: about 11 oclock.  does anyone know of  any mods to tame the beast a bit?  i'd like for both channels to saturate at around 2-3 oclock, like they should.  any ideas?


cheers
phil

[anchovie]

Have you worked on a tube amp before? Poking around inside one might kill you!

Schematic is here: http://www.schematicheaven.com/newamps/peavey_xxx.pdf

All of the preamp stages have cathode bypass caps, hence the gobs of gain. A starting point would be to remove C19.

Unless you are not confident in working inside the amp, in which case you should consider trading it in for a something a bit less "metal"!

[philbinator1]

Have you worked on a tube amp before? Poking around inside one might kill you!

Schematic is here: http://www.schematicheaven.com/newamps/peavey_xxx.pdf

All of the preamp stages have cathode bypass caps, hence the gobs of gain. A starting point would be to remove C19.

Unless you are not confident in working inside the amp, in which case you should consider trading it in for a something a bit less "metal"!

Yeah i know they can be dangerous, hence the post before i try anything.  And i love the metal!  I'm  all about the metal.  but,
playing in a covers band i need a bit less for that...would changing this resistor change both channels? 

oh yeah what kind of safety procedures are standard when working on amps?


cheers man   

[anchovie]

would changing this resistor change both channels? 

It's a capacitor, and you'd want to remove it rather than change it. It will affect both channels. If there's still too much distortion, C20 could be taken out as well.

Make sure you have a good read of this: http://www.geofex.com/tubeampfaq/tube_amp.htm

[petemoore]

would changing this resistor change both channels?  

oh yeah what kind of safety procedures are standard when working on amps?
  Be a qualified technician, anything less is taking your own life in hands that haven't learned to grip yet.
 That means know and understand your power supplies before opening one.
 Have a plan before going in. Personally I think the plan is a dangerous waste of time anyway. You have a normal type channel right there. Shop for a tube amp with a distortion channel you like instead, then use the normal channel after having figured out that all the mods in the world might even sound 'good'...if you survive the minefields of HV.
 What you can do at 9v, lots of tweeking...highly recommended.
 Those big amps are...I don't know what they're for, probably some big dude with a big stage, and a big stak-o-speakers, with a normal sized guitar...and some qualified technician/tweek hacker re-engineered the whole shootin' match to make 'His' guitar tone.
 And that tone is actually the normal channel with 9v or 18v tweeks. All the internal attempts to get 'his' tone in the amp happen to be further downstream in the signal path to make the same normal-channel-distorted-but-mainly driving the output tubes to distort. I've never actually seen a 'his channel' amp that even sound remotely like him anyway.

[philbinator1]

would changing this resistor change both channels? 

It's a capacitor, and you'd want to remove it rather than change it. It will affect both channels. If there's still too much distortion, C20 could be taken out as well.

Make sure you have a good read of this: http://www.geofex.com/tubeampfaq/tube_amp.htm

sorry i meant capacitor not resistor      thanks for the faq, i'll give it a good read.