Tube Amp Channel Switching - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 19th November 2009, 01:59 AM   #1
diyAudio Member
 
Join Date: Nov 2009
Location: Mesa, AZ
Default Tube Amp Channel Switching

I'm implementing a channel switch for a small tube amp I'm building and need some help. Here's what I want to do:
  1. Switch between 2 seperate gain controls, each one being a dual pot.
  2. Have a toggle switch on the front panel.
  3. Have a footswitch pedal that disengages the front panel switch when plugged in.
  4. An LED that lights for each channel, regardless of which switching method is used.

Any ideas or schematics out there I can reference? Thanks, guys.
  Reply With Quote
Old 19th November 2009, 05:29 PM   #2
m6tt is offline m6tt  United States
diyAudio Member
 
Join Date: Aug 2007
I make guitar amps, but I've never really been into the mesa boogie channel switching relay thing. Instead, I'll make separate preamps if I need them, and then use those pots with the integrated switch on the back. I'll LED bias the last stage in each pre, but like this:

Cathode ---> (+) LED (-) ----> Switch ----> Ground.

Resistors would work too, but you can panel mount the LED to indicate the channel is on.
If you turn the volume to "off" for a channel, the cathode gets lifted, and thus no sound. If there are two channels in parallel, you can get one or both. To use a footswitch, use a closed-circuit (shorting) 1/4 jack and have it swap the pot switch for the footswitch when the 1/4 is installed.

I generally use a floating or appropriately referenced filament supply, since the cathode will go up to B+ potential when lifted.

I hope this helps, it's the easiest way to implement multiple channels i've come up with lately (just used it in a big 100W with high gain & low gain guitar + high gain mic pre).
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Channel Switching AmpBuilder225 Tubes / Valves 19 1st April 2009 08:21 PM
Channel Switching Noise with Dish 612 DVR Jon Giard Digital Line Level 0 29th March 2009 04:30 AM
DIY amp channel switching AmpKiller66 Instruments and Amps 5 3rd August 2007 04:19 AM
Channel Switching Real McTube? jjai Tubes / Valves 1 22nd July 2005 09:24 AM


New To Site? Need Help?

All times are GMT. The time now is 06:12 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2