Guitar amp effects loop finally done. - diyAudio
Go Back   Home > Forums > Live Sound > Instruments and Amps
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Instruments and Amps Everything that makes music, Especially including instrument amps.

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
Thread Tools Search this Thread
Old 21st March 2009, 03:27 PM   #1
jjman is offline jjman  United States
diyAudio Member
Join Date: Jan 2009
Default Guitar amp effects loop finally done.

Thanx to Sy for steering me to use an input tranny for my guitar amp enhancement project. Original thread:

Phase flip needed -Interstage Transformer?

It’s a parallel effects loop. I wanted to be able to use reverb and/or delay but running either before the main input doesn’t work correctly when cranking this amp. This because the 3rd preamp stage clips and compresses when cranked (as it should) resulting in the reverb/delay portion of the sound being “blocked” in a nasty way. Now I finally put it all together. (Being out of work frees up plenty of time for these things )

I was committed to using only one tube stage for the loop and wanted to re-flip the phase in the loop so there is zero risk of it phase-canceling with the base/dry signal. Using a resistor and a pot I determined the correct voltage divider setup to tap some signal off the output of the 3rd preamp stage. My table-top reverb unit has a “line level” mode with a clip indicator light so I set the “send” strength to the loop to be just below the point that clips the effect unit when cranked. I then replace them with resistors to match the setting.

Attached is the final schematic for the loop. At the full-dry blend setting there is also some signal thru the loop which is fine. At full-loop setting the reverb is more than “wet” enough. At middle settings the full (good) distortion and compression of the amp is intact along with the added reverb from the parallel loop. I verified that the various stages in the amp are still clipping in there proper sequence so that “mojo” has not been compromised.

Thanx again !
Attached Images
File Type: jpg loop-scheme.jpg (20.4 KB, 169 views)
  Reply With Quote


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
Valve effects loop eeka chu Instruments and Amps 6 16th October 2011 01:11 PM
Guitar effects - where to start? Instruments and Amps 18 22nd March 2009 05:01 PM
effects of gain selector switch in the feedback loop? scone Chip Amps 13 4th March 2005 06:22 PM
Tube effects Loop Schematics... ? psychodave Tubes / Valves 0 23rd February 2005 06:40 AM
On board effects to a guitar? Newpaltzwonder Instruments and Amps 6 22nd April 2003 07:47 PM

New To Site? Need Help?

All times are GMT. The time now is 11:21 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2