Parallel effects loop for Marshall style amps

Info for maintaining and tweaking your amp to perfection.

Moderator: VelvetGeorge

Post Reply
catalin gramada
Senior Member
Posts: 182
Joined: Sun Feb 08, 2009 1:54 pm
Just the numbers in order: 7
Location: everywhere in Europe

Re: Parallel effects loop for Marshall style amps

Post by catalin gramada » Tue Feb 10, 2009 1:56 am

Hi Larry,
Thanks for schematic
I want to do a separate FX module to use with all amps I have, so I must do another power supply. I intend to use a ECC83, what line voltage you suggest for anode ? ( I already have available a 350Vcc power supply ).
Thanks
Catalin

User avatar
novosibir
Senior Member
Posts: 4654
Joined: Tue Nov 22, 2005 2:32 pm
Just the numbers in order: 7
Location: Nuernberg, Germany
Contact:

Re: Parallel effects loop for Marshall style amps

Post by novosibir » Tue Feb 10, 2009 2:50 pm

catalin gramada wrote:I want to do a separate FX module to use with all amps I have, so I must do another power supply. I intend to use a ECC83, what line voltage you suggest for anode ?
320...350V

Larry
The fault almost always is sitting in front of the amp :wink:

Larry's Website now with included Pix's Gallery

catalin gramada
Senior Member
Posts: 182
Joined: Sun Feb 08, 2009 1:54 pm
Just the numbers in order: 7
Location: everywhere in Europe

Re: Parallel effects loop for Marshall style amps

Post by catalin gramada » Tue Feb 10, 2009 7:47 pm

Hi,
Need 4,7K resistor and 20u cap if I do a separate power supply with own filtering (220u) ?

Thanks
Catalin

User avatar
yobdab68
New Member
Posts: 16
Joined: Tue Jan 20, 2009 11:31 am
Location: italy

Re: Parallel effects loop for Marshall style amps

Post by yobdab68 » Wed Feb 18, 2009 6:37 am

Hi Larry , I try a loop in a Marshall 50 watt, It was a kind of KOC - Tut loop but I was not much satisfied.

I read a lot here 'bout your loop so if You could send me the schematics i 'll give it a try.

Thanks.
the most of the sound comes ...raising the master! :)

User avatar
novosibir
Senior Member
Posts: 4654
Joined: Tue Nov 22, 2005 2:32 pm
Just the numbers in order: 7
Location: Nuernberg, Germany
Contact:

Re: Parallel effects loop for Marshall style amps

Post by novosibir » Thu Feb 19, 2009 12:09 am

catalin gramada wrote:Need 4,7K resistor and 20u cap if I do a separate power supply with own filtering (220u) ?
No, if you get out of your power supply ripple free 320...350V DC

Larry
The fault almost always is sitting in front of the amp :wink:

Larry's Website now with included Pix's Gallery

rip
Senior Member
Posts: 567
Joined: Tue May 13, 2008 1:14 am

Re: Parallel effects loop for Marshall style amps

Post by rip » Thu Feb 26, 2009 11:03 pm

Hey Larry I was wondering are both 22uF caps 450V?

Also have trouble sourcing these caps, can a 30uF be used? Any ill effects?

Or maybe a 32x32uF cap can?

Thanks
Rip

User avatar
novosibir
Senior Member
Posts: 4654
Joined: Tue Nov 22, 2005 2:32 pm
Just the numbers in order: 7
Location: Nuernberg, Germany
Contact:

Re: Parallel effects loop for Marshall style amps

Post by novosibir » Thu Feb 26, 2009 11:13 pm

One is a cathode cap, where 16V wouldt be plenty, the HV cap can be higher than 22µ no prob!

Larry
The fault almost always is sitting in front of the amp :wink:

Larry's Website now with included Pix's Gallery

rip
Senior Member
Posts: 567
Joined: Tue May 13, 2008 1:14 am

Re: Parallel effects loop for Marshall style amps

Post by rip » Fri Feb 27, 2009 4:31 pm

novosibir wrote:One is a cathode cap, where 16V wouldt be plenty, the HV cap can be higher than 22µ no prob!

Larry
Can a higher value like 30uF be used on the cathode cap as well?

Thanks again for the help
Rip

User avatar
Ennkuhl
New Member
Posts: 5
Joined: Sat Feb 14, 2009 7:37 pm
Just the numbers in order: 7
Location: Perpignan, PO, France
Contact:

Re: Parallel effects loop for Marshall style amps

Post by Ennkuhl » Sat Feb 28, 2009 7:57 pm

Hello Larry,

I'm interesting by your FX loop.
Could I have please the schematics of your FX loop ?

Thanks
Laurent

User avatar
ß@®+
New Member
Posts: 5
Joined: Sun Jan 11, 2009 3:27 pm
Just the numbers in order: 7
Contact:

Re: Parallel effects loop for Marshall style amps

Post by ß@®+ » Mon Mar 02, 2009 10:48 am

Hi Larry. I finally finished my amp. Your FX loop is working brilliantly! Thanks!
Building a JCM800 from scratch: http://barth.nxserve.net/" onclick="window.open(this.href);return false;

rip
Senior Member
Posts: 567
Joined: Tue May 13, 2008 1:14 am

Re:

Post by rip » Mon Mar 02, 2009 11:35 am

novosibir wrote:
antosimoni wrote:also can I use a 20u/450V instead of the 22 one??
Shure, all values from 16
Hey Larry I found this post soo... anything 16uF and up for the filtering?

And again what are the alternatives for the cathode? 22uF and up?

Will any of this affect tone?

Thanks
Rip

zevoz
New Member
Posts: 1
Joined: Mon Mar 02, 2009 3:29 pm
Just the numbers in order: 7
Location: MA

Re: Parallel effects loop for Marshall style amps

Post by zevoz » Mon Mar 02, 2009 4:41 pm

Hi Larry:
I'm very interested in your loop. Any chance I could still get a copy?
Thanks:
George

samwheat
New Member
Posts: 34
Joined: Sat Feb 17, 2007 10:27 pm

Re: Parallel effects loop for Marshall style amps

Post by samwheat » Mon Mar 23, 2009 6:38 pm

Thanks Larry !!!!

User avatar
novosibir
Senior Member
Posts: 4654
Joined: Tue Nov 22, 2005 2:32 pm
Just the numbers in order: 7
Location: Nuernberg, Germany
Contact:

Re: Parallel effects loop for Marshall style amps

Post by novosibir » Mon Mar 23, 2009 6:53 pm

Ennkuhl wrote:Could I have please the schematics of your FX loop ?
zevoz wrote:I'm very interested in your loop. Any chance I could still get a copy?
Once again guys!

As I already wrote in the 1-st post of this topic, loop requests ONLY via PM AND included email address!

Loop requests in this topic or requests by PM, but w/o email address will be regarded like not written!

Keep in mind, that I can't put a .pdf document in a PM 8)

Larry
The fault almost always is sitting in front of the amp :wink:

Larry's Website now with included Pix's Gallery

erigm
Senior Member
Posts: 736
Joined: Wed Feb 01, 2006 11:29 am
Contact:

Re: Parallel effects loop for Marshall style amps

Post by erigm » Tue Apr 07, 2009 9:29 pm

Larry,

I put your loop into my new amp (completely modded Fender Bassman 10). Thank you very much for providing that schematic!

I like it a lot so far, but I've noticed a couple of things. The loop send control "thumps" when I turn it all the way down. Does this mean I have some DC across the pot?

Also, I noticed the "dry" path's tone is quite a bit brighter than the "wet" paths tone, even with nothing in the loop. I think I may try a different value of bypass cap across the 220k, or remove it all together. Any suggestions?

Thanks!!!

Eric
erigm

Post Reply