1987 clone mods.

General discussion area for tube amps.

Moderators: pompeiisneaks, Colossal

Smokebreak
Posts: 1391
Joined: Tue Dec 18, 2012 5:53 pm
Location: Texas

Re: 1987 clone mods.

Post by Smokebreak »

That's a neat mod Roberto. Do you find the bypass-limiting resistor works for all volume levels, once set to the user's liking?
User avatar
roberto
Posts: 1841
Joined: Tue Nov 27, 2007 4:45 pm
Location: Italy

Re: 1987 clone mods.

Post by roberto »

Not exactly. That's why I wrote to test the resistor at different volumes.
You have to find a compromise at the volume you are more used to play.
User avatar
roberto
Posts: 1841
Joined: Tue Nov 27, 2007 4:45 pm
Location: Italy

Re: 1987 clone mods.

Post by roberto »

Of course the LARMAR can be switched in/out to obtain two different volumes.
GtrScott
Posts: 19
Joined: Fri Oct 17, 2008 8:50 pm

Re: 1987 clone mods.

Post by GtrScott »

Thanks so much for all the responses!!!
Tone Lover wrote: PS. it might save you from this horrible addiction called amp building once you smell the smoke your lost.<G>
It's too late for that! Although my tech knowledge is too light for a build for sure.

I'm comfortable with the relay setup and install to switch the pots. I'm just looking for the best way to achieve that and keep the tone I have.
JoeCon wrote:Guys

Sounds like he wants to control both channels with one pot, so wouldn't a dual pot work here? Come off the bright and normal coulpling caps to a dual pot...

How to use the second volume for a "foot switchable volume" I don't get...
Actually, I thought combining the channels might be cool, but since I like the tone I have, I've re-thunk it and think it's prudent to not combine the channels

This whole idea comes from a Plexi RI that John Suhr modded for me some 15 years ago. It has a PPIMV and two separate Volumes that I can footswitch between. The sweet thing about the switchable volumes is that I can bump my volume mid song for solos without any tone change.
Tone Lover wrote:Leave them stock and boost the front end with a clean boost for your solo. I know its not the answer you want.
So far, every boost (clean boost, OD, etc) I've tried changes the tone. It seems that anything changing the level hitting amp changes the tone some. Whereas the Suhr mod above works like I went and twisted the volume knob.

I'm going to open my plexi and look a little closer at what John did around the two volumes. Then maybe I can come back with questions that are more to the point.
Scott
RockinRocket
Posts: 652
Joined: Sun Nov 20, 2011 5:23 am

Re: 1987 clone mods.

Post by RockinRocket »

Smokebreak wrote:
Looking at the schematic, you'l see that depending on where the unused pot is in it's rotation, you can get anywhere from 470K to 1470K to ground.
When playing through the bright channel and having the normal channels pot on zero. The resistance is 470k to ground correct?
Smokebreak
Posts: 1391
Joined: Tue Dec 18, 2012 5:53 pm
Location: Texas

Re: 1987 clone mods.

Post by Smokebreak »

Yep, that's why you just see 470K on a lot of single channel plexi type amps.
Post Reply