Zero Loss Effects Loop In A Mod 5 Peacemaker Help Needed

[echoplexi1974]

I have a Mojave Peacemaker that I recently purchased from bognermatchless. I believe it was also owned by Stuntdouble. Also I believe it was modded to Mod 5 specs by Rockstah Mark Abrahamian. This amp has been well documented here at the Metro site: http://forum.metroamp.com/viewtopic.php ... &sk=t&sd=a" onclick="window.open(this.href);return false; It is a sweet sounding amp and it is a joy to play! I'm loving it!

Anywho, I have installed a Zero Loss Effects Loop to the amp. I'm a bit confused and how to tap the loop. I believe the Mod 5 is considered a 2203 spec? Or is it a 1959 spec? If it is a 2203, does one wire go to the dual pot master volume on the back of the amp and the other to the treble pot wiper (middle lug)?

Any help would be much appreciated!!!

[SDM]

does one wire go to the dual pot master volume on the back of the amp and the other to the treble pot wiper (middle lug)?

No, please don't try to attach the loop to the PPIMV on the back!

A "traditional" mod 5 is basically just a 2203 with a PPIMV added. So, the mod usually has both a pre-phase inverter master volume (normal/typical Marshall master volume, single pot), and also a PPIMV (post-phase inverter master volume, the dual pot on the back). Typically there is a 220K resistor between the normal MV and the tone stack in a Mod 5. So, the proper install would be tone stack-> loop -> 220K feeding the normal/pre -PI master volume.

So, the install is almost the same as the loop instructions show for a 2203, only difference here is that you may have a 220K inserted before the normal master (which is again is a single pot), hence will attach the loop output there to the free end of the 220K headed to the normal master instead of attaching it directly to the regular master volume pot lug.

Hope that makes sense, browsed the thread you linked quickly but didn't see any pics of the amp after modding, so yours may vary from the "traditional" mod 5 specs. If you have the PPIMV (dual pot on back) and a normal pre-PI/traditional single pot master though, the above directions should apply. If no 220K between tone stack and normal master, then install is just exactly like the loop instructions show for a regular 2203. If your amp varies further from the "typical" mod 5, let me me know.

[echoplexi1974]

Thanks for the quick response SDM!

Since this is a Peacemaker, maybe Mark had to wire this one differently. All I know is that it sounds just like what I hear from his other Mod 5 clips that he posted, which is killer tone! Just need a loop to make it gigable...

The controls on the front panel are Bass, Low-Mid, High-Mid, Treble, Volume and Volume. The 2 volumes on front act as if they are preamp controls. The outside volume is like a treble enhanced preamp and the inner volume is like a bass enhanced preamp. Blending the two is quite fun and interesting The PPIMV on the back of the amp is the master volume.

The install went pretty well. Everything was within spec concerning tapping off the PI supply. I did wire it up following the 1959 instructions and it worked, sort of.... My digital delay was somewhat distorted and I could not get a volume boost by running a eq pedal through it (bumping the volume slider up slightly).

Here is a picture of the amp with the effects loop installed. I left the loops tap wires out of the circuit until we figure whats going on...

[SDM]

Looks like your "bass volume" (as I think it's labelled on your panel) was rewired as a regular master volume, amp was indeed converted to basically a 2203 with PPIMV (ala mod 5). Thus the loop should be installed as I described above (i.e. exactly as per a 2203 install in the loop instructions). Your "treble volume" (pot closest to input jacks) is a traditional 2203 preamp gain now in actuality.

The PPIMV does serve as the "final" master in this setup. Since the normal master precedes the PPIMV, the normal master will seem to/does act as a gain control depending on how the controls are set. For example, you could get a more stock 2203 experience by cranking your PPIMV to max, then using your "bass volume" as your overall master instead.

That was before the loop install, will get that functionality back, but as is now in the pic there and based on your description, looks like the normal master has been defeated by removing the middle lug wire that was feeding the PI input? That's means the normal master (or bass volume if you prefer) does nothing now, is that correct? Possible there's a little jumper hidden there I cannot see, but doubt it if this was a mod Mark did. So, that wire from normal master to PI lug will need go back in to do the preferred/usual 2203 loop install here.

As a side note, if the normal master is fully cranked, first volume/pre-amp gain is also up pretty well, means your PI is already clipping/out of headroom. So, trying to boost volume or such with a loop will not work, will only add more clipping/distortion as the PI has nothing else left to give you. Essentially, based on the pic above/your description, since the normal master was likely defeated here, that's roughly equivalent to how you are running things now. Is why you did not get a volume boost, why the delay seemed a bit dirty. You are just clipping the PI hard and out of headroom.

Once things are rewired/loop is hooked up properly as per a usual 2203 install, will need to tweak your regular master to a lower level to allow to the PI some headroom if you'd like a boost in the loop to increase volume. Lower you can set it, cleaner your delays and such will be as well.

Hope that helps.

[echoplexi1974]

Okay, got it working!!!

I added the wire back from the PI input to the Master Volume middle pot lug. Removed jumper wire from master to treble pot and then tapped the loop leads in there. Works great now!!!

Thanks so much SDM for your help! I guess I was confused by the PPIMV being in there. I have a habit of making things more complicated then they should be!

Metroamp, excellent service as always!!! I wish there were more people like you in this business. You guys the best!!!

[echoplexi1974]

Hi SDM,

Quick question, what is the purpose of the 220k resistor from the master to the treble pot? Since mine did not have one installed, do you think it's necessary to have one installed?

Thanks!!!