3 channel Triple Rectifier Loop Mod.(Parallel to Series)

[dlabrecque]

If your footswitch effects loop in/out no longer works, you could try doing it with your effects unit. It would likely mean some customized patch programming where you turn off relevant effects with a foot tap on your effects unit instead. Or, more simply, you could have some patches that use effects and some that don't.

 

[cscotto]

Hello Everyone,

I just bought a 3 channel Triple Rectifier, and I want to mod the loop to serial. I read through the whole thing, and I have to say I agree with 94Tremoverb. I would not do the other mod. In fact, I just did for lack of a better term the "Mix Pot Serial Mod" tonight, and it works perfectly. I got the mod from the Boogie Board a few years ago, but I cannot seem to find the original post. I have pictures and a schematic that I will add. Here are the details:

1) All functions remain intact: solo switch and FX switch (however, not as you would expect).
2) The Send knob still controls the volume into the effects unit.
3) The Mix knob does nothing.
4) If you remove the cable when the loop is engaged, there is no sound. No bleed through of any signal bypassing the loop.

I only noticed one strange bit of behavior. When you switch the loop out with the footswitch, the volume drops as if some of the signal is going to ground, which makes it seems like the FX switch is not working. In order to hear the normal volume, you have to have the loop engaged. This may be a problem with my particular Triple since my Tremoverb which has the same mod does not behave this way.
On the Tremoverb, with the loop selector switch set to external switch, the F/X switch simply switches the effects in or out. The loop active master is active with both the effects switch on or off.

Here is the "Mix Pot Mod:"

 

[RDW1988]

Hey guys,

I'm new here, and I'm the owner of a 3ch Dual Rectifier.
The effects loop is a parallel one, and I'd like to mod it to a serial.

I opened up my rectifier, but I'm not sure which wires I need to cut.
Do I need to cut all three of them, or just one?
Here's a pic I took.

 

[cscotto]

hi, I took my 3 channel dual to a technician after failing to mod it myself (it would still have some unprocessed signal going through the loop), he did it (tone was better after his mod) and still I had some residual signal passing through it. I told him, he did some tests and told me that the residual signal was due to some "grounding return" (whatever that means, providing i translated it correctly hehe) and the whole grounding scheme had to be rearranged...

Basically the residual signal I was hearing was very low (and wouldn't get lower when I crank the amp's volume) but still sucked tone if I tried to delay the 100% of the signal a few miliseconds as I am trying to do.

If I put a 1 sec. delay in the loop 100% wet, I will hear the guitar as I play it very quiet and a second later I will hear the delayed signal much louder. I'm using the TC Gforce and I'm sure the returned signal is 100% wet

anyone's got any information about this? any idea? I wrote mesa boogie but had no reply yet

I did the FX Mix Pot Mod to my 3 channel Triple. I get some residual signal when pull the cable from the FX unit out of the return to the amp. I started another thread to try and track down the source of this "bleed." I saw the reply from Boogie on the V4 tube. I am skeptical.
I tried your 1 second delay, and the results were interesting. First, I have a G major 2. I set the kill dry to off, so all the signal goes through the effects processing. Next I chose a dynamic delay and set it to 100% wet and 1 sec. I plucked a note. By the way, this was on Channel 3 with high gain settings. At first, all I heard was the delayed note, 1 second after I plucked it. A little closer listening, and I hear the guitar string when I pluck the note as if the guitar was not plugged into an amp. 1 second later, I hear the note coming from the G Major-2. Next, I put my ear next to the speaker, and plucked the note. This time I heard the note coming from the speaker but it is no louder than plucking the string without being plugged into the amp. In fact, it is lower than that because I had to have my ear next to the speaker to hear.
Once, I set the G Major 2 back to its original settings (kill dry off), I do not hear any bleed through or tone suck. I am going to just be satisfied with it for now.
I am still going to try to track down the source of the bleed through, and if I find it I will post it in the other thread.

All the best

 

[cscotto]

Hi RDW1988,

I do not know why I cannot quote your post, but I will describe the wire to remove. The three you have circled are correct, but you only remove the wire on the far left facing the picture. In other words, labeling the wires 1, 2, and 3 from left to right facing the picture, you remove wire 1. If you look closely at the pad it is soldered into, you can see a little trace that connects it to the trace above it. That long trace comes from the Send pots middle wire or wiper pad. Make sure put electrical tape on the exposed wire end.
HTH

 

[mikey383]

hi, I took my 3 channel dual to a technician after failing to mod it myself (it would still have some unprocessed signal going through the loop), he did it (tone was better after his mod) and still I had some residual signal passing through it. I told him, he did some tests and told me that the residual signal was due to some "grounding return" (whatever that means, providing i translated it correctly hehe) and the whole grounding scheme had to be rearranged...

Basically the residual signal I was hearing was very low (and wouldn't get lower when I crank the amp's volume) but still sucked tone if I tried to delay the 100% of the signal a few miliseconds as I am trying to do.

If I put a 1 sec. delay in the loop 100% wet, I will hear the guitar as I play it very quiet and a second later I will hear the delayed signal much louder. I'm using the TC Gforce and I'm sure the returned signal is 100% wet

anyone's got any information about this? any idea? I wrote mesa boogie but had no reply yet

I did the FX Mix Pot Mod to my 3 channel Triple. I get some residual signal when pull the cable from the FX unit out of the return to the amp. I started another thread to try and track down the source of this "bleed." I saw the reply from Boogie on the V4 tube. I am skeptical.
I tried your 1 second delay, and the results were interesting. First, I have a G major 2. I set the kill dry to off, so all the signal goes through the effects processing. Next I chose a dynamic delay and set it to 100% wet and 1 sec. I plucked a note. By the way, this was on Channel 3 with high gain settings. At first, all I heard was the delayed note, 1 second after I plucked it. A little closer listening, and I hear the guitar string when I pluck the note as if the guitar was not plugged into an amp. 1 second later, I hear the note coming from the G Major-2. Next, I put my ear next to the speaker, and plucked the note. This time I heard the note coming from the speaker but it is no louder than plucking the string without being plugged into the amp. In fact, it is lower than that because I had to have my ear next to the speaker to hear.
Once, I set the G Major 2 back to its original settings (kill dry off), I do not hear any bleed through or tone suck. I am going to just be satisfied with it for now.
I am still going to try to track down the source of the bleed through, and if I find it I will post it in the other thread.

All the best

There is a design flaw in the Rectos that does not allow the loop to be 100% serial. At best, you'll have about 90/10.

Although according to a few threads I've read, Mesa will not acknowledge this flaw.

I did the serial loop mod on my 2 channel Dual, and still had dry signal coming though the amp.

 

[glassjaw7]

hi, I took my 3 channel dual to a technician after failing to mod it myself (it would still have some unprocessed signal going through the loop), he did it (tone was better after his mod) and still I had some residual signal passing through it. I told him, he did some tests and told me that the residual signal was due to some "grounding return" (whatever that means, providing i translated it correctly hehe) and the whole grounding scheme had to be rearranged...

Basically the residual signal I was hearing was very low (and wouldn't get lower when I crank the amp's volume) but still sucked tone if I tried to delay the 100% of the signal a few miliseconds as I am trying to do.

If I put a 1 sec. delay in the loop 100% wet, I will hear the guitar as I play it very quiet and a second later I will hear the delayed signal much louder. I'm using the TC Gforce and I'm sure the returned signal is 100% wet

anyone's got any information about this? any idea? I wrote mesa boogie but had no reply yet

I did the FX Mix Pot Mod to my 3 channel Triple. I get some residual signal when pull the cable from the FX unit out of the return to the amp. I started another thread to try and track down the source of this "bleed." I saw the reply from Boogie on the V4 tube. I am skeptical.
I tried your 1 second delay, and the results were interesting. First, I have a G major 2. I set the kill dry to off, so all the signal goes through the effects processing. Next I chose a dynamic delay and set it to 100% wet and 1 sec. I plucked a note. By the way, this was on Channel 3 with high gain settings. At first, all I heard was the delayed note, 1 second after I plucked it. A little closer listening, and I hear the guitar string when I pluck the note as if the guitar was not plugged into an amp. 1 second later, I hear the note coming from the G Major-2. Next, I put my ear next to the speaker, and plucked the note. This time I heard the note coming from the speaker but it is no louder than plucking the string without being plugged into the amp. In fact, it is lower than that because I had to have my ear next to the speaker to hear.
Once, I set the G Major 2 back to its original settings (kill dry off), I do not hear any bleed through or tone suck. I am going to just be satisfied with it for now.
I am still going to try to track down the source of the bleed through, and if I find it I will post it in the other thread.

All the best

There is a design flaw in the Rectos that does not allow the loop to be 100% serial. At best, you'll have about 90/10.

Although according to a few threads I've read, Mesa will not acknowledge this flaw.

I did the serial loop mod on my 2 channel Dual, and still had dry signal coming though the amp.

That really sucks. My amp would be 100% perfect for my needs if the loop wasn't designed this way. I think I'm to the point where I'm going to buy a power amp and slave out for delay and verb.

 

[DS-1]

I have a Triple Rectifier that always sounded bad with loop enabled, even with only a patchcord from send to return, so with no effect.

The problem is: with the loop on (with or without effects in the loop, it doesn't matter), lowering the Output level and going up with the Master on every channel, it adds some fuzzy distortion to the sound.

Example: with the loop off, on the green channel I have a really nice clean sound having master and gain set at 12 o' clock. If I use the same setting, enabling the loop, I have a really fuzzy clean channel, no matter how I set the Output master.

I did the parallel/serial mod, just unsoldering the dry end of the Mix pot, but I didn't fix the problem.

Then, I tried to do a more focused serial mod, removing the 2 J175 from send/return circuit, as reported on the first page of this thread.

Again, I still have the fuzzy sound problem. I even tried to swap some preamp tubes in the s/r position. No way to fix it.

Can you please tell me if this is "normal" for the Rectifier users?

 

[dlabrecque]

Can you please tell me if this is "normal" for the Rectifier users?

I'd say no. I don't have fuzzy sound problem. The serial loop mod is alleged to be able to fix a "sound suck" issue that's about phase cancellation from a digitally processed (slightly delayed due to processing latency) signal in the FX loop mixing with some of the original dry signal.

Realize that only one channel is clean on a Recto. The other(s) is/are meant to be fuzzy, dirty, distorted.

 

[DS-1]

Realize that only one channel is clean on a Recto. The other(s) is/are meant to be fuzzy, dirty, distorted.

I know this. I'm able to ear the real Recto sound, with the loop off.

Unfortunately, I have this problem and I really don't know how to fix it.

I only removed the 2 s/r J175, not the J175m, but I suppose it is used for the mute channel switching, so I don't have to remove it, isn't it?

 

[dlabrecque]

Realize that only one channel is clean on a Recto. The other(s) is/are meant to be fuzzy, dirty, distorted.

I know this. I'm able to ear the real Recto sound, with the loop off.

Unfortunately, I have this problem and I really don't know how to fix it.

I only removed the 2 s/r J175, not the J175m, but I suppose it is used for the mute channel switching, so I don't have to remove it, isn't it?

I don't know how the circuitry works, sorry. If you're getting a fuzzy clean channel for no good reason, I'd say there's something wrong with your amp. Mind sounds nice 'n' clean with the FX loop in our out. Your problem doesn't sound like it's related to the serial/parallel issue, BTW.

Why don't you call Mesa tech support and see what they say?

 

[DS-1]

Unfortunately here in Italy there isn't a good technical support for Mesa amplifiers.

I've written a mail to the american Mesa Boogie, I hope they can tell me more.

 

[mastora]

Try putting the send/return pots at the back of the amp to 12 oclock position.

 

[DS-1]

I've tried, but it works in the same way.

 

[dlabrecque]

Are you certain you're sending a clean tone into the amp? Have you tried it with several different guitars?

Also -- are you sure you're not overdriving the amp's input? All pedals turned off? Passive pickups on the guitar?

 

[DS-1]

Are you certain you're sending a clean tone into the amp? Have you tried it with several different guitars?

Also -- are you sure you're not overdriving the amp's input? All pedals turned off? Passive pickups on the guitar?

I've tried all the things you wrote. Obviously, no pedal was connected in the input.

All guitars are with passive guitars. Also, I've tried with single coils and humbuckers: always the same result.

The "overdriven" sound you can ear pumping up the master on the channels, with the loop on, is really unnatural. So it makes me think about a broken thing into the amp.

 

[dlabrecque]

I'd forgotten that the fuzzy sound was only with the loop engaged. That eliminates the possibility of the problem being at the input. Sorry. Sure sounds like something's broken in the amp.

I'd think your best bet is to take it into a good, local guitar amp technician.

 

[DS-1]

I'm trying to find a good local technician who has experience with Mesa products.

In the meantime, I restored the parallel loop and all the transistors.

By the way, the problem remains even with the parallel loop.

 

[DS-1]

I wrote to the Mesa Italian referent, in the meantime I'd like to try several things to see if the problem is in the loop, or in the preamp-power amp section.

Do you think is it possible to use the "slave out" jack, instead of the send to use my pedals?

Then, if not possible, I'll use it into another power amp section, like the "return" of my Marshall 6100.

 

[dlabrecque]

I wrote to the Mesa Italian referent, in the meantime I'd like to try several things to see if the problem is in the loop, or in the preamp-power amp section.

Do you think is it possible to use the "slave out" jack, instead of the send to use my pedals?

Then, if not possible, I'll use it into another power amp section, like the "return" of my Marshall 6100.

Looks like the Slave jack won't work for you. From the manual:

This 1/4" jack and control provide a signal derived from the speaker jack. Perfect for using
either the DUAL or TRIPLE RECTIFIER Solo Head as a master pre-amp, or additional power amps may be connected for more power when needed. Some players use this to derive an FX Send Signal and go to other amps for their wet sound.

NOTE: Once a signal is taken from the Slave, it can not be inserted back into the FX Loop Return jack or a feedback loop will occur. Much like holding a microphone into the PA system's cabinets...a loud high pitched
squeal will occur.

Since there's no way to get the signal back into the amp downstream from this point, you won't be able to get the signal to the power amp section. You could go into another power amp, if you wanted; that's what the jack is designed for.