Synergy - identical Red and Blue channels - do they really sound the same ?

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Telmar

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A friend of mine, who introduced my to MTS-Synergy three month ago, once said to me:
"I am absolutely sure I can spot a difference between "the identical Red and Blue channels" !
At the beginning, when my RM-100 was not converted with the Yumeo-MIDI-mod I didn't care.
But when I was able to switch between Red and Blue I recognized a difference, too.

Being a technician myself and servicing and repairing tube amps for about 10 years,
till I quit a while ago and being into tube amps for 30 years now I was curious.
First an easy explanation for the non-tech folks here,
so please you other tech guys don't blame me for not being 100% correct.
I think it's helping more people when I stick to the basics.

The general idea of the MTS- and Synergy-system is to have 5 tube stages for the amp designer to work with.
The first stage is located inside the host amp, and it's using one half of a 12AX7 / ECC83 tube,
the other four stages are located on the module itself, using two 12AX7 / ECC83 tubes.

This is important to understand: a double triode tube consists of two amps in one glass bottle !
That's why it's called DOUBLE triode ! (I attached a picture of a 12AX7 lps by Sovtek,
because this is a tube where it's very easy to see for everyone, just by looking at it.
 

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Some very basic amp designing rules (this is important to understand the Red-Blue-Phenomenon):

- to create more gain, you need more tube stages
- to be able to shape the gain structure the way you want, you need more tube stages
- you can design a clean channel with one tube stage only (Vox and Fender did it)
- for a medium gain amp three stages are enough (cathode follower stage does not count as a gain stage)
- for a super flexible high gain monster designer tone you need all five stages (guess why this system has five...)

Now that I've explained this basic rules, a thought might crawl into the mind of a careful reader:
"If Synergy has a maximum of five stages, what do they use the leftovers for in a medium gain design?"
(since you don't need five stages to build a Marshall 800 or AC-30 type of medium gain circuit as I lined out above)
GOOD QUESTION ! :geek:
 
It is not very clever to trust your ears, when it comes to something like this.
There have been tests in the past that proved you might hear a difference
just because someone tells you that two things are not identical,
but in reality they changed not a single thing during the test !
Our brain is always tricking us into things like this !
So I came up with the idea to do a simple measurement, period.

How the test was set up:
I set the EQ to the middle position and the output level to maximum.
The input signal was provided my a MOTU M2 and was so low to cause no distortion.
The gain trimming was done with the gain pot and this was the only variable.
For a quick test, this is the most accurate thing I could do right now.

Some more amp building rules:
potentiometers differ relatively large in value, setting them to their minimum (makes no sense in our case)
or to their maximum (remember what I did with the output volume pot? 100% !) makes a lot of sense.
 
The SLO Module:
The SLOs design is definitely a very well-thought-out high gain design.
If you look at the schematics, you'll notice that it uses five stages for its sound.
I did not reverse engineer the Synergy-SLO, but I think it's safe to say
they might just A-B-switch the gain and volume pots with a relay.
If you look at the graph nearly nothing has changed between the Red and Blue channel
and the gain pot settings to achieve this are also identical.
 

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The 800 Module:
The Marshall 800 design makes use of three stages only to get its gain,
and a fourth stage that connects the bare preamp with the EQ section.
This fourth stage is a bit special, because it's called a cathode follower and provides no gain at all.
Some manufacturers add it in front of the EQ-section, because it is able to deliver a lot of current
and with some EQ-designes that makes absolutely sense. And it adds its own color to the sound.

Did you count the stages with me ? Three for the gain and one for the current. What does the fifth stage do ?
As I mentioned above, I did not reverse engineer a Synergy-module so far.
So be cautious at this point, because I start to assume, even I was told not to do so when I was an apprentice some decades ago.

Tubes vary very much in their values, unless you buy selected or even matched tubes.
Usually selected means the tubes are in a certain range, and matched means
the company who selected them tried to find two or more tubes that are as identical as possible.
You can even buy tubes where they tried to find a tube with their two systems in a glass bottle
that are as identical as possible (very laborious and even more expensive).

So just look at the graphs and at the modules pot positions.
Not very identical, right ?
I think this is caused by switching not just two sets of pots in and out,
I think this is caused by two slightly different gain stages !
The reason for this might just be two different tube stages, as I lined out above,
or slightly different designs of a specific Red and Blue tube stage that is A-B-switched.
 

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The AC Module:
This is also a low to medium gain design and if you look at the graphs and the picture
it might be the same case of stage instead of pot switching as I lined out above,
when I wrote about the 800 module.
 

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I will measure all my other modules as well in a couple of days,
and I am currently thinking about an idea how I can prove
my assumptions on the stage vs pot switching theory.
Or maybe I am wrong, we'll see.

To Be Continued . . .
 
"Pot switching" or "Stage switching" ?

There are currently 8 Synergy modules marked "IDENTICAL CHANNELS - switch not needed" by Synergy.
Here is the table I am talking about, I marked all this channels.
Currently, I own six of them: 800, BE, HBE, DS, AC and SLO.

I disassembled all the six I own, to find out if I was right or wrong with my
"stage-switching-theory" I mentioned above. Aaaaaand ... I was wrong !

Synergy makes no use of all four available stages in their low and medium gain designs.
One of the stages is simply not used in these modules: 800, BE, DS and AC
The HBE and SLO are high gain designs, so they make use of all four stages.
 

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The DS Module:
As it turned out, this is a medium gain design, with just three of the four tube stages in use.
But look at the graphs, these channels can not sound identical at all.
The gain pots are not at the same spot (no picture here).
I gain matched the area between 1 and 2 kHz with the bright switch engaged
and simply turner the bright switch off for the normal (without bright switch) measurement.
 

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The BE Module:
Very simple here. Medium gain design with three of the four tube stages in use.
The graphs are completely identical, gain post are at the same spot (no picture here).
 

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The HBE Module:
This high gain design utilizes of all four tube stages of course.
The graphs match perfectly, gain pots are at the same spot.
 

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My conclusion so far:
The Blue and Red channels do not sound the same, necessarily.
If the graphs do not match, this is completely out of question.
A different frequency response creates a different tone.

But I think I am able to spot a slight difference in the dynamic behavior
even in the BE, HBE and SLO module, but it's very subtle.
Or maybe I am just tricked by the A-B-phenomenon, who knows.
I did my measurements with a sine sweep at a low input volume to prevent distortion.
So maybe there is a difference that shows when you apply a highly dynamic signal as a guitar.

To find that out and to be 100% sure, one will have to reengineer a module completely.
But I am not in the mood to do this at the moment, I don't think it's worth the effort.

If I can get my hands on a PLEXI and a METROPLEX module, I will measure them
and share the measurements with you folks.

Bye for now, and make some great music with MTS and Synergy !
 
It is a basic notion of physics that no two things can be identical. This is even more so the case with electronics, slight variant tolerances between every single component across the entire complex circuit would allow for slight variances. So setting both channels the same will never really match them seems to be rather a misnomer to compare. Indeed merely by having the pots to adjust you could probably never get them exact as so many other things could be slightly different within the circuit. Synergy probably means they did not design the channels to be differently voiced or have drastically different gain stage structure or EQ spectrum.
 
It is a basic notion of physics that no two things can be identical. This is even more so the case with electronics, slight variant tolerances between every single component across the entire complex circuit would allow for slight variances. So setting both channels the same will never really match them seems to be rather a misnomer to compare. Indeed merely by having the pots to adjust you could probably never get them exact as so many other things could be slightly different within the circuit. Synergy probably means they did not design the channels to be differently voiced or have drastically different gain stage structure or EQ spectrum.
That's exactly what I tried to line out !
If we accept this little variations, we can easily ignore the variants within the modules with the same frequency response, BE, HBE and SLO.
But some modules sound (because of the difference in frequency response) and feel (because of the difference in gain structure) not the same.
The DS module is the one that really sticks out, different gain structure and different frequency response.
This is the one where is definitely more going on than just switching two sets of pots OR the circuit is very sensitive to part tolerances.
But just reverse engineering will reveal what it is.
 
Oh, I forgot something ...
It was not my aim to make Synergy look bad. Not at all !
I really think MTS and Synergy is one of the greatest things that happened to the electric guitar in decades.
I sold all my amps and rack gear when I had my system for some weeks, no kidding !

My aim was just to clarify that "do I hear the grass grow thing" for myself, and then I decided to share my findings.
 
I just have to say playing guitar for eons and having gone through so much gear I am sure I cannot remember half of it; Synergy has been the best development in guitar amplification since the first amps were rendered. Fantastic product, and while I am highly critical and hard to please with most gear, I have zero issues negative w Synergy. I just hope they continue on and come up with some more great modules. I am running a double SYN2 rig into a SYN 50/50 and gessssh nothing has ever sounded this good and this consistent, low noise and just outstanding tones. Combined with my hand picked pedal board it is indeed a touch of sonic heaven to play.
Yes, indeed there are slight variances in the many modules that make them a little different in gain structure and feel. Finding the ones that sing to your playing is just a jewel. Bravo SYNERGY!
 
Oh, I forgot something ...
It was not my aim to make Synergy look bad. Not at all !
I really think MTS and Synergy is one of the greatest things that happened to the electric guitar in decades.
I sold all my amps and rack gear when I had my system for some weeks, no kidding !

My aim was just to clarify that "do I hear the grass grow thing" for myself, and then I decided to share my findings.
ditto on that....I would love to know more of the internal circuit workings and what components get altered to voice a module. Very cool frequency spectrum analysis provided above, loving it!
 
Oh, I forgot something ...
It was not my aim to make Synergy look bad. Not at all !
I really think MTS and Synergy is one of the greatest things that happened to the electric guitar in decades.
I sold all my amps and rack gear when I had my system for some weeks, no kidding !

My aim was just to clarify that "do I hear the grass grow thing" for myself, and then I decided to share my findings.
I’d like to know if the bb-be uses all 4 gain stages , I’m guessing it prob only uses 3 . I have a question for you , is the tube in the syn 2 v1 if so which tubes in the module are v2 and v3 when facing the module knobs ?
 
The BE and the BE-BB are not the same module.
The BE has two identical crunch / medium gain channels.
The BE-BB has two differen channels, a clean and a crunch channel.
The BE-BB crunch channel sounds very much the same as the BE channel,
but the BE-BB clean channel is completely defferent and it has it's own EQ section.

I would say the BE-BB uses all four stages, but I have to look it up to be sure.

I don't know how Randall or Synergy are distributing the part designations,
but usually you start with V1 for rhe input tube.
The zwo tubes located inside of the modules should normally be V2 and V3.
FX-send-return is the next tube being V4 and the phase inverter should be V5.

I got no clue which tube is V2 or V3 in the module.
Maybe it changes from module to module. Not very likely, but possible.
 
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The BE and the BE-BB are not the same module.
The BE has two identical crunch / medium gain channels.
The BE-BB has two differen channels, a clean and a crunch channel.
The BE-BB crunch channel sounds very much the same as the BE channel,
but the BE-BB clean channel is completely defferent and it has it's own EQ section.

I would say the BE-BB uses all four stages, but I have to look it up to be sure.

I don't know how Randall or Synergy are distributing the part designations,
but usually you start with V1 for rhe input tube.
The zwo tubes located inside of the modules should normally be V2 and V3.
FX-send-return is the next tube being V4 and the phase inverter should be V5.

I got no clue which tube is V2 or V3 in the module.
Maybe it changes from module to module. Not very likely, but possible.
This was my assumption also. I reallt
Appreciate the help . Maybe I’ll reach out to synergy and see what they say.
 
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