Synergy Diezel Herbert in MTS problem solved !

[Telmar]

Hi again,
I was able to find out what's missing, and I thought it's better to start a new thread with a new headline for folks who search for a fix for this.
As I mentioned before, the problem is not the recessed pin "C" that carries the anode voltage.
The issue is that the Herbert module makes use of the two pins "H" and "J" and these pins are not uses my any other module.
So far, so good, but what are these pins for ?

 

[Telmar]

Here is the solution !

The "Herbert" uses an OpAmp, probably for some active filtering, that needs a bipolar voltage, usually +/- 15 Volts to work.

Here is the way the current flows:
1.) Voltage input at pins "J" (positive) and "H" (negative)
2.) 22 Ohm resistors R30 (positive) and R32 (negative)
3.) regulators "IC1" (78L12 / positive)and "IC2" (79L12 / negative)
4.) OpAmp pin "8" (positive) and pin "4" (negative)

So all you need is to built a tiny +/- 15 Volt (+/- 13,7 Volt in theory) power supply and connect it to pin "J" (positive) and pin "H" negative

BUT PLEASE CHECK MY DRAWING ! ! !

I AM NOT RESPONSIBLE FOR DAMAGED OR BURNER EQUIPMENT ! ! !

 

[Telmar]

I don't have a mini PSU at hand, but I got a bigger one to test my findings, and guess what ... It's working !

 

[Telmar]

One correction please !
I said "connectors H and G" in the video, but it's "connectors H and J" !

 

[Plexz]

Nice work and thanks for sharing.

 

[Telmar]

No problem, I am into Synergy-MTS for about three months now, and I've drawn a lot of information from this forum.
So being a technician myself, I thought it's time to give something back to the community.

 

[Telmar]

By the way ...
Is here a technician in this forum who is able to measure the exact voltages used by Synergy ?
One would have to measure the 5th and 6th contact of the lower row, counting from left to right against ground (housing, etc.).
I am just curious what's exactly going on ...

 

[Telmar]

Last update about this "Herbert-Bipolar-Supply-Voltage-Thing", for the folks who want to know it.

I was able to get my hands on a SYN-1 unit, and what was the first thing I did ?
RIGHT ! I used it with my modular synth to emulate the behavior of a tube Trautonium and ...

Okay, okay, it was not the first thing I did, but at least it was the second (after some weeks ...).
YESSS ! I measured the supply voltages, you need to get the Herbert-Module running in an MTS-amp.

So here it comes.
Positive: +18,4 Volt with no load / +17,6 Volt with Herbert-Module
Negative: - 19 Volt with no load / - 18,3 Volt with Herbert-Module
As it turned out, it's an unstabilized voltage.
Mission accomplished, case closed, thanks for tuning in !

 

[marl3y]

Sorry, this is a little difficult for me to track, would you be willing to summarize? I have both Egnater and Randall module chassis and am trying to sort of what, if anything, can be done to accommodate the Synergy Herbert module. Can power be tapped or added to those amps to work with the Herbert and no negative effects on the amp or other modules? Thanks for all your experimentation.

 

[marl3y]

Following up to my own questions... I posted this on the MTS FB group, but sharing here too.

Anyone attempt to modify their RM100 or MOD 50 to be compatible with the Herbert Module. As far as I know that's the only Synergy module that's not backward compatible with other MTS chassis.

I have also confirmed those connectors in the SYN1 do in fact supply +19 and -19 VDC. FYI, the connections in questions are positions 5 and 6 on the lower side of the connector, when viewed from the opening in the chassis.
I picked up this pos/neg buck converter and powered it from the 17 VDC unregulated supply on the MOD 50. It does in fact provide +15 and -15 VDC outputs.
https://www.amazon.com/dp/B07SFLVGMJ...
However, when I measure connections 5 and 6 (H and J above) detailed above on the MOD 50 and RM100 I find on both amps position 6 has around 2.7 VDC on it. So, I'm not sure if these are actually used from something or not. Either way they appear be connected to something so I'm curious if anyone knows what these positions were used for on the legacy amps.

...turns out this is only true (pin 6 having voltage) for the second slot on the MOD 50 and the third slot on the RM100. I'm not sure what this is for, but probably best not to connect -15 VDC to it. Curious as to what it could be for since I don't see those connections being used on any Egnater/Randall modules. However, H and J on slot 1 of the MOD 50 or 1 and 2 of the RM100 appear to be unconnected to anything. So, possibly they can be used to support the Herbert with the above power supply.

 

[[email protected]]

I have a Randall rm50 combo amp and all the components say mod 50 on rhem...I wonder if it's possible to find a cheap , by cheap I mean less then 500 dollars in parts to mod my combo. Anything more I might as well buy another sny2

 

[marl3y]

Hold tight... I'm trying what I referenced above. Will report back.

 

[marl3y]

OK, was finally able to get back at this. Short story... it works just fine. No additional noise or anything like that. I used the 15 VDC pos/neg power supply I listed above and fed it via the 17 VDC supply on the board. Wired it to back of the card connector positions "H" and "J" as Telmar identified. "J" is +15 and "H" is -15 VDC. On the MOD 50 I only added support for the Herbert module in the first slot. There is some circuitry on the "H" connector in the second slot. For the RM100 amps you could use slots 1 and 2, but the third one has the same wiring as the second slot on the MOD 50/RM50. Not sure what it is, as the models don't seem to have anything on this pins, but here's the section of the schematic on the RM100. I can live with just using that one slot for the Herbert module when I want to use it.

Here are some pics showing the install and wiring. Thanks for all who have done the hard work and showed interest.