Racking Amek Einstein - Project COMPLETED!!!

[Didierterrific]

You could try, bu normally XLR PIN1 connects directly to case only and not to PCB

for all the XLR PIN 1 ?

 

[Didierterrific]

what are the transformer specs?

Toroid and Symetrizer are ok for you ?

 

[Whoops]

The toroid is a Talema TRT30218 : 2x18v 30VA

I think that gives you around 830mA per rail, I think that should be more than plenty for 2 channel strips plus 2 stereo balancing boards.

But if you have a bigger transformer try it out, it's the troubleshooting stage so have to keep eliminating possibilities.

When I did my build it worked flawlessly first time and completely silent

 

[Whoops]

for all the XLR PIN 1 ?

Well shields in balanced lines are an extension of the case and not 0V reference.

some good reads explaning the PIN1 problem:

https://www.ranecommercial.com/legacy/note151.html

https://www.ranecommercial.com/legacy/note165.html

 

[Whoops]

the symetrizer module is this one :
https://www.audiophonics.fr/en/preamp-module/module-unbalanced-to-balanced-symetrizer-ne5532-btl-stereo-p-12296.html

Do you have the schematic for that module?
I would like to analyze how the grounding is done in that one

 

[Didierterrific]

Do you have the schematic for that module?
I would like to analyze how the grounding is done in that one

I have only these two picks

 

[Didierterrific]

Do you have the schematic for that module?
I would like to analyze how the grounding is done in that one

 

[Whoops]

I have only these two picks

No worries, but it had to be the schematic, easier to understand

 

[Didierterrific]

Hi Whoops,
I tryed the cap and the resistor, connect one XLR PIN 1 to the case.
Same thing.

For try, I disconnect the symetrizer module, I lost 10db but there is no more buzz.

Maybe the problem is the symetrizer module...

 

[Whoops]

Hi Whoops,
I tryed the cap and the resistor, connect one XLR PIN 1 to the case.
Same thing.

For try, I disconnect the symetrizer module, I lost 10db but there is no more buzz.

Maybe the problem is the symetrizer module...

Yes, could be in the grounding of the symetrizer module making a ground loop with the wiring from the channel strip, because the symetrizer has it's own PSU, thats why I wanted to see the schematic to understand better how it's done there and check if it would interfere with the rest of your wiring.

When I did this project I used the SSL9K balancing boards, they're some really simple pcbs and circuit, each pcb is for 2 channels, and uses a DRV134 or THAT Chip for the balancing, pretty simple and efficient.
I might still have some of these boards to spare if you want to try out, otherwise it will be possible to buy them here in the forum from some members, Gustav (present pcbgrinder) sold a lot of those back in the day

 

[Didierterrific]

Yes, could be in the grounding of the symetrizer module making a ground loop with the wiring from the channel strip, because the symetrizer has it's own PSU, thats why I wanted to see the schematic to understand better how it's done there and check if it would interfere with the rest of your wiring.

When I did this project I used the SSL9K balancing boards, they're some really simple pcbs and circuit, each pcb is for 2 channels, and uses a DRV134 or THAT Chip for the balancing, pretty simple and efficient.
I might still have some of these boards to spare if you want to try out, otherwise it will be possible to buy them here in the forum from some members, Gustav (present pcbgrinder) sold a lot of those back in the day

Yes I'd like to try your board. How can we do ?

I ask to Gustav few weeks ago, but he no longer sells these boards.

Thx Whoops

 

[Whoops]

Yes I'd like to try your board. How can we do ?

I ask to Gustav few weeks ago, but he no longer sells these boards.

Thx Whoops

When I go back to the workshop I will check to see if I can find them.
If not just ask in Black Market, there should be a lot of them in drawers of members here

 

[Didierterrific]

When I go back to the workshop I will check to see if I can find them.
If not just ask in Black Market, there should be a lot of them in drawers of members here

Ok Thank you !!

 

[Didierterrific]

Hi Whoops,

I started from zero with another channel strip, PSU, symetrizer, case etc.
A non-racked channel is completely silent. Once installed in the rack it becomes noisy ...
So !
after a ton of tests in all directions, I get a good compromise, not perfect but good by disconnecting pin 1 from all the outputs and by connecting the 0v of one of the channels to the ground of the most distant Symetrizer.
the farthest point was the least noisy.

As shown in the schema attached.

Does that make sens for you ?

Thx

Didier

 

[Whoops]

Does that make sens for you ?

If it works and is noiseless fine, maybe it works for you.

Personally to make sense for me, I would have to see the schematic of the balancing module.
I don't do grounds that way.
XLR's PIN1 only connect to chassis, 0V and Chassis only connect at 1 point though a resistor and cap (but must connect at one point), I don't mix 0V reference (also called audio ground) with chassis connections

 

[Whoops]

In your last layout I really don't get why symetrizer module 1 Center tap input (drawn has Ground|) is connected to the PSU 0V.
That's a ground loop right there

 

[Didierterrific]

In your last layout I really don't get why symetrizer module 1 Center tap input (drawn has Ground|) is connected to the PSU 0V.
That's a ground loop right there

Y es I agree, but this way there is no more buzz...

 

[Whoops]

Y es I agree, but this way there is no more buzz...

Well if it works and is silent, then thats good enough

;D ;D ;D

 

[Didierterrific]

If it works and is noiseless fine, maybe it works for you.

Personally to make sense for me, I would have to see the schematic of the balancing module.
I don't do grounds that way.
XLR's PIN1 only connect to chassis, 0V and Chassis only connect at 1 point though a resistor and cap (but must connect at one point), I don't mix 0V reference (also called audio ground) with chassis connections

0V and Chassis only connect at 1 point though a resistor and cap : You talk about the  Toroid 0v ?
I don't mix 0V reference (also called audio ground) with chassis connections : Wich 0v You talk about ?
Sorry for my questions...

 

[Whoops]

0V and Chassis only connect at 1 point though a resistor and cap : You talk about the  Toroid 0v ?
I don't mix 0V reference (also called audio ground) with chassis connections : Wich 0v You talk about ?
Sorry for my questions...

There's no Toroid 0V, I think you mean the Center Tap.

You should read the Rane links I provided, then it would be more clear