Mix Buzz Internal Crush-N-Blend Add-on Board

[Bobby Baird]

This is the support thread for the IJ Research designed internal mix circuit add-on board. Originally designed for "Mixbuzz1" bus compressor as an optional dry wet mix. Later it was going to be implemented for the "Mixbuzz 500" as a modular add-on board, but never completed. I decided to finish the original modular idea Igor had envisioned. Here we have the Mix BuZZ Crush-N-Blend Add-on Board. Board measures 89.408mm x 114.3mm.
You can find boards here: Addon: Crush N Blend PCB for the SSL 4000 Compressor, 15,00 €

 

[Bobby Baird]

Documents.
Demo:

 

[Bobby Baird]

Reserved.

 

[Bobby Baird]

Sled and final panel design.

 

[SIXTYNINER]

coooooooool supernice job !

possible an option for DOA opamp like 2520 & Co. in the future ?

 

[Bobby Baird]

I don't believe having 4 2520 op-amps would be a cost effective solution when all you need is 2 TL072 so that wouldn't be possible.

 

[SIXTYNINER]

I don't believe having 4 2520 op-amps would be a cost effective solution when all you need is 2 TL072 so that wouldn't be possible.

if they do not give any benefit to the sound ,
actually would not make sense ,

 

[Bobby Baird]

This should work for GSSL

 

[innercityman]

This should work for GSSL

Does this schematic wiring layout come from Living note's Crush N blend rev 6 or Igor's version ?
In fact I've installed years ago the Living Note's version into my GSSL, and remember wiring it up exactly this way. But I had an issue that I've never been able to fix up... Right channel is 6db louder than Left one when C N B engaged. So I was wondering if swapping my version with Igor's one could solve my issue...

 

[Bobby Baird]

Yes, it's the same dry wet points on the GSSL as Living Note's schematic wiring layout. Igor never had a version for GSSL I'm aware of.

 

[Bobby Baird]

This circuit is simple. Basically an unbalanced internal linear cross-fader. One would just need to insert in any processor after the first de-balancing stage and before the final balancing stage. Refer to this schematic for the original implementation. The main difference between the mix buzz compressor and GSSL. The Gyraf version has 2 NE5532 to balance the signal at the output, whereas the mix buzz has a balanced line driver.

 

[sam system-d]

Hi everyone. I tend to try not to ask/cry for help whenever I can, but I might be missing something here.
I've build 2 Mixbuzz500 recently with success. One with the CnB, the other one without it. They both compress and sound really great by themselves. I only have a problem with the CnB addons.
When engaged, only dry signal come through.

I've check :
- Resistors values - all good
- Capacitors value and direction - all good
- Diode value and direction - all good
- Relay type and switching - all good, they switch when the spdt is on, all working properly according to the schematic
- Omeg Dual gang 10k lin is used here. Working properly (reading 9k20 and 9k60) Wiring is good (no PAN effect, just plain silence, or dry sound)

For tension :
IC 1 & 2 both receive +16v on pin 8 and -16v on pin 4 - all good.
Relays receive +12v from U1 - all good

I've checked for shorts, I couldn't find any.

SJ1 and SJ2 are NOT connected on this unit.

In other words, I'm stuck, and I hate not understanding why it's not working. Must be something stupid simple, but I can't see it. If anyone has any idea, I'd take it. Thanks.

 

[Bobby Baird]

When engaged, only dry signal come through.

SJ1 and SJ2 are NOT connected on this unit.

If using the CnB board with Mixbuzz 500 SJ2 needs a link.

Either solder "SJ2" are link pins with short wire CNB1 & CNB2 on CNB1&2_ch.1 and ch.2 headers on the CnB board.

SJ1 no link

 

[Bobby Baird]

Here's some pics. I put links on the CnB board. Small white wire on CNB1&2_Ch.1 outer terminals. Then link CNB1&2_Ch.2 there is a small black wire that is hard to see in the picture. Link those outside terminals together.

 

[Bobby Baird]

Pay attention to the signal flow through the SJ2, SJ1, CNB1, CNB2, CNB3, & CNB4 points with the Add-on in Circuit.

 

[sam system-d]

Must be something stupid simple, but I can't see it.

Pay attention to the signal flow through the SJ2, SJ1, CNB1, CNB2, CNB3, & CNB4 points with the Add-on in Circuit.

That's it. When you think you can read a schematic and just go over it thinking you got it....
Thanks Bobby, it works perfectly. I love this place.