MixBuzz500 build/support tHread

[rob_gould]

Pull out the audio VCA and jumper VCA-In to VCA-Out (pins at center of the smaller VCA module sides) with a piece of wire (diameter and length of a paper clip might come handy if you have the VCA pins in sockets). If you now have undistorted audio with unity gain level, you know the culprit ...

Hi Harpo,

This went off the boil for a bit but I want to get back on it now.  I will do perform the test you suggest this weekend. 

Do I need to remove both VCAs or can I just test one channel and leave the Gold Can in the other channel?

Thanks,

Rob

Doesn't matter. Your measure for unity gain (complete unit, XLR voltage in=XLR voltage out) at the jumpered/audio-VCA removed channel. If you have more than one multimeter and a spare jumper, you could measure both channels simultaneously for whatever reason.

I've finally got this on the bench and started to test, aaaaaand

Now the unit doesn't pass audio on either channel when it is in normal or GSSL mode. In bypass audio passes cleanly. Turning any of the controls has no effect on this.

Currently I have the left hand side with VCA in jumpered to VCA out and the right hand side still has the gold can in place.

I'll start going through the circuit to see where the signal gtes lost tomorrow. Strange that both sides have the same behaviour. That points to the control board being the culprit in would guess...

 

[rob_gould]

Hmm, very odd indeed.

As soon as I engage the compressor in either GSSL or 4000 mode mode, I lose signal at the input on both L & R channels

So that indicates that when I switch in the compressor, something is shorting the audio signal to ground, correct?

 

[rob_gould]

Edit...  Stupid patchbay wiring error

 

[rob_gould]

OK, so finally back on track from your advice from a few months ago Harpo.

I've connected VCA in to VCA out on the right hand channel, and I get unity gain.  Left hand side with Gold Can still installed remains the same.

So, the problem is with the VCAs, or the choice of components around them.

Any recommendation on which component values to start tweaking to get this working properly?

Thanks,

Rob

 

[rob_gould]

Pull out the audio VCA and jumper VCA-In to VCA-Out (pins at center of the smaller VCA module sides) with a piece of wire (diameter and length of a paper clip might come handy if you have the VCA pins in sockets). If you now have undistorted audio with unity gain level, you know the culprit ...

Hi Harpo,

This went off the boil for a bit but I want to get back on it now.  I will do perform the test you suggest this weekend. 

Do I need to remove both VCAs or can I just test one channel and leave the Gold Can in the other channel?

Thanks,

Rob

Doesn't matter. Your measure for unity gain (complete unit, XLR voltage in=XLR voltage out) at the jumpered/audio-VCA removed channel. If you have more than one multimeter and a spare jumper, you could measure both channels simultaneously for whatever reason.

I've finally got this on the bench and started to test, aaaaaand

Now the unit doesn't pass audio on either channel when it is in normal or GSSL mode. In bypass audio passes cleanly. Turning any of the controls has no effect on this.

Currently I have the left hand side with VCA in jumpered to VCA out and the right hand side still has the gold can in place.

I'll start going through the circuit to see where the signal gtes lost tomorrow. Strange that both sides have the same behaviour. That points to the control board being the culprit in would guess...

 

[Estudis Ground]

Hi,
I'm going to build a mix buzz comp and I was wondering if there's somebody sharing a trustable and tested BOM from Mouser's


thanks in advance

 

[mrdarwin]

Hi there!
Just bought a fully built but never used Mixbuzz 500.
Calibrated sym, 5k1 to RV1, unit works fine... but threshold is too low: when I apply a +4dBu sine, ratio 2, fast attack and release and threshold to +15, the unit compress to 8dB!
I removed the 50k trim behind the meter, and no change... any idea? is it normal? same settings on my SB4000 and not same result... it appears the threshold is too "low"...
thanks

 

[ramshackles]

Hallo

Are there DIYers out there who would be interested in a parts kit for this beast?

I'm considering reviewing the BOM & layout, updating components (I think the THAT VCA is obsolete for example) and creating a parts kit...

 

[Claudio]

Are there DIYers out there who would be interested in a parts kit for this beast?

Yes, that would be interesting indeed!

 

[indraperkasa]

Hallo

Are there DIYers out there who would be interested in a parts kit for this beast?

I'm considering reviewing the BOM & layout, updating components (I think the THAT VCA is obsolete for example) and creating a parts kit...

yes, i’m in!

 

[2Low]

Hallo

Are there DIYers out there who would be interested in a parts kit for this beast?

I'm considering reviewing the BOM & layout, updating components (I think the THAT VCA is obsolete for example) and creating a parts kit...

yes please !

 

[Catrunes]

finally got one of my 2 built and working just great.
one problem though is that when release is set to .1 the audio distorts. any ideas before i start digging for info?

 

[Rob Flinn]

Could someone mail me the docs for this project please ?

 

[GREAT TIME]

I could use docs as well, all links on this thread are broken

 

[dmp]

Here's what I have
Rename attachment back to .zip

 

[Enchilada]

If this is a defunct project and no longer being sold, does anyone have Eagle files or PCB traces for etching?

 

[JMan]

I don't think it's defunct, just old and not seeing much traffic these days. I believe that Frank at frontpanels.de now sells the project.

 

[culteousness1]

Yupp, Frank has a PCB kit, a front panel and a bracket for sale:

https://shop.frontpanels.de/Bus-Compressor
Cheers,
Carsten

 

[Bobby Baird]

Gonna start my Mix Buzz now. Can anyone confirm that the 500 ohm trimmer & R13 on the back of the time constant board can take the place of R60 to adjust the ratio's? It's not in the schematic, but probing with continuity meter tells me that's what it is there for most likely. I'm gonna socket all of the adjustable parts to be safe.

 

[HerbertR]

I hope this helps. I built two of them. I mounted the trimmer and resistor on the upper side - see photo
By the way .... Its a fantastic 500 Version of Gyrafs GSSL with SSC and Turbo Board,..