rob_gould

Re: MixBuzz500 build/support tHread
« Reply #340 on: December 08, 2015, 05:13:09 PM »
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

Re: MixBuzz500 build/support tHread
« Reply #341 on: December 12, 2015, 05:07:09 AM »
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?
« Last Edit: December 22, 2015, 09:50:55 AM by rob_gould »

rob_gould

Re: MixBuzz500 build/support tHread
« Reply #342 on: December 19, 2015, 06:00:11 AM »
Edit...  Stupid patchbay wiring error
« Last Edit: December 22, 2015, 09:40:20 AM by rob_gould »

rob_gould

Re: MixBuzz500 build/support tHread
« Reply #343 on: December 22, 2015, 06:45:09 AM »
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
« Last Edit: December 22, 2015, 09:54:09 AM by rob_gould »

rob_gould

Re: MixBuzz500 build/support tHread
« Reply #344 on: December 22, 2015, 09:56:27 AM »
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...


Re: MixBuzz500 build/support tHread
« Reply #345 on: April 04, 2017, 02:52:47 AM »
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

Re: MixBuzz500 build/support tHread
« Reply #346 on: May 07, 2017, 04:17:46 AM »
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


 

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