MixBuzz500 build/support tHread

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rob_gould

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Jul 8, 2007
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Harpo said:
rob_gould said:
Harpo said:
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

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Jul 8, 2007
Messages
1,283
Location
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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

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Jul 8, 2007
Messages
1,283
Location
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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

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Joined
Jul 8, 2007
Messages
1,283
Location
Netherlands
rob_gould said:
Harpo said:
rob_gould said:
Harpo said:
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

New member
Joined
Sep 27, 2013
Messages
1
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

Well-known member
Joined
Apr 24, 2013
Messages
164
Location
France
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

Well-known member
Joined
Dec 18, 2011
Messages
521
Location
Riorges, France
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

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Joined
Dec 9, 2017
Messages
55
ramshackles said:
Are there DIYers out there who would be interested in a parts kit for this beast?
Yes, that would be interesting indeed!
 

indraperkasa

Member
Joined
Jun 29, 2018
Messages
7
Location
Indonesia
ramshackles said:
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

Well-known member
Joined
Mar 21, 2005
Messages
52
Location
Germany
ramshackles said:
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

Active member
Joined
May 1, 2017
Messages
35
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?
 

dmp

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Joined
Oct 28, 2009
Messages
3,043
Location
Madison, WI
Here's what I have
Rename attachment back to .zip
 

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Enchilada

Well-known member
Joined
Aug 24, 2011
Messages
323
Location
Australia
If this is a defunct project and no longer being sold, does anyone have Eagle files or PCB traces for etching?
 

JMan

Well-known member
Joined
Oct 26, 2019
Messages
295
Location
Chicago
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.
 

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