MixBuzz500 build/support tHread

Hi,

I've not given up, but I've spent the last two days quadruple checking and everything looks right to me. I am stumped as to what else is causing this misbehavior and/or where else to look...

I will continue with it, I must be missing something despite my scrutiny. It's the proverbial needle in a haystack!

Thanks,
Chris

Just for test, pull out the VCA's or balanced line driver/receiver out of sockets and check if you get audio in both gssl and 4k modes.
There was an issue about a year ago, +/-15V was not connected to control board. However, all this is strange, I have to meditate on your MB500 issue
Edit: sorry, sorry, this is not the issue. Check the ribbon cables, maybe, control voltage does not arrives from control board to vca's.
Or, maybe, short somewhere.
Tell if you found something, I have now more time for forum fun, we'll try to pass together with scope on all points.

Hi Igor,

This past week I took a break from the MixBuzz and worked on my NV73 "The Don" pair. Also got a new Tek scope to play with (2245A) very nice since my Tek 485 died...

I will revisit the MixBuzz in a day or two and will report back.

Thanks,
Chris

fazeka said:

Hi Igor,

This past week I took a break from the MixBuzz and worked on my NV73 "The Don" pair. Also got a new Tek scope to play with (2245A) very nice since my Tek 485 died...

I will revisit the MixBuzz in a day or two and will report back.

Thanks,
Chris

Click to expand...

TEKTRONIX 2245A!!! Yep, very nice thingy. I cannot live with digital scopes. Mean, it is great for tracing the signals, but
something is wrong here. I am big fan of 5000/7000 family, have working 5110, 7603 and D13 on workshop.
For now, bought crazy thingy - HP1980B, for $80 from surplus, it do everything I need except... well, ok, it isn't job for an oscilloscope

Cool than, post here, will try to help in free minute!

My unit is working! After a brief hiccup with a mis-wired power connector (was thinking wires should go straight across, when of course they should be mirror-image), and some confusion around SJ3 (I didn't know it was there... couldn't figure out why my relays weren't working!).

I had a Sifam meter from my first project (a failed GSSL) which doesn't work anymore apparently. It's really kind of fun using it without the meter though! I am just running an OH mic from some drums I recorded at Sound City (RIP) to test it. Sounds amazing... really cool at extreme settings (at least on this drum overhead, I would be more delicate on a mix for sure). I already want more of them!

An odd thing that happens - when I turn sidechain filter up to "T" area - I get blistering levels, which remain even after I turn the knob back the other way. If I switch the ATK around it goes away. Strange...

I put in RV1 before I read Igor's note about it. Is there a way to measure it in circuit to get the proper resistance?

Thank you Igor!

Tim

Got a nice working assembled compressor here. My only beef with it at the moment is that the meter action seems quite sloppy. It doesn't have that satisfying snap of the SSL compressor. Do folks think this is the meter itself (Hairball) or the circuit / calibration?

http://www.youtube.com/embed/H-rYyAg_Zxk

I think it's just the meter itself. They have a new offering in the presentor series...FR, for fast response.

http://www.sifam.com/meterCategory.asp?cat=Presentor%20-%20FR

The original Sifams seem to do fine in the G384... but mine isn't a Sifam, it's a Hairball. I didn't see anything about the meter calibration in the docs... did I miss something?

In other news I am using the Mixbuzz on a mix right now and it sounds great!

Tim

Sorry to bug y'all but I'm confused on this meter issue. I installed the trimpot by the meter but I can't find it's adjustment procedure mentioned anywhere by Igor or others. I can't believe that the meter is inherently so bad. It bounces every time it comes back from deflection. I'm all for using my ears but...

Meter calibration: with 1ma FSD meter, no need.
R50 = 2k can be changed to get correct reading.

An odd thing that happens - when I turn sidechain filter up to "T" area - I get blistering levels,
which remain even after I turn the knob back the other way. If I switch the ATK around it goes away. Strange...

I put in RV1 before I read Igor's note about it. Is there a way to measure it in circuit to get the proper resistance?

Just desolder it and install 0.25W 1% 5k1 (IIRC, see BOM).

Maybe c24 is leaky, btw. Check all solderings, should be something wrong

has anyone compared this to the serpent audio sb4001? also has/will anyone ever considered making a demo video to show the compability of this unit?

So could I install one VCA on each replacement board or do I need to install all four?  Can I do a any combo as long as each card has the same amount as the other one.  Like 2x2 or 3x3 or 1x1?

Thanks
-Scott

Can anyone tell me where to buy the 10K Lin pots for MakeUp gain and Threshold for Igors MixBuzz 500? The farnell part number for the bourns pots on Igor's BOM appears to have a different pinout than on the pcb.

Cheers

I've used that pots from bom and they work fine so i think that you might be confusing the pinout?
Anyway, get the pots from bom and you'll be safe.
Hope it helps

ArnauTS said:

I've used that pots from bom and they work fine so i think that you might be confusing the pinout?

Click to expand...

Doh! .... thanks, you're absolutely right, i was looking at some pads on the circuit board under where the pot is mounted, thinking thats the pot connections, now i look again and I see the three pads along one side of the pot which is consistent with the bom pot.
Thank you thank you .... now back on track

Anyway to get the PCB's for this unit?

Or even better: a kit?

I'll be supplying them in a few weeks.

This is a great compressor, I use it all the time.

@ramshakles

Great! Can you please drop me a PM when that happens?

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