MixBuzz500 build/support tHread

[Igor]

Got a good question by e-mail and like to share it:

Will a dbx 202xt work fine in the unit? I can get a pair of them. Would the input resistance be different from the 202x?

According to 202XT datasheet, voltage control constant is -20db/volt, same as 202x.
Input impedance is 1k25/same again. Control port impedance is 810...832R, by datasheet, it is same as 202x....
DBX202XT has different control schematic than 202X, it use both inverting and non-inverting ports of VCA's.
IMHO, bit useless...anyway, so they did
Try R6=3k74, R3=4k99, R100=909R. IMHO this will work fine.

 

[stereokillah]

same value as 202X

 

[Igor]

I never tried 202XT, but 99.9% yes.
X and XT using different schematics for control port,
in XT version, control voltage goes to both + and - control ports of VCA's
(inverted to EC- and non-inverted to EC+).

 

[jensenmann]

Gentlemen, what´s up with our twin-x galery? Igors link to his zip files doesn´t work anymore. Igor, any chance to host it somewhere else?

 

[AudioGimmer]

Hi.
Please excuse some noob questions. I'm in the UK and I'm having trouble sourcing some parts. Farnell's site always wants to direct me to their US supply for lots of the parts, and don't seem to have some parts in the right size. e.g. control PCB C30/31 220UF in 2.5mm pitch.
UK people, who do you look to first for components?

I was going for Panasonic for the general electrolytics, is there a particular series I should be looking for? and how about for the audio grade electrolytics? Panasonic again, or Nichicon or?

Jensenmann, do you mean the docs for Mixbuzz? I saw them still up there earlier? I can email them to you if you pm me.

Thanks and apologies...

 

[Igor]

C30/C31 can be 3.5mm pitch, 8 mm diameter as well. Will fit fine.

I like these caps (again, personal taste, your choice can be different:
http://il.farnell.com/jsp/level5/module.jsp?moduleId=en/388706.xml
http://il.farnell.com/jsp/level5/module.jsp?moduleId=en/438036.xml

 

[Igor]

@jensenmann: strange...it works now!
In case you need docs to be sent to your mail, feel free to email/pm.

 

[dbeeson]

Hi,
What are the specs of the Elma knobs you used in this build?  I'm looking to order some. Thanks!

 

[zayance]

Hi,
What are the specs of the Elma knobs you used in this build?  I'm looking to order some. Thanks!

No Elma here, Lorlin and Bourns, documents (BOM etc...) can be found on first page.

 

[AudioGimmer]

C30/C31 can be 3.5mm pitch, 8 mm diameter as well. Will fit fine.

I like these caps (again, personal taste, your choice can be different:
http://il.farnell.com/jsp/level5/module.jsp?moduleId=en/388706.xml
http://il.farnell.com/jsp/level5/module.jsp?moduleId=en/438036.xml

Thanks Igor I'll get back to filling the order form....

Farnell's site is sloooooow

AG

 

[desol]

Received the MixBuzz today...this sunny day. Like clockwork...as usual Igor.

 

[JamesW]

C30/C31 can be 3.5mm pitch, 8 mm diameter as well. Will fit fine.

I like these caps (again, personal taste, your choice can be different:
http://il.farnell.com/jsp/level5/module.jsp?moduleId=en/388706.xml
http://il.farnell.com/jsp/level5/module.jsp?moduleId=en/438036.xml

Thanks Igor I'll get back to filling the order form....

Farnell's site is sloooooow

AG

Digikey list these Panasonic caps under "M" series

 

[stereokillah]

hi,soon i 'll have to calibrate the unit

i did it like that

DBX202X has internal resistors on inputs 8x10K, than, .
Control port impedance is 832 Ohm. I.e. R4=3k74, R3=4k99, R100=909R.

THAT2180C, don't install SC_SYM trimpot and R33.
There's no need for A version VCA in sidechain.

Sidechain trimpot (RV1) on audio PCB: changes threshold point... install 5k1 and forget.
Threshold trim (TR_TRM): changes threshold zero. Omit (install nothing) and forget!!!

well just need:Audio: adjust for 0.0 mV DC at IC11b, NE5532, pin1 it's trimmer SYM right?

could i calibrated it one board audio by one without controle board if not one by one with controle board?

cause i'll used the card edge connector linked to 51X prototyping PCBs

thanks

 

[dbeeson]

Hi,
What are the specs of the Elma knobs you used in this build?  I'm looking to order some. Thanks!

No Elma here, Lorlin and Bourns, documents (BOM etc...) can be found on first page.

I believe Igor used Elma knobs (not switches) for his build.  I am a noob, I wanted to know where to source those knobs.
Thx.

 

[stereokillah]

yes i think you right it's elma knobs perhaps you could find it on farnells

 

[zayance]

I believe Igor used Elma knobs (not switches) for his build.  I am a noob, I wanted to know where to source those knobs.
Thx.

Oh excuse my french, i mismatch knobs with pots  :, yes elma knobs, well Farnell has black ones and some in grey, you have to choose the cap color and with or without line, or arrow on the bottom, just put Elma in the search field, and i found a swiss distributor that has most of them, but never dealed with them yet, www.distrelec.ch, you need to choose your county tough, price changed according to that, better to live in EU.

 

[dbeeson]

I believe Igor used Elma knobs (not switches) for his build.  I am a noob, I wanted to know where to source those knobs.
Thx.

Oh excuse my french, i mismatch knobs with pots  :, yes elma knobs, well Farnell has black ones and some in grey, you have to choose the cap color and with or without line, or arrow on the bottom, just put Elma in the search field, and i found a swiss distributor that has most of them, but never dealed with them yet, www.distrelec.ch, you need to choose your county tough, price changed according to that, better to live in EU.

C'est pas grave!    I'm finding it very difficult to find a lot of audio electronic parts here in Ontario.  I'm sure some of you Ontarians on this forum could chime in with info, it would be greatly appreciated.  The best around here is Sayal, but their selection is limited.  I'm sure there's some hidden Gems in Toronto.

 

[Igor]

well just need:Audio: adjust for 0.0 mV DC at IC11b, NE5532, pin1 it's trimmer SYM right?

If everything assembled ok, yes

could i calibrated it one board audio by one without controle board if not one by one with controle board?

Yes, to check if the audio path is OK it is enough.
To check the compressor, everything-both audio boards
and control board - should be powered!

cause i'll used the card edge connector linked to 51X prototyping PCBs

Of course.

I'm finding it very difficult to find a lot of audio electronic parts here in Ontario.

I didn't used any exotic parts. Most of stuff available from Mouser/Farnell/Digikey.
THAT chips, meter and ELMA knobs, are all available from Farnell/Newark.
Please let us know what parts are hard to source for you.

 

[AudioGimmer]

cause i'll used the card edge connector linked to 51X prototyping PCBs

thanks

Hey Stereokillah.

Do you have many spare edge connectors like in the picture? I'm building my mixbuzz for a 6 slot lunchbox and it's tight in there. They'd be handy for making a testing setup.

AG

 

[Igor]

Please PM me, I did some test PCB's like on the picture.
Can send a pair on request for free, just pay shipping cost.