MixBuzz1 Build/Support thread

[Igor]

I use hex standoffs, same as for DB connectors with NC thread or M3.

 

[piano]

FOR USA SOURCE - EAO SWITCHES - POWER & BYPASS SWITCHES Are these the correct switches and will they fit one over the other in a 1 rack unit?

---EAO 01-281-025 SWITCH HERE $24.12 http://www.newark.com/eao/01-281-025/switch-pushbutton-dpst-1no-1nc/dp/30B3689
---You can get the lenses HERE (red) $1.98 http://www.newark.com/eao/01-951-2/lens-square-red/dp/91B2351?Ntt=91B2351
---and HERE (white) $2.16 http://www.newark.com/eao/01-951-9/lens-square-white/dp/66F9722?Ntt=66f9722

However Igor, what lamps do I use? 12 Volt or 24 Volt or something else?

---12 Volt HERE http://www.newark.com/eao/10-1109-1329/lamp-incandescent-slide-12v/dp/76K1087?Ntt=76k1087
---24 Volt HERE http://www.newark.com/eao/10-1112-1279/lamp-incandescent-slide-24v/dp/76K1088?Ntt=76k1088

 

[Igor]

FOR USA SOURCE - EAO SWITCHES - POWER & BYPASS SWITCHES Are these the correct switches and will they fit one over the other in a 1 rack unit?

---EAO 01-281-025 SWITCH HERE $24.12 http://www.newark.com/eao/01-281-025/switch-pushbutton-dpst-1no-1nc/dp/30B3689
---You can get the lenses HERE (red) $1.98 http://www.newark.com/eao/01-951-2/lens-square-red/dp/91B2351?Ntt=91B2351
---and HERE (white) $2.16 http://www.newark.com/eao/01-951-9/lens-square-white/dp/66F9722?Ntt=66f9722

However Igor, what lamps do I use? 12 Volt or 24 Volt or something else?

---12 Volt HERE http://www.newark.com/eao/10-1109-1329/lamp-incandescent-slide-12v/dp/76K1087?Ntt=76k1087
---24 Volt HERE http://www.newark.com/eao/10-1112-1279/lamp-incandescent-slide-24v/dp/76K1088?Ntt=76k1088

Lamps: 12V, preferable, LED.
Switches CAN fit one over the other in 1RU.....
Please check your case dimensions, I used Schroff MULTIPAC PRO 1U 280 D
and it has only 36mm useful height inside, BUT, even in this case,
a pair of EAO or RAFI buttons can fit one over another
(the hole diameter 16mm, distance between centers 18mm).

Check page 6 of datasheet, it appears like right type-LATCH,
for some strange reason, they call it MAIN (maintained action).... OK, should work.

IMPORTANT.

If somebody use it as MAINS AC switch, there's RAFI pushbutton which CAN be used for this operation.
Check by datasheet if your pushbutton can be operated under ~250V and, after soldering the wires,
put 20mm shrink tube over all to be at safe side!

 

[Igor]

BTW.
Regarding the lamps: I use with EAO old blown-out lamps,
soldering 5mm ultra-bright LED instead of bulb, and put external resistor.

If somebody like to use the incandescent lamps (bulbs) with EAO, the resistors which going to LED's
(R3, R5, R96, etc) HAVE to be changed to 60...100 Ohm, 1/2W.

 

[piano]

Thank You Igor.

Specifically WHAT resistors should HAVE to be changed to 60...100 Ohm, 1/2W? ("ect." are not good for an amateur like me) Thank you!

 

[Igor]

If incandescent lamps used:

For bypass, or COMP IN  pushbutton, it is R96; should be 60...100 R, 1/2W
If you use EAO/RAFI switch at place of C&B, or MIX, it is R5; should be 60...100 R, 1/2W
For GSSL (or TURBO), or LINK switch, it is R3, should be 150...330 R, 1/2W

I hooked the POWER LED to +12V  connector, which goes to LED meter, thru 2k4 resistor;
Use 60...100R in series in case of incandescent lamp here as well.

Why do we need these resistors? Simple answer, avoid changing the lamps every month.

I recommend to use LED's. The rest is depending on taste. Of course, incandescent lamps looks more vintage,
funny and serious, reminding us the era of Studer controls, 4000G mute's and other fancies,
BUT the lamps aren't reliable, and, for example, 2-5 bulbs every month are changed in DB on their 6000 desk,
which using loads of these lamps. We had same experience with EAO and bulbs in La-Vi discrete class A console we built,
and changed everything to LED's.

 

[briomusic]

Just wanted to say I got my mixbuzz up and running with pretty much everything working well 

Few problems left to deal with:

Meter in IN and OUT modes only shows signal applied to the right channel, but on both bargraphs. What could be causing this? (When calibrating I also noticed that only the right-hand Offset and Range trimmers had any effect on the LED meter.)

S/C HPF settings 40Hz and 80 Hz behave the same, will have to look for solder bridges I guess.  :

One more question is it safe to operate the Mixbuzz with the meter driver board detached? I had to do this to get to the C&B trimmers located underneath, and noticed the PSU getting a lot hotter (all LEDs lit on the disconnected LED meter)

 

[Igor]

Just wanted to say I got my mixbuzz up and running with pretty much everything working well 

Few problems left to deal with:

Meter in IN and OUT modes only shows signal applied to the right channel, but on both bargraphs. What could be causing this? (When calibrating I also noticed that only the right-hand Offset and Range trimmers had any effect on the LED meter.)

S/C HPF settings 40Hz and 80 Hz behave the same, will have to look for solder bridges I guess.   :

One more question is it safe to operate the Mixbuzz with the meter driver board detached? I had to do this to get to the C&B trimmers located underneath, and noticed the PSU getting a lot hotter (all LEDs lit on the disconnected LED meter)

HURRAY!!!!! Tell us more, please.

Meter problem: no oscillation or something is wrong with commutator on LED logic meter board.
The displays are switched with approx. 200Hz frequency (the pcb design and grounding schematic done well, hehe, who did it?
therefore, no sign of switching noise in audio!!!)


BTW, there are no any known probs, fixes or issues with Mixbuzz1, and we already assembled 8 of them.

It is OK to run MixBuzz1 with meter driver board deattached, just close power when attaching/deattaching.

 

[jandoste]

Hi Igor,

I did my first calibration and I have much more sound to the left than the right (1left +2 right side )
on the ratio board I used 1m2 instead of 1m5 ??? and I got problem here I get some distortion with the ratio pot,
with ratio;
- 1,5(dist)
- 2(dist)
- 4(dist)
- not with 6
- 8 and 10(dist)
any idea?

Thanks,

 

[KrIVIUM2323]

Hi Igor and all.

Mine is slowly building(3 check process each board takes time...  : ).

I've got a question about psu: which value for fuse (EU: 220/240v main 2x18V 30VA transfo)?

Thanks.

 

[AW_music]

Hi igor.
Many thanks, we've received all the IC's.
Some questions.

1.  In the soundpath you say THAT1246 for IC1L, IC1R  , but you have sent us INA137PA ..... it's ok to use them ??

2.  We are going to use ELMA's for Threshold and MAKEUP: can you give us the resistor values to use with your pcbs??? We have to use 21 positions, right?

Regards

 

[KrIVIUM2323]

INA137PA ..... it's ok to use them

INA 137P are direct substitute for 1246.

ELMA's for Threshold and MAKEUP: can you give us the resistor values to use with your pcbs

Take a look there:

http://www.groupdiy.com/index.php?topic=28274.msg344252#msg344252

[Silent:Art] give a link to an excel sheet to compute values for substituing log pot with stepped log rotary switch. You choose the number of steps, value of total R and here you go.  8) 

 

[Igor]

we've received all the IC's.

Duh.... Hopefully, no missing parts anymore.
I checking myself all the kits for F76 now, to avoid this kind of headache. F@ng time consumer

1.  In the soundpath you say THAT1246 for IC1L, IC1R  , but you have sent us INA137PA ..... it's ok to use them ??

Of course. It is same specs line receiver; sound-both are very clean; THAT has laser-trimmed resistors and can be used in MS matrix...
we don't need it here, and statistically, 4 of 10 of INA137 can be used for 90 db separation after LR-MS-MS-LR in MS matrix as well.
The rest is same specs. One chip better 5% here, another is better 5% there.
At the moment we assembled the kits, distributor had 137's in-stock and 1246's were unavailable (5-7 weeks delivery).
Same price, same specs.

2.  We are going to use ELMA's for Threshold and MAKEUP: can you give us the resistor values to use with your pcbs??? We have to use 21 positions, right?

10k lin pots are used at place of THRESHOLD and MKUP. You need 40x 499R resistors with ELMA, that's it.
Can be calculated in Android using special script, but what is the reason?

 

[jandoste]

Hi Igor,

I did my first calibration and I have much more sound to the left than the right (1left +2 right side )
on the ratio board I used 1m2 instead of 1m5 ??? and I got problem here I get some distortion with the ratio pot,
with ratio;
- 1,5(dist)
- 2(dist)
- 4(dist)
- not with 6
- 8 and 10(dist)
any idea?

Thanks,

Bump

 

[briomusic]

Still trying to get to the bottom of my metering problem (meter only showing right hand signal on both bargraphs). On the link from the meter driver to the led pcb there are two connections named LEDVU-7 and LEDVU-9. Both of these have voltages that change according to the level of the input signal. However, LEDVU-7 has a positive voltage and LEDVU-9 has a negative voltage. I guess they should both be positive?

(Just trying to isolate the problem to either the driver or led board...)

 

[marcfrom]

I building two DBX202X REPLACEMENT BOARDS.

If i understand well for CBP20, CBP21, CBP22, CBP23 i can use any value between 47N and 220UF.

Someone can confirm and what the best value for this caps?

Marc

 

[bastrika]

Hi , i finished mine last week . It works perfect , sounds pretty nice and clear.No noises or hums.It is very quiet..
I used  OPA134 in audio path cause i have those at home, and i like it.  Same in C&B , used 2134.
In sidechain i used THAT2180 from my old GSSL. Install classic attack/release, that  is the reason i have this front panel
I will try the attack/mod  release and then make a front panel.
Passed all test with success.
Only thing i have to change is 33R 2W from PSu cause i used relays around 300 ohms .
Thank you Igor for this great project...
i will try to post some pics later

 

[jandoste]

Awesome! Congrats!

 

[Sylvain D.]

Excellent work bastrika!
Can't wait to get mine

Sylvain

 

[jandoste]

Hi Igor,

I did my first calibration and I have much more sound to the left than the right (1left +2 right side )

Bump

Bump  ???