MixBuzz500 build/support tHread

[Igor]

First, let's check the voltage beween gnd and wiper of threshold pot,
it should change from approx. +6.5 to -6.5 Volt when rotating the THRESHOLD pot.

Then, let's check if audio passing thru sidechain: feed about 1V RMS sinus 1Khz to input, set 4000 mode,
sidechain filter OFF, check with scope at IC3d (14), IC3A (1), there should be sinus 0.5V RMS;
than, check if there's a signal on CTL pin 5 (10 pin IDC connector);
than, check the signal on IC11A (1), sinus, it's amplitude changes with position of threshold pot;
than, check if rectifier works-on IC10A, (1) should be rectified full-wave signal when threshold set to low (CCW);
than, check if there's a voltage CTL-10, should be saw-looking signal which changes depending on amount of compression and time constants;
than, check the voltage on IC7D (14), this is the control voltage (should be meter deflection), etc.....

Before all this,
Check jumpers;
Check if CTL and SC cables going to their channels respectively,
i.e., CTL1, SC1 to left and CTL2, SC2 to right channel;
Check all connections etc...

Of course, there is a little mistake, wrong connection or wrong component somewhere
Cool let's find it....me a way curious

 

[kibadachi]

When i checked the voltage between gnd and and wiper i found some "forgotten" solderings on the control board. fixed and working!
Thanks Igor for the starting point.
Now that the interns are working i have to find some knobs to match the sonical with the aesthetical.

Any recommendations for the F' rite Red lookalike knobs or some anodized aluminium colored knobs with skirts?
I also like the knobs that Skylar rendered. ( http://www.groupdiy.com/index.php?topic=37604.msg463588#msg463588 ) Any of these knobs available in real life?

 

[Igor]

That's good!!!! Have a fun doing music with your Mixbuzz500!!

I am not best source for knobs advice.... ELMA is my personal taste;
another funny option:
http://www.smallbearelec.com/Detail.bok?no=782
Many others are available, check Banzai, Smallbearelec etc for knobs....

 

[culteousness1]

Hey all,

I just tested my finished unit. First without ics everything was alright.
Then I put in the ics and tested again.

Unfortunately two resistors (R47, R44) on one board went up in smoke and started glowing  .

Other board seems to be working.

Thanks in advance!

Greetz from Cologne,
Carsten

 

[Igor]

Check the direction of IC's and if there's no shorts...

 

[culteousness1]

Thanks for your reply Igor!

Good news! Your diagnosis was right. I inserted IC10 in the wrong direction  .

Now I have to replace those resistors and proceed checking.

Greetz,
Carsten

 

[johnny dance]

I know its lazy, but does anyone have a farnel or mouser cart made u for this? I am about 40% putting one together but thought I would ask

OK so i sort of pulled the digit out and put together a close to complete cart...
-I have a 65quid resistor kit in there (easier for me, but not nessecary)
-Missing a few of the caps, the wiring, and the DBX replacement pin connectors I think

-Is there anything else missing, over/underspec'd (it looks $$$y)

Line No. Order Code Qty Description Mftr. & Part No. RoHS Line Price

1 3322592 30 CAPACITOR CERAMIC 0.22UF, 50V, Y5V, RADIAL VISHAY BC COMPONENTS - K224Z15Y5VF5TL2 Y-EX 1.53
2 1141760 10 CAPACITOR, 22PF, 50V, NP0, RADIAL VISHAY - K220J15C0GF53L2 YES 1.36

3 1311572 2 CAPACITOR SILVER MICA 33PF, 500V, RADIAL CORNELL DUBILIER - CD15ED330JO3F YES 1.96
4 1311557 4 CAPACITOR SILVER MICA 33PF, 500V, RADIAL CORNELL DUBILIER - CD10ED330JO3F YES 6.2

5 1311576 4 CAPACITOR SILVER MICA 56PF, 500V, RADIAL CORNELL DUBILIER - CD15ED560JO3F YES 4.08
6 1669202 10 CAPACITOR, 15NF, 50V, 5% PANASONIC - ECQV1H153JL YES 0.81

7 1669204 10 CAPACITOR, 22NF, 50V, 5% PANASONIC - ECQV1H223JL YES 0.9
8 1744826 10 CAPACITOR, FILM, 50V, 47NF PANASONIC - ECQV1H473JL YES 0.66

9 1744827 10 CAPACITOR, FILM, 50V, 68NF PANASONIC - ECQV1H683JL YES 0.61
10 1744829 10 CAPACITOR, FILM, 50V, 0.22UF PANASONIC - ECQV1H224JL YES 0.91

11 1712374 8 CAPACITOR POLYESTER 0.15UF, 63V, RADIAL EPCOS - B32529C154J YES 0.69
12 1744833 10 CAPACITOR, FILM, 50V, 1UF PANASONIC - ECQV1H105JL YES 2.6
13 1702698 8 ALUMINUM ELECTRO. CAPACITOR VISHAY BC COMPONENTS - MAL214066221E3 YES 5.84
14 8767408 20 CAPACITOR, 47UF, 50V PANASONIC - ECA1HAM470X YES 2.74
15 8766940 4 CAPACITOR, 10UF, 35V PANASONIC - ECA1VAD100X YES 0.68

16 9341234 100 RESISTOR, 0.25W 1% 12K MULTICOMP - MF25 12K YES 2.3
17 9342362 1 RESISTOR, KIT, 0.25W 1% E6 MULTICOMP - MF0W4FFE006KIL YES 65.66

18 1354171 12 AMP, VOLT CONTROLLED, TRIMMABLE, 2181 THAT CORPORATION - THAT2181AL08-U YES 65.52
19 1426379 2 OP AMP, DUAL LOW NOISE, SMD, SOIC8 ON SEMICONDUCTOR - NE5532AD8G YES 2.76

20 1354147 4 LINE RECEIVER, BALANCED, 1246, DIP8 THAT CORPORATION - THAT1246P08-U YES 11.56
21 1354158 8 LINE DRIVER, BALANCED, 1646, DIP8 THAT CORPORATION - THAT1646P08-U YES 28.32

22 1354168 2 AMP, VOLT CONTROLLED, PRETRIM, 2180 THAT CORPORATION - THAT2180CL08-U YES 7.58
23 1103005 4 IC, OP AMP, DUAL JFET, DIP8 TEXAS INSTRUMENTS - TL072ACP YES 4.36

24 1105902 4 IC, OP AMP, QUAD JFET, DIP14 TEXAS INSTRUMENTS - TL074ACN YES 2.92
25 1384133 20 SWITCHING DIODE, 100V, 150mA, DO-35 NTE ELECTRONICS - 1N914 YES 0.84

26 1467514 4 DIODE, STANDARD, 1A, 1000V, DO-41 FAIRCHILD SEMICONDUCTOR - 1N4007 YES 0.32
27 9526820 20 INDUCTOR, AXIAL MURATA - BL01RN1A1D2B YES 4.2
28 9265252 20 INDUCTOR, FERRITE BEAD, 105Z MULTICOMP - MCAB 035090-33 YES 1.56
29 9353011 4 TRIMMER, SMD, 12 TURN 50K BOURNS - 3269W-1-503LF YES 17.88
30 9480218 4 RELAY, PCB, DPCO, 12VDC MULTICOMP - HRS2H-S DC12V YES 6.24

Line No. Order Code Qty Description Mftr. & Part No. RoHS Line Price Line note
31 636332 12 HEADER, STRAIGHT, 10WAY AVX INTERCONNECT - 008380010000010 YES 16.2
32 636034 12 SOCKET, IDC, 10WAY AVX INTERCONNECT - 008290010000011 YES 17.52

33 1106784 8 HEADER, STRAIGHT, 10WAY HARTING - 09 19 510 7324 YES 8.32
34 1818129 20 PLUG & SOCKET CONN, HEADER, 3POS, 6.35MM MOLEX - 10-84-4030 TBA 7.28

35 1847277 12 PLUG & SOCKET CONNECTOR, HEADER 3POS 3MM MOLEX - 43650-0324 YES 19.51
36 1426380 2 IC, OP AMP, DUAL LOW NOISE, PDIP8 ON SEMICONDUCTOR - NE5532ANG YES 2.42

37 9843817 10 DIODE, SMALL SIGNAL, DO-35 FAIRCHILD SEMICONDUCTOR - 1N914 YES 0.53
38 1780709 2 LED, 3MM, RED, 200MCD BIVAR - 3SURC YES 0.37

39 1384846 6 LED, 5MM, YELLOW, 6.3MCD, 585NM CHICAGO MINIATURE LIGHTING - 4304H7 YES 0.92
40 9490272 2 IC, V REG +12V, 78L12, TO-92-3 NATIONAL SEMICONDUCTOR - LM78L12ACZ YES 0.82

41 9490396 2 IC, V REG -12V, 79L12, TO-92-3 NATIONAL SEMICONDUCTOR - LM79L12ACZ YES 1.08
42 1123700 4 SWITCH, 2POLE, 6 POS LORLIN - CK1060 YES 5.68

43 1123703 1 SWITCH, 4POLE, 3 POS LORLIN - CK1062 YES 1.42
44 1123699 1 SWITCH, 1POLE, 12 POS LORLIN - CK1059 YES 1.42
45 1550189 1 SWITCH, SOLDER TAG, 3PDT, ON-OFF-ON MULTICOMP - 1M33T1B5M1QE YES 2.14
46 7991967 1 SOCKET, PCB, 0.1 20WAY" HARWIN - M20-7822046 In Stock
47 1022262 10 HEADER, 1ROW, 20WAY HARWIN - M20-9992046 YES 7.5
48 9358323 2 POTENTIOMETER, 10K BOURNS - PCW1J-B24-KCB103L YES 12.26
49 9608648 1 TRIMMER, 24 TURN 50K VISHAY SPECTROL - M64W503KB40 Y-EX 1.35

50 1262061 1 METER, 19W, 0-1MA SIFAM - 19W0-1MA0-100 YES 41.89
51 1262079 1 BEZEL, FRONT, 19W SIFAM - 19W, BEZELB YES 1.71

52 1141778 10 CAPACITOR, 0.22UF, 50V VISHAY - K224K20X7RF53L2 YES 3.3
53 9750878 10 CAPACITOR, 0.1UF, 63V EPCOS - B32529C104K YES 2.8

54 9750908 5 CAPACITOR, 0.33UF, 63V EPCOS - B32529C334K YES 1.8
55 9750916 5 CAPACITOR, 0.47UF, 63V EPCOS - B32529C474K YES 3.15

56 9691936 5 CAPACITOR, 220UF, 10V PANASONIC - EEUFC1A221 YES 0.92
57 1765147 2 RESISTOR, METAL FILM, 2KOHM, 500mW, 1% VISHAY DALE - CMF552K0000FHEB YES 0.46

58 1106093 2 IC, OP AMP, LOW NOISE, 5534, DIP8 TEXAS INSTRUMENTS - NE5534AP YES 1.72

 

[culteousness1]

One more working unit here after some minor errors!

Now I can start the F76 build. Any news on the F76 support thread, Igor?

Thank you for this project, Igor!

Greetz from Germany,
Carsten

 

[Marcocet]

I know its lazy, but does anyone have a farnel or mouser cart made u for this? I am about 40% putting one together but thought I would ask

OK so i sort of pulled the digit out and put together a close to complete cart...
-I have a 65quid resistor kit in there (easier for me, but not nessecary)
-Missing a few of the caps, the wiring, and the DBX replacement pin connectors I think

-Is there anything else missing, over/underspec'd (it looks $$$y)

https://uk.farnell.com/jsp/profile/viewSavedCart.jsp?orderId=o1540218006

Link's not working.

 

[Igor]

Hey Carsten, that's great news!
Enjoy your MixBuzz, and tell us about sound!
Yes, I starting F76 build/support thread within few minutes...
Kits will be sent this week (I hope.. Sorry for delay, guys.

@johnny dance: I cannot login with this link. Please pass thru BOM little-by-little.
For all important parts there are Farnell p/n's.
BOM doesn't has p/n's for resistors etc as there is a lot of choice.

 

[johnny dance]

Just put my most recent cart above... most of it is there I believe... any major errors?

 

[zayance]

Just put my most recent cart above... most of it is there I believe... any major errors?

Well you're asking Igor to do your job, the best way to be sure of the order is to have board in front of you, and BOM, while you're searching around check the board and dimensions, never know some parts can be big, and just cross mark each components, everybody here bothers doing that, and it's part of the deal and fun of DIY 
And if you don't have the board still, well wait for it then....

 

[johnny dance]

Just put my most recent cart above... most of it is there I believe... any major errors?

Well you're asking Igor to do your job, the best way to be sure of the order is to have board in front of you, and BOM, while you're searching around check the board and dimensions, never know some parts can be big, and just cross mark each components, everybody here bothers doing that, and it's part of the deal and fun of DIY  
And if you don't have the board still, well wait for it then....

Hey Happy to do my own job, not a problem. actually was just sharing to help anyone else in my boat trying to order most of the parts for this, might make it easier for someone else that's all... I mean I've already put the BOM together.. .all I need to do is click 'buy'...  8)

And as far as the benefit to me it was more... 'hey i didn't use that i used this and it sounds great/is cheaper'.... etc... might make life easier for everyone else. 

 

[zayance]

Just put my most recent cart above... most of it is there I believe... any major errors?

Well you're asking Igor to do your job, the best way to be sure of the order is to have board in front of you, and BOM, while you're searching around check the board and dimensions, never know some parts can be big, and just cross mark each components, everybody here bothers doing that, and it's part of the deal and fun of DIY  
And if you don't have the board still, well wait for it then....

Hey Happy to do my own job, not a problem. actually was just sharing to help anyone else in my boat trying to order most of the parts for this, might make it easier for someone else that's all... I mean I've already put the BOM together.. .all I need to do is click 'buy'...  8)

And as far as the benefit to me it was more... 'hey i didn't use that i used this and it sounds great/is cheaper'.... etc... might make life easier for everyone else. 

Ah Yes of course, thanks for the effort 

 

[dandeurloo]

Hey guys, I have been finally able to start testing and calibrating the Mixbuzz.  I have found a few problems but I have a few questions to help solve a few more things. 

1.  both channels track together but don't have the same output.  They are off by a few db and seem to act respond slightly different to compression at different thresholds.  Any idea where to look. (I used 1% resistors everywhere)

2.  my switch for the release time has been broken so I wonder if that could mess with the 2 channels.  So I pulled it out.  Is there a simple way to jumper the switch to a position so I can finish testing until the replacement shows up?

3.  For calibrating do I just need to set the threshold as high as possible (for no compression) and the gain to zero.  Then measure IC11 for DC offset?

4.  I have read the entire thread a few times looking for trouble shooting ideas and looked over the boards for mistakes a number of times.  I'm gonna go look again with fresh eyes but I thought I would post to see if anyone had any ideas.  Or do they just not track exactly the same left to right like one would think?

Thanks guys, I can't wait to finally have this one done and in use.

 

[dandeurloo]

Update:

1. I replaced the broken switch.

2. I was able to trim the audio VCA to .062 THD

3. I added a 1k trim pot before the VCA in order to match the gain on the tow channels.  now both channels put in and out 0.000 db!



PROBLEM:
in both the 4000 and the GSSL modes I get nothing from the side chain.  The threshold and gain both don't change a thing, at all.  Both channels.  So I must have something pretty obvious over looked.  I've looked these boards and schematics over 100 times and still can't find it.  Any help would be appreciated.

I'm so close and with the added trim pots added before the VCA this thing should track very nice.  I can't wait to hear it!

 

[reanimatorstudio]

Where to get the edge connector for the little test-pcb's (the ones with the XLR's) in Europe?

 

[culteousness1]

I searched for them at Farnell without luck.

So I ordered mine from Volker at the WM.

 

[reanimatorstudio]

Thanks culteousness1, Volker for the edge connector. One working Mixbuzz500 more.

I first installed 100k instead of 100 ohm for R60 on the control board. Result low output with a slight increase if I turned the Threshold down. Unit is sounding great now. Thanks again Igor!!

I tested my Mixbuzz 500 not assembled yet in the frame and with a DC power supply. You can limit the current (to 15mA) and save you from burning expencive IC's.
One disadvantage is that you can easily put the connectors for SC and CTL in the wrong position. I did it for a short moment. The current limiting on my power supply and the smart lay out saved me and nothing got damaged.
If you are testing one channel at a time, don't forget to connect the CTL-flatcable to the other channel too, otherwise the unit will stay in bypass (relais connected in series between both channels).

Now I have to finish my: How to build Mixbuzz500 step by step.

 

[reanimatorstudio]

I need some help with the SYM trimmers. I have no distortion meter so I used the method Igor suggested 0 volts on the output pins of IC 11 (opa2604). The thing is that it is constant drifting. In the beginning much more and after 30 minutes some millivolts. The other thing is that the trimmers are at there end position and I'm using 4x 2181A's on the VCA boards and also 2181A in the sidechain. (It was cheaper to order 10 x 2181 of the same model)


Is there some freeware distortion meter?

Do I leave out R33 and SC_SYM and forget the DC on pin 1  of IC11?

Is there another way?