Help with Dual Balanced (ring) Modulator / Soundtronics kit

[bassculture]

Hello all !

i am building some yusynth modules.

Boards are good quality & shipping was fast

A have trouble with the ring mod >

Both sides are showing similar behaviour
althought measurements on 2nd amp of TL072 1 & 2 are not the same.

behaviour is : no (ring mod at) output, only very low level input 1 + 2
(bleedthrought i suppose - approx 20x less level than input )

I'm using a +/- 15V Power Supply



here are my voltages :

TL072 n1:
0
7,29
7,27
-14,87
0
0
-0.05
+15.15

MC1496 n1 :

-4,16
-0,59
-0,62
-4,19
-14,34
14,56
0

15
0
15
0
14,56
0
-14,86



TL072 n2 :
0
6,22
6,21
-14,86
0
0
-0.24
+15,16

MC1496 n 2 :
-4,19
-4,90
-4,9
-4,24
-13,17
+12,41
0

13,04
0
13,05
0
12,45
0
-14,87

[bassculture]

pictures below >>

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Yusynth ring mod board.JPG
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[bassculture]

/// and posting this as a reminder...

If Yves Usson is around >

what does he meant by "this module can be used as voltage controlled distortion or clipping module"
modulating Audio w/ Fixed CV is the way ?
then it'll clip in the TL072 first stage ?

[yusynth]

It seems that the ground pad of the input connector misses a track to actually connect it to the ground, thus the 1.5K (R8 and R30) is not connected to the ground although it should be. Connect a wire between the ground pad pf this connector to the closest ground track.

There is also a missing track between R16 and the ground track.

Sorry about that I will have this corrected and will publish an erratum on Soundtronics

[bassculture]

thank you very much for your quick reply !

someone has to crash-test those new PCB's ! this is DIY after all

I'll try this and post pictures as soon as i can get back to the soldering desk !

[bassculture]

Corrections done.

Here is a picture of them >

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IMG_2352-Yusynth-dual-balanced-modulator-corrections.jpg
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[blue hell]

Nice solder work too :-)

[bassculture]

@bluehell

thanks !