ssl clone behaved horrible-but getting better...pics added

i used my clone with the nice highpass filter in the master bus for some tracks with good results...
in a new track i noticed that it doesnt compress anymore as before...so i tried it also with other tracks: same result...

its like every little transient triggers the ssl far too soon now, which results in an ugly and slowly pumping effect...i tried it also on the drumbus with the same result i have to mention...also i played around with the release and the attack setting of course, but it always makes the same bad effect...

now ,where shall i start to look at?
i dont know so much of electronic,specially with chasing for mistakes...

this unit with the highpass filter is the first unit i builded...possibly the mistake is in the highpass filter?

any advice is welcome :grin:

Try removing the filter and then use the error-tracing from the giant ssl-thread..

Jakob E.

I would reverse all the recent changes and adds and check at each step if errors disappear. Good luck :thumb:

hmm, one of my SSL's has been acting up as well, although I am not sure if it is related to the sidechain filter board. What happens when you turn the unit off and then back on again?

you mean powerwise?
sound is immediately there,but sounds funny from the first moment on...

Can you elaborate on what "sounds funny" means?

just look at the beginning of my thread please

after the ssl has been sitting on the shelf for some months now, today i turned it on again...

aah ja, and it doesnt make a fifference if the sidechainboard is connected...

it behaves cool for a very short time (<1 min maybe) then it starts to pump again in the way i described in the beginning of the thread

one more funny thing:
if i put a testtone(sine,square,noise,etc) into it the treshold doesnt seem to have any function-the meter is not mooving at all

any ideas ?

One of the +/-12V regulators getting too hot, and then shutting down?

Check that you have all voltages - including +/-15 and +/-12V at the right places when the unit starts misbehaving.

Jakob E.

7915 is around 55
7815 is around 70

79L12 is around 40
78L12 is around 46
degree

voltages on the regulators are fine

voltages on that 2180 (not the sidechain) are 3 volt (pin 5) and 15 volt (pin 7)

:shock:

i think it should be 15 volt on both pins 5 and 7 - right?

no i am wrong...on the circuit diagram it says the the pins of the vca`s are connected with 15 volt directly

but when i look on the board there is a resistor of 3,9k fed from the 15 volt before it gets on the pin of the vca...

so i found out that mine is actually 3,9k but according to this link
http://fucanay.fischerworks.com/diy/gssl/gssl_vca.html
it should be 5,1k

could this difference lead the ssl into the funny pumping behaviour?

can somebody lead me to important voltage measuring points please?

oops...i found out that i forgot to put one capacitor on the board - shame on me

now the clone sounds much better...still i am measuring only 3 volt on pin 5 of the vcas after the resistor, but 15 volt before the resistor :roll:

can somebody please tell me why i should read 15 volt on pin 5 when there is a resisitor before the vca feeding the 15 volt?

here is a picture of my clone

[quote author="digichild"]oops...i found out that i forgot to put one capacitor on the board - shame on me

now the clone sounds much better...still i am measuring only 3 volt on pin 5 of the vcas after the resistor, but 15 volt before the resistor :roll:[/quote]


can somebody please give me advice on this measurepoint or point me in a direction to understand why i have such a difference in the voltage...

i really want to understand why this can happen

thank u all :grin:

digi, you measure 15V before the resistor and just 3V after that resistor???
perfekt!
remember what a resistor does......

regards
toby

hallo toby

thats what i thought too...but then i found these measurepoints in the forum:
(http://www.groupdiy.com/index.php?topic=47&postdays=0&postorder=asc&start=1620)

Channel VCAs

1. 0V
2. 0V
3. 0V
4. -0.52
5. -14.97
6. 0V
7. 14.69V
8. 0.44V

and thats what i dont understand

can u clarify this for me?

thanks digichild

Please look up the datasheets for the VCA's, and search this forum for previous discussions. That should explain all.

Jakob E.