SSL comp question to Jakob

[tubemonkey35]

So what's the best and most current Schemo to work from Jakob?

 

[gyraf]

The schematic at the gyraf page is the currently most correct. But it needs some minor changes, yes.

Jakob E.

 

[Fredrik]

Hello,


I have a question about available shematics for rev#7 pcb from swedish chef. I have downloaded a rev#7 shematic from gyraf.dk but the vca´s in this version is still 202´s and there seems to be a 10k resistor on pin 4 that is left out. From what I can see on the PCB there is a 10k resistor mounted in series with the 1M resistor going to the 50k trim (dist trim).

Now I´m thinking about using that 1281 for VCA´s and 1280 in the sidechain (since there is no trim potetiometer on the card). Accordin to the documentation on the THAT webpage I understand that the resistor on pin4 should be 220k for the 1281B instead of the 10k+1M present on the pcb. Also that value seems high even for the 2150, fo what reason has it been choosen?

If I would change this value and skip one resistor and go for the recomended 220k value, would I mess up relationships i the circuit in some way? and altering the impedance?

Also there is a 3,9K resistor on pin5, giving the vca it´s juice (I think) on the THAT documentation this value is 5,1K. Is there a specific reason that the 3,9K value has been choosen?

Sorry if the qustion seems obvious, I thought I better ask.

Much respect :guinness:

F

 

[ironmonkee]

i posted this in the newbie section before jakob says i should post it here again.

hi
since this is the newbie section here i will ask some questions.

1. i build the ssl clone without the sidechain pcb. (maybe i add this in my second try after i get the first one to work). so what does that change?
2. is there a scematic that schows exactly how to connect the different Pcb's, power supply and knobs to the Pcb???
3. i use the 2180's so heard that you can leave out some parts. i found different threads but i don't found one that gives a 100% answer
4. a lot of threads say that u have to use different resistors if you use the behringer meter which resistors are these.
5. on my pcb (audiokitchen) is one 100k resitor that is a 127k resitor on different schematics i found here in that forum.

i'm sure that i will have more questions but maybe some one can help me with these.

this far i'm so happy that this forum exists because i really like building audio gear. you guys do a great job here.
thanks in advance
Eric

and excuse my bad english (i'm german)

 

[JayDee]

i posted this in the newbie section before jakob says i should post it here again.

hi
since this is the newbie section here i will ask some questions.

welcome...

1. i build the ssl clone without the sidechain pcb. (maybe i add this in my second try after i get the first one to work). so what does that change?

You may google first what a sidechain does? The sidechain pcb does nearly exactly the same than in any other compressor (also in VST).

2. is there a scematic that schows exactly how to connect the different Pcb's, power supply and knobs to the Pcb???

should be printed on the schematic. there´s not too many connections to make.

3. i use the 2180's so heard that you can leave out some parts. i found different threads but i don't found one that gives a 100% answer

The 2180 is pretrimmed in distortion, as far as I rmember you can leave out the 50k trimmer and the 1M resistor on each channel.

4. a lot of threads say that u have to use different resistors if you use the behringer meter which resistors are these.

The 2k resistor should be changed, but actually i don´t know the specs from the behringer meter right now...

5. on my pcb (audiokitchen) is one 100k resitor that is a 127k resitor on different schematics i found here in that forum.

you have to be more precise on that one...

I can also help you in DEUTSCH !

i'm sure that i will have more questions but maybe some one can help me with these.

this far i'm so happy that this forum exists because i really like building audio gear. you guys do a great job here.
thanks in advance
Eric

and excuse my bad english (i'm german)

 

[pedroplanet]

ok, to ease everyone's tension.... over the weekend I cut the ground loops on the pcb and did some measurements..  

ground loops left alone
faders@unity
GSSL@unity
-70db with slight hint of 60hz

ground loops cut
faders@unity
GSSL@unity
-71db with slight hint of 60hz

I don't see much improvement in noise floor or 60hz hum from cutting the ground loops.

My gssl has -71db hiss and very little 60hz on right channel. and -65db more 60hz than hiss on the left channel.

this is my problem.
what's going on with my left channel? changed the cables, same thing... any ideas? Please help me, I'm going crazy! ???

 

[Stagefright13]

I am not having any problems with my GSSL made from GYRAF specs. In fact since I built it I don't think I can record without it. I am spoiled!

I did add the super sidechain and totally satisfied me! Altho there are other mods. Like Turbo etc.

 

[Stagefright13]

Typically the problems on the GSSL are solder bridges. It's very easy to link the wrong pad that way. If ya got a bunch of noise it is not circuit related. I made 2 silent ones. And regret selling my spare motherboard when times were tight...

John 

 

[Stagefright13]

I will post in the GSSL thread where this belongs. But I used this as a guide and works perfect. Go to the gssl help thread.

John

 

[JayDee]

yes, SSL works great.


Problems are most solder bridges or wrong or damaged parts. check double !

 

[marcfrom]

Hi, do i have to using 50K trim whith DBX 202 VCA's?

 

[gyraf]

..please use the other, that is, the "official" ssl help thread..!

Jakob E.