GSSL HELP THREAD!!!

[vertiges]

Grooveteer,

The bypass simply "cuts" the sidechain signal path ; audio still passes the VCA's.

What about your voltages ? Are they correct ?

eD

 

[stitch-o]

[quote author="Vito Janeiro"]Decreasing. There is plenty of makeup-gain available.

I need it to trim the parallel bus level after the automation for example...[/quote]

how a bout installing a -20db pad switch? Thats where I'd start...

 

[Harpo]

[quote author="Vito Janeiro"]Hello everyone and thanks for the nice forum.

I have a chance to compare the GSSL to original SSL 4000 console master compressor (G+) and I just have to wonder how it´s possible that the clone sounded so good but even punchier than the SSL compressor!

Nice job Jakob and everybody who have participated to the developing process, to the clone and the original!

Only thing I´d like to modify is the makeup gain, I´d like to be able also reduce the volume when compressor is active. Any idea how to do it?

Wbr,

Vito[/quote]
Hi Vito,

a trimmer/potentiometer, (you need 2 for left/right or a stereo pot) wired as rheostat in series with the 15k* labled resistor, leading to pin 1 of the audio-vca should do the trick.
In this circuit the vca is always in circuit. Unit bypassed, the control voltage is 0V, resulting in a vca current-in=current-out condition. The voltage gain of the vca with following buffer is -av=Rfb/Rin, from the schematic = 15k/15k*. Increasing the 15k* resistor to 30k (others used a 27k here) set this stage to a voltage gain of 0,5 or -6dB to catch the 6dB from the ballancer at output.
Wiering a 47k pot in front of the 15k* will reduce your volume, varying from 0dB to -12dB. (leave the 15k* resistor connecting to vca-pin1 in circuit, to limit the current going into the vca and in case the potentiometer fails open one day). Hope, this is of any use.

-Harpo

 

[Vito Janeiro]

Thanks Harpo!

 

[jrfred453]

I just wired up a GSSL enough to test it out. The Ratio knob seems to be bypassing when in the middle position but works great in the other two positions. I used a couple Alpha rotary switches and one Lorin switch(for release) and I'm not happy with them. I have ordered all new Lorin switches from Mouser just haven't gotten here yet. Is the 1.8M resistor controlling the middle position ratio (4:1?)? What else should I check? Just wanted to ask here first in case someone had an idea. Thanks

 

[jrfred453]

I figured it out on my own! A 510 ohm resistor instead of 510K might make it act like that, huh?

 

[jaydeluca]

alright i have a bit of a beginners question...

but i have started working on my first gssl... i have all the resistors in place and now im working on the jumpers and ic sockets when i ran into a small issue

im looking at my ic sockets, and where they go on the board...

i have found where they all go except for my 16 pin sockets...

in all the pictures i have looked at, they show singe in-line sockets with 8 pins... and i have sockets that are dual 8 pin... did i get the wrong part here?

also, i am going to be using the THAT 2180 VCA's and i have left out the components that the schematics have told me to leave out.. now my question is should i be placing jumpers in their place? or just leave them be?

thank you for your patience... i have tried searching for these answers with no luck

 

[Dr nEon]

Hi jaydeluca

I don't know what BOM you are working from , but I think you ought to be using the 16 pin sockets to split up to use as 8 SIL sockets to fit the vcas into ....well, that's what I did anyway..

Check this link , ...it's the bible as far as vca variations and what to leave out etc....

http://diy.fischerworks.com/gssl_vca.shtml


Cheers

nEon

 

[jaydeluca]

thank you

so i need to remove the 3K9 resistors and replace them with 5K1's?

those were the only ones that were not identified on file i used

 

[jaydeluca]

and how do i go about "splitting" them up? i dont want to damage anything

 

[Dr nEon]

you can find reference to this on Gyrafs original gssl page on his website..

...but it will depend on what types of 16 pin sockets you have...

for instance , i used the 'turned pin' type sockets , which have a rather skeletal frame , that is , you don't need to cut much away to separate them ..

IF you're using those , well, I just use a junior hacksaw to split them lengthways.. u can always use a small file to neaten up the stubs , but be careful filing the plastic on these delicate things because you can expose the pins if you are too agressive...

i haven't found a better way than that..the ones I use will shatter if u try sniping them with cutters etc..

There's the TL074 as well which is 14 pin ...maybe you already got that one sorted , but again, I (and probably most people) just butcher a 16 pin socket..

nEon.

 

[jaydeluca]

thank you very much

i appreciate your patience

 

[jaydeluca]

i have run into another small problem...

the tantalum capacitors i purchased from digi-key seem to be the wrong "kind" ?

i purchased 35V ones after reading somewhere in the forum that you can do that..

these are what mine look like (just the style, not the actual values)
http://www.toboc.com/images/productimages/58727_TH.jpg

and i am unsure about how to mount these, if its even possible.

should i order new ones?

the digi-key part numbers are
6.8 uF 35 V 478-1742-1-ND
.47 uF 35 V PCT6474CT-ND

Thanks for your time

 

[jaydeluca]

also, for the 100p capacitors...

it says in the part list im following that you only need 9, but there are places on the board for 10 of them. Im assuming to put all 10 in place?

 

[vertiges]

[quote author="jaydeluca"]also, for the 100p capacitors...

it says in the part list im following that you only need 9, but there are places on the board for 10 of them. Im assuming to put all 10 in place?[/quote]

There are 9 x 100pF and 1 x 10pF ! :wink:

eD

 

[vertiges]

[quote author="jaydeluca"]i have run into another small problem...

the tantalum capacitors i purchased from digi-key seem to be the wrong "kind" ?

i purchased 35V ones after reading somewhere in the forum that you can do that..

these are what mine look like (just the style, not the actual values)
http://www.toboc.com/images/productimages/58727_TH.jpg

and i am unsure about how to mount these, if its even possible.

should i order new ones?

the digi-key part numbers are
6.8 uF 35 V 478-1742-1-ND
.47 uF 35 V PCT6474CT-ND

Thanks for your time[/quote]

Yes, I'm afraid you have to order new ones. You bought SMD type : http://en.wikipedia.org/wiki/Surface-mount_technology
You need radial / Through holes ones.

Those are the Digikey ref # I used on my first GSSL :
0.47u 50V : Digikey # P2071-ND
6.8u 50V : Digikey # 399-3653-ND

eD)))

 

[vertiges]

[quote author="jaydeluca"]
i have found where they all go except for my 16 pin sockets...

in all the pictures i have looked at, they show singe in-line sockets with 8 pins... and i have sockets that are dual 8 pin... did i get the wrong part here?

[/quote]

As Dr nEon said, you have to cut them in two. I use a little metal saw.
That's not easy, don't rush and take your time.

[quote author="jaydeluca"]
also, i am going to be using the THAT 2180 VCA's and i have left out the components that the schematics have told me to leave out.. now my question is should i be placing jumpers in their place? or just leave them be?

[/quote]

It' very well explained on the Matt's DIY Pages !
You have to remove : 4 x 10k, 2 x 68R and 2 x 1M. Just remove them, no jumper.

eD)))

 

[jaydeluca]

[quote author="vertiges"]

There are 9 x 100pF and 1 x 10pF ! :wink:

eD[/quote]

?

 

[vertiges]

You're damn right ! There are 10 ! :roll:

Yes, you have to solder all of them.

eD))

 

[jaydeluca]

thanks for all your replies and time so far!

i really appreciate the help

-Jay