GSSL HELP THREAD!!!

[Chrome Heart]

So I've checked the solders as you say and now, the problem of different levels in bypass mode has gone ! Thanks !
But the GSSL still doesn't work properly. The signal seems overcompressed, only with a slow attack I can hear something on the loudest parts. (don't know if I'm very clear !)
Could it be a problem inside one lorlin switch ?

It seems unlikely that it would be the lorlin switch. I would reiterate arrigotti's post and check, recheck, and check again for a simple mistake. Check all the cap and resistor values and make sure they are correct. Recheck the VCA's and make sure the are working, as well as the op amps. Youd be surprised what you might miss. Ive built three of these units and I can tell you, its easy to miss something simple

 

[intellijel]

I bought my gsssl boards and parts over a year ago but only this week finally managed to build them.

My gssl boards are rev7 and I have a GSSL SuperSidechain Filter from J. backhaus  rev A

I have not been able to find any info on the J. Backhaus PCB (like a BOM). Is this still a good board or should I just order the Gustav SSC?

Anything else I should know about Rev7 gssl boards that have been radically changed now?

thanks!  (sorry I know this is an overdone topic)

 

[stereokillah]

intellijel,
don't know about your S. sidechain, but for you gssl board wich vca would you use

 

[geetar_king]

intellijel:

i have the same SC board. yep still a good board if you haven't abused it!  I haven't installed it either. Just sitting in my toolbox.

for BOM, try this site. german, but it will help with the component values. don't ask me to translate though!
http://www.sdiy.de/de/projects/superSC.html

also read this: Joachim (aka sonicwarrior) has some plots from testing posted on page [4] of this one.
http://www.groupdiy.com/index.php?topic=16113

Also good - take a look at this site. I think Joachim's board is very similar if not the same. Can't remember, i went through the above thread about 8 months back...
http://picasaweb.google.com/barclaycon/GSSLSuperSidechainPCB#5186631869292869794

sorry, can't help with the Rev 7 GSSL board

 

[stereokillah]

ok the version 7 seems to be the same of rev 9 just little modifications about part no pcb
check it, http://www.gyraf.dk/gy_pd/ssl/ssl.pdf

Just some change about your vca choice should be done.

 

[intellijel]

intellijel,
don't know about your S. sidechain, but for you gssl board wich vca would you use

I have THAT2181's  ...

 

[intellijel]

intellijel:

i have the same SC board. yep still a good board if you haven't abused it!   I haven't installed it either. Just sitting in my toolbox.

for BOM, try this site. german, but it will help with the component values. don't ask me to translate though!
http://www.sdiy.de/de/projects/superSC.html

also read this: Joachim (aka sonicwarrior) has some plots from testing posted on page [4] of this one.
http://www.groupdiy.com/index.php?topic=16113

Also good - take a look at this site. I think Joachim's board is very similar if not the same. Can't remember, i went through the above thread about 8 months back...
http://picasaweb.google.com/barclaycon/GSSLSuperSidechainPCB#5186631869292869794

sorry, can't help with the Rev 7 GSSL board

The nice thing about the Gustav boards is that there are provisions for relays and lot's of nice details on hooking it up (great photos by another forum user...can't remember name at the moment)

 

[stereokillah]

here you have some modifcation for each vca
http://diy.fischerworks.com/gssl_vca.shtml

 

[allinbang]

Thank you every one in here  it seems that the gssl is now FINALLY working , I decided to re-solder all the pot meters and lorlins on  the control board and believe it or not that actually fixed the problem. I am not completely sure what the problem was but at least I found out that I made 1 mistake : one of the lorlin switches was displaced (I think it was the release switch) I don't know how that would cause distortion but hey I build the thing wrong and now I build it right and it works 

Allin

 

[kambo]

hi, newb
just finished gssl... first DIY after 30+years... good to be back
all seems working fine... no hum. no smoke sounds good...
i havent received the meter yet...

couple of problems...
control panel parameters all working.... but
1. its doesnt seem to squeeze even on 1:10 ratio with lowest thresh hold.
2. gain make up only making 3-4db make up only

using 81C chip. i made all the standard THAT  adjustments.


EDIT : its all fine.... bad/cracked cable on 10pin controller board connection...

 

[intellijel]

What fuse should I put in the IEC connector?

slow blow or fast blow?

rated for 250VAC and what current?

I am in north america (120VAC) and the gyraf site said the fuse should be rated for 25W. So would that mean I want a fuse rated for 25W/120V = 0.25A ?

 

[dissonantstring]

hi intellijel,
you can use a 1/4W (0.25W) fuse rated for 250V.
definitely use a slo-blow type especially if you are using a toroidal PSU transformer (high in-rush current on power up). 
regards,
grant

 

[intellijel]

hi intellijel,
you can use a 1/4W (0.25W) fuse rated for 250V.
definitely use a slo-blow type especially if you are using a toroidal PSU transformer (high in-rush current on power up). 
regards,
grant

thanks for the info! I only have a 1a on hand at the moment which I will use temporarily until I can get a 0.25A

 

[penguin]

just finished sll... doin test measurements before i connect any audio.

i have noticed that voltage controls for threshold and makeup gain as follows:
when i tweak the 50K pots
i measure variable DC on TL072's out 1 and 7, which is fine...
i measure variable DC on before 620K and 220K on schematic... which is fine....

but no variable DC on pin 2, 3, 5, 6 on TL072....  its some fixed values... i cant measure any variable DC there!
is this the way it should react? is so, how much  DC i should be measuring there...

thank ytou

EDIT : 702 typo to TL072

 

[penguin]

at no input signal

TL072 pin 7 with 50k pot
-0.12 mV to -2.1dcV
it doesnt look like -20 to +20 db makeup gain to me....
connected audio, and its very little gain make up.

same problem on threshold too.... it doesnt really grab any audio...

controller board cable connections checked. 50K pot connections checked...
by pass switch checked...

what is the usual cause for this... where shall i look... after i double check everything....
( i did checked many times so far )


using that2181A chip
sound very clean. no distortion...

 

[drive]

I have built 2 comps and a freind has built one, they work great but ....
the more I turn up the output knob the more buzz and hum I get and this on all three machin's.
So we where thinking that maybe it could be from the power supply path since everything is on the card.
maybe we could get rid of the buzz with an external power supply.
Any one else noticed this probleme and solved it ?

 

[penguin]

i have checked for all the control voltages... they all working in control board and main board.
bypass working.
all adjustments are making sense in a way.
checked for dioes, all fine
replaced ICs, fliped around etc... all seems fine... no distortion etc.
but,
general output is lower than input around 4 db, in by passs and unity gain..
makeup gain is not giving much, just a little, towards end... but CV is working perfectly and passing to main board...
(TL072 pin 7 with 50k pot -0.12 mV to -2.1dcV)

please help

 

[penguin]

ok, i went through all tests... etc... and guess what.
all my 100 ohms were 10K  ;D
it was an excellent experience tho... i know inside_outside of the gssl now.

 

[thwop]

??? I have ordered 22uf 25v low esr caps as per jacobs parts list only to notice that the schematic shows them as 35v

Will my 25v caps do, or do I need to swap them for 35v ones.

My gut feeling is that they will be OK.

But I'm just a simple shepard.

 

[kambo]

25V is fine.