GSSL HELP THREAD!!!

[xqqxqq]

I have a SL911, where to find the input and output connection method?

Thank you!

 

[gyraf]

..please specify what you mean by SL911..??

 

[schrobbelbop]

... the voltage drops even more and my meter led dims..

Your meter LED (sure its an LED and not a light bulb?) should not be supplied by the +12V or -12V rails.
Maybe reconnect your meter LED ( 0V -->|--1K2-- -15V ) or ( +15V -->|--1K2-- 0V ) for a blue LED with typical VF3.3V @10mA.
You already have double checked parts values and parts orientation?
Power down, disconnect the turbo board, temporary remove the sidechain VCA, TL074 and TL072 on main pcb, power up and check for correct +/-12V voltages, else replace the broken 78L12 or 79L12 regulator.
Power down and put the chips back in one by one. Power up and measure rail voltages again after each chip. If a rail now drops in voltage, the last chip you put back in is probably broken. Now reconnect the turbo board as described by Expat Audio.

Thanks for the tips harpo! gonna try it this morning. The meter is LED by behringer . connected on the control pcb indeed.

 

[Jazzboms]

Hi
Got some problems with makeup and threshold on my new built gssl. The symptoms are weird. With no threshold, the makeup gain doesnt work until its at max, then it goes to max gain. From zero to max with nothing between. It passes clean audio with, as far as I can hear ,no hum or noise.
With max threshold, and min makeup, I got a lot of distortion, but the distortion decreases when i increases the makeup, but it doesnt make more gain. Again at max makeup, the gain sudden increases to max.(The distortion increases while turning the threshold)  Also the distortion increases when higher ratio. So the conclusion is that instead of compression, it distorts.
With no threshold the unit passes audio nice.
I have checked for shorts, but I cant find any, and my soldiering looks ok. But obvious something is wrong. The op-amps and VCAs doesnt go hot except the TL074 feels a little more hot than the others. Have replaces my opamps and VCA.(Maybe all my extra opamps and vcas also are broken.....)
Havent done any measuring other than checked the main +/- 15/12. The + 15 is 14.77 and the -15 is -15.02.
The meter is not connected.


Thanks for reading!
Best

Your opamps and vca's are fine.  something is wired wrong somewhere.  recheck your wiring and check for solder bridges or incorrect component values.

Hi
Have checked around, and cant find any errors. One thing I have discovered, fooling around on the PCB, is when I removed the 22 cap near the TL072 my makeup did work as it should, but not the threshold. But this 22 cap is probably driving the TL074.
Do you think that my problem is in the sidechain section? Anybody knows where to start error seaking?
Thanks.

 

[Harpo]

Hi
Have checked around, and cant find any errors. One thing I have discovered, fooling around on the PCB, is when I removed the 22 cap near the TL072 my makeup did work as it should, but not the threshold. But this 22 cap is probably driving the TL074.
Do you think that my problem is in the sidechain section? Anybody knows where to start error seaking?
Thanks.

The 22uF cap next to the TL072 is in between the sidechain rail voltages 0V and -12V, so there obviously is something wrong with your +/-12V rails.
Temporary remove the sidechain VCA, TL072 and TL074. Check for correct voltages (TL072 socket pin4 should read -12V, pin8 should read +12V). All fine moving on, else replace the broken 78L12 or 79L12 regulator. Now with bypass switch turned off (compressor engaged) measure voltage at "E". This should vary between 0V and +12V when turning the makeup pot. All fine moving on, else replace the broken 50K lin pot or correct your bypass wiring at the switch. Next measure voltage at "F". This should vary between -12V and a little above 0V when turning the threshold pot, assuming you have the 47K between +12V and the ccw pots end soldered on. All fine moving on, else replace the broken 50K lin threshold pot. Next put your chips back in one by one, checking for correct +/-12V rail voltages after each step to weed out a faulty opamp or VCA (see two posts above).
Good luck.

 

[xqqxqq]

..please specify what you mean by SL911..??

Solid State Logic 9000 series in the SL911 Channel Strip

 

[Jazzboms]

Hi
Have checked around, and cant find any errors. One thing I have discovered, fooling around on the PCB, is when I removed the 22 cap near the TL072 my makeup did work as it should, but not the threshold. But this 22 cap is probably driving the TL074.
Do you think that my problem is in the sidechain section? Anybody knows where to start error seaking?
Thanks.

The 22uF cap next to the TL072 is in between the sidechain rail voltages 0V and -12V, so there obviously is something wrong with your +/-12V rails.
Temporary remove the sidechain VCA, TL072 and TL074. Check for correct voltages (TL072 socket pin4 should read -12V, pin8 should read +12V). All fine moving on, else replace the broken 78L12 or 79L12 regulator. Now with bypass switch turned off (compressor engaged) measure voltage at "E". This should vary between 0V and +12V when turning the makeup pot. All fine moving on, else replace the broken 50K lin pot or correct your bypass wiring at the switch. Next measure voltage at "F". This should vary between -12V and a little above 0V when turning the threshold pot, assuming you have the 47K between +12V and the ccw pots end soldered on. All fine moving on, else replace the broken 50K lin threshold pot. Next put your chips back in one by one, checking for correct +/-12V rail voltages after each step to weed out a faulty opamp or VCA (see two posts above).
Good luck.

Thanks!
Did as you suggested
Without the VCA, tl074 and lt072 i have -11.97 on pin 4, and +11.97 on pin 8, so that is checked ok.
With VCA(2181) and TL072 i have the same, but with the TL074 pin 4 is -11.99, and pin 8 is +1195. I dont know if this is crusial? I have also meassured this with the same results with a new TL074
The makeup and threshold behaved as you wrote on E and F.
But the compressor still behaves like earlier.
Any other ideas?
I  have checked and recheked for bridges, wrong components, and wrong directions, but have not found any, but Im not 100% sure.
Anyway, big thanks for helping. I knows more how to test now.

 

[schrobbelbop]

... the voltage drops even more and my meter led dims..

Your meter LED (sure its an LED and not a light bulb?) should not be supplied by the +12V or -12V rails.
Maybe reconnect your meter LED ( 0V -->|--1K2-- -15V ) or ( +15V -->|--1K2-- 0V ) for a blue LED with typical VF3.3V @10mA.
You already have double checked parts values and parts orientation?
Power down, disconnect the turbo board, temporary remove the sidechain VCA, TL074 and TL072 on main pcb, power up and check for correct +/-12V voltages, else replace the broken 78L12 or 79L12 regulator.
Power down and put the chips back in one by one. Power up and measure rail voltages again after each chip. If a rail now drops in voltage, the last chip you put back in is probably broken. Now reconnect the turbo board as described by Expat Audio.

Thanks for the tips harpo! gonna try it this morning. The meter is LED by behringer . connected on the control pcb indeed.

might be a stupid thing but the 0V line to the pcb is the same as earth (chassis)? my transformer has no 0V line so i connected 15/15V and 0 From ground. is that okay?
I'm measuring 12v at 7815 and 9 at 7915 with disconnected circuits. im getting confused!

 

[onlymeeee]

my transformer has no 0V line so i connected 15/15V and 0 From ground. is that okay?

Can you post a datasheet?

http://www.diyfactory.com/data/transformer_connections.gif  (centre tap setup is what you need) 

Probably wise to post what traffo you have, and how you're setting it up

 

[pietro_moog]

hi guys. my gssl is making me mad.
today i heard a very big noise from the Left channel.
i checked every pin of every IC and everything was fine, except there was 12v on pin 7 and pin 1 of the left 5532.
i swapped this with the other balancing out 5532, then with the ones on the SSC board.
every IC is fine.

i don't understand..
i used for a week without any problem..
i powered it on/off several times, and the problem is persistent.

thanks guys

 

[Harpo]

might be a stupid thing but the 0V line to the pcb is the same as earth (chassis)? my transformer has no 0V line so i connected 15/15V and 0 From ground. is that okay?
I'm measuring 12v at 7815 and 9 at 7915 with disconnected circuits. im getting confused!

I might misread your post, but you seem to have a mains transformer with only a single 15V secondary.
This build calls for either a center tapped 30V secondary transformer, sometimes listed as 15-0-15V, or a transformer with 15V dual secondary windings that can be connected to behave like the center tapped one.
Your chassis/shield is always connected to safety ground that don't need any connection to 0V. If it helps for a better sleep, you can join this 0V with your case/safety ground in exactly one spot, called star ground, so look twice when using metal/conducting pcb standoffs, ... to prevent ground loops.

 

[Harpo]

i checked every pin of every IC and everything was fine, except there was 12v on pin 7 and pin 1 of the left 5532.

The opamp might be running open loop, so check for bad solder at the 15K feedback resistor connection between NE5532 pin6/7. The (-)12V at pin1 is a follow up.

 

[schrobbelbop]

might be a stupid thing but the 0V line to the pcb is the same as earth (chassis)? my transformer has no 0V line so i connected 15/15V and 0 From ground. is that okay?
I'm measuring 12v at 7815 and 9 at 7915 with disconnected circuits. im getting confused!

I might misread your post, but you seem to have a mains transformer with only a single 15V secondary.
This build calls for either a center tapped 30V secondary transformer, sometimes listed as 15-0-15V, or a transformer with 15V dual secondary windings that can be connected to behave like the center tapped one.
Your chassis/shield is always connected to safety ground that don't need any connection to 0V. If it helps for a better sleep, you can join this 0V with your case/safety ground in exactly one spot, called star ground, so look twice when using metal/conducting pcb standoffs, ... to prevent ground loops.

europe.origin.electrocomponents.com/webdocs/0da0/0900766b80da0cc3.pdf

is my transformer I've now used Vsec/0v connection and ground for 0 on the pcb.
It is a dual secondary winding.

 

[Harpo]

...so i connected 15/15V and 0 From ground...

edit: http://www.europe.origin.electrocomponents.com/webdocs/0da0/0900766b80da0cc3.pdf
is my transformer I've now used Vsec/0v connection and ground for 0 on the pcb.
It is a dual secondary winding.

Tie black and yellow secondary wires together (AFTER making sure, the hard to see isolation paint is scrapped off the transformers lead ends ) and take this junction to the center pin on the pcb transformer connection for your 0V. Red wire goes in one of the outer AC holes, orange wire in the remaining outer AC pcb connection, so all 3 holes on pcb are wired.
BTW adding a location to your profile might help to better help you as this is a intercontinental forum.

 

[Autophase]

WOW,
Just finished my GSSL and it works perfectly. The bass of a mix i ran through it just sounds nicer. I love it!
I'm so surprised, I started one a few months back but it had so many problems and my soldering wasnt all that, so I started from scratch, i was expecting a few small problems but nothing, it seems to work perfectly
Thanks so much to everyone in here who gave me advice over the months, and to everyone who made this project possible.

 

[gyraf]

..please specify what you mean by SL911..??

Solid State Logic 9000 series in the SL911 Channel Strip

.. this thread is about the GSSL-clone...?!?

Jakob E.

 

[ummmdan1]

Hi Everyone,

Just a quick question, I saw someone ask a similar one a while back, but as a bit of a newbie I think I need a few more details!
I want to add a jewell type pilot light to my Gssl as the power on indicator, and have a 6.3v one similar to the kind you'd find on a fender amp.
where would be the best place in the circuit to connect this, and what resistors would I need to use (depending on where I connect it) if you see what I mean! I have a 25VA toroidal transformer.
I have read in a different thread that you could used an LED in the jewell lens instead of the pilot light to lower the power consumption, would this be a better idea? if so what type of LED would be best?

Thanks  so much

dan

 

[pietro_moog]

hi guys.
i'm going crazy over here.
funny stuff:
    -i have a 2x15v toroid, and the voltage out of my CRC board is -18.7v and +19.9v. how is that possible?
-sometimes my +15v regulated power rail disappear. it becomes something like 0.11v on the multimeter.
sometimes is back. i don't understand why. (does the 7815 go crazy when it's supplied with 20v?)
    -i have +10.5 and -10.5 on pin 2 and 6 of an output 5532 and +12 and -12 on pin 2 and 6 of the other.
      i've read the schematics, i checked with the multimeter and i have 15k resistance between pin 6 and 7 on both 5532 and
      10k resistance between pin 6 and 2 on both ICs.
 
i'm going crazy.

 

[pietro_moog]

so, i founded a ground error i made yesterday, that could explain something

now +15v power rail is here, and stable.
i swapped VCAs with the ones in the sidechain circuits and the 10/12v on the 5532 are gone ( at least for now.., i'll check the sound
in bypass tomorrow)
is it possible that a ground problem burned out the VCAs, because it seems now..

 

[regularjohn]

Hi Everyone,

Just a quick question, I saw someone ask a similar one a while back, but as a bit of a newbie I think I need a few more details!
I want to add a jewell type pilot light to my Gssl as the power on indicator, and have a 6.3v one similar to the kind you'd find on a fender amp.
where would be the best place in the circuit to connect this, and what resistors would I need to use (depending on where I connect it) if you see what I mean! I have a 25VA toroidal transformer.

Incandescent lamps should be run directly from the power trafo secondary.  I'd use a 2W resistor at least.  To figure out the value, use ohm's law.