GSSL HELP THREAD!!!

[geetar_king]

I'd check continuity on the control board for that attack switch. 

Check continuity between point labelled 'A' and each of the points 1 thru 6.

 

[bassculture]

thanks for answering !

but maybe we misanderstood.

i've no problem with my time constant - everything is alright.

i thought that 6th position thing was a new mod / feature to the comp.

now i suppose it's not...

 

[trancedental]

Should check the other 12V regulators so you can rule those out too.

OK I'm going to get some new regulators Monday, 7915 / 7815 15V & 79L12 / 78L12 12V & was wondering if I should replace any of the connected components, resistors & caps?

Or just replace 7915/7815's & take some new readings?

???I've got some readings of around 5.5VDC on the TL074 & on the VCA sidechain sockets but thats about all I can find worth mentioning!

Cheers for the help!

 

[guavatone]

Gyraf has the Voltage rails labeled on his PCB and project files.  I would check those numbers before putting opamps in.  This is easy if you have IC sockets, and PITA if you don't.  If your numbers or way off you may mess up some parts I think.  I had some fault in my power rails and was afraid of blowing one of those pricey THAT chips, but it ended up fine.

Have you checked for Soldering errors?  I had some issues with pads that were very close and a small amount of solder mad a bridge between pads that shouldn't have been connected.

 

[trancedental]

I would check those numbers before putting opamps in. 

Right I've replaced the 7915/7815 the pair of 22uf adjacent caps, the 79L12/78L12 & & .1uf adjacent cap. Nothing installed apart from the TL074 Control Board & XLR i/o's not connected.

I've got 14.5 & -8.5DC readings on the jumper rails  near the VCA's now? ??? Mains 244VAC

I'm assuming that there's still some problems, looking at the schematic I'm thinking of replacing the 10R's & 100uf caps ? :

Thanks JK

 

[geetar_king]

Hows the board grounded? 

I know I was getting funny readings when it wasnt grounded right.  If your XLRS aren't connected like you said, place your one multimeter probe at the ground pin on the output header and double check your rails.

 

[trancedental]

Hows the board grounded? 

I've done a star ground as recomended earlier in this (long............) thread. Same as used for valve guitar amps so even I understand the idea! ???

Just plugged the XLR headers in & have 14.9 -15.8VDC readings now with just the TL074 installed. (Control PCB unconnected)

Is it OK to put the opamps in & start taking some readings? I need to work out the pinout numbers of these opamps first!

I need to get some sleep before I start though:'(

Cheers JK

 

[geetar_king]

Sounds like grounding coulda been the issue there. Okay, well your readings are close. Usually would like to see closer to 15 than that.  What's your multimeter like?  Might be out a bit on the readings.

I'd say you sound okay to pop in everything. Hookup the control board first though. And then power up and check your voltage readings again.  Also check pin 4 and 11 on the TL074 socket, and pins 4 and 8 on the TL072 socket. Should be seeing +12 and -12 Vdc

Pin layouts on the TL072 and TL074 are below.

 

[trancedental]

Cheers Guitar King ;D

Latest readings with Control PCB & XLR's connected with just TL074 / TL072 installed.

VAC 238

14.9 / -15.2

TL074 Pin 11 -12.2 Pin 4 12.0

TL072 Pin  8 -12.0  Pin 4 -12.2

Not surprised with voltage readings that are slightly out, had this with valve guitar amps as well, many PT's sold in UK are 230VAC Euro rated when UK / IRL run on 240, my mains often goes over 245 or more : 4.5% can make a difference!

Here's the multimeter I'm using http://www.amazon.co.uk/Rapitest-Dm-25-Digital-MultimETer/dp/B0001P0JZK

EDIT Readings with everything on board & connected apart from VCA's

15.03 / -14.82

TL074 Pins 4 / 11      -12.01  / 12.2

TL072 Pins 4 / 8        -12.08 / 12.2

NE34's  Pins 4 / 8        -14.8 / 15.00 Beside VCA's

NE34's  Pins 4 / 7        -14.8 / 15.01 XLR ins

NE32's Pins  4 / 8        -14.8 / 15.01 XLR outs

Does that seem OK? ???

 

[geetar_king]

Sounds right on the money trancedental. 

 

[feza]

Okay, so I'm still troubleshooting my GSSL. Problem again is no compression. Makeup gain is working fine, and unit passes clean audio.

I was reading a post about the same problem occuring on a bad connection on the bypass switch.  I just wanted to double check that my bypass wiring is correct, so I can rule that out.

I'm using a 3PDT switch. First set of poles for the compression "On, Com, Off" as on the PCB layout.  Other set of poles for defeating Makeup Gain when out. Last set of poles for the LED indicator.

I have posted a diagram of my wiring setup, added on to Gyraf's control board layout.  Is this right? I think it is, makeup works fine. Are my compression poles backwards maybe?

Hey,

I'm having a hard time understanding the logic behind the toggle switches. Having bought a SPST and a 3PDT switch gives me more reason to do research. I've quoted Geetar's solution and it is exactly what I want as well. But there are a lot of 3PDT switches. What I have is an ON-OFF-ON variant, will it work as pictured?

What I prefer is some good directions of the toggle switch's logic so that research can be done without depending for answers here. There are things on google, maybe needs more patience from me.

Thanks! Highly appreciated. 

Found some usefull sites, very anyones interest :

http://www.geofex.com/ left upper corner named 'the technology of the bypass switch'
http://www.1728.com/project2.htm more basic info (with enough pictures  )

 

[geetar_king]

The On-Off-On has three positions. The difference with an ON-ON, is that there is no middle or off position, it only has two positions on the toggle. So it's either ON one way, or ON the other way.

I think the On-Off-On will work fine, and should be wired the same, but you will just have that middle position where the compressor isn't IN or in Bypass mode.

Referring to my diagram, switch ON one way will connect the top two pairs. OFF will connect nothing. And ON the other way will connect the bottom two pairs of poles.

Cheers

 

[feza]

Thanks for your thorough reply!

I've ordered an ON-ON 3PDT switch today with some knobs as well. Just want the same toggle configuration what you have. These are the knobs with the Purusha case :

http://www.banzaieffects.com/product.php?productid=17455

Yeah man, almost done. 

 

[bassculture]

question to the SSL specialists :

yesterday i welcome a sound engeneer at a venue.
he has a GSSL he bought a few day ago from a german guy.

he has the sidechain w/ THR**ST on it, but didn't know what it was for.
so i showed him - he was very pleased.

but he also has a knob with a "crush" label, with 6 position (off - C1 - C2.... C5)
we didn't have time to open the compressor and look what's inside.
but the result seemed to be more and more compression from C1 to C5 position


i've almost finished two working GSSL with sidechain & turbo.

i haven't managed to find any usefull info on this "crush" mod...


and if someone know aboout this "crush" thing, PLEASE TELL ME !!!!

 

[trancedental]

OK I finally got some compression! : Sometimes cuts out with some distortion but I'll further check the Control PCB later tomorrow

I've got the THAT 2180LC's installed as per http://diy.fischerworks.com/gssl_vca.shtml Just wondering if I should cut or bend the pin 4 as some builders have suggested in other threads?

Suppose it won't do me no harm to build another as I've got everything but the case / VCA's??? And I can test the Control PCB by swapping them over!!!

Cheers & thanks to all on here for the help!

 

[dalmaproductions]

Hi everyone,
1st post! Just finished building my first project(gssl), and everything works Ok, when the unit is passing sound to the outputs. Voltages are good, controls all work.

The problem is, sometimes, on startup, It will not pass sound, and I need to restart it a couple of times without signal to the input, or wait and restart, to get it working normally.

My friends gssl does exactly the same thing. Is this a known issue? What could be the problem?  ???
Thanks!

Miguel

 

[janczmok]

Hi there,

some easy questions ( as i found some time to work on my G-SSL again):

a) I use a toroid transformer (220V primary, 2 x 16V secondary); do i connect it to the
    'external transformer' or to the output on the board for 2 x 15V (where the on-board
    transformer should reside). I assume the last one.
b) Light for the Meter, where do i connect it ?

thanks for info. i surely might have some more questions when i finished cabling.

 

[gyraf]

Hi everyone,
1st post! Just finished building my first project(gssl), and everything works Ok, when the unit is passing sound to the outputs. Voltages are good, controls all work.

The problem is, sometimes, on startup, It will not pass sound, and I need to restart it a couple of times without signal to the input, or wait and restart, to get it working normally.

My friends gssl does exactly the same thing. Is this a known issue? What could be the problem?  ???
Thanks!

Miguel

We earlier warned agaianst voltage regulators named TS7815 (and possibly TS7915) - as these seems to be prone to "hang" at power-up.

Check which supply voltage it is that goes missing at no-start condition, and change this regulator to a different type.

Jakob E.

 

[geetar_king]

a) I use a toroid transformer (220V primary, 2 x 16V secondary); do i connect it to the
    'external transformer' or to the output on the board for 2 x 15V (where the on-board
    transformer should reside). I assume the last one.

Should be okay to connect at the 3-pin header at the corner of the board. Also make sure your rectifier is in the corner as well and not at mid-board.

b) Light for the Meter, where do i connect it ?

Depends on what kind of light you have for the meter - LED?  You can take power off of the corner of the control board for an LED. I think there's a 1K limiting resistor in the corner and you can directly hook up an LED or two here. Depends on if you are using a light for any other indicators. I have taken power off of there for a few LEDs and it works well. You could also change the resistor depending on your LED configuration.  A separate power supply board is another option.

 

[janczmok]

Stupid question then regarding both connectors: What is the difference ?