GSSL HELP THREAD!!!

[regularjohn]

Hello all,

I really want a big fat meter like regularjohns build! I'm putting mine in a 2U case.

I'm really new at this, will this meter work?

http://www.mouser.com/ProductDetail/Simpson/04610/?qs=JX1bQUixcTnt%2fTjEkNc3Ig%3d%3d

Is there anything I need to do to make certain meters work?

Thanks for your help!

That meter will work, but holy crap that's expensive!!!  Get em off ebay.  I never pay more than $20 for a meter.
Also, don't expect the meter to light up blue!  I drill holes in the meter casing and install LED's myself.
What you will need to do, is install a 5K trimpot in place of the meter resistor.  
Then you can calibrate the meter so that it's perfectly accurate.

 

[Autophase]

Hi,
I'm having trouble finding the 0.47u and 6.8u tantalum caps in 50V. The suplier I am using for nearly all the other comonents has these caps in 35V, will this be sufficient?

 

[Harpo]

Hi,
I'm having trouble finding the 0.47u and 6.8u tantalum caps in 50V. The suplier I am using for nearly all the other comonents has these caps in 35V, will this be sufficient?

yes. They won't see more voltage than the supply feeding the opamp (+/-12V in this spot).

 

[Autophase]

Hi,
I'm having trouble finding the 0.47u and 6.8u tantalum caps in 50V. The suplier I am using for nearly all the other comonents has these caps in 35V, will this be sufficient?

yes. They won't see more voltage than the supply feeding the opamp (+/-12V in this spot).

Thats what I assumed, much appreciated.

 

[Autophase]

ok this is probably going to be the most remedial question ever asked on this thread (feel free to laugh)
My Toroidal transformer came the other day, I took the bubblewrap off it, underneath that there is a thin layer of polythene wound around the the transformer, ie through the middle.
now I'm guessing YES, but, am I ok to remove this?

 

[bpucekov]

NO DONT remove this

 

[regularjohn]

ok this is probably going to be the most remedial question ever asked on this thread (feel free to laugh)
My Toroidal transformer came the other day, I took the bubblewrap off it, underneath that there is a thin layer of polythene wound around the the transformer, ie through the middle.
now I'm guessing YES, but, am I ok to remove this?

Absolutely DO NOT remove that.

 

[Autophase]

ok this is probably going to be the most remedial question ever asked on this thread (feel free to laugh)
My Toroidal transformer came the other day, I took the bubblewrap off it, underneath that there is a thin layer of polythene wound around the the transformer, ie through the middle.
now I'm guessing YES, but, am I ok to remove this?

Absolutely DO NOT remove that.

Ha ha, proof there is no such thing as a stupid question.
Thanks guys, much appreciated.

 

[involver]

Hi everyone,

I've finally got my GSSL up and running (only took a year!). It all seems to work OK except for a problem with the threshold that I can't seem to find an answer for.

The useful range of the threshold seems to be in the 1st 1/4 of the threshold pot. When I turn the threshold pot all the way down I hear a small 'click' sound(or possibly an electrical arc) come from it, the power led goes out, and the compressor starts distorting. If I add the 47k resistor to the positive leg of the threshold pot (as shown in the schematic) it will not have the "click"/electrical arc problem but I can only just get the unit to compress a little by playing a very loud signal before running out of headroom.

Any ideas whats going wrong here?
Thanks!

 

[radiance]

Any ideas whats going wrong here?
Thanks!

Probably a short in the control board connection. What voltage do you measure on the three legs of the threshold pot when you put the wiper in the middle? (without the 47K resistor in place)

 

[involver]

Any ideas whats going wrong here?
Thanks!

Probably a short in the control board connection. What voltage do you measure on the three legs of the threshold pot when you put the wiper in the middle? (without the 47K resistor in place)

OK, I worked out what was wrong - I had gat a couple of the wires mixed up on the threshold pot. Now I have a new problem. Everything seems to be working right except the meter moves if I change the threshold level (even if there's no audio input). Off to search for the answer unless anyone knows what to check next!  ???

 

[radiance]

What voltage do you measure on the three legs of the threshold pot when you put the wiper in the middle? (without the 47K resistor in place)

 

[MikeyT1987]

Thanks for your response regularjohn. And thanks for saving me a hundred dollars!!

Does that mean I can use any meter with that 5K trimpot? I found one that has a range of DC 0-300 MA.


Thanks again!!

 

[regularjohn]

Thanks for your response regularjohn. And thanks for saving me a hundred dollars!!
Does that mean I can use any meter with that 5K trimpot? I found one that has a range of DC 0-300 MA.
Thanks again!!

No, the 5K trimpot is for calibrating it so that it accurately displays gain reduction.  It goes in place of the 2K meter resistor.
Most people just pop that 2K resistor in there and don't realize that their gssl meter is probably not accurate.  With a trimpot you can precisely calibrate it by running a test tone into the comp and using a level meter (I use the meters on my 2 track deck) after the comp to see if it's actually reducing the amount of gain that the meter says.

You have to use a meter that has a full scale deflection of 100uA or 1mA.  You can also use values in between the two, for example 200uA or 500uA.  If you use a meter less than 1mA you need a shunt resistor in parallel with the meter.  The value of the shunt is something you kind of need to find experimentally.
You might be able to get away with a meter is high as 2mA, but the circuit is not really designed for a meter larger than 1mA.  A 300mA will certainly not work at all.
The thing about finding meters on ebay is that it's a waiting game.  But well worth the savings.

 

[MikeyT1987]

Wow, thanks for all that information. Is there anything else I should know before buying a meter? So you are saying that if I get a meter that is 1ma that the 5K trimpot would work for calibration.

As well, if I want an LED light, what are the requirements for the LED. And where do you connect the LED in the chain. As you said I will have to drill holes the meter casing.

You're the man regularjohn!

-Mike

 

[regularjohn]

The 5K trimpot will work for calibration for any meter between 100uA and 1mA.  It's just so you can fine tune the resistance value instead of plopping a 2K resistor in there, which may or may not be the exact resistance value you need for accurate metering.  I solder a clipped resistor leg into each solder pad of the meter resistor so that they stick up through the pcb like goalposts.  Then - since trimpots have 3 legs - solder the center leg to one of the outer legs, it doesn't matter which one.  Then solder the outer legs of the trimpot to the "goalpost" legs you soldered into the pcb.  Does that make sense?  It's just cause the legs of the trimpot aren't long enough to fit through the pcb in place of a resistor.

I pull the LED from the LED solder pads on the gssl daughterboard.  I just "extend" the LED legs with wires.

If you buy a meter though, make sure it's not a sealed or ruggedized meter.  As the name suggests, they are sealed.  So you can't open them to install an LED.  It helps if you can view pics of the rear of the meter.  If there are 3 or 4 very small screws in the casing, that likely means that you can open it.  If the back looks like a solid formed piece of metal it's likely a sealed meter.

 

[pkarr]

Hello, I really Need your HELP, Please. I built me my 1st DIY project, The GSSL. I didn't add sidechain or Turbo mod yet, maybe later when it will work because I have big problem with my GSSL. The Ratio, attack and Release don't work... I turn the switches and it doesn't change the sound... Nothing move. The Threshold, bypass and Make up work very well, I hear the changes when I turn them. I controlled all the solders on main and control board, all are Ok, I controlled the connection between Main and Control board, everything is OK too. I haven't bridge on the solders, they don't touch between them, I changed the TL074, Tl072, THat 2180 on sidechain main board, I changed the 2AOP in the output. I tried different Cable for connect it to my Mixer. I really hope you could help me. Thank you very much. Cheers. Alexandre from France

ps: my AOp are 604 and 2604, VCA THAT2180LA

 

[regularjohn]

Hello, I really Need your HELP, Please. I built me my 1st DIY project, The GSSL. I didn't add sidechain or Turbo mod yet, maybe later when it will work because I have big problem with my GSSL. The Ratio, attack and Release don't work... I turn the switches and it doesn't change the sound... Nothing move. The Threshold, bypass and Make up work very well, I hear the changes when I turn them. I controlled all the solders on main and control board, all are Ok, I controlled the connection between Main and Control board, everything is OK too. I haven't bridge on the solders, they don't touch between them, I changed the TL074, Tl072, THat 2180 on sidechain main board, I changed the 2AOP in the output. I tried different Cable for connect it to my Mixer. I really hope you could help me. Thank you very much. Cheers. Alexandre from France

ps: my AOp are 604 and 2604, VCA THAT2180LA

There is a small jumper that must be installed on the "control" pcb right next to where the meter attaches, and it's very easy to miss.  Do you jumper this?

 

[pkarr]

yep, I soldered this jumper on the control PCB. All my Voltages are good. I Tested all the AOP, TL, VCA.....all voltages are good. I have the +15 and -15, +12 and -12. I tested all my solders, everything seem to be ok, I changed the TL074. The problem is I don't hear difference in the sound when I do a short attack and release or a long attack and Release. It's exactly the same sound. I change the ratio and it doesn't work too. I try different levels on the threshold, still the same sound. I hear a difference in the volume sound of course when I turn the threshold and Make up, but no difference in the Compression with Ratio, attack and release. I tried with my DBX 266XL and I hear the difference when I try different Attack, ratio and Release. Not with my GSSL. I changed the THAT 2180 in the sidechain part on the main board. I tested the 10 connectors between Main and COntrol Board, everything is well linked. That's Crazy. Thanks

 

[Autophase]

i think ive ordered something wrong on the rotary switches.
This is what i have
2 of : 3 pole 4 way solder lugs, converted to 2 way (for on off & bypass)
1 of : 2 pole 6 way, converted to 5 way (for release)
1 of : 2 pole 6 way (for attack)

now I have a 2 pole6 way left over, but i see on the control board the ratio as more holes at the centre of the switc, it seems only the centre hole is connected.
Just t clarify,my remaining 2x6 is useless?
What do i need for the ratio?