GSSL HELP THREAD!!!

[regularjohn]

Id like to see a fuzzy photo if you have one ;D.

Haha, touche`!  ;D

It's just a meter that I picked off ebay.  There's loads of great vintage meters that'll work for gssl's that go for under $10. 
Great place for knobs too!

I put psu bypass caps on everythign I build, and I've also been retrofitting all my non diy gear with em as well.  It really does make a noticeable difference.

 

[Autophase]

Sorry I have anohter CAP question.
On the BOM it states 50v rated for the polyester caps. Can I use 150V or 250V rated ones instead if all the other specs are the same? The V rating is just how much juice it can handle surely?

 

[onlymeeee]

Providing they'll fit, sure. 
Yes, it's a max voltage rating as you thought.

 

[Chrome Heart]

If its in a 1RU you might have to fold them in half. 

 

[Autophase]

If its in a 1RU you might have to fold them in half. 

im thinking of something a bit different for the case.

 

[hotbaby]

hi,
my gssl needs to power on/off several times till it works.
It lies in my room just some month and i can not find the thread where exactly this problem
was discussed.
Did someone figure out how i can make this unit work?

My second gssl works just fine. I gone for the resistor mod and trim pot for the "A" THAT. maybe the power is different to this THAT that this unit works better than my THAT "lb" unit without mods...
both are with turbo board.
but maybe it is a bad rectiver or something with the power preparation...

thanks for any help that i can put the gssl back to the place where it is destined for

 

[MartyMart]

Sorry I have anohter CAP question.
On the BOM it states 50v rated for the polyester caps. Can I use 150V or 250V rated ones instead if all the other specs are the same? The V rating is just how much juice it can handle surely?

Be aware that the GSSL is a tight layout so anything but VERY small caps in all the 100n positions will
be a problem.
50v and 63v small box caps with a 5mm spacing are fine, bigger stuff will be "up against" other components
and will hamper your fitting other parts.
I use 63v poly caps from AVX and MKT and they are the perfect size, 5 x 5 mm and 2mm thick.

Marty.

 

[gyraf]

hi,
my gssl needs to power on/off several times till it works.

Early in this thread we warned against some specific brand voltage regulators that tended to "latch up" like that.

I'd say try replacing all your voltage regulators  (7815-7915-78L12-79L12) with a different brand - that should do it.

Or more sophisticated: try measuring your power rails at a "failed" power-up to see what voltage is missing - and replace that regulator.

Jakob E.

 

[hotbaby]

Jakob,
Thank you very much.
I will do so.

thanks.

aaron

 

[Autophase]

Hi,
Another question from me.
Now I have searched for this and found some info, but I just need to be 110% sure.
So I went for the THAT2180 not the 2181.
So just to clarift, i dont need to add the trim pot to the board? do i need to put a jumper across it?
Also I hear I should bend back pin 4 from all 3 2180's, is the correct.
again sorry for the question im sure the answers are here to, but I jsut dont want to damage the VCA's
Thanks for your help.

 

[radiance]

So just to clarift, i dont need to add the trim pot to the board? do i need to put a jumper across it?
Also I hear I should bend back pin 4 from all 3 2180's, is the correct.

No trimmer needed...no need to bend pin 4 IF you remove the 68R, 10K and 1M resistors which are located in the area between the trimmer and pin 4. If you take a closer look at the pcb > follow the traces which are connected to pin 4 , you will see which resistors.
also, no jumpers ....

Or, leave everything in and DO bend pin 4....your choice...

 

[Autophase]

So just to clarift, i dont need to add the trim pot to the board? do i need to put a jumper across it?
Also I hear I should bend back pin 4 from all 3 2180's, is the correct.

No trimmer needed...no need to bend pin 4 IF you remove the 68R, 10K and 1M resistors which are located in the area between the trimmer and pin 4. If you take a closer look at the pcb > follow the traces which are connected to pin 4 , you will see which resistors.
also, no jumpers ....

Or, leave everything in and DO bend pin 4....your choice...

Fantastic, thanks roland.
Tranny literally just arrived.
woo hoo.

 

[Chrome Heart]

So just to clarift, i dont need to add the trim pot to the board? do i need to put a jumper across it?
Also I hear I should bend back pin 4 from all 3 2180's, is the correct.

No trimmer needed...no need to bend pin 4 IF you remove the 68R, 10K and 1M resistors which are located in the area between the trimmer and pin 4. If you take a closer look at the pcb > follow the traces which are connected to pin 4 , you will see which resistors.
also, no jumpers ....

Or, leave everything in and DO bend pin 4....your choice...

Heres a helpful link (posted many times here) by Matt Fischer regarding the THAT VCA's in the GSSL.
http://diy.fischerworks.com/gssl_vca.shtml

 

[Autophase]

can i use 2amp diodes instead of 1.5a?

 

[Autophase]

can i use 2amp diodes instead of 1.5a?

also can i get 63v caps instead of 50v?

 

[Harpo]

can i use 2amp diodes instead of 1.5a?

also can i get 63v caps instead of 50v?

All (6) single diodes are 1N4148 (or 1N914 or 1N4448 for the unlikely case you can't source these).
The only higher rated diodes are inside the bridge rectifier. If this rectifier fits the pcb, a 2A part with at least same voltage rating is an improvement to a 1.5A part.
You can use 63V rated caps instead of 50V rated parts, just look for outer dimensions and pin spacing. (35V rated caps are enough for all caps in the gssl, in most spots even less will do)

Adding a location to your profile might help to better help you.

 

[Autophase]

can i use 2amp diodes instead of 1.5a?

also can i get 63v caps instead of 50v?

All (6) single diodes are 1N4148 (or 1N914 or 1N4448 for the unlikely case you can't source these).
The only higher rated diodes are inside the bridge rectifier. If this rectifier fits the pcb, a 2A part with at least same voltage rating is an improvement to a 1.5A part.
You can use 63V rated caps instead of 50V rated parts, just look for outer dimensions and pin spacing. (35V rated caps are enough for all caps in the gssl, in most spots even less will do)

Adding a location to your profile might help to better help you.

Thank you very much for the advice, really appreciate everyones help.
Should have everything i need by next week then i can get on with soldering.

 

[Hammond]

What's the best substitute for the output 5532's?
Thanks

 

[regularjohn]

What's the best substitute for the output 5532's?
Thanks

There's really not a whole lot to be gained by replacing the 5532's with something "better".  I mean you can go ahead and spend 4 or 5 times as much on something else, but the difference to me in this compressor design isn't worth it.  It's much more worth the effort to get 2181 VCA's and trim and calibrate them properly.  And if you're looking for serious mojo, add some lundahl LL5402's on the output.

But if you really want to spend more money, check out the LME49860.  They're very smooth and even across the frequency spectrum.  You'll need to add some decoupling caps to the back of the pcb though from both power rails to ground. 
I would not recommend the OPA2604, which for some reason people always rave about, but to me sounds awful and fatiguing to the ears.

 

[radiance]

Yes, stick with the 5532's....find yourself some Philips or Signetics and your golden...