Author Topic: Improve your GSSL... for free! (Read 8504 times)

audiophreak · « **Reply #20 on:** December 25, 2009, 06:48:56 PM »

Hi,
   I'm using a DPDT toggle for " Comp. In / Out " instead of a rotary switch, its just what I happen to have,

  quote from SSLtech : On the component overlay (second page) two wires going to the "bypass switch" are marked "Defeat makeup when out". One connects to Pole 'A', and the second connects to contact A2.

Firstly, REVERSE these two wires. -If you (as I've done) noticed that it's just a simple "make" connection and possibly just connected them in no particular order, you need to make sure that the wire at the board end which is physocally CLOSEST to the 750K resistorneeds to be connected to the POLE (common contact) of the switch, and the other wire to the second contact.

Now, finally solder a wire to GROUND from the other contact "A1". -There's already a handy ground available at contact 1 of pole 'C' if you need it... ("C1" on the rotary switch as shown).

   ... so I would connect the " Com " to the Com. or middle contact on the switch, then the " On " to one of the other contacts, and the " Off " to the other. Is this correct ?, and do I still need to connect a " Ground wire " to the " Off" contact ?

EDIT : - I just had a DUhhhh moment -

- so do I just solder a bridge for the " Defeat Gain " or do I need to connect the " A pole and A1 " to the DPDT switch ?

Thanks, sorry for the Newb stuf..

Thanks,
Chip

audiophreak · « **Reply #21 on:** December 25, 2009, 08:35:57 PM »

I really do apologies, I need to think more before taking up space here..

is this the correct wiring for a DPDT toggle for GSSL bypass ?

Harpo · « **Reply #22 on:** December 25, 2009, 09:29:05 PM »

Yes.
Your 'CLOSEST to the 750K resistor' pole connection, trace going to 'E' on the molex-terminal,
the 'A2' pin of your switch drawing (might better be relabled 'A'), going to the wiper of the Makeup pot,
'Off' and 'Ground' of your switch drawing connect to the same 0V rail. Just link both pins at the switch and connect with one wire to 'OFF' on pcb for easier assembly.

audiophreak · « **Reply #23 on:** December 25, 2009, 10:24:53 PM »

Thanks Harpo !

Your help is most appreciated.

EDIT: - on closer inspection, the "A" is the pole of the rotary switch, so I think the " other " would be " A2 " as in the GSSL PDF...yes...? I also re-labeled the graphic in my previous post to try to be as clear as your description.

Harpo · « **Reply #24 on:** December 25, 2009, 11:59:26 PM »

Quote from: audiophreak on December 25, 2009, 10:24:53 PM

EDIT: - on closer inspection, the "A" is the pole of the rotary switch, so I think the " other " would be " A2 " as in the GSSL PDF...yes...? I also re-labeled the graphic in my previous post to try to be as clear as your description.

>.. the "A" was the pole of the rotary/DPDT switch - before this mod.
Whatever you like to call these pins/poles, just reverse both wires connecting to lorlin A/A2 from Jakobs schematic, otherwise the makeup pot dialed cw will shunt the +12V rail to 0V. Keith already explained it perfectly clear.

audiophreak · « **Reply #25 on:** December 26, 2009, 12:06:11 AM »

Yes..I think I got it now, if my graphic is confusing, I'll remove it, I don't want to post false information, and thanks again for your patients.

livingnote · « **Reply #26 on:** December 28, 2009, 01:35:46 AM »

Aha? So it's the CV opamp's inverting input to ground it is after the resistor? Kinda getting
my head not quite wrapped around it though - like, does some stray voltage impress itself
on the timing salad before it when the 620k is just dangling in midair like that and that sends
some weird fixed CV to the VCAs?

*scritchscratch*

SSLtech · « **Reply #27 on:** December 28, 2009, 04:11:18 PM »

Timing salad?

Instead of shorting the input to ground and 'killing' it, it just opens the input, but there's a lot of copling between it and the other lines running to and form the main board, running through the ribbon cable. -In among it all, there's rectification at the detector, and the 'spikes' tend to couple into the (VERY high impedance) input.

So you kill the input by shorting it to ground, and all is well again.

Keith

idylldon · « **Reply #28 on:** December 28, 2009, 09:25:44 PM »

Quote from: SSLtech on June 22, 2009, 11:46:23 AM

one of which -while not yet ready for announcement (a couple more weeks, we expect)- should significantly improve the performance. -As with the 'turbo', it's designed to be easily retrofittable to any existing GSSL, or incorporated into a new build.

Did I miss this? Is it in a new thread?

Cheers,
--
Don

livingnote · « **Reply #29 on:** December 30, 2009, 03:05:56 AM »

Ah...so, here I see CV to SC which lands in the -12v via some
resistors, and then CV to VCA...are they the culprits?

SSLtech · « **Reply #30 on:** December 30, 2009, 09:42:16 AM »

Quote from: idylldon

Did I miss this? Is it in a new thread?

It's the C/R/C. I just installed three new mastering suites, and hooked my current GSSL test mule into one outboard matrix for listening/evaluation.

The bench figures are about 17dB improvement in the noise floor, but that's just numbers, I wanted to HEAR it...

The outboard matrix in this particular room comprises:
1x Maselec MPL-2 (limiter/De-Esser)
1x GML 9500 Mastering Equalizer (with SEPARATE outboard PSU's for each channel... ludicrously obsessive!)
1x Tube-Tech SMC-2B (multiband compressor/limiter)
1x Manley Masive Passive

Listening tests gave the following result:

The noisiest item in the chain is the Tube-Tech.
The Second nosiest item in the chain is the GML.
The remaining items appear to be all more-or-less equally quiet: they are the Maselec, the Manley and the GSSL.

Without the CRC (I made it 'patchable'), the GSSL was the LOUDEST item in the chain.

Quote from: livingnote

Ah...so, here I see CV to SC which lands in the -12v via some resistors, and then CV to VCA...are they the culprits?

I don't think that I understand the question..? Are you asking about which signals crosstalk TO the sidechain CV?

If so, I think it's the lines which go to and from the ratio network, which contain a 'chopped' and 'brutalized' signal, since it's right in the middle of being rectified, and a long way before being smoothed. -And I suspect that they are capacitively-coupled (which means that only the 'sharp transitions' are coupled) into the (very high-Z) input...

Thus the best way to stop it 'spilling' is to make the input look at ground, and stop 'sniffing the air' for interesting-looking waveforms...

Keith

Keith

mikeyB · « **Reply #31 on:** December 30, 2009, 10:33:41 AM »

Quote from: SSLtech on December 30, 2009, 09:42:16 AM

Quote from: idylldon
Did I miss this? Is it in a new thread?

It's the C/R/C.

Keith

Keith

What IS this mod - am i right in thinking this is a power supply c-r-c filter? I've searched and searched on all ssl related threads and just cannot find the relevant information. Can anybody advise on this, please?

bassculture · « **Reply #32 on:** December 30, 2009, 02:27:28 PM »

also, any info on the tube-o-ed GSSL ?

a simple tube stage would be nice...

jdbakker · « **Reply #33 on:** December 30, 2009, 03:15:11 PM »

Quote from: mikeyB on December 30, 2009, 10:33:41 AM

What IS this mod - am i right in thinking this is a power supply c-r-c filter? I've searched and searched on all ssl related threads and just cannot find the relevant information. Can anybody advise on this, please?

http://www.groupdiy.com/index.php?topic=35641.0
http://www.groupdiy.com/index.php?topic=30615.0
http://www.groupdiy.com/index.php?topic=36883.0
http://www.groupdiy.com/index.php?topic=35660.0

JD 'not affiliated' B.

mikeyB · « **Reply #34 on:** December 31, 2009, 08:16:10 PM »

Quote from: jdbakker on December 30, 2009, 03:15:11 PM

Quote from: mikeyB on December 30, 2009, 10:33:41 AM
What IS this mod - am i right in thinking this is a power supply c-r-c filter? I've searched and searched on all ssl related threads and just cannot find the relevant information. Can anybody advise on this, please?

http://www.groupdiy.com/index.php?topic=35641.0
http://www.groupdiy.com/index.php?topic=30615.0
http://www.groupdiy.com/index.php?topic=36883.0
http://www.groupdiy.com/index.php?topic=35660.0

JD 'not affiliated' B.

Thankyou for pointing me in the right direction. After all that - I had a separate PCB for the PSU, so line noise has not been an issue in my build!!
Good to know though - i'm due to build another soon!!
Thanks once again JD

ptron · « **Reply #35 on:** January 22, 2011, 11:28:20 PM »

im just thinking if i got the SSC, turbo and CRC boards, my bypass switch is coming from the SSC board ... is there a need / way of doing this mod???

thanks keef!

canidoit · « **Reply #36 on:** January 23, 2011, 12:08:17 AM »

Keith is the bypass distortion a musical distortion? Like some people use the API 2500 without compression just so that it adds mojo to audio?

sheadstedford · « **Reply #37 on:** January 23, 2011, 03:24:59 AM »

Quote from: bassculture on December 30, 2009, 02:27:28 PM

also, any info on the tube-o-ed GSSL ?

a simple tube stage would be nice...

What he said!
Just got a simple srpp and might put it in the output stage....any thoughts

jdbakker · « **Reply #38 on:** January 25, 2011, 06:24:05 AM »

Quote from: sheadstedford on January 23, 2011, 03:24:59 AM

Quote from: bassculture on December 30, 2009, 02:27:28 PM
also, any info on the tube-o-ed GSSL ?

a simple tube stage would be nice...

What he said!

Read the entire thread.

It was a joke, based on a typo Keith made in Reply #7. To spell it out: he wrote tuboed instead of turboed.

JDB.

ptron · « **Reply #39 on:** March 06, 2011, 01:41:03 PM »

bump bump

.. sorry to ask same thing again but tbh i dont notice any distortion while on bypass... maybe its my ears or my room or i dont know how it sounds... but is this mod going to help if im using the SSC board`s "sidechain in/out" and not the regular control board`s

News:

Author Topic: Improve your GSSL... for free! (Read 8504 times)