"Unison Design" GSSL Finished! Pics inside

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ytsestef

Well-known member
Joined
Jul 2, 2009
Messages
192
Location
Athens, Greece
:eek: :eek: FINISHED MY GSSL!!  :eek: :eek:

Here are some pics:  ;D ;D ;D

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I used THAT2180AL08-U for VCAs, Sidechain and Turbo Board.
I did the following mods:

- Removed both 10k resistors from each VCA circuit (that is four resistors)
- Removed 68R resistor from each VCA circuit
- Removed 1M resistor from each VCA circuit
- Removed 47R resistor (pin4) from Sidechain
- Removed 47R resistor (pin4) from Turbo Board.
- Changed 3k9 resistor to 5k1 for each VCA circuit
- Changed the meter resistor from 2k to 4,7k (Behringer meter)
- Did the PSU mod which adds two 100nF/50V caps and a 1N4007 diode underneath the 79L12
- Changed 1000uF/63V caps to 2200uF/63V caps
- Switched 91k and 750k auto-release resistors in Control Board.

Sounds awesome. I want to thank everyone for making this a reality!

One of these days I'll try to post a video describing my powerup problem. I wonder why hasn't anyone answered yet.  ??? Is it that rare?

I also wonder if this will make it in the DIY gallery meta  :p

Anyway,
Cheers

Next project: SSL 9K!

Stefanos.

PS: On the last picture some potatoes can be seen under the table (the photos were taken in the kitchen). They sound very good, too  :p
 
nice! hopefully I'll get to mine soon.. no idea on your power-up probs, did you search through the SSL thread? If you click "print" it brings up the whole thread on one page, making it pretty easy to do keyword searches.
 
Thanks! Of course I did search, but I only found a guy who had that same problem* but he seems to had some specific brand of 7xL12 regulators which the circuit -for whatever reason- doesn't like. But it appears this is not the case with mine. That's why I did the PSU mod and changed the big caps to 2200uF. It did got better (doesn't do it that often) but it persists.

* The problem:
One out of two times the the 12V rail (can't remember whether it is +,- or both) disappears upon startup. The power led doesn't work and the meter shows ~4 dB reduction. When I switch it off the meter needle slams its way to its resting position and the power led blinks. When I switch the unit on again, everything works flawlessly. After the modifications (psu and caps) it happens 1 out of 5 times. Much better, but I think I camouflaged it :-[

okgb said:
the hand labeling looks good  , almost purposeful

thanks a lot, it actually is purposeful!
when I make something I want to keep the costs down (when it comes to looks only), and I want it to look like DIY (but not ugly) because that's what it is!
 
Tha anoikso thread "how many greek are here anyway??!?" sto telos mou fainetai!
Euxaristo poli fileV9977.  ;)

That trafo is very cool indeed, and a piece of cake to wire and mount!

regularjohn said:
I like the hand-labeled front panel!  Reminds me of boutique guitar pedals.  Where'd you get the orange meter?  Very nice!

I got the behringer meter from diypartssupply.com with a white led, took it out and soldered a 12V orange one in its place with such specs so that it would double as a power led.
 
what i meant was , looks like a font
created for a casual look  , not snobby or too overly serious
i couldn't print that nice myself , hope it serves you well
 
ChrioN said:
Sick look! Where did you get the case? Looks really sturdy.
I got the case from a local store in greece, it is cheap as hell (about 20 euros) and it falls far away from sturdy.
It is the wobbliest aluminium I have ever dealt with. At least it looks good and it's easy to drill. ::)

okgb said:
what i meant was , looks like a font
created for a casual look  , not snobby or too overly serious
i couldn't print that nice myself , hope it serves you well

I used a very fine tip and I took it slowly, took me 10 minutes to write so little stuff. With patience anything is possible I guess  :D

Kingston said:
What does that "aarhus" mode do?

It merely disables the turbo board and acts like Jakob's original design. I just used expat audio's terminology ( "Aarhus / Oxford" instead of "Turbo off / Turbo on"). Sounds more funky that way  :)
 
good-looking stuff, enjoy!!  :)


(pantou uparxoun koinezoi kai ellhnes  ;D)
 
Hey, take a listen to the noise level on silence, and let me know if you hear some low-level 100Hz hum.

If you do, let me know... I've just finished another "bolt-on" board to solve the issue, and I'm looking for a guinea-pig to test it.

Installation takes TWO minutes or less, by the way.

Let me know if you're interested.

Keith
 
Nice one, Keith! I think my GSSL fortunately doesn't qualify as a guinea-pig.
I put it through Elemental Audio's IXL plugin and found the following (see attachment)

The gain makeup is turned all the way clockwise, and still about -78 noise floor (it is not scientifically tested, with dummy loads etc) and the frequency response of the noise seems to be 60Hz mains hum with its harmonics and some hiss rather than 100Hz. It can't be heard unless I crank up the volume where the music is VERY LOUD, so I guess it is insignificant / normal  :-\

Correct me if I'm wrong.
What causes the 100Hz hum anyway?
 

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great build!

re your mains hum, you might want to try

1. twisting your AC cabling, in and out of you mains tx

2. use off board Recitifier and smooting caps...there is a drawing some where..this really works...mine was silent after this.

3. also turn your torroid for least amount of hum....ive never got any futher milage with this but worth a try.

cheers
Pete
 
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