GSSL HELP THREAD!!!

[monobass]

This weekend I fired up & tested my gssl  for the first time everything worked directly and the unit sounds very nice
I first builded a standard GSSL without modPCBs (SSC, turbo & CrC) so I certainly know I have a working one before I start with the mods ..

Hey Arnold this is my plan too, what current is your power transformer rated at? I'm wondering if 0.5A is enough to power that lot.
I'm also considering adding the Expat Audio CRC board. Maybe even a second SSC

 

[kante1603]

Thanks Udo... I'm guessing they are around 20mm diameter?

Hi,
I'm not sure where you are located,but here's a german site,looks like the 21mm small type.
I always buy the knobs directly from them.

http://www.sibalco.de/index.php/produkte/drehknoepfe/spannzangenknoepfe.html

Hope to have helped,

Udo.

 

[dennisp]

See if you get a -12V reading now. If yes, swap the resistor with the cheapest opamps (TL072/074) and measure again...
hope this helps...

Hi Mattnezz,

I really appreciate your help  8)

I tried your suggestion but the only result was that Voltage dropped to 23.3V not much, but it made me investigate further.

If I measure between 0 and the 7915 an 7815 Regulators, I get the following readings:
-14.8, -23.3, +14.8, +23.3

My reasoning on this would be that, since +12V is fine, something is missing or wrong in the path towards the -12V.

Any ideas?

Positive regards
Dennis

 

[Harpo]

All voltages except -12V are fine. The -12V measures -23.6V and I have no idea what could be wrong.

I'd read it as a short between pins 2/3 of the 79L12 (solder blob or pcb traces shorted). Use magnifying glas to spot it.

 

[dennisp]

All voltages except -12V are fine. The -12V measures -23.6V and I have no idea what could be wrong.

I'd read it as a short between pins 2/3 of the 79L12 (solder blob or pcb traces shorted). Use magnifying glas to spot it.

I hope that I was measuring off the wrong point and I think it's quite fine.
I was reading off at the solder island just below where the text says -12V, but actually I think that the -12V is referring to the pcb trace next to the text saying -12V, because when I measure at one of the solder islands on that lane it measure -11.8V

So I hope I'm all good and this will help someone else (please tell me if I'm right or wrong).

Positive regards,
Dennis

 

[Mattnezz]

I'm not very familiar with the boards because I etch my own and have no silkscreen.
I think it's good practice to always measure voltages at the IC pins.

 

[dennisp]

At the top IC pins for the TL074 it does read -11.89 in one corner and +11.88 in the diagonal opposite corner, so I interpret that as I'm good to go and can assemble the rest and finally test it  8)

Thanx for helping out!

Positive regards
Dennis

 

[dirtyhanfri]

Hi

I'm driving mad with the 2181C calibration

Using this one, (2181C) should I jumper the 10K resistor on the VCAs, etc. as stated on this link? (http://homepage.mac.com/marten.thielges/gssl/calibration.html or this one http://diy.fischerworks.com/gssl_vca.shtml)

I tried it yesterday, and the unit was working faulty, so I went back to the "original" resistor values, and then realised the wire going from the main pcb to the control board was faulty...

Building was smooth, but getting this thing to work propperly is being hard, anyway, I like what I can hear, so I think it will be worth...

 

[Harpo]

Using this one, (2181C) should I jumper the 10K resistor on the VCAs, etc. as stated on this link? (http://homepage.mac.com/marten.thielges/gssl/calibration.html or this one http://diy.fischerworks.com/gssl_vca.shtml)

??? Both advises say the same for the different 10K resistors in question.
Remove the 10K between all VCAs pins 3/5,
jumper/short out the 10K connecting between VCAs pin4 and the THD-trimmer for the audio-VCAs,
remove the 68Rs between VCAs pin4 and gnd,
substitute 130Ks for your 'C'-type VCAs instead of the 1Ms between the now jumpered 10Ks and the THD-trimmers for the audio-VCAs.
If you jumpered the 10Ks between pins 3/5, you'd need a little luck that your VCAs survived.

 

[dirtyhanfri]

If you jumpered the 10Ks between pins 3/5, you'd need a little luck that your VCAs survived.

I didn't short them, I shorted the right 10k, but thanks for the advice.

Tomorrow I'll go back on the unit, make this changes and then look if everything is ok. Today I reworked the wire from main pcb to control board and some issues are gone, but others are coming, my meter reads compression but there's not audible effect, also, the Make up gain switch worked fine, as the bypass, I'd swear this has been discused before, I'll look the thread...

 

[dennisp]

I tried searching as I know the answer is somewhere but I just can't find it... So sorry if this question has been asked here before:
What are the bypass differences between "on", "com" and "off"?

Also, as I don't yet have DPDT switches yet, shouldn't the GSSL work if I short wires running from all 4 solder islands not stating "off"?
I seem to getting either thresh hold or makeup gain working, but not both at the same time, and it is hard for me to hear if ratio, attack and release are working  ???

Positive regards
Dennis

 

[dennisp]

And it works beautifully!!!  8)

I found out that I needed to short the C2 ("com") and C ("on") together and then short the A2 (next to 750K resistor) and A (the other next to the 750K resistor) and not all 4 shorted together  :

So I can now confirm that you need to measure on the pcb lane to the left of the text stating -12V to actually measure that -12V is correct or measure the corners of the IC pins on the IC socket that are at the top of the pcb!

Now it's playtime! 

Positive regards
Dennis

 

[mushibu09]

Hello, Sorry if this is in the wrong place new here!

first time to make my own! got money want to do something I can say I worked on that i can use with my music. so this came up! and I have only ever build kits (mainly Velleman) WOulod have used the Tube one but I don't think I would be much use to tubes as they are so delicate.

I am goign to build the http://www.gyraf.dk/gy_pd/ssl/ssl.htm but I am unsure ona  few things, wondered if i could get some help with this.

Main:
Power, I am going to be using this http://uk.farnell.com/multicomp/vtx-146-030-115/transformer-30va-2x-15v/dp/1675052 is there anythign else i need to do for this? or is this right?
On the PCB there is a part saying "Mount these only if External Transformer, would I need to do this? with the Above?
the THAT 2181 chip what model? i have found this http://www.profusionplc.com/pro/gex/pcatdtl0?ipartno=THAT2181BL08-U is this right or do i need to use another one?
where to get the DC Regulators; 7815, 7915, 78L12, 79L121 DC?
the Rotory switches unsure what it means so i  found these need to knwo if i am have it right? http://uk.rs-online.com/web/p/rotary-switches/0665196/ and http://uk.rs-online.com/web/p/rotary-switches/0665196/
and MOST OF ALL the Dimensions of the Front and BAck Panel of the 19" rack case, I will be using a 2U one, I would Like to knwo of the size of holes i have to cut ands the lay out.

Little importance;
what is a Bridge reflector, round type? and where would i get it? do I need a PSU PCB?
Can I use a LED Meter insted of the 1mA DC Full scale meter? ifi  can then would a mono level work fine?
the PCB for this I have found one that is this one but no reply yet, and one on here by Gustav. but not sure which of his is for this?

also if others are trouble but got bits that i don't pleae let me knwo where to get these bits,

I have the Resistors (Metal Film Resistor 0.25W 1% from BitsBox.co.uk) and Capacitors from same place apart from Tantalum ones as didn't have the higher V'

thank you.

sorry if it's in wrong place and to much to ask.

 

[dennisp]

Hi there Mushibu09,

I cannot help you with where to get the parts as I'm in Denmark and all the little components can be bought in just about any electrical shop (isn't there a shopping list on these forums with relevant links to electronic shops?).

Anyways - the toroidal transformer you link to looks just fine, and you are right that you would solder the wires on the part saying "Mount only these...". If you had a print mountable transformer you would put in inside the rectangle on the print itself.
It's just for making it easy to do you own choices that both options are available - I do however understand that many advice against using a print mountable transformer as some humming or noise seems to occur if the transformator is too close to the rest of the components.

About the THAT2181 it looks like that is just the right one to use if you want it to be pre-calibrated. I'm personally using the THAT2180 and have adjustable resistors to be able to calibrate it myself (just finished mine and so far I haven't done any calibration yet).

The rotory switches from Lorlin are fine - the cool thing about these are that you can configure how many steps/positions they should have by simply popping the small round metal plate with a tab going down and then place the tab at the desired position (first hole enabling 2 steps/positions, second hole enabling 3 steps/positions etc).... you are linking to the same Lorlin switches though - but it looks just right.

The dimensions for the Front and Back panel - well if you print out the Gyraf PDF you would get the correct sizes and placements - however this is for a 1 unit case (and it will fit in a 1 unit case).
Many prefer to get real professional Front Panels by some company called Schaeffer (do a search), and I will too some day but for know I just drilled the holes with a step drill bit (not sure what it's called in Denmark but is is a drill bit that has many sizes in like a pyramid shape.

I use the Gustav prints which consists of a main PCB and a Control PCB and that is all that is needed for a basic GSSL.

I hope others can help with the rest - happy DIY building - it's quite satifying when you're done with it and can test it - I can tell you that it sounds GREAT on drums  8)

Positive regards
Dennis

UPDATE: I forgot to tell that I'm looking into using an LED meter as well - the best source so far has been this build by Flav:
http://www.groupdiy.com/index.php?topic=39866.msg492742#msg492742

I haven't built it yet though but I have gotten the parts except for the power board, which I'm not entirely sure if needed though...

 

[mushibu09]

Thank you

Ahh.

the transformer, great expensive too, by any chance know what holes it's to be soldered into? as on UK 230v-250v

I'm going to stick with the calibrated one as i don't knwo how to calibrate it!

CUting on my case is on line now, as my mates dad works in steel pannel factory in charge of thje cutting so i can get that for free! and painted

the switches i had no idea i just look and the name and went for it! so please got it right, and the PCB will be ordering today!

thank you once again Dennis

the LED meter looks good will give it a better look ina  moment, and I don't know if need the power part either which is why i was a bit eekkk..

Leo

 

[dennisp]

Hi Leo,

Yes the toroidal transformer would be connected as the following:
The 0V (Blue) and the 230V (Brown) should go to the IEC plug - there is a standard for which pins to connect each, but I don't remember, so I'll have a look when I get home from work.
If I remember correctly the 0V (Red) should be connected to the top pin (of the 3 pins in the upper left corner), the VSec (Yellow) AND the 0V (Black) should be connected to the middle pin and the VSec (Red) should be connected to the bottom pin... but again I'll check when I get home from work.

The bridge reflector (is that the one that makes sure that AC is turned into DC?) should then be placed in the round 4 pin place just next to it (if it was a print mounted transformer it would be placed in the round 4 pin place in the middle to the left instead as it depends on where you connect the wires to the pcb).

Positive regards,
Dennis

 

[kante1603]

@Leo,

I wonder if it is good for you to build this.
You're working with mains voltages at the psu part-doing things wrong can probably kill you-
This is no joke!!!
Since you don't know what a "bridge reflector" is (it is called bridge rectifier btw) it might be good to study some electronics basics first.
Or get help from a friend knowing things like that and learn from him.
I really don't want to bother you,trust me,what you are doing can be very dangerous.
The more I read this thread the more I am getting nervous.

Sorry,

Udo.

 

[mushibu09]

I know how to deal with mains electric, it's just the wireing part eg to the board I knwo how to wire ther IEC and i do have a friend that is going to work on it with me! the build! same as one doing the panels, he's done a couple other thjings with mains him self! i already thought of the unsure part

and Dennisp, UK plugs are Green and Yellow Which is the Ground ( think if i remember it takes the excess and sends it to the 'ground or/and back to the plug)  Live 230V is green and Neutral receives the 230V after been through 'appliance'.

and It was more what holes for what cable!

 

[dennisp]

I know how to deal with mains electric....

Yeah - I'm not sure either why Udo is that concerned with you building an SSL compressor - it gets much worse when dealing with tubes as these are really high voltage and will kill you in an instance!

and Dennisp, UK plugs are Green and Yellow Which is the Ground ( think if i remember it takes the excess and sends it to the 'ground or/and back to the plug)  Live 230V is green and Neutral receives the 230V after been through 'appliance'.

Yes - that means that the Toroidal 230V (Brown) should be connected to the pin in the IEC plug that goes to Socket Live (Green) and the Toroidal 0V (Blue) goes to the pin in the IEC plug that goes to the Socket Neutral (Is that blue or black by any chance)?
The Ground (or Earth as it is commonly called) should be connected to pin1 on the XLR outputs and these will be connected to 0 via the output pins on pcb.
Check this page for standards on which pins on the IEC plug should be Live, Earth and Neutral:
http://www.electronics2000.co.uk/pin-out/iec.php

The wiring on the 30V side of the Toroidal transformer should be as I described but I see know that I named the wrong colours (I mentioned red twice - first one should be orange - sorry about that).
In the top left corner of the mounting side of the pcb, the 3 squares next to the place for the bridge rectifier (yes that was the name in english) are the ones I'm talking about when connecting the 30V side of the Toroidal transformer.
The correct order would be (those are the ones placed on the right side in the datasheet for the Toroidal transformer):
Top pin: orange (0V)
Middle pin: yellow (VSec) and black (0V) shorted together
Bottom pin: red (VSec)

Update: I call them pins as I've mounted pin rows (not sure what they are called in English)... they look like this:
http://www.el-supply.dk/?Gid=611&VNr=5556.02
And I've soldered the wires to wires with houses that fit (not sure again what it's called in English)... and they look like this:
http://www.el-supply.dk/?Gid=616&VNr=5595.03

The bridge rectifier would then be placed directly next to those pins and the + marked on the bridge rectifier must match the right top pin marked + on the pcb.

I hope that was more clear?

and It was more what holes for what cable!

I'm not sure what you mean here - Are you talking about the holes in the rack box (front and back)?

In the back I have drilled holes for the XLR plugs that are about 15mm (and small 2mm holes for the screws).
For the IEC plug I actually just made a drawing on the back panel with a pencil by measuring the IEC plug and then cut it with a dremel with a fiberglass reinforced cutting wheel (remember to protect your hands and face as these are known to break and fly towards you at a dangerous speed!).
Instead of XLR plugs you could also use stereo female Jack connectors and these would probably need holes at about 6mm...

In the front I drilled holes for the Lorlins at about 9mm - I do know however that some prefer to make an extra aluminum plate inside the casing (behind the front panel) as to hide the nuts... then you would drill the 9mm holes on the aluminum plate and then 6mm holes for the shafts on the Lorlins.
About the metering - it depends on how you would place the LEDs (maybe a plastic or epoxy "mounting something" - but do mind not to cut too much in the front panel as it has to carry some weight)... as well as how big the LEDs you choose.

If that was not what you meant by what holes for what cable I do believe I did answer you...
Look at the schematics on page 2 in these pages: http://www.gyraf.dk/gy_pd/ssl/ssl.pdf

Positive regards
Dennis

 

[kante1603]

I know how to deal with mains electric....

Yeah - I'm not sure either why Udo is that concerned with you building an SSL compressor - it gets much worse when dealing with tubes as these are really high voltage and will kill you in an instance!

Not in general,it depends on some more things like time,current,voltage,resistance of the body etc.
I "survived" several accidents on the back of tv sets when I was a young radio and tv electrician,that is more than 20kvac at a time under a microsecond at nearly non-measurable current.Same thing as discharging one self at an iron door and so on.
Here's something to read if you want.
http://en.wikipedia.org/wiki/Electric_shock

Udo.