GSSL HELP THREAD!!!

[laus]

Thanks very much Purusha, I'm going to try this immediately.

I have another question about a bypass led : is it possible to have a bypass led which indicate the bypass model and if yes, how I can wire it??

Best
Laus

 

[Purusha]

Yes it's possible but than you need triple switch (three rows of three pins). So the third row would turn the LED on and off.

 

[sounden]

I think this would work?
I have toughts of steeling current from "Power ON" LED to bypass LED

3pol/2ways switch

OFF (NOT BYPASSED)
A-------o o----A1--->(not connected)
C-------x----x----C1--->OFF (to PCB)
+LED---o o----LED-- (not connected)

ON (BYASSED)
A------x-----x------A2 (connected bypass gain makeup)
C------x----x------C2--->ON (to PCB)
+LED--x----x-------LED--> (to PCB)

Do you think I got it right?

This topic helped me alot to understand the lorlin functions
http://www.groupdiy.com/index.php?topic=12627&highlight=lorlin+switch

 

[Purusha]

Why don't you make a drawing of all connections in Corel or Photoshop? I don't know about others but I am not sure if I understood your explanation. It might be OK.

 

[sounden]

Ok! Hopefully I explain myself enough now =)

Regards

 

[Purusha]

It looks OK. :thumb:

 

[sounden]

Nice! then I will try this as soon as I get my last components.

 

[laus]

Hello
The SSL clone works fine (thanks Purusha) but I have a "hum problem".
I already read the thread and wire my inputs to the case ( and I also try outout but nothing change), my IEC to the case and try to move the toroid transformer but nothing change.
I don't think the hum comes from the input because it still here with no input.
Therefore, the hum grown up when I put my finger on the 22µF caps near the inputs.
No ideas
If anyone can help me it would be great

thanks a lot

Laus

 

[Purusha]

Sorry can't help you with the hum problem. My first tested G-SSL works fine although it's still outside the chassis.

 

[DQ]

Hello ..

first of all i want to thank jacob, gustav and everyone else in the forum.
I have built my GSSL and it's my first DIY project and it's sounds great!!

I have a couple of issues I should solve though..

I have a HUM problem on both channel (altough LEFT ch is noisier).
I have not totally assembled the GSSL but i have placed it in the rack case and done al the grounding (at least i think so..)
I have checked the bridge rectifier output and it gives me +19.02 and -19.13. The recitfier is W08M


The output of the regulators are:
+14.77
-14.81
+11.99
-11.99

I have noticed that if i connect togheter pin1 of the XLR input to the other PIN1 the noise come down a bit.
I tried to move the toroidal transfrmer but nothing change. BTW I have a 2x15V 30VA

I also noticed that if i switch off the unit and turn it back on sometimes the compression doesnt work , toghter with the LED. If i wait a bit and turn it on again it works fine.

I hope someone can give me some advice and suggestions..

Many thanks..

 

[Pri]

Hi,
well i thought i had it all running fine, but i have 4dB less output on the right channel (thought it was my mixer who wasn't working right).
I did some measurering and found out that i always have like 5,2 Volt on the negative output. Even without any signal passing :? .

But if i put a sine wave through i get like 3.9 Volts on the other outputs, but on the negative of the right channel it is still 5,2 Volts.. I don't have a clue what could be wrong 'cause besides that it is working right.

I made some slight changes but i had that problem before, so i don't think that they effected that problem (i change the 100k to 120k, and the 2k to 1,2K for the meter, and put 47k on the + leg of the threshold pot)

any things i should check??

Thanx in advance,
Niklas

 

[Purusha]

Swap opamps and VCAs, maybe you will get closer to the problem.

 

[Pri]

yeah, should have tried that :thumb: .
That really was causing the difference. Thanx a lot...

By the way, what is difference between NE5532N/AN/AP?? I had Ns in there and now put some AP s in. I did not hear a difference (with a sinewave, though :green: )..
How do you guys know where to put the 0dB mark for the threshold on the front panel? How can I measure it (sorry if you had that question before, just ignore it).

Thanks again and good night

Niklas

 

[DQ]

Ok,

I found out the problem regarding the fact that sometimes the compressor doesnt work , It should be the 78L12 that sometimes get's stuck on - 0.7V or something like that..

I still have quie a lot of hum (more on one channel) though..

does anyone have suggestions?....

Thanks!

 

[fucanay]

I've been doing some testing on one of my SSLs and there seems to be a bit of noise and wanted to see what you guys think.

I took these screen captures in 3 different states with no audio passing through the unit.

1. SSL hooked up, but powered off. http://fucanay.fischerworks.com/diy/gssl/SSL_off.gif

2. SSL powered on, lowest makeup gain. http://fucanay.fischerworks.com/diy/gssl/SSL_in.gif

3. SSL powered on, max makeup gain. http://fucanay.fischerworks.com/diy/gssl/SSL_max_makeup.gif

I hear this noise and it kind of bothers me, but I'm not sure that it isn't normal. Any comments?

Matt

 

[DQ]

Hello again..

sorry for keep writing about the hum on my ssl , but i cant solve the problem.
It's quite loud , especially on the left channel.
I have read many old post about the problem and have rewired all the grounds copying the same setup as Greg from an old post, I also tried with plastic spacers or isolating completely the PCB from teh chassis, but still no luck.
everything else seems to work just fine.

I noticed one thing though.
If i run a cable from the chassis to the ground positioned where the 1000uF condemsers are , the noise come down quite a lot but still there. If i run the same cable to the other side of the PCB's ground there's no change.
Yesterday running another extra cable i managed to bring the noise down a lot but unfortunately now that i assembled the machine i can't remember where that was..)
I don't know , but to me it really seems there's some kind of ground loop, but i a total newbie and i am not experienced at all with this kind of troubleshooting..
As i said on the previous posts i chacked all the voltages at the various stages and seemed fine.

I hope someone can give some advice.....

thanks!

 

[Greg]

DQ: Grounding issues are hard to troubleshoot via internet. Can you post a picture and I'll try and take a look to see if anything jumps out at me.

 

[DQ]

Hi greg...

here's a pics..

http://www.unbearablerecordings.co.uk/z/sslwithhum.jpg

i put a note where the extra wire is..

I hope you get some ideas or suggestions...

thanks!!

 

[fucanay]

The way the toroidal is hooked up seems strange to me. The way mine is, is that 2 wires are hooked together and they provide the 0V used as reference ground (i think). Do you have a datasheet for the transformer you used? Maybe it has something to do with that.

Matt

 

[Purusha]

Maybe you should use the shielded cables from the PCB to the XLR connectors and not regular wires :shock:

BTW I am using the same meter. Let me know it's accuracy when you are done with meter calibration. Mine does the job very well up to 6dB of GR, above that it goes off.

What VCAs are you using?