GSSL HELP THREAD!!!

[vertiges]

louder,

With a decent level of signal at the inputs and with the threshold completely CCW (all the way to the left) you should have a lot of compression (10-20 dB, even more) whatever attacks/release/ratios settings you set.

eD)))

 

[vertiges]

Hi,

Here are the measurement I've done with RMAA.
http://audio.rightmark.org/index_new.shtml

A) First column : the results I get when connecting the ouputs directly to the inputs of my Fireface 400.
B) Second column : the results I get when connecting my second GSSL (Black Gates caps (audio path), Wima caps, Nichicon PW, THAT 2181 AL)
C) Second column : the results I get when connecting my second GSSL (Panasonic caps, THAT 2181 AL)

(the two GSSL were in bypass)

Questions :

1) I used the RMAA for calibrating the distortion trimers of the VCAs. Is this correct ?
2) There is a big difference in THD between the two units... Is this caused by the fact I used better caps in the 2nd unit ?
3) Strange thing about the 1st GSSL. When I make the measurement of the two channels separately (MONO MODE) I get results about 0.003 % of THD. In STEREO MODE, I mean when I make the measurement of the two channels together, the THD raises to 0.019 % :shock:.
With the 2nd GSSL, I get the same results in MONO and STEREO modes...
Any ideas ?

Thanks !

eD)))

 

[Osse]

Hi

I'm building one GSSL right now, but when I turned it on, my Behringer meter went up in smoke!

I've checked the Voltage from the transformer, and it's steady 38.6V.

I've got another fully working unit to compare with, and it's 5.5V to the meter, but I havn't dared to turn my unit on to see if it's 5.5V to it too. I've connected it the same way as the working unit.

Now I wonder, could this have harmed any other parts of the cirquit? as I said, it's 38.6V, just as it should, so I wonder if it's just probably some problem in the connection of the meter?

Do I dare to turn the unit on, do some voltage tests, and maybe see if the unit compresses as it should?

What's ur suggestions.

Thanks a lot

 

[vertiges]

[quote author="Osse"]Hi

I'm building one GSSL right now, but when I turned it on, my Behringer meter went up in smoke!

I've checked the Voltage from the transformer, and it's steady 38.6V.

I've got another fully working unit to compare with, and it's 5.5V to the meter, but I havn't dared to turn my unit on to see if it's 5.5V to it too. I've connected it the same way as the working unit.

Now I wonder, could this have harmed any other parts of the cirquit? as I said, it's 38.6V, just as it should, so I wonder if it's just probably some problem in the connection of the meter?

Do I dare to turn the unit on, do some voltage tests, and maybe see if the unit compresses as it should?

What's ur suggestions.

Thanks a lot[/quote]

Hi Osse,

You shouldn't have powered up your circuit with the ICs before having checked all the voltages. (And before having checked and re-checked all the values of the components, if there are bad solder joints, shorts, etc.)

The B-Meter is rated at 25mA / 2.5-3 Volts.

Where and how did (between which points?) you measure the 38.6 Volts ? AC ? DC ?
What transformer did you use ? How is it wired ? Have you got any pic ?

eD)))

 

[Osse]

Oh, sorry, seems like I left some important info out in the last message.

What do you mean with check the values of the components, do you mean the whole cirquit board, or one component at a time? One and one i've already done.

http://www.ladda-upp.com/bilder/3900/picture-1
http://www.ladda-upp.com/bilder/3901/picture-2
http://www.ladda-upp.com/bilder/3902/picture-3
http://www.ladda-upp.com/bilder/3903/picture-4

I got 38,6v AC between the separate green and red wire from the transformer.

On the places on the PCB that you think it's missing components, it doesn't I've just placed them on the Soldering side.

 

[vertiges]

Osse,

I've checked very quickly... (I'm busy)

1) Could you measure the voltages at the +15 and -15 Volts points ? (DC, red probe on the +/- 15 and the black on your star ground)

2) There are missing caps !??!

3) Have you compared the voltages at the pins of the ICs to the ones from the working unit ?

Where these wires are connected ???

What are the brand and the model # of your transformer ?
There are 7 wires, I'm not familiar with that... :roll:

eD)))

 

[Osse]

Hi again Vertiges, and thanks so much for your help!

The caps aint missing, they are at the soldering side.

The two wires you pointed at is soldered at the big capacitor nearest the front panel, one at each pole, just as the working one I've got allready.

I havn't dared to turn the unit on again, should I do it and check voltages at the 2 +15v and -15v places?

thanks once again!

 

[Osse]

If I understood it correctly, I was supposed to check voltages between the -15 and +15 places, and the place where the grounds meet?

On the working unit, it's 31.9V on the +15, and zero volts on the -15.

 

[vertiges]

[quote author="Osse"]If I understood it correctly, I was supposed to check voltages between the -15 and +15 places, and the place where the grounds meet?

On the working unit, it's 31.9V on the +15, and zero volts on the -15.[/quote]

You should have + 15 on the +15 and - 15 Volts on the -15 (DC voltages)

I was close to say that the ground of the main PCB was "floating" but it's seems to be grounded by center wire of the input.

You haven't answered to my questions : # number of the transfo, how the led of the meter is connected (red and blue wire ?), missing caps ?

eD)))

 

[Osse]

yes I have :grin:

one reply above.

The trafo# I can't find but the company is named Toroidy.
Yes, it has got -15 and +15.

But I tried to insert it in a audio chain, and there is no sound comming throught it, just a LITTLE bit when I've got my speakers at highest, is there any more ways to troubleshoot it?

me and a guy at another forum realized that it's just the Diode in the meter that blew, as I didn't have any resistor before it, but obviously there is some other problem too...

 

[vertiges]

[quote author="Osse"]yes I have :grin:

one reply above.
[/quote]

:shock: ... oh well...

[quote author="Osse"]
The trafo# I can't find but the company is named Toroidy.
Yes, it has got -15 and +15.

But I tried to insert it in a audio chain, and there is no sound comming throught it, just a LITTLE bit when I've got my speakers at highest, is there any more ways to troubleshoot it?

me and a guy at another forum realized that it's just the Diode in the meter that blew, as I didn't have any resistor before it, but obviously there is some other problem too...[/quote]

Do not try with your speakers !!! :shock: Be careful !!! EDIT : I mean unless you're sure everything is ok !

If you connected the led of your meter without resistor, it's normal that you blew it ! Maybe you could put the led of the meter in series with the "power on" one. Or from the same point you used but with a resistor in series !!!

For the other problems... You have to check and re-check everything.
You are lucky to have a working unit to compare to. There is also this thread : full of informations ! It's during the troubleshooting we learn the most ! :wink:

eD)))

 

[discobloud]

Quick newbie question about using a 0-10A meter

I want to use this http://tinyurl.com/3w8cw9 for my next GSSL


what sort of resistance or pad would i need to be able to use this.
or better yet, which chapter in navy NEETS should I read.

Thanks

Mark

 

[vertiges]

Hi Mark,

I'm not sure you can use this meter...
Because it this case you don't wanna reduce the current with a resistor... On the contrary, the needle of this meter needs more current to move.

For example with a 100uA meter, you'll need a 20k resistor intead of a 2k.
Here, we're talking about 10A FSD instead of 1mA FSD !!! 10000 times more ! :shock:

BUT, there is maybe a resistor inside the meter you can take off... :roll:

eD)))

PS : ordering in China : the shipping sometimes takes forever !

 

[discobloud]

thanks for the lesson eD. i'll find a better suited meter.

Mark

 

[karl j]

Okay, I'm a little late on posting my finished GSSL pics. I went to Chicago to visit family for a while, got delayed getting home because of the American Airline MD-80 thing, and yesterday had knee surgery! Please excuse any bad typing or senseless wording, I am on pain killers.

Here they are:


The Purusha case worked out well. I don't have the patience to do the layout stuff, and he already did a nice job on the layout. What a great time saver.

Now I have to order the PCB for the second case I've got. Maybe I'll use that "Turbo" side-chain thing that's going around now.

 

[karl j]

Okay, how do I post pics? :grin:

 

[vertiges]

Hi karl,

First, you have to find a place for uploading you pics. The pics are not "stored" in the forum.

Secondly, you just have to post the links to your pictures... write your link, select it and click on "Img" button above...

From the forum rules post :

HELPFUL RESOURCES FOR MEMBERS:

*Here's a spot to upload files and images related to the discussions on these pages: http://groupdiy.twin-x.com/index.php

eD)))

 

[ixi]

Hi guys!

I can't find how to wired bypass switch for ssl on Purushas case (6 polls switch, bypass + led )
Long time ago find i one picture, now i can't fined it !

Thx
ixi

 

[vertiges]

[quote author="ixi"]Hi guys!

I can't find how to wired bypass switch for ssl on Purushas case (6 polls switch, bypass + led )
Long time ago find i one picture, now i can't fined it !
ixi[/quote]

Are you talking about this one ? :

eD)))

 

[ixi]

delete