If you have a 1mA meter, then you have an error. Check this thread for error tracing.
Jakob E.
Jakob E.
GSSL HELP THREAD!!!
- Thread starter hairyandy
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Help Support GroupDIY Audio Forum:
tommypiper
Well-known member
Jacob, thanks. Could you please answer some of the questions I asked?
Yes, I already know that I have an error. That's why I'm asking questions!
Yes, I have been error tracing and checking for several weeks. That's all I've been doing. And I have reread this thread three times front to back (and I have 40 pages of notes I refer to as well.)
But, because I don't understand which components are being referred to in the discussions and answers, I don't know how to understand what is being said.
Specifically, where are these resistors located (on the schematic and layou)t that people are mentioning?
WHere is the related info you mentioned, please?
Please answer my questions, that could help a lot.
Yes, I already know that I have an error. That's why I'm asking questions!
Yes, I have been error tracing and checking for several weeks. That's all I've been doing. And I have reread this thread three times front to back (and I have 40 pages of notes I refer to as well.)
But, because I don't understand which components are being referred to in the discussions and answers, I don't know how to understand what is being said.
Specifically, where are these resistors located (on the schematic and layou)t that people are mentioning?
WHere is the related info you mentioned, please?
Please answer my questions, that could help a lot.
There is only one 2K resistor - and that is the one for meter sensitivity.
pegging meter means that either you mounted wrong, shorted something, or you have completely wrong voltage at the point in the sidechain from which we tap a bit of voltage/current for the meter. Look at the schematic. Try to understand what goes on. Find the relevent parts on the pcb. check if they behave as expected.
As always:
Check and recheck components, values, orientations, soldering, interwireing, appropiate voltages at appropiate points.
The whole ratio compensation for That218x thing is an entirely different matter, nothing to do with metering. it involves a change of a 100K resistor to a 127K resistor - look at the updated page at Gyraf - this is the ONLY 127K resistor in the circuit.
Jakob E.
pegging meter means that either you mounted wrong, shorted something, or you have completely wrong voltage at the point in the sidechain from which we tap a bit of voltage/current for the meter. Look at the schematic. Try to understand what goes on. Find the relevent parts on the pcb. check if they behave as expected.
As always:
Check and recheck components, values, orientations, soldering, interwireing, appropiate voltages at appropiate points.
The whole ratio compensation for That218x thing is an entirely different matter, nothing to do with metering. it involves a change of a 100K resistor to a 127K resistor - look at the updated page at Gyraf - this is the ONLY 127K resistor in the circuit.
Jakob E.
tommypiper
Well-known member
OK, thanks, that helps.
(I did not realize the 100k resistor was ratio discussion and not meter discussion, confusing, because it is mentioned in posts about meter adjusting. I'm easily confused on this project without part numbers.)
I will put the 2K meter sensitivity resistor back in and continue the saga...
I am using 2150 THATs -- does that mean I use a 100K or 127K resistor?
Thanks.
(I did not realize the 100k resistor was ratio discussion and not meter discussion, confusing, because it is mentioned in posts about meter adjusting. I'm easily confused on this project without part numbers.)
I will put the 2K meter sensitivity resistor back in and continue the saga...
I am using 2150 THATs -- does that mean I use a 100K or 127K resistor?
Thanks.
If 2150, then use the old 100K resistor.
Dr nEon
Well-known member
Hi Jakob!
I have just been carrying out the new mods you have published on your site , for the gssl .
Since mine has 2180LA inside ,I have read all the threads on what to leave out around pin 4 etc..
However, the issue of the 10k resistor linking pin 3 and 5 is not included in your update , and I have been searching to find out what is your opinion about this modification .
The suggestions to remove it ,are based on the THATs app notes pdf , but I'm keen to know if U "o.k." this mod , because this project is your baby ..
cheers!
I have just been carrying out the new mods you have published on your site , for the gssl .
Since mine has 2180LA inside ,I have read all the threads on what to leave out around pin 4 etc..
However, the issue of the 10k resistor linking pin 3 and 5 is not included in your update , and I have been searching to find out what is your opinion about this modification .
The suggestions to remove it ,are based on the THATs app notes pdf , but I'm keen to know if U "o.k." this mod , because this project is your baby ..
cheers!
Hi Neon,
The 10K can probably be removed if THAT says so, but I havent tried that out in real-life. The unit works very nicely with it in-circuit.
Jakob E.
The 10K can probably be removed if THAT says so, but I havent tried that out in real-life. The unit works very nicely with it in-circuit.
Jakob E.
Dr nEon
Well-known member
OK! so ,maybe I'll give it a go , and see!
There has also been talk of changing the summing resistors to a higher value , but I don't understand why people are doing this . I have 2180LAs inside , and since doing your ratio mod , my ratios are fine , the unit certainly is not overcompressing!
Infact , now with the threshold mod , the onset of compression is so smooth and transparent , its almost needing to have a bit of the ssl crunch added back in again!!!
Mind you , I'm only testing at the moment with stuff off cd , already mixed ...I'll check it out with some raw drums and bass etc..
If I do find that I need a bit more clout when the compressor kicks in , would there be an alternative resistance value ,somewhere in between, for the thresh pot leg??
Its all so fascinating..!! ..after 20 years mixing thru these things , starting to learn how those familiar characteristics are being created...amazin!!
cheers Jakob!
nEon
There has also been talk of changing the summing resistors to a higher value , but I don't understand why people are doing this . I have 2180LAs inside , and since doing your ratio mod , my ratios are fine , the unit certainly is not overcompressing!
Infact , now with the threshold mod , the onset of compression is so smooth and transparent , its almost needing to have a bit of the ssl crunch added back in again!!!
Mind you , I'm only testing at the moment with stuff off cd , already mixed ...I'll check it out with some raw drums and bass etc..
If I do find that I need a bit more clout when the compressor kicks in , would there be an alternative resistance value ,somewhere in between, for the thresh pot leg??
Its all so fascinating..!! ..after 20 years mixing thru these things , starting to learn how those familiar characteristics are being created...amazin!!
cheers Jakob!
nEon
Dr nEon
Well-known member
Hi Roger !
Thanks for explaining! Now I can see why those resistors would be changed..
OK so i've done a little testing on mine...
I assume that to test the cv,that would be pin 3 on the left and right vcas?
I am checking for DC . I put the black probe of my dmm to chassis , and the red to pin 3 .
I fed in a sine tone (did test at 1k and also at 300Hz)
Set compression to -20db mark on my meter :
Left vca = 105.5 mV Right vca = 106.7 mV
Then I pushed compressor to peg the meter past the scale:
left & right vcas = 128 mV
So what do u think , guys? I hope this was the correct way to test this , but if it is , then does it mean I can leave the summing resistors as they are?
Or is 128mV too much?
Cheers nEon x
Thanks for explaining! Now I can see why those resistors would be changed..
OK so i've done a little testing on mine...
I assume that to test the cv,that would be pin 3 on the left and right vcas?
I am checking for DC . I put the black probe of my dmm to chassis , and the red to pin 3 .
I fed in a sine tone (did test at 1k and also at 300Hz)
Set compression to -20db mark on my meter :
Left vca = 105.5 mV Right vca = 106.7 mV
Then I pushed compressor to peg the meter past the scale:
left & right vcas = 128 mV
So what do u think , guys? I hope this was the correct way to test this , but if it is , then does it mean I can leave the summing resistors as they are?
Or is 128mV too much?
Cheers nEon x
Dr nEon
Well-known member
OK will do that now!
One thing I forgot to mention is that I did the ratio mod so far with a 120K resistor...NOT 127K ....I'm having a hard time finding a 127K one..!
The 120K is pretty close , but I'd like to try 127K.
Would there be any downside in just putting in, say, a 6K8 next to the 120K to make up the difference ?
I'm also interested in what ,if any, sonic difference there is between the 3k9 , and 5k1 replacement .
Should the 3k9 on the sidechain also be changed for 5k1?
Really appreciate your help in understanding this , Roger !
Cheers , nEon
x
:thumb:
One thing I forgot to mention is that I did the ratio mod so far with a 120K resistor...NOT 127K ....I'm having a hard time finding a 127K one..!
The 120K is pretty close , but I'd like to try 127K.
Would there be any downside in just putting in, say, a 6K8 next to the 120K to make up the difference ?
I'm also interested in what ,if any, sonic difference there is between the 3k9 , and 5k1 replacement .
Should the 3k9 on the sidechain also be changed for 5k1?
Really appreciate your help in understanding this , Roger !
Cheers , nEon
x
:thumb:
emtee
Well-known member
[quote author="Dr nEon"]
The 120K is pretty close , but I'd like to try 127K.
Would there be any downside in just putting in, say, a 6K8 next to the 120K to make up the difference ? [/quote]
As long as it's in series with the 120k, it'll work just dandy.
The 120K is pretty close , but I'd like to try 127K.
Would there be any downside in just putting in, say, a 6K8 next to the 120K to make up the difference ? [/quote]
As long as it's in series with the 120k, it'll work just dandy.
Dr nEon
Well-known member
Great! :grin:
Thanks Emtee !
I wasn't sure if running thru two components in stead of one would upset impedance , at this point in the circuit. But I'll go for it, since u r giving me the green light!
I'm still very interested in whether anyone out there has detected any audible difference between leaving the 3k9 in , and replacing with 5k1..when using 2180LA .
So I'll fine tweak this ratio now , and then tune the meter as Roger described!
Many thanks , fellas !
nEon
Thanks Emtee !
I wasn't sure if running thru two components in stead of one would upset impedance , at this point in the circuit. But I'll go for it, since u r giving me the green light!
I'm still very interested in whether anyone out there has detected any audible difference between leaving the 3k9 in , and replacing with 5k1..when using 2180LA .
So I'll fine tweak this ratio now , and then tune the meter as Roger described!
Many thanks , fellas !
nEon
Dr nEon
Well-known member
Hi all!
Roger , I have just set the meter up as u instructed...used 2k2, and now I have correct gr indication...everything cool...CHEERS :guinness:
One final question : I noticed that there is a 1mV difference between the left and right vca's pin3 .
This is at any setting , i.e whatever the gain reduction is indicating(even if the threshold is lifted to stop any compression showing) , the voltage at pin 3 right is always 1mV higher than pin 3 left.
Is this negligible ?
When I assembled the circuit ,I checked and matched values of all resistors etc...I have double checked as best as I can(in circuit) , but I don't see an obvious problem.
...almost ready to put the lid back on!!
nEon.
Roger , I have just set the meter up as u instructed...used 2k2, and now I have correct gr indication...everything cool...CHEERS :guinness:
One final question : I noticed that there is a 1mV difference between the left and right vca's pin3 .
This is at any setting , i.e whatever the gain reduction is indicating(even if the threshold is lifted to stop any compression showing) , the voltage at pin 3 right is always 1mV higher than pin 3 left.
Is this negligible ?
When I assembled the circuit ,I checked and matched values of all resistors etc...I have double checked as best as I can(in circuit) , but I don't see an obvious problem.
...almost ready to put the lid back on!!
nEon.
JRE Productions
Well-known member
I used the 5K1 from the start and it works great. I too used the 2180 VCA. I also changed my resistor to 127K too.
Mine works as expected and sounds excellent!'
Joe
Mine works as expected and sounds excellent!'
Joe
Hi all.
I am having a bit of a problem with my first GSSL.
I am using THAT2181LA for my VCAs.
The unit is distorts like crazy when I turn it on.
When the threshhold is turned all the way counter clockwise, there are barely no sound, and as I turn it clockwise, then the distorted sound will start playing from right to left. The bypass switch does not seem to work.
Meter is all the way to the right.
I did test taking all the VCAs off and jumping the pin 1-8 on right and left VCAs and there were no distortion.
What could be the problem?
I hooked up all the components as described on this http://homepage.mac.com/marten.thielges/gssl/calibration.html.
I am having a bit of a problem with my first GSSL.
I am using THAT2181LA for my VCAs.
The unit is distorts like crazy when I turn it on.
When the threshhold is turned all the way counter clockwise, there are barely no sound, and as I turn it clockwise, then the distorted sound will start playing from right to left. The bypass switch does not seem to work.
Meter is all the way to the right.
I did test taking all the VCAs off and jumping the pin 1-8 on right and left VCAs and there were no distortion.
What could be the problem?
I hooked up all the components as described on this http://homepage.mac.com/marten.thielges/gssl/calibration.html.
Hi Luigi,
Have you read through this whole thread? The idea about having these long threads is that if you read through them, there is a good chance that a problem has been had and fixed before..
For your problem - which I believe we've had a couple of times before - there's a good chance that you have left out a wire link that goes on the control-PCB, just above the connector to the mainboard.
Jakob E.
Have you read through this whole thread? The idea about having these long threads is that if you read through them, there is a good chance that a problem has been had and fixed before..
For your problem - which I believe we've had a couple of times before - there's a good chance that you have left out a wire link that goes on the control-PCB, just above the connector to the mainboard.
Jakob E.
Sorry for asking all sorts of questions..
I was just testing and swapping the VCAs and 5534s.
When I swapped the 5534 from left to right, a static sound started to play from my left channel in 1 sec interval.
Til then, everything sounded ok ( well with distortion), but now, right channel is gone, and static from left.
Did I damage the 5534?
I was just testing and swapping the VCAs and 5534s.
When I swapped the 5534 from left to right, a static sound started to play from my left channel in 1 sec interval.
Til then, everything sounded ok ( well with distortion), but now, right channel is gone, and static from left.
Did I damage the 5534?
It's hard to tell.
Try going over the unit minutely and check all the things that has been mentioned in this thread.
Jakob E.
Try going over the unit minutely and check all the things that has been mentioned in this thread.
Jakob E.
Hello guys,
Stupid qustion comming... :roll:
I´m about to order some parts for the gssl and wondering about the 80V-0.1A value stated next to the 1N4148 small signal diode.
I can´t find any 1N4148 with a maching value. The closest would be 100v-150mA would this be sufficient? Further is this important other than giving the lowest tollerable value in this design?
Guessing that this would be the same for the caps then right?
Thank you
Stupid qustion comming... :roll:
I´m about to order some parts for the gssl and wondering about the 80V-0.1A value stated next to the 1N4148 small signal diode.
I can´t find any 1N4148 with a maching value. The closest would be 100v-150mA would this be sufficient? Further is this important other than giving the lowest tollerable value in this design?
Guessing that this would be the same for the caps then right?
Thank you
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