JasonWWW
Active member
That front panel design is GREAT!
My GSSL - finally finished
- Thread starter [silent:arts]
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Help Support GroupDIY Audio Forum:
Greg
Well-known member
[quote author="Purusha"]Peter, can you recommend a good spot where to take the voltage from for the thrusty?
Would + - 15V be also OK? I think it would be just the same.[/quote]
Yup.
Also, you might want to consider some type of heatsink for the +/-15V regulators. In a standard GSSL, they run a little warm, but this isn't a big deal. Adding two more 5532 will draw a little more (don't know how much off hand). So a small heatsink isn't a bad idea (but make sure they don't touch), or maybe case mounting this is a good idea.
It might not be necessary, but just a thought.
Would + - 15V be also OK? I think it would be just the same.[/quote]
Yup.
Also, you might want to consider some type of heatsink for the +/-15V regulators. In a standard GSSL, they run a little warm, but this isn't a big deal. Adding two more 5532 will draw a little more (don't know how much off hand). So a small heatsink isn't a bad idea (but make sure they don't touch), or maybe case mounting this is a good idea.
It might not be necessary, but just a thought.
Purusha
Well-known member
[quote author="JasonWWW"]That front panel design is GREAT![/quote]
Thanks. I can upload the Corel file ready for printing job if someone wants it :wink:
Thanks. I can upload the Corel file ready for printing job if someone wants it :wink:
Purusha
Well-known member
Hi Greg,
if I would only know what a heatsink is :green:
if I would only know what a heatsink is :green:
kruz
Well-known member
a heatsink is any thermal dissipation thing
like this one:
like this one:
Purusha
Well-known member
I thought so. OK, so where should I put it? Next to the 7915 and 7815?
Greg
Well-known member
Take a look at the picture for reference:
http://members.cox.net/capstanrecording/DIY/G1176/G1176_PCB.JPG
It's that black thing mounted directly to the regulator. Ever notice the hole in the heatsink (or more general in a TO-220 package transistor)... that's for a heatsink.
But in your case, you have the +15 and -15 regulators right next to one another. So be careful because you don't want the heatsinks to touch, unless you positive they're isolated from the regulator. I've seen picutures of some people mounting the regulators to the cases (isolated of course) and running wires to the PCB.
But the heatsink might not be necessary. Perhaps you can just build it without and see how hot the regulator gets. If it gets so hot you can't keep your finger on it, then use a heatsink.
http://members.cox.net/capstanrecording/DIY/G1176/G1176_PCB.JPG
It's that black thing mounted directly to the regulator. Ever notice the hole in the heatsink (or more general in a TO-220 package transistor)... that's for a heatsink.
But in your case, you have the +15 and -15 regulators right next to one another. So be careful because you don't want the heatsinks to touch, unless you positive they're isolated from the regulator. I've seen picutures of some people mounting the regulators to the cases (isolated of course) and running wires to the PCB.
But the heatsink might not be necessary. Perhaps you can just build it without and see how hot the regulator gets. If it gets so hot you can't keep your finger on it, then use a heatsink.
Purusha
Well-known member
Thanks Greg,
I'll do that. Let's see. I will also need the extra +-12V for relays for the true bypass. If needed I will move and solder the regulators on the euro board where my Thrusty is right now and use some extra heatsink coolers.
I'll do that. Let's see. I will also need the extra +-12V for relays for the true bypass. If needed I will move and solder the regulators on the euro board where my Thrusty is right now and use some extra heatsink coolers.
Purusha
Well-known member
I have a question regarding those two 47K summing resistors on the main PCB. I know when the filter is used than those two are to be removed. OK, here my dillema starts, in the thread about calibrating the ratio and threshold there are suggestions to replace those 47Ks to 120K resistors, but now they are not there anymore so which resistors are now taking their place on the filter?
I also don't know what are those trim pots on both filters for?
Does adding the HP filters change the ratio or threshold behavior?
I also don't know what are those trim pots on both filters for?
Does adding the HP filters change the ratio or threshold behavior?
martthie_08
Well-known member
For setting the threshold to your taste. Originally the hp filter was unity gain, but in the design process of the filter pcb it was made variable gain.
yes, that is what the trim pot is for: getting your threshold level right. This has nothing to do with ratio adjustment, btw.
Purusha
Well-known member
OK, thanks for clearing this :thumb:
clintrubber
Well-known member
[quote author="Purusha"]I also don't know what are those trim pots on both filters for?
[/quote]
You mean VR2 & VR3 in this schematic ?
http://home.hetnet.nl/~chickennerdpig/FILES/API/API-Thrust-HPF-circuit_20060310.pdf
Please do read those notes in that schematic, all info was there already.
Note *1*.
[/quote]
You mean VR2 & VR3 in this schematic ?
http://home.hetnet.nl/~chickennerdpig/FILES/API/API-Thrust-HPF-circuit_20060310.pdf
Please do read those notes in that schematic, all info was there already.
Note *1*.
Purusha
Well-known member
Yes, VR2 and VR3. I have to check your pdf file again. Sometimes I can be a little sloppy ...
Which pin of the VCA should I meassure?
Purusha
Well-known member
I am new to this DIY process so I am a little hesitating when things come to measurements. Just to be sure, the pin 1. starts on the marked VCA side or on the opposite side? You know one side of the VCA is marked on the top to know which side is right when you put them in. I checked the pdf for 2181 and the pin 3 is the Ec as you mentioned.
Should I be passing the audio signal through when measuring or not necessary?
Should I be passing the audio signal through when measuring or not necessary?
Purusha
Well-known member
Final check if I understood everything before I do this.
When you say "set the ratio to 20:1" you mean 10:1?
Regarding the measuring process, the + (red) cable from the volt meter goes to the pin 3 and the other one goes to the XLR ground connection in the input or output section, yes? Maybe this question sounds a little funny for experts but anyway, better to ask than to be sorry later.
When you say "set the ratio to 20:1" you mean 10:1?
Regarding the measuring process, the + (red) cable from the volt meter goes to the pin 3 and the other one goes to the XLR ground connection in the input or output section, yes? Maybe this question sounds a little funny for experts but anyway, better to ask than to be sorry later.
Purusha
Well-known member
Thanks, I got it now :thumb: :grin:
will report back what I measured...
will report back what I measured...
Purusha
Well-known member
OK, here is what I got
Threshold fully CCW = 139.4 mV
Threshold 12 o'clock = 40 mV
Threshold fully CW = 0.4 mV
The VCA next to the one I measured had up to 0.2 mV difference.
Is this normal?
Threshold fully CCW = 139.4 mV
Threshold 12 o'clock = 40 mV
Threshold fully CW = 0.4 mV
The VCA next to the one I measured had up to 0.2 mV difference.
Is this normal?
Purusha
Well-known member
METER CALIBRATION
Just experienced another surprise... when doing meter calibration or at least tried to calibrate it :green:
1) First thing what I noticed was that when sending 1KHz at 0dB through G-SSL it came back -5.8dB. Is this normal?
BTW I changed the 15K to 27K.
2) OK, than I matched the gain with makeup pot to get back the unity gain 0dB from the G-SSL. Just to mention I replaced the 2K resistor with the 4K7 trimpot for better meter adjustments. Than I turned the threshold pot CCW so I could read 10dB GR on the meter. But the actual GR on my DAW was showing only -4.2dB although the trimpot was at the max resistance 4.7K. If I am right than around 10K of resistance would bring my meter to the proper values to get the 10dB meter scale working. IS THIS NORMAL?
Description: METER, EDGE INDICATING 100UA; Accuracy:+/-20%; Depth, Meter Movement FSD:0-100µA; Resistance, coil:1750R;
When I bought this meters I followed my friend's advice coz I didn't know a thing about what I need and what were the values needed. I hope this are usable. I paid a lot of money for 12 meters. 100uA = 0.1mA? Am I screwed or can this be adjusted with more resistance?
Just experienced another surprise... when doing meter calibration or at least tried to calibrate it :green:
1) First thing what I noticed was that when sending 1KHz at 0dB through G-SSL it came back -5.8dB. Is this normal?
BTW I changed the 15K to 27K.
2) OK, than I matched the gain with makeup pot to get back the unity gain 0dB from the G-SSL. Just to mention I replaced the 2K resistor with the 4K7 trimpot for better meter adjustments. Than I turned the threshold pot CCW so I could read 10dB GR on the meter. But the actual GR on my DAW was showing only -4.2dB although the trimpot was at the max resistance 4.7K. If I am right than around 10K of resistance would bring my meter to the proper values to get the 10dB meter scale working. IS THIS NORMAL?
Description: METER, EDGE INDICATING 100UA; Accuracy:+/-20%; Depth, Meter Movement FSD:0-100µA; Resistance, coil:1750R;
When I bought this meters I followed my friend's advice coz I didn't know a thing about what I need and what were the values needed. I hope this are usable. I paid a lot of money for 12 meters. 100uA = 0.1mA? Am I screwed or can this be adjusted with more resistance?
Purusha
Well-known member
I hope I didn't discouraged anyone to help me because of my bold mods :green:
Just a few more things and then I won't bother you so much anymore :wink:
Just a few more things and then I won't bother you so much anymore :wink:
Greg
Well-known member
If your threshold was fully clockwsise and sending in 1.23VAC since, then this is definitely NOT normal.
The 2K resistor will vary depending on your meter. Since you're using a 100uA, you need to shunt it with a resistor. If you didn't already do this, check the schematic I think it's 330R. This is probably why your resistance is so high.
The 2K resistor will vary depending on your meter. Since you're using a 100uA, you need to shunt it with a resistor. If you didn't already do this, check the schematic I think it's 330R. This is probably why your resistance is so high.
