PYE Compressor/Limiter Thread *boards shipping* BOM up!
- Thread starter abechap024
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The meter feeds back into itself like that? Hmmmm
shot
Well-known member
You have INPUT POT labeled twice!
desol
Well-known member
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- Jun 20, 2005
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Hey guys. Haven't been here in a while, had some things come up which took me away from this awesome compressor.
Kind of strange to see all these issues etc going on? ...and abe's no longer around?
I don't believe it. Seems like too nice of a guy. ;D
Def still full tilt on this project...in a bit, when things get smoothed out. Nice to see you guys are ironing out some of these details, for us slower types.
Kind of strange to see all these issues etc going on? ...and abe's no longer around?
I don't believe it. Seems like too nice of a guy. ;D
Def still full tilt on this project...in a bit, when things get smoothed out. Nice to see you guys are ironing out some of these details, for us slower types.
I see it more that the community is coming together to get something working. Abe has been quite busy lately and doesn't have much time to hit the boards lately. And yes, Abe is an awesome guy, but sometimes the more important things take up our time.
tazwolf
Well-known member
Hi
Does anybody have any suggestions as to where is the best place to take the audio signal from if I want to display audio input level on a LED VU meter?
/Taz
Does anybody have any suggestions as to where is the best place to take the audio signal from if I want to display audio input level on a LED VU meter?
/Taz
shot
Well-known member
tazwolf said:
I guess it would be on the input transformer's output (or at the input leg of C3; or at the input leg of the IN potentiometer). But you'd need to add a driver of some sort depending on what kind of meter you're using.
shot
Well-known member
Now I have a question!
PN3640 is obsolete almost everywhere I searched!
I can get MMBT3640 which is from the same product line but it's SOT-23 package. I could solder wires on it's legs and connect it on the board but it would look ugly and may be prone to break after some time.
On some place I found info that MPS3640 is supposed to be replacement but it's values on datasheet differ a bit. Can this be used? (this one is available in a local shop and it's cheapest!)
Luka
PN3640 is obsolete almost everywhere I searched!
I can get MMBT3640 which is from the same product line but it's SOT-23 package. I could solder wires on it's legs and connect it on the board but it would look ugly and may be prone to break after some time.
On some place I found info that MPS3640 is supposed to be replacement but it's values on datasheet differ a bit. Can this be used? (this one is available in a local shop and it's cheapest!)
Luka
Biasrocks
Well-known member
sr1200 said:
Fair enough, but I would expect for at least the first round of building the guy that developed the project be present to iron out things.
That includes providing an up to date schematic which takes about 5 minutes time. Instead we had to put one together by reverse engineering!
I would suggest that this build thread be one of Abe's priorities until things are sorted. Lot's of questions remain.
Mark
shot
Well-known member
mdainsd said:
Yeah well, seem like only Mouser carries them!
Someplace I read that it was discontinued in 2012.
My problem is that in my country Mouser charges too much for shipping. It's not affordable to pay 10 times the price for it!
Could someone check the links to datasheets I put in my previous post and cross check if MPS3640 would work. ;D
I did cross check and noticed MPS3640 has positive current values, while PN3640 has negative. (in fact it's just the same numbers but without minus sign so I'm hesitant to think it's maybe ok). It could be it's a different switching transistor, but why would it be listed as replacement... uhh... im confused...
Shot,
The MPS3640 data sheet I looked at has "negative values" listed. Its a PNP switching transistor, which is what is called for. What I do see for both types is that the pinout (when looking at it with the flat facing you is) from left to right e,b,c.. Be sure to double check before installing. The pinouts on the board are c,b,e for that transistor. Abe used the square pad at each transistor site for the collector (or maybe more correctly "pin 1" as the majority of the transistors used have the collector on pin 1), and I added those to my schematic..
The MPS3640 data sheet I looked at has "negative values" listed. Its a PNP switching transistor, which is what is called for. What I do see for both types is that the pinout (when looking at it with the flat facing you is) from left to right e,b,c.. Be sure to double check before installing. The pinouts on the board are c,b,e for that transistor. Abe used the square pad at each transistor site for the collector (or maybe more correctly "pin 1" as the majority of the transistors used have the collector on pin 1), and I added those to my schematic..
Besides the meter issue, what other questions remain? I'll see if i can get them answered.
shot
Well-known member
mdainsd said:
Yeah, I also cross checked those two datasheets and MPS3640 seems to be biased for positive current while PN3640 is for negative. Beside that, all the values are exactly the same. All but one - they differ in Rise Time. Maybe there's some other transistor similar to MPS3640 but in the negative current range that will do.
Bruno2000 was kind enough to promise to send me couple of PN3640's.
Thumbs up for him!! So I'll go with suggested part.But there may be other builders with no access to Mouser, or Mouser stops carrying them since they are already discontinued, so it would be cool to have an alternative for this switching transistor.
I'm still tempted to put sockets in the TR11 position and try different transistors beside the suggested one. That may happen when I finish my unit. But now it's far from being finished since I'm waiting for transformers and some other parts. I ordered them just recently.
shot
Well-known member
sr1200 said:
In context with meter issue, try to ask what would it take to be able to use regular vu meter!
I have a lot of regular (mostly cheap chinese) vu meters that look cool and I'd like to use a couple. I guess that would require adjusting value of R65 and R67. But if there's anything specific on that...
And also, what would be the difference if R38 is fitted with 12mH inductor compared to 100R resistor.
Should I just forget the inductor and go with the resistor? I get the impression most of you guys did that without problems...
tazwolf
Well-known member
Hii
Do any of the transistors need to be matched?
/Taz
Do any of the transistors need to be matched?
/Taz
@ Taz, not to my knowledge. My unit works fine, i didn't match anything.
@shot, we're barely getting questions regarding the circuit as is, don't think we're going to get an answer about a possible mod, but I'll ask. As far as the difference goes, just socket the part and try both and see what sounds better. I did the 2 inductors on mine.
@shot, we're barely getting questions regarding the circuit as is, don't think we're going to get an answer about a possible mod, but I'll ask. As far as the difference goes, just socket the part and try both and see what sounds better. I did the 2 inductors on mine.
Shot.
"And also, what would be the difference if R38 is fitted with 12mH inductor compared to 100R resistor.
Should I just forget the inductor and go with the resistor? I get the impression most of you guys did that without problems..."
It is a L/C network vrs a R/C network for the -12V regulator used to power the SC. It wont affect anything, use the resistor.
"And also, what would be the difference if R38 is fitted with 12mH inductor compared to 100R resistor.
Should I just forget the inductor and go with the resistor? I get the impression most of you guys did that without problems..."
It is a L/C network vrs a R/C network for the -12V regulator used to power the SC. It wont affect anything, use the resistor.
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