I decided to build a Ross compressor clone using the layout from the Tonepad site (http://www.tonepad.com/getFileInfo.asp?id=9) using all the add-on parts for the Ross compressor and I was using the voltage charts off of the Fuzz Central site for reference (http://fuzzcentral.ssguitar.com/ross.php).
I etched my own circuit board (no open traces detected). Used 2n5088s in stead of 2n3904s. There were a few components I couldn't get the exact value, but I chose the next highest value, so I don't think that it would make that much difference (221pf instead of 220pf, .068uf instead of .05uf). I am using a 500K rev log pot for the sustain control.
What it's doing - bypass operation ok, no sound when engaged. I originally had tantalum caps in place for all the electrolytics, but after it wouldn't work I switched them back to electrolytics. I have swapped the IC out with no luck. Measured all my resistors prior to installation and triple checked the pcb for unwanted solder traces and have found none.
voltages: taken with the sustain control all the way down and the 2k trimpot set to the middle position per the Fuzz Central site (no switched mods added)
power at 9v pad on pcb - 9.6v
IC1
1 - 143mv
2 - .60v
3 - .61v
4 - 0v
5 - 1.4v
6 - 2.9v
7 - 9.6v
8 - 142mv
Q1
C - 7.56v
B - 2.4v
E - 2.0v
Q2
C - 7.1v
B - 2.9v
E - 2.4v
Q3
C - 9.6v
B - 100mv
E - 0v
Q4
C - 9.6v
B - 45mv
E - 0v
Q5
C - 9.6v
B - 9.6v
E - 9.6v
Diodes
D1
A - 0v
K - 9.6v
D2
A - 0v
K - 47mv
D3
A - -0v
K - 29mv
From what I can tell, my problem lies at pins 2 & 3 of the IC, which leads me to think the problem is at Q1, but the voltages there aren't far from the Fuzz Central readings (except for the readings at Q5).
Any little kick in the right direction would be greatly appreciated. :)
Quote from: Plinky on July 28, 2007, 05:06:45 PM
What it's doing - bypass operation ok, no sound when engaged. I originally had tantalum caps in place for all the electrolytics, but after it wouldn't work I switched them back to electrolytics. I have swapped the IC out with no luck. Measured all my resistors prior to installation and triple checked the pcb for unwanted solder traces and have found none.
voltages: taken with the sustain control all the way down and the 2k trimpot set to the middle position per the Fuzz Central site (no switched mods added)
power at 9v pad on pcb - 9.6v
IC1
1 - 143mv
2 - .60v
3 - .61v
4 - 0v
5 - 1.4v
6 - 2.9v
7 - 9.6v
8 - 142mv
From what I can tell, my problem lies at pins 2 & 3 of the IC, which leads me to think the problem is at Q1, but the voltages there aren't far from the Fuzz Central readings (except for the readings at Q5).
Any little kick in the right direction would be greatly appreciated. :)
First of all I would like to salute you to an all exemplary posting of your technical problem with Oh! so many voltage readings... :)
1. The voltage on IC pin 2,3 should be higher yes so right now C... (why do people leave out component numbers? BAD idea!... ) the capacitor to the right of
Q1 is turned the wrong way. Because of the erronious voltages. Pull out Q1 of the sockets temporarily and pull out the IC too.
2. Now meassure the resistance from the IC pin 2 to ground and V+ and post your readings...
3. An OTA bias input is referenced to ONE diod voltage drop... pin 5 should be ~6V. Sounds like the IC could be oriented the wrong way...
oskar
I can only assume you mean the 1uf electro just after the emitter on Q1. Both it and the IC are oriented exactly like the photos on Tonepad
http://www.tonepad.com/photoessay.asp?photoEssayID=32&sequenceNo=3
Is there a problem with the layout that I haven't found?? From looking at the schematic and the layout they're both correct.
If I turn up the sustain control all the way, the voltage on pin 5 of the IC will read about 6.8v. This reading was taken with the sustain all the way off (counter-clockwise), just like the instructions on the Fuzz Central site. According to that page, it should be around .6v, but I am using a 500k rev. log pot for the sustain control rather than the 500k linear that is asked for, so that may the difference there.
Quote from: Plinky on July 29, 2007, 11:13:50 AM
If I turn up the sustain control all the way, the voltage on pin 5 of the IC will read about 6.8v. This reading was taken with the sustain all the way off (counter-clockwise), just like the instructions on the Fuzz Central site. According to that page, it should be around .6v, but I am using a 500k rev. log pot for the sustain control rather than the 500k linear that is asked for, so that may the difference there.
No! It should be around 0.6V anyway.
Quote from: Plinky on July 29, 2007, 11:13:50 AM
I can only assume you mean the 1uf electro just after the emitter on Q1. Both it and the IC are oriented exactly like the photos on Tonepad
Yes after the emi... erh!... arrow thing. :P Again, what is the resistance to ground from the inputs of the IC?
Sooner or later I'm going to ask you for a pic of the pcb. Sooner... pic please? Booth sides.
Quote from: Plinky on July 29, 2007, 11:13:50 AM
Is there a problem with the layout that I haven't found?? From looking at the schematic and the layout they're both correct.
Hardly. The amounts of buildreports at Tonepads indicates no problems at all.
Quote from: Plinky on July 29, 2007, 11:13:50 AM
If I turn up the sustain control all the way, the voltage on pin 5 of the IC will read about 6.8v. This reading was taken with the sustain all the way off (counter-clockwise), just like the instructions on the Fuzz Central site. According to that page, it should be around .6v, but I am using a 500k rev. log pot for the sustain control rather than the 500k linear that is asked for, so that may the difference there.
The internal diode on input 5 on the 3080 chip goes to pin4/ V-. There isn't a proper connection from pin4 V- to ground, otherwise it
would definitely be around 0.6V
EDIT! Added 3080 schemo from the datasheet... Most IC schematics leave out lots of details but I think this is the actual one because
the 3080 is that simple...
Note D1/Q3 this is why we know the voltage should be 0.6V at pin5.
(http://i194.photobucket.com/albums/z305/owallgren/CA3080.png)
:)
oskar
Give me sec...The transistors aren't socketed. :( I'll post my findings ASAP. :)
Quote from: oskar on July 29, 2007, 08:23:58 AM
Pull out Q1 of the sockets temporarily and pull out the IC too.
Now meassure the resistance from the IC pin 2 to ground and V+ and post your readings...
Do you mean the V+ & V- pins on the IC socket or the power & ground pads on the pcb???
Quote from: Plinky on July 29, 2007, 12:47:27 PM
Quote from: oskar on July 29, 2007, 08:23:58 AM
Pull out Q1 of the sockets temporarily and pull out the IC too.
Now meassure the resistance from the IC pin 2 to ground and V+ and post your readings...
Do you mean the V+ & V- pins on the IC socket or the power & ground pads on the pcb???
I meant on the PCB but they should really be the same...
I only meant pull out the transistor if it IS in a socket... don't desolder anything for this!
Too late! Not a big deal. I can solder it back in real quick, and I have plenty of replacements. :D
resistance readings:
pin 2 of IC socket to 9v pad - 254 K ohms
pin 2 of IC socket to grnd pad - 257 K ohms
I wasn't sure at first, so I also measured from pin 2 of the IC socket to pin 4 (V-) and from pin 2 to pin 7 (V+). I ended up with identical readings. :D (257K & 254K)
Quote from: Plinky on July 29, 2007, 12:57:16 PM
Too late!
oops! :P
Quote from: Plinky on July 29, 2007, 12:57:16 PM
resistance readings:
pin 2 of IC socket to 9v pad - 254 K ohms
pin 2 of IC socket to grnd pad - 257 K ohms
I wasn't sure at first, so I also measured from pin 2 of the IC socket to pin 4 (V-) and from pin 2 to pin 7 (V+). I ended up with identical readings. :D (257K & 254K)
Should be 400-500k on both readings... sort of... I think... etc.
Which brings me to suspect cap marked Cc turned wrong way or just bad or shorted... or a combination of these!
What does Vb read and what is the voltage on Cc?
Quote from: oskar on July 29, 2007, 01:16:28 PM
What does Vb read and what is the voltage on Cc?
Not sure what Vb was or where to measure it (yet :D).
I did previously measure both sides of the 1uf electro. If I remember correctly, it was about 2-2.1v on the neg. side of the cap (about the same as at the emitter of Q1) and about .5-.6v on the pos. side (close to what I was getting at pin 2 of the IC).
No. the voltage between Rd, Re...
EDIT (I've been drinking way too much coffee, again...)
1. Voltage between cap Cc,Rd,Re
2. Vb = bias voltage... check upper left part of drawing.
http://www.tonepad.com/getFile.asp?id=9
Quote from: oskar on July 29, 2007, 01:26:25 PM
EDIT (I've been drinking way too much coffee, again...)
Ditto. You ought to try soldering on a caffeine rush. ;D
Quote
No. the voltage between Rd, Re...
9.6v going into Re, 5.04v out, 5.04v into Rd, .6v out (like a good little noob I replaced Rd, which did no good :D)
Quote
1. Voltage between cap Cc,Rd,Re
2. Vb = bias voltage... check upper left part of drawing.
http://www.tonepad.com/getFile.asp?id=9
Had 4.8v at the pos. leg of Cc
measured voltage at Rb - had 3.1v at the top, 2.7v at the bottom
Quote from: Plinky on July 29, 2007, 02:04:09 PM
Quote from: oskar on July 29, 2007, 01:26:25 PM
EDIT (I've been drinking way too much coffee, again...)
Ditto. You ought to try soldering on a caffeine rush. ;D
I did it for a living... I worked with pcb's in a heatcamerafactory last summer... all on caffeine. They even sent the stuff into orbit.
:) everytime they check the shields on the spaceshuttle for dammages... It's with machines I've actually been into... and if they mention
it on the news... it means I'm sleepless... (caffeine or not!) :P
Quote from: Plinky on July 29, 2007, 02:04:09 PM
9.6v going into Re, 5.04v out, 5.04v into Rd, .6v out (like a good little noob I replaced Rd, which did no good :D)
Voltage in the crossing Rd,Re,Cc should be arund 7Volts (leave the soldering iron for a while... ;) )
Something is sinking the durrent dropping the voltage to 0.6V (which happens to be a diode forward voltage drop... but not necessarily (don't touch that iron))
Could you please tell me the colour code on the 1M resistors? ( and don't change them... yet!)
Quote from: Plinky on July 29, 2007, 02:04:09 PM
Had 4.8v at the pos. leg of Cc
measured voltage at Rb - had 3.1v at the top, 2.7v at the bottom
Now wait a minute!
the positive leg of Cc is 4.8V and Rd, Re is 5.04... they are connected and should read the same!
Vb is 3.1V which sounds good.
0.6V out of Rd, that is at the trimpot? WHIT THE IC NOT IN THE SOCKET? ???
And replacing Rd? You're definitely on the case... but at least leave the resistors, you measured them before you put them in
and they are not that sensitive. Look for shorts and unsoldered parts instead...
I'm off for a late dinner and some TV... it's 20.50 in Stockholm
I need to catch some sleep... I'm back tomorrow... :)
Thanks for the help. It's about 2pm here in Dallas, Texas. I have some errands to run, but when I get a chance, I'll definitely look this over and post my findings. :D
QuoteVoltage in the crossing Rd,Re,Cc should be around 7Volts (leave the soldering iron for a while... ;) )
Something is sinking the current dropping the voltage to 0.6V (which happens to be a diode forward voltage drop... but not necessarily (don't touch that iron))
Could you please tell me the colour code on the 1M resistors? ( and don't change them... yet!)
That's what I was thinking (sounded like a good thing to say ;) ). The colors of the 1M resistors are brown, black, black, yellow
QuoteHad 4.8v at the pos. leg of Cc
Now wait a minute!
the positive leg of Cc is 4.8V and Rd, Re is 5.04... they are connected and should read the same!
Oops! I just had a poor connection with my test lead. I double checked and it's 5.04v at the pos. leg of Cc. :D
Quote
0.6V out of Rd, that is at the trimpot? WITH THE IC NOT IN THE SOCKET? ???
That is with the IC installed. I removed it and took readings again:
1 - 0v
2 - 5.0v (huh?!?!?)
3 - 5.0v (wtf?!?!?!)
4 - 0v
5 - 8.8v
6 - 2.9v
7 - 9.6v
8 - 0v
QuoteAnd replacing Rd? You're definitely on the case... but at least leave the resistors, you measured them before you put them in
and they are not that sensitive. Look for shorts and unsoldered parts instead...
Doing that at this moment (yet again). :D
Readings with the IC removed
1 - 0v <---- not connected
2 - 5.0v (huh?!?!?) <---- the error (the 3080! is gone...)
3 - 5.0v (wtf?!?!?!) <---- the error (this means the resistor/capacitor net in front of the OTA is working as it should)
4 - 0v <------ ground
5 - 8.8v <---- bias good
6 - 2.9v <---- looks good
7 - 9.6v <---- connected!!!
8 - 0v <---- not connected
... All well!!!
The case looks like this...
1. IC turned the wrong way
The IC could have written signs on it but the notch/indent indicates the pins one and eight.
2. IC is wrong IC not a 3080
It has the text 3080E (or some other letter) on the back?
3. IC is bad.
Well if it aint case one or two I'll drop a mail to Intersil and ask if there has been problems with this chip...
Could you please report on the exact text on the back of the chip...
It isn't very likely for the IC to be wrong... less likely for two of them failing... actually the whole batch that theese chips came
from could be wrong, I've actually experienced it, but it isn't very likely at all.
It looks to me like the 3080 is turned the wrong way/ or is not a 3080 after all or whatever... I've seen some pretty freaky errors but
in this case I don't suspect intersil(who made the chip) to have done wrong.
QuoteThe case looks like this...
1. IC turned the wrong way
The IC could have written signs on it but the notch/indent indicates the pins one and eight.
2. IC is wrong IC not a 3080
It has the text 3080E (or some other letter) on the back?
3. IC is bad.
Well if it aint case one or two I'll drop a mail to Intersil and ask if there has been problems with this chip...
Could you please report on the exact text on the back of the chip...
It isn't very likely for the IC to be wrong... less likely for two of them failing... actually the whole batch that theese chips came
from could be wrong, I've actually experienced it, but it isn't very likely at all.
It looks to me like the 3080 is turned the wrong way/ or is not a 3080 after all or whatever... I've seen some pretty freaky errors but
in this case I don't suspect intersil(who made the chip) to have done wrong.
The CA3080E is not from Intersil. It's from Harris Semiconductor. I bought 5 of them online from Effects Connection.
http://www.effectsconnection.com/oscommerce/product_info.php?cPath=36&products_id=266&osCsid=a29e1c803ac9c6f232b2c05a3eedf9bc
On the back is some raised lettering (L5 in a circle). The pic on the store website is identical to what I have. I have the notch on the IC and socket pointed towards the 2K trimpot, just like all the pics I've seen.
Quote from: Plinky on July 29, 2007, 06:10:49 PM
The CA3080E is not from Intersil. It's from Harris Semiconductor. I bought 5 of them online from Effects Connection.
http://www.effectsconnection.com/oscommerce/product_info.php?cPath=36&products_id=266&osCsid=a29e1c803ac9c6f232b2c05a3eedf9bc
On the back is some raised lettering (L5 in a cirle). The pic on the store website is identical to what I have.
Intersil bought harris ------ voilá! :P
You bought FIVE?! Just pop a fresh one in there then!... what are you waiting for? :o
QuoteYou bought FIVE?! Just pop a fresh one in there then!... what are you waiting for? :o
Just tried all I had (4) - no change in voltage. :( This reminds me of some cars I've worked on. After throwing about 3 parts at it, chances are that won't fix it. :D
I'm off to see Andy Timmons at the Granada tonight. If I can get my camera to agree with me, I'll take some pics front and back of the pcb and wiring.
I have no more ideas for the moment... :'(
I dropped a message to effectsconnection to see if someone else had complained...
???
Alright. Got some fresh batteries in my camera, although I wish that would help me take a better picture (photography is my brother-in-law's dept.). ;D
(http://i172.photobucket.com/albums/w27/plinkytx/IMG_1197.jpg)
(http://i172.photobucket.com/albums/w27/plinkytx/IMG_1196.jpg)
(http://i172.photobucket.com/albums/w27/plinkytx/IMG_1185.jpg)
(http://i172.photobucket.com/albums/w27/plinkytx/IMG_1188.jpg)
Disregard the yellow lead (it broke from the switch while taking these pictures :D)
This is the first Tonepad layout I've used, so let me know if something appears wrong with the offboard wiring.
On a side note, the LED isn't working. I looked at the circuit and it appears to be wired correct but I haven't checked the LED yet.
You did have a cable in the input jack when you probed the pcb did you? DID YOU? ??? :)
It is easy to forget and would make the 3080 appear to be ungrounded...
oskar
Quote from: oskar on July 30, 2007, 04:13:33 PM
You did have a cable in the input jack when you probed the pcb did you? DID YOU? ??? :)
It is easy to forget and would make the 3080 appear to be ungrounded...
oskar
Yup, I did. Made it real fun to keep the pcb from falling off the bench. :D
It isn't really a closeup... but this looks like a bad solderjoint.
(http://i194.photobucket.com/albums/z305/owallgren/IMG_1188.jpg)
Maybe you should call Ross customer service?! ::)
Yeah, I noticed that after I took the pic. I sucked all the solder out to make sure there was nothing shorted underneath, and resoldered it. ;D
Quote from: oskar on July 30, 2007, 04:27:46 PM
Maybe you should call Ross customer service?! ::)
Was that really necessary??? :)
4 uggly little arrows... this looks like traces of copper that should have been etched... can't really see. :o
(http://i194.photobucket.com/albums/z305/owallgren/traces.jpg)
That's probably just the light. There's no short in any of those spots.
Anybody else care to chime in??? I've checked all the solder joints and all are clean and not shorted.
yeah, I'll help you bump this... Help over here!
Honestly I'm clueless... :P --- But brother, I checked your link and you shure can play...
Quote from: oskar on July 31, 2007, 01:30:29 PM
yeah, I'll help you bump this... Help over here!
Honestly I'm clueless... :P --- But brother, I checked your link and you shure can play...
lol!!
At least I have something going for me. :D
Is it possible from the pics to determine if I have the offboard wiring correct?? Like I said before, this is the first Tonepad layout I've done so the offboard wiring is completely different. I need to debug the LED. At least maybe I can get it to work. :D
Mark Hammer is floating around the forums at the moment. Maybe I can channel out and get his input. :)
I only glanced at the wiring...
The problem is that it doesn't explain the voltages at the input of the OTA. If I can find time and
components and if, if , if... I could breadboard the OTA part of the machine and try to duplicate
this particular error but... I don't have time. At least not tonight.
:'( :'( :'( :'( :'( :'( :'(
Well, I have enough spare parts, so I may just do the same myself. Lord knows I need to brush up on my schematic reading skills. :D
EDIT --- This post censored! ::) --- due to violations of fundamental laws of physics!
OTA CA3080 test
(http://i194.photobucket.com/albums/z305/owallgren/rosscircuit.png)
I tried to replicate your problems with the circuit above, but only with DC levels as I don't have a scope...
( - ) indicates I forgot to measure this one...
All measures was taken while sweping the pot (470k) and in the instances where the value changed it has been
given as an interval.
V+/pin7 removed
| pin | V |
| 2 | 2.3 |
| 3 | 2.3 |
| 4 | 0.0 |
| 5 | 6.0-8.5 |
| 6 | 0.0 |
| 7 | 0.0 |
|
Ground pin removed
| pin | V |
| 2 | 4.6 |
| 3 | 4.6 |
| 4 | - |
| 5 | 4.7-6.7 |
| 6 | 1.4 |
| 7 | 9.2 |
|
Both V+ and ground pins removed
| pin | V |
| 2 | 4.6 |
| 3 | 4.6 |
| 4 | - |
| 5 | 4.6-6.6 |
| 6 | 0.5 |
| 7 | 0.0 |
|
Also, shorting pin6 to ground didn't make any difference on the other pins as expected.
I didn't manage to replicate your problems, sorry. I even turned the chip around (with a 100R resistor on V+) but
it didn't come close to reasonable.
I have no clue to why this can be. If there where any problems with HF instability ringing I would most surely have missed this but
oscillations reads out on a DMM in DC mode as a voltage so it probably would have shoved up somehow (and perhaps did...)
The transistor you traded for have more than two times Hfe than the 3094's but I don't see what difference it would make in
this case.
I don't want any more nightmares and I want the voices to stop too. :icon_twisted: ----moahahahahahaha!
Hello,
I ordered 3 Harris CA3080E's from Effects Connection for a 1980 Dynacomp I acquired without the chip.
I am having the exact same problem!
I have tried, literally everything (desoldering all the legs of components to b+ which could be causing signal drain, desoldering all the other ground connections). The voltages are fine without the chip in place, once I place the chip in, I get around .6 volts. I even made a little bridge with another socket so I could just connect pins 2&3 to the chip. Voltages are good until I connect pin 4, at which point they all drop to .6. I tried lowering the 470k to 100k and it raised one pin to .9 with the other still at .6.
All three chips the same. Given the original poster's experience and my own, I really think that the batch of CA3080e's at effects connection is bad. :(
I have no idea how to get this thing to work at the moment....
PS I also get .6 volts on pin 1 which is supposed to have no connection.
It's another chip marked wrong?! ...or the bonding machine is set up with the wrong program... :icon_eek:
maybee you can save them and sell them as relics to IC-collectors years from now?
I measured pin 1 and 8 on my 3080's and they're unconnected allright.
:P skar
EDIT
Quote from: Jackie Treehorn on August 03, 2007, 07:14:22 PM
All three chips the same. Given the original poster's experience and my own, I really think that the batch of CA3080e's at effects connection is bad. :(
If this is so at least the error is spotted. It's a bad case considering the chip is obsolete.
I believe the problem you are having it due to the fact, that we got no review of the Timmons concert!! ;D
That man plays an amazing guitar.
mfg Jake
Sorry guys... for some reason I stopped getting emails about replies to this thread. :(
So I'm not the only one with this problem, eh?? I just made an order from Small Bear. Maybe I can get a couple of CA3080s from him and see if it is in fact a bad batch of ICs from FX conn. Maybe Jake and me should both contact FX Conn with our dilemma?
Looking at your test schematic oskar, I noticed that the IC power & ground pins are reversed. In the 3080 datasheet and on the tonepad layout, pin 4 is V- and 7 is V+. Any particular reason for this???
BTW, Timmons put on another good show as usual. Since he signed on with Favored Nations he doesn't play around Dallas much anymore and it's harder to get a moment to talk with him like in the past. He was surrounded on all sides by fans so I didn't get to say hi to him after the show. Although, he still reads all the email from his site and I did get to chat with him briefly before the soundcheck. Truly one of the most humble and nicest guys I've had the pleasure of meeting. :D
I fired off a mail to fxconnection just in case but they didn't answer...
Quote from: Plinky on August 05, 2007, 12:23:20 PM
Looking at your test schematic oskar, I noticed that the IC power & ground pins are reversed. In the 3080 datasheet and on the tonepad layout, pin 4 is V- and 7 is V+. Any particular reason for this???
Because I'm just that stupid...
Quote from: Plinky on August 05, 2007, 12:23:20 PM
So I'm not the only one with this problem, eh?? I just made an order from Small Bear. Maybe I can get a couple of CA3080s from him and see if it is in fact a bad batch of ICs from FX conn. Maybe Jake and me should both contact FX Conn with our dilemma?
I still don't think it's a bad batch, but you can't rule it out... I've seen bad batches of components before (maxim rs232), things started to freak out at work
and eventually they sent failing components to a lab that cracked them open and just put them under a microscope. You could really see strange oxidpatches and scratches on the photos. Still it's highly unusual.
Quote from: Plinky on August 05, 2007, 12:23:20 PM
BTW, Timmons put on another good show as usual. Since he signed on with Favored Nations he doesn't play around Dallas much anymore and it's harder to get a moment to talk with him like in the past. He was surrounded on all sides by fans so I didn't get to say hi to him after the show. Although, he still reads all the email from his site and I did get to chat with him briefly before the soundcheck. Truly one of the most humble and nicest guys I've had the pleasure of meeting. :D
Timmons... who? ???
ps. check out my uberamazing schemo in the FX-X voting thread!!!
:P skar
www.andytimmons.com
Great guitar player. I have both of his Ibanez signature models - the AT100 and AT300.
Not sure how long it will take FX Conn to reply since he's in the process of moving to North Carolina. The site said approx. 3 weeks. :icon_neutral:
I went ahead and ordered a couple of 3080s from Steve at Small Bear. That should determine if the chips are ok or my construction skills are lousy. :D
Ok. Long thread... double_check resistance pin5 to V+...
otherwise... It should work!?
?
Wasn't sure where again, so I made a couple of measurements. :)
Pin 5 to Pin 7(V+) - 600 megohm
Pin 5 to 9v input on pcb - 600 megohm
DUDE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It's the chip!!. I just got my order from Small Bear. Steve's 3080s are different than what I got from FXConn (RCA instead of Harris/Intersil). All the voltages at the IC are perfect - 4.85v on pins 2 & 3, .6v on pin 5. I'm posting this just as I took the readings. Will post later with sound results.
I don't use a compressor regularly, so I'm not sure if it's working or not. I notice a level change, but that's it at the moment. I wish this would've happened sooner. I have to get ready for a gig, so I have to wait until I recover tomorrow to play with this. :(
Quote from: Plinky on August 11, 2007, 05:37:54 PM
DUDE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It's the chip!!. I just got my order from Small Bear. Steve's 3080s are different than what I got from FXConn (RCA instead of Harris/Intersil). All the voltages at the IC are perfect - 4.85v on pins 2 & 3, .6v on pin 5. I'm posting this just as I took the readings. Will post later with sound results.
I can sleep again... :'(
Same source though I think... RCA (marked CA) where bought by Harris who where bought by Intersil...? ...something like that...
Yes, it is the chip. I picked up a couple NTE996's yesterday (which are relabeled LM3080's, actually) and got my dynacomp working.
I've been tweaking it and haven't had time to post! The stock circuit didn't sound that great, kind of harsh, noisy, and distorted, so I've been doing Ross/Saffron Squeeze type mods and swapping the ceramic/electrolytic coupling caps with film caps. Putting the 10k on the collector of Q1 with 33 mf of filtering was the push over the edge! Quiet and more lush!
From what I can tell it's working (see earlier post concerning performance :) )
My big problem is at the moment I don't have a real good clean amp to really test it out. I sold my Deluxe Reverb reissue, my sister's boyfriend has my Blues Jr., and
I don't feel like unloading my Stiletto from the truck (very nice clean for a 2 channel high gain amp). Having said all that, all I have at the moment is a Torres overhauled silverface Champ (I installed kit #3 - the whole shibang :)). It's got a great clean sound, but it starts to break up at about 5 so it's really hard to tell without a lot of on/off comparison.
The pedal is very quiet for one that is not enclosed. I built the Ross version, so I have the cap/resistor combo you spoke of and more. : D I have a gig coming this Saturday, so hopefully I can get it enclosed and test it out at full stage volume. I still have the first pcb I did that I thought was faulty. I may just try that one - it's populated with tantalum caps instead of electrolytics. :D
BTW, Thank you for all your help with this project Oskar. I greatly appreciate it. ;)
You're welcome... :)
I'm glad I stuck with it, even though I didn't feel good at all about seeing this thread bump right up again.
I'm still curious about what precisely is the matter with them chips ( knowing you they're all thrown away by now...? ).
oskar
QuoteYou're welcome... Smiley
I'm glad I stuck with it, even though I didn't feel good at all about seeing this thread bump right up again.
I'm still curious about what precisely is the matter with them chips ( knowing you they're all thrown away by now...? ).
oskar
What's wrong with the thread continuing for so long? I've seen plenty of threads here way longer than this one.
I haven't thrown them away. I sent an email to John at FXConn to see about getting a refund or some known good replacements. :D
Now the 4 Intersil chips I ordered from Small Bear arrived. Interestingly enough, they sound somewhat different than the LM3080. They get more squeeze/squish and sound bolder, whereas the LM3080 is a bit more subtle. There were also differences in the attack time of the Intersil chips. I found one that had a bit slower attack which let the transient come through pretty well; lots of slam before the squeeze. There was another that just got the click, which I didn't like much. Then some were fast with the compression coming on immediately.
I'm really liking the pedal now. It's got a great Little Feat type sound!