Hi all. Question about the signal path for the abdx. I'm getting dry output, but no delay and have nothing on pin 7 of IC2. I tried two different ICs in IC2 with the same result. I'm not sure the signal is getting to IC2. Should I have a somthing on pin 6 of IC2 even if that IC isn't working? I traced the signal to the left side of C4 and R7. That seems to be where it stops. Nothing on the right sides.
Thanks!
It's normal to not hear the signal at the inverting input of IC1A, but you should have something at the output (pin1). If there's no output there, you need to investigate. Take some voltage readings on the IC, check your soldering on the IC pins.
Great, thanks for the quick reply! I think that confirms what I was thinking. I'll focus on getting a signal on pin 1 of IC1A.
Sure. After that, take a listen to pin6 and pin7 of IC2. Those are the input/output of the compander.
I am still trying to make progress on the signal getting to the sa571, but haven't succeeded yet. I tried a different lf353 and checked continuity on all the components in the area.
Here are my voltage readings:
LF353
4.66
4.66
4.66
0
4.66
4.66
4.66
9.2
SA571
1.21
1.80
1.80
0
1.80
1.80
3.09
1.80
.85
1.80
1.80
9.20
1.80
4.71
4.71
1.80
V3205D #1
0
4.07
2.33
2.33
0
1.86
4.06
8.18
V3205D #2
0
4.06
2.57
2.57
.125
6.6
4.06
8.19
3102 - Clock
8.19
4.07
0
4.07
4.01
4.01
4.01
7.67
Any help is appreciated.
Thanks!
Just bumping this, because I still need help. I'll post some pictures later.
I'm back. I waited to revisit this build until I could finish populating my second abdx board. My first parts order got lost in the mail so it took awhile. I just finished populating it and I'm having the exact same problem as the first. I'm not getting a signal on pin 1 of IC1A. I'm getting a signal on pin 2 and the sides of C4 and R7 that are connected to pin 2. The sides of C4 and R7 connected to pin 1 I get nothing.
Here are some photos. I'm hoping something will stand out to someone as populated wrong or is it possible both of my LF353s are bad? They're labeled LF353P and are from Tayda.
Thanks for your help.
(http://img.photobucket.com/albums/v655/mmerring/IMG_0991.jpg) (http://smg.photobucket.com/user/mmerring/media/IMG_0991.jpg.html)
(http://img.photobucket.com/albums/v655/mmerring/IMG_0989.jpg) (http://smg.photobucket.com/user/mmerring/media/IMG_0989.jpg.html)
(http://img.photobucket.com/albums/v655/mmerring/IMG_0985.jpg) (http://smg.photobucket.com/user/mmerring/media/IMG_0985.jpg.html)
(http://img.photobucket.com/albums/v655/mmerring/IMG_0982.jpg) (http://smg.photobucket.com/user/mmerring/media/IMG_0982.jpg.html)
(http://img.photobucket.com/albums/v655/mmerring/IMG_0981.jpg) (http://smg.photobucket.com/user/mmerring/media/IMG_0981.jpg.html)
Power to your BBDs is wrong, you should have near 8v2 on Pins 5 & 8, seems power is being grounded by your readings up there...
Pins 2 & 6 (clock) should be the same and near half supply too and you have those readings as being 2 & 7 by the looks of it.
Take v3205 readings again on both builds.
Scruffie, thanks for your help. I did have pins 5-8 on the BBDs reversed in the readings above so pin 8 is actually the one I'm getting no voltage. I checked continuity with ground on all the pins and only pin 1 is connecting on both BBDs.
Pin 8 seems to be getting the correct voltage on the newer build.
For the clock I'm getting around 4.1 on both 2 & 6. Pin 7 on the clock is a little less at 4.02. Not sure I'm following you with what you're saying about the clock readings.
Original Build: Second Build:
IC1 - LF353 IC1 - LF353
1 4.63 1 4.67
2 4.63 2 4.67
3 4.6 3 4.67
4 0 4 0
5 4.6 5 4.67
6 4.61 6 4.67
7 4.63 7 4.67
8 9.28 8 9.39
IC2 - SA571N IC2 - V571D
1 1.01 1 1.05
2 1.8 2 1.92
3 1.8 3 1.92
4 0 4 0
5 1.81 5 1.92
6 1.8 6 1.92
7 3.08 7 3
8 1.81 8 1.92
9 1.81 9 1.92
10 4.72 10 5.37
11 4.72 11 5.37
12 1.81 12 1.92
13 9.24 13 9.39
14 1.8 14 1.92
15 1.81 15 1.92
16 0.84 16 0.91
IC3 - V3205D IC3 - V3205D
1 0 1 0
2 4.08 2 4.11
3 2.34 3 3.86
4 2.34 4 3.9
5 8.19 5 8.25
6 4.07 6 4.11
7 1.86 7 0.83
8 0.16 8 7.72
IC4 - V3205D IC4 - V3205D
1 0.02 1 0
2 0 2 4.11
3 2.59 3 3.82
4 2.59 4 3.84
5 8.19 5 8.26
6 4.07 6 4.11
7 6.62 7 1.48
8 0.19 8 7.72
IC5 - CD3102GP IC5 - CD3102GP
1 8.2 1 8.26
2 4.07 2 4.11
3 0 3 0
4 4.07 4 4.11
5 4.01 5 4.07
6 4.14 6 4.15
7 4.02 7 4.02
8 7.67 8 7.73
I'm building one of these as well and i have only put on the resistors, is there a reason you left out D3 on both and also are the jumpers set correctly? It's hard to tell from the pictures.
Quote from: muehring on July 10, 2013, 02:33:43 AM
Scruffie, thanks for your help. I did have pins 5-8 on the BBDs reversed in the readings above so pin 8 is actually the one I'm getting no voltage. I checked continuity with ground on all the pins and only pin 1 is connecting on both BBDs.
Pin 8 seems to be getting the correct voltage on the newer build.
For the clock I'm getting around 4.1 on both 2 & 6. Pin 7 on the clock is a little less at 4.02. Not sure I'm following you with what you're saying about the clock readings.
Original Build: Second Build:
IC1 - LF353 IC1 - LF353
1 4.63 1 4.67
2 4.63 2 4.67
3 4.6 3 4.67
4 0 4 0
5 4.6 5 4.67
6 4.61 6 4.67
7 4.63 7 4.67
8 9.28 8 9.39
IC2 - SA571N IC2 - V571D
1 1.01 1 1.05
2 1.8 2 1.92
3 1.8 3 1.92
4 0 4 0
5 1.81 5 1.92
6 1.8 6 1.92
7 3.08 7 3
8 1.81 8 1.92
9 1.81 9 1.92
10 4.72 10 5.37
11 4.72 11 5.37
12 1.81 12 1.92
13 9.24 13 9.39
14 1.8 14 1.92
15 1.81 15 1.92
16 0.84 16 0.91
IC3 - V3205D IC3 - V3205D
1 0 1 0
2 4.08 2 4.11
3 2.34 3 3.86
4 2.34 4 3.9
5 8.19 5 8.25
6 4.07 6 4.11
7 1.86 7 0.83
8 0.16 8 7.72
IC4 - V3205D IC4 - V3205D
1 0.02 1 0
2 0 2 4.11
3 2.59 3 3.82
4 2.59 4 3.84
5 8.19 5 8.26
6 4.07 6 4.11
7 6.62 7 1.48
8 0.19 8 7.72
IC5 - CD3102GP IC5 - CD3102GP
1 8.2 1 8.26
2 4.07 2 4.11
3 0 3 0
4 4.07 4 4.11
5 4.01 5 4.07
6 4.14 6 4.15
7 4.02 7 4.02
8 7.67 8 7.73
Right, the new build voltages are better for the most part so we'll focus on that one
The only thing off is your Bias voltage on Pin 7 of both BBDs, it's very low, should be near half supply... adjust the trims, if it wont get near 4.1V check values for R19 & 20 and 25 & 26 and what value did you use for R55 and R27? You may need to reduce them if the trim will not get the voltage up to 4.1V +/-1.5V.
Quote from: jimilee on July 10, 2013, 03:18:42 AM
I'm building one of these as well and i have only put on the resistors, is there a reason you left out D3 on both and also are the jumpers set correctly? It's hard to tell from the pictures.
Bean suggests to in the build docs for certain build set ups... however as far as I can see from the schematic it
should be in there for the 3205 version.
[/quote]
Bean suggests to in the build docs for certain build set ups... however as far as I can see from the schematic it should be in there for the 3205 version.
[/quote]
I've read the BOM ove and over and I don't see where he suggests leaving off D3. I see where he suggests leaving off D1 and the last 3 resistors though. I'm building the 3008 version and it's a bit intimidating. Sorry for the hi-jack.
Thanks! I'll try to get the voltage up on pin 7 and check those resistors. Do you think that would effect the signal at pin 1 on the LF353?
For D3 it depends on the clock you're using. Here is the info from the build docs:
NOTE: if you are using the MN3101 with the v3205, you must use D3 to approximate the correct Vgg voltage for pin8 of the clock (14/15 of Vdd). In all other cases (including when using an MN3102, BL3102 or v3102) you should omit D3. The 3102 variety clocks automatically generate the correct Vgg voltages needed in each case.
Quote from: muehring on July 10, 2013, 02:17:32 PM
Thanks! I'll try to get the voltage up on pin 7 and check those resistors. Do you think that would effect the signal at pin 1 on the LF353?
For D3 it depends on the clock you're using. Here is the info from the build docs:
NOTE: if you are using the MN3101 with the v3205, you must use D3 to approximate the correct Vgg voltage for pin8 of the clock (14/15 of Vdd). In all other cases (including when using an MN3102, BL3102 or v3102) you should omit D3. The 3102 variety clocks automatically generate the correct Vgg voltages needed in each case.
And there you have it, thank you. I think I"m just going to put mine on the back burner for a while.
I've just noticed you used multi-turn trimmers, you probably haven't made a value mistake and you're just gunna have to sit there and turn them for ages to get the bias voltage up :D while checking for signal at the output of each BBD.
Get them up to about 3V on Pin 7 before you start checking for signal and then keep turning.
Yeah, I probably cranked those trimmers too far and brought the voltage down when trying to find the middle position for biasing.
I'll report back when I have a chance to make the adjustments.
Quote from: muehring on July 10, 2013, 02:17:32 PM
Thanks! I'll try to get the voltage up on pin 7 and check those resistors. Do you think that would effect the signal at pin 1 on the LF353?
For D3 it depends on the clock you're using. Here is the info from the build docs:
NOTE: if you are using the MN3101 with the v3205, you must use D3 to approximate the correct Vgg voltage for pin8 of the clock (14/15 of Vdd). In all other cases (including when using an MN3102, BL3102 or v3102) you should omit D3. The 3102 variety clocks automatically generate the correct Vgg voltages needed in each case.
I was reading up on this yesterday.... The first line of this note is quite clear, but I'm still not sure if D3 needs to be in place when building an MN3005/MN3101 ABDX.... Anybody know this? Sorry for the hijack....
Paul
Quote from: DutchMF on July 10, 2013, 04:03:14 PM
Quote from: muehring on July 10, 2013, 02:17:32 PM
Thanks! I'll try to get the voltage up on pin 7 and check those resistors. Do you think that would effect the signal at pin 1 on the LF353?
For D3 it depends on the clock you're using. Here is the info from the build docs:
NOTE: if you are using the MN3101 with the v3205, you must use D3 to approximate the correct Vgg voltage for pin8 of the clock (14/15 of Vdd). In all other cases (including when using an MN3102, BL3102 or v3102) you should omit D3. The 3102 variety clocks automatically generate the correct Vgg voltages needed in each case.
I was reading up on this yesterday.... The first line of this note is quite clear, but I'm still not sure if D3 needs to be in place when building an MN3005/MN3101 ABDX.... Anybody know this? Sorry for the hijack....
Paul
No, leave it out.
Thanks Scruffie!!
OK, I was able to get the voltage up on pin 7 on each BBD pretty quickly, but still no signal on pin 1 of LF353 or any of the pins on the compander or BBDs. I took the bias voltage from 3.1 volts to around 6v when testing for a signal.
I was also able to get the voltage to 7.63 on pin 8 of the BBDs on the first board. C19 wasn't connecting to pin 8 of the clock. Not sure why, but I put a jumper between those. Same problem with the signal on that board.
Any thoughts? I think I'll order some new LF353s since I don't think it makes sense that the signal dies on pin 2 there.
Quote from: muehring on July 11, 2013, 02:12:27 AM
OK, I was able to get the voltage up on pin 7 on each BBD pretty quickly, but still no signal on pin 1 of LF353 or any of the pins on the compander or BBDs. I took the bias voltage from 3.1 volts to around 6v when testing for a signal.
I was also able to get the voltage to 7.63 on pin 8 of the BBDs on the first board. C19 wasn't connecting to pin 8 of the clock. Not sure why, but I put a jumper between those. Same problem with the signal on that board.
Any thoughts? I think I'll order some new LF353s since I don't think it makes sense that the signal dies on pin 2 there.
That is odd as your voltages look okay...
Got any other dual opamps you can try in there?
I just tried a OPA2132PA and a TL072. Same problems. I'm pretty stumped. It looks like the inverting inputs of the lf353 are pins 2 and 6. I get a signal on both of those. In madbean's reply he mentions it's normal to not hear a signal at the inverting input. Should I not have a signal at these pins?
Just seen you said you get dry output, your opamp is fine.
Taking V readings on all the transistors.
Here are the transistor readings:
first board Second Board
Q1
C 9.44 C 9.44
B 4.34 B 4.33
E 3.93 E 3.90
Q2
C 9.44 C 9.44
B 3.07 B 2.99
E 2.50 E 2.42
Q3
C 9.44 C 9.44
B 4.24 B 7.02
E 3.67 E 6.43
Q4
C 9.44 C 9.31
B 3.66 B 6.41
E 3.08 E 5.81
Thanks Scruffie!
Maybe I missed it, are you sure the bbd's are good?
Quote from: jimilee on July 12, 2013, 09:06:28 PM
Maybe I missed it, are you sure the bbd's are good?
They're new Cool Audio v3205 BBDs, no reason all 4 should be dead unless they were really badly mishandled.
This is odd, your voltages all look within limits, you have dry signal yet have 2 separate builds not firing up...
I'll have a think what to do next when my heads working.
I'm following this thread very closely as my ABDX has developed a similar problem.
Dry signal gets through but no delay. The only difference is that if I toggle the power on and off a few times the delay kicks-in and it works as it should. It does this both in and out of the box and with different power supplies. It might be a different issue but it might help the troubleshooting process (haven't had the time to do this yet).
Also using v3205's.
I wonder if the Cool Audio chips are the issue? How many people have built this with these chips? Has anyone had any issues with powering the effect? Where did you source the chips?
Quote from: Scruffie on July 13, 2013, 09:05:21 PM
This is odd, your voltages all look within limits, you have dry signal yet have 2 separate builds not firing up...
This is indeed odd.
Quote from: twin1965 on July 13, 2013, 11:14:03 PM
I'm following this thread very closely as my ABDX has developed a similar problem.
Dry signal gets through but no delay. The only difference is that if I toggle the power on and off a few times the delay kicks-in and it works as it should. It does this both in and out of the box and with different power supplies. It might be a different issue but it might help the troubleshooting process (haven't had the time to do this yet).
Also using v3205's.
I wonder if the Cool Audio chips are the issue? How many people have built this with these chips? Has anyone had any issues with powering the effect? Where did you source the chips?
Quote from: Scruffie on July 13, 2013, 09:05:21 PM
This is odd, your voltages all look within limits, you have dry signal yet have 2 separate builds not firing up...
This is indeed odd.
It is possible there is a bad batch, but there could also be a bad batch of companders or user error or lack of ESD handling, I wouldn't jump to the BBD being the issue (people seem to do this as it's the most expensive part).
And you say the delay
does work some times so it's not the BBD.
Start a thread and post your voltages.
Na, I just thought I'd ask cause it wasn't mentioned and it seems to be stumping you guys. Bad parts is the worst kind of trouble shooting for sure.
Quote from: Scruffie on July 13, 2013, 11:48:03 PM
Start a thread and post your voltages.
Will do. Have already started troubleshooting.
Quote from: Scruffie on July 13, 2013, 09:05:21 PM
This is odd, your voltages all look within limits, you have dry signal yet have 2 separate builds not firing up...
I'll have a think what to do next when my heads working.
Thanks! Let me know if you have any ideas. Good to know my voltage readings are OK. I'll keep checking components and continuity with the schmatic and see if I can figure it out. I don't think it's the BBDs or compander because there is no signal going into either.
Did you manage to fix the problem?
I would be interested to know what the outcome of your troubleshooting was.
I haven't had much free time to work on it, but plan to get back to it this week. I'll post any updates here.
I made a little bit of progress today I guess. I'm getting one repeat now. It's pretty gritty sounding and I have to strum hard to get it to repeat. I tried to calibrate according to the instructions, but I don't have a signal at any pin of the BBDs still nor at pin 6 of the compander or pin 1 of LF353. I did notice that when probing the input I still get the repeat. I feel like the input should be clean. Any thoughts?
Wait, so your signal is not clean on input? Something isnt right for sure.
Yeah, I'm getting the delay at the input.
Now that these aquaboys have been sitting on my desk idle for about six months I think I'm going to start digging in again. Anyone have any fresh ideas?
Also, if anyone wants to help me out and take a stab at trouble shooting one I'd be willing ship one and trade something or paypal for the help.
how did you connect the audio probe? sounds like guitar into probe and fx out into the amp? otherwise delay at the input makes no sense.
Yeah, the way you described is how I audio probed it.
Does it make sense to have delay at the input with that setup?
yes, makes perfect sense! what you're doing is nothing more than sending the signal through the input, from where it passes through the whole circuit to the amp. That's why you got signal on the inputs of the opamps, too; it's supposed to be the other way around: guitar into fx input, and the audio probe connected to the amp. now you use the probe to pick up the signal at any point of the circuit you want, and it doesn't pass the rest of the circuit so you could exactly tell where the signal gets lost.
If you're already getting delay it should just be misbiased, try adjusting the trimpots with the probe hooked up to the amp :)
Awesome, thanks for the help! I'll try probing the other way around tonight.
You called it DonDougie! Apparently the only thing wrong with both of these boards was my backwards audio probing. I plugged the audio probe in the amp and got a signal at all the right spots. Thanks so much!
I have one boxed up and it sounds amazing. Definitely worth the wait.
Glad you got it working! I agree, it's a really great sounding circuit.