I just put together an Aquaboy DLX 2015. I get clean signal but no delay at all. My voltages seem good except for pin 8 on the MN3101 is only 0.5v. I did omit D3 since I'm using the new MN3005. So I'm getting the same voltage on C19. Does this sound right?
I'm going to post my other voltages in a minute. Just wanted to ask the first question
What voltage are you running it at?
Sorry...running it at 9v
(http://i767.photobucket.com/albums/xx317/d14m23/Mobile%20Uploads/2016-04/BB994BA3-1712-48BB-B9B1-A619E8989BA7_zpsiwxygywd.jpg) (http://s767.photobucket.com/user/d14m23/media/Mobile%20Uploads/2016-04/BB994BA3-1712-48BB-B9B1-A619E8989BA7_zpsiwxygywd.jpg.html)
(http://i767.photobucket.com/albums/xx317/d14m23/Mobile%20Uploads/2016-04/97E9C01F-77C8-40B8-A5CA-D4A677C5E3C2_zpsz4w3bklr.jpg) (http://s767.photobucket.com/user/d14m23/media/Mobile%20Uploads/2016-04/97E9C01F-77C8-40B8-A5CA-D4A677C5E3C2_zpsz4w3bklr.jpg.html)
Just realized I have the same voltage on pin 8 of both bbd's :o
Voltages look okay at a glance to me (0.56V on Pin 8 of the 3101 is fine, Vgg is 14/15th Vdd so 8.47/15 = 0.56V) your bias on the 1st BBD is low though.
Haven't gone over your compander voltages in depth but they look reasonable, possibly a little low on the compressor output at pin 7.
Are you powering this with a battery? 8.6V for supply is a bit low.
Quote from: Scruffie on April 12, 2016, 06:02:19 PM
Voltages look okay at a glance to me (0.56V on Pin 8 of the 3101 is fine, Vgg is 14/15th Vdd so 8.47/15 = 0.56V) your bias on the 1st BBD is low though.
Haven't gone over your compander voltages in depth but they look reasonable, possibly a little low on the compressor output at pin 7.
Are you powering this with a battery? 8.6V for supply is a bit low.
Using a power supply. I guess I could put on one of my adjustable plug and raise it to 12 volts. I just don't want to run it 15 volts since I don't have it regulated
Quote from: Scruffie on April 12, 2016, 06:02:19 PM8.6V for supply is a bit low.
One version of the board had a 10R power supply resistor. 40mA would drop .4V across 10R.
Op: Where's the signal disappear when you audio probe?
Quote from: midwayfair on April 12, 2016, 06:16:33 PM
Quote from: Scruffie on April 12, 2016, 06:02:19 PM8.6V for supply is a bit low.
One version of the board had a 10R power supply resistor. 40mA would drop .4V across 10R.
Op: Where's the signal disappear when you audio probe?
But a DM-2 only draws about 10mA, but I forgot this has an optical modulation section which would add more :) Anyway, I was just ruling out a weak battery.
I also didn't check the transistor voltages, Q3&4 are not right.
Quote from: midwayfair on April 12, 2016, 06:16:33 PM
Quote from: Scruffie on April 12, 2016, 06:02:19 PM8.6V for supply is a bit low.
One version of the board had a 10R power supply resistor. 40mA would drop .4V across 10R.
Op: Where's the signal disappear when you audio probe?
That's what's really weird. I seem to not get a clear signal anywhere. I've used my probe many times with success. I even built another one, but I can't even get a clear signal when I put it on the input jack. But I get clear bypass signal and clean signal with the delay on. It's really weird. I'm going to try to play with it some more tonight
Quote from: Scruffie on April 12, 2016, 06:22:10 PM
Quote from: midwayfair on April 12, 2016, 06:16:33 PM
Quote from: Scruffie on April 12, 2016, 06:02:19 PM8.6V for supply is a bit low.
One version of the board had a 10R power supply resistor. 40mA would drop .4V across 10R.
Op: Where's the signal disappear when you audio probe?
But a DM-2 only draws about 10mA, but I forgot this has an optical modulation section which would add more :) Anyway, I was just ruling out a weak battery.
I also didn't check the transistor voltages, Q3&4 are not right.
I was wondering about those, since those pins don't go to ground. I have them socketed. I wonder if they aren't making a good connection. I'll reflow those once my baby boy goes to bed, lol
Also read the build doc again very carefully. There are a few subtle things in there, like leaving out D2 with your setup. Might not be related to your problem, but I spent an hour removing/swapping parts after I thought I was close to finished and went through the build doc again.
I had a similar problem when I built mine, and eventually realized I left a jumper out (C40). There are a few direction on the true bypass page I missed first time around.
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I had it buffer bypass at first and then switched it to true bypass thinking that it might help.
I just took out the socket on Q3 and solder it straight in. Still the same voltages on q3 and q4. Got 8.65, 0, 0 on both. Tried looking for solder bridges and don't see any
Edit: d2, d3, r58, r59 have been omitted. R27, r55, c40 have been jumpered
Did some trouble shooting. I got the audio probe going and getting signal on pin 7 of ic3. I'm getting audio on another pin but I can't remember which one.
I think my problem is with q3&4. I can't figure out why both get voltage in but nothing out. I reflowed all the solder in that area. I've switched out different transistors and nothing changes.
Any ideas?
Well you have 3.48V on IC4s outputs, find out where between that and Q3s base the voltage drops off.
Tracked it down to the cancel trimmer. Reflowed the solder and now I get correct voltages on both q3&4. Still no delay. The audio is coming out of pin 3&4 of the bbd, but I'm not getting any audio out of the cancel trimmer. Setting the trimmer halfway my voltages on all 3 pins is 3.3v
Edit: I was looking at the schematic wrong. Looks like I need to probe between ic3&4
Well, now I'm just getting clock noise on pins 3&4 of the first bbd and it goes all the way to pin 7 of the second bbd :-\
Are you sure you are biasing correctly? I used a fequency analyzer iPhone app to determine the clock fequency when audio probing pin2 of IC5. Set the clock to around 6.5khz, then audio probe the first BBD on pin 3. What I didn't realize first time around was that bias trimmer 1 will be almost completely clockwise to pass delay.
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Can't bias it. I'm not getting any repeats on pins 3 or 4. Just clock noise. My clock is set at 6.5 Hz, which is fully clock wise on the trimmer
Edit: Just checked again and the lowest I can get the clock is 7.2kHz
Turn the clock up to 11.48kHz. I can get delay but only with both bbd's in. So I can't bias it like the dock says. Should I be looking at C33 and possibly changing it
alrighty....I got this bad boy working. I couldn't bias it without both bbd's in. I also changed out C33 to a 150pF, even though my other was measuring at 117pF. That made a huge difference in the clock trimmer, which gave me a huge range to work with. Everything is biased and now I just need to make an enclosure for it. :)
Quote from: Orbis_Ignis on April 13, 2016, 11:40:00 AM
alrighty....I got this bad boy working. I couldn't bias it without both bbd's in. I also changed out C33 to a 150pF, even though my other was measuring at 117pF. That made a huge difference in the clock trimmer, which gave me a huge range to work with. Everything is biased and now I just need to make an enclosure for it. :)
Thats awesome news.. way to stick with it man!
Cody
Way to go!
Thanks guys! I guess I should also mention that I had to use my audio probe to bias the two bbd's. I would get any delay out until I biased both of them. Now I have a sweet sounding delay with very long delay time. Can't wait to get this thing boxed up.