Aquaboy DLX problems

[Orbis_Ignis]

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

[Martan]

What voltage are you running it at?

[Orbis_Ignis]

Sorry...running it at 9v

[Orbis_Ignis]

Just realized I have the same voltage on pin 8 of both bbd's 

[Scruffie]

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.

[Orbis_Ignis]

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

[midwayfair]

8.6V 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?

[Scruffie]

8.6V 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.

[Orbis_Ignis]

8.6V 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

[Orbis_Ignis]

8.6V 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

[Martan]

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.

[dannoceti]

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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[Orbis_Ignis]

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

[Orbis_Ignis]

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?

[Scruffie]

Well you have 3.48V on IC4s outputs, find out where between that and Q3s base the voltage drops off.