My aquaboy dx build- dry signal, no delay mn3005

[thorpy6]

Hi, I hate having to ask for help but....... I'm stuck.
I've spent the day building an aquaboy dx using:

2x tested mn3005 (tested in a dod fx90)
1x tested sa570 compander
1x mn3101 also tested

I've tried everything I can think of, including:

reflowed all joints
Checked all resistors
Checked all caps
Checked polarity/ orientations

The good:

Bypass is clear
Dry signal is good
I get clock noise when I adjust the clock trimmer (9v on pin 1)
The vactrol and lfo portion is working- rate and depth knobs work
The mix knob works
The depth knob adjusts the freq of the clock noise heard

The bad:

No matter what I do there is no delay at all.


I had d3 installed initially- cut out now- mn3101 retested and still works
Running at 9v and see 9v at the pin 1 of each mn3005.

What else can I do? Any suggestions?

[jighead81]

Exact same thing I got going on, except I'm running a little under 15v

[Scruffie]

Full voltages from both of you

[jighead81]

I don't know what happened, but I swapped 10k's for the 39k's I had in R13 & R14, I moved the bias trims CW in small increments until the repeats were clean.  I still got some tweaking to do, but it's useable now

[Scruffie]

I don't know what happened, but I swapped 10k's for the 39k's I had in R13 & R14, I moved the bias trims CW in small increments until the repeats were clean.  I still got some tweaking to do, but it's useable now

You're looking to bias the compander output to 1/2 supply, so what's the voltage on Pin 7 & 13 of the 570/571.

[thorpy6]

I don't know what happened, but I swapped 10k's for the 39k's I had in R13 & R14, I moved the bias trims CW in small increments until the repeats were clean.  I still got some tweaking to do, but it's useable now

You're looking to bias the compander output to 1/2 supply, so what's the voltage on Pin 7 & 13 of the 570/571.

With the 10k's in 13 and 14 as per the docs, I get 2.94v on pin 7 and 1.89v on pin 13. Worth increasing the values of 13 and 14?

[jighead81]

Gonna try some different values there also, I couldn't get any delay just trying to calibrate IC3, once I put in both IC's I had a delayed signal and went from there.

[Scruffie]

I don't know what happened, but I swapped 10k's for the 39k's I had in R13 & R14, I moved the bias trims CW in small increments until the repeats were clean.  I still got some tweaking to do, but it's useable now

You're looking to bias the compander output to 1/2 supply, so what's the voltage on Pin 7 & 13 of the 570/571.

With the 10k's in 13 and 14 as per the docs, I get 2.94v on pin 7 and 1.89v on pin 13. Worth increasing the values of 13 and 14?

You can socket them and try 15-18k, although I do seem to recall actually the DM-2 is biased a little low naturally... bit late on the evening to brush up on my compander knowledge though.

Are you sure about your pin 13, that should be your supply.

Full voltages from both of you would make the whole thing clearer.

[thorpy6]

Are you sure about your pin 13, that should be your supply.

Full voltages from both of you would make the whole thing clearer.

My error, I counted down on lhs rather than up. I'll correct tomorrow and give a full voltage readout for all chips.

[jighead81]

3.07v on pin 7
1.8v on pin 13

Does that seem right?

[Scruffie]

3.07v on pin 7
1.8v on pin 13

Does that seem right?

Please also post full voltages, it's very difficult to tell with snap shots.

But no, pin 13 is the voltage on the 570/571, 1.8V would be wrong, but if you have 3.07V on 7 it's likely there's a mistake in your readings, as I said, full voltages will clear things up.

[jighead81]

Sorry, goofed on pin 13, here's the voltages for NE570N.  I think I might be losing power somewhere. As soon as I turn the pedal on, the 15v from the regulator drops to around 10v.

1.37 on 1
1.82 on 2
1.82 on 3
0.0 on 4
1.82 on 5
1.82 on 6
3.07 on 7
1.82 on 8
1.82 on 9
4.84 on 10
4.83 on 11
1.82 on 12
10v on13
1.82 on14
1.82 on 15
.90 on 16

[Scruffie]

Yeah that ain't right, something is drawing too much current/shorting or your regulator is faulty/not getting enough voltage.

[jighead81]

Regulator reads at 14.95 until I hook it up to the board, then it drops to around 10v and fluctuates with the blinking of the mod LED. Tried 4 other regulators, same problem. I got a leak somewhere. Thanks so much for your help man!

[Scruffie]

Regulator reads at 14.95 until I hook it up to the board, then it drops to around 10v and fluctuates with the blinking of the mod LED. Tried 4 other regulators, same problem. I got a leak somewhere. Thanks so much for your help man!

Tried disconnecting that LED? (if that's a separate one to the vactrol one disconnect that too).