EH Deluxe Memory Man V5 Effect Pedal Needs Help

[misterc57]

Yes and yes.

Pins 1,3,7 should sit at -7.5V.

U1 1,3,7 all about -7.5V

U1 has signal at 1,3,5 but none at pin 7

No DC at pin 4, should this be -15V ?

[Helmholtz]

Pin 4 of U1 goes to power supply point B. Should be close to -15V.

[Helmholtz]

I don't think it's possible to have -7.5VDC at pins 1 and 7 without a supply voltage at pin 4.

U1 B is a simple buffer, signal levels at pins 5 and 7 should be the same.

[misterc57]

I had the pinouts wrong. Argh.

1,3,7 at .-7.9

signal at 1,3,7

[misterc57]

U6

[misterc57]

On this pedal for ICs, it appears that ground is at -15V and what would be + is actually ground?

U6

pin 13 at ground

pin 4 has -15.7 V

I have signal at NE570 pins 1,2 3, 6, 7.

No signal on the upper half pins.

signal input is pin12, no signal. Pin 12 has -13.8 V

signal output is pin10, no signal. Pin 10 has -7.1 V


Took U6 out, no visual issues, sprayed the socket.

Still no output.

Bad U6 ???

As a test only to rule out U6, is it possible to jump pins 7 to 10 to see if effects work? Bad idea?

[misterc57]

U1B pin 6 has a signal that is very scratchy sounding with noise (sounds like Morse code).

That same signal is present on the connected side of R7 but I hear nothing on the other side of R7.

Can any of this imply a bad R7 or bad U1B?

R7 reads 199K ohms.

Thank you

[misterc57]

Have I lost my advisors?

[Helmholtz]

Please don't rely on me to give good guidance here.
I can answer a few basic questions only, as I'm not familiar with the unit, the circuit and some ICs.

On this pedal for ICs, it appears that ground is at -15V and what would be + is actually ground?

Yes, ground and Vcc pins of ICs will be reversed, i.e. -15V goes to the ground pin and Vcc is connected to circuit ground.

That same signal is present on the connected side of R7 but I hear nothing on the other side of R7.

The lower end of R7 is AC grounded via C17, so should have no signal.
No reason to suspect R7.

[misterc57]

Please don't rely on me to give good guidance here.
I can answer a few basic questions only, as I'm not familiar with the unit, the circuit and some ICs.



Yes, ground and Vcc pins of ICs will be reversed, i.e. -15V goes to the ground pin and Vcc is connected to circuit ground.



The lower end of R7 is AC grounded via C17, so should have no signal.
No reason to suspect R7.

I greatly appreciate any help I can get.

I did not notice the lower end of R7 is at ground (via C6 on the schematic I am looking at).

I was trying to figure out where the input signal is coming from on the NE570 pin 12. Is it coming from NE570 pin 1?

Schematic attached.

electro-harmonix-deluxe-memory-man-delay-reissue-rev-d-schematic.pdf

[Helmholtz]

I did not notice the lower end of R7 is at ground (via C6 on the schematic I am looking at).

Yes, in this schematic the cap is C6.

U9 should have output signal at pins 2, 3 and 10.

[g1]

I did not notice the lower end of R7 is at ground (via C6 on the schematic I am looking at).

I was trying to figure out where the input signal is coming from on the NE570 pin 12. Is it coming from NE570 pin 1?

Schematic attached.

[ATTACH]n985150[/ATTACH]

So the unit you have is using four MN3008 rather than two MN3005 ?

[misterc57]

So the unit you have is using four MN3008 rather than two MN3005 ?

MN3005.

Sorry I posted the wrong schematic. I have too many versions on my PC.

EH deluxememoryman.pdf

Where I am at now is I have replaced U1 (because I was hearing noise) and I only have output at U1, all the other 4558s have no signal on their outputs. I have tried to trace the signal but I could not figure out where it fails. Seem to to be many things going on that effect signal.

I have gone in several circles on this one and I am throwing up the white flag.

I am very grateful to all of you for the assist.

Going to pass this one to someone else.

Thank you