PLEASE Help with a MXR 118 Vintage Delay - IC pin Voltages

[jimitrader]

This pedal seems like it should be working. producing sound on both on/off

I am getting voltages throughout the board


Sprague capacitor says 500D 400-25 usa 7922H readout says 439 UF? (cant find much info on this cap)

here are the ic pins voltages
does it seem like based on these voltages it should work?


thanks in advance for any help
1979 MXR 118 Vintage Delay - IC pin Voltages:
4013B

   
• 12
• 7.84
• 7.91
• 0
• 7.87
• 0
• 0
• 11.99
• 11.98
• 7.95
• 12
• 7.44
• 12
• 11.99

4001

   
• 8.40
• 8.43
• 0
• 12
• 0
• 0
• 0
• 12
• 7.91
• 7.88
• 0
• 0
• 0
• 12

Reticon R5101 (anyone have a image of the pinout on this chip?)

   
• 0
• 0
• 2.77
• 3.24
• 0
• 0
• 0
• 11.93
• 11.80
• 2.77
• 0
• 0
• 7.24
• 11.93
• 5.34
• 0
• 0
• 0
• 2.77
• 9.17
• 9.17
• 0.04

4558
#1

   
• 11.38
• 11.34
• 0.74
• 0
• 0.73
• 11.36
• 11.38
• 12

#2

   
• 6.06
• 6.06
• 4.10
• 0
• 5.98
• 6.01
• 5.98
• 12

#3

   
• 6.42
• 6.23
• 4.12
• 0
• 5.99
• 5.99
• 3.84
• 12

#4

   
• 11.34
• 11.30
• 0.80
• 0
• 0.77
• 11.34
• 11.37
• 12

[idy]

You have not explained what it does. Any sound? works in bypass?

Setting up an analog delay requires some know-how, suggested O-scope...once it is working....

Does that schematic even apply to your pedal? What is a 5150 or 5051. Only 5150 I know is "danger to self and others!" There are several versions of this effect. That schematic is an early version.
The schematic lists:
2x4558 opamps
1x1458 opamp
Ne571 commander
3xSAD1024 BBD
CD4016 analog switch
CD4015 shift register
CD4069 Hex Invertor
CD4013 flip-flop

[idy]

This might be it. It uses the R5101 at least.

[jimitrader]

You have not explained what it does.

Any sound?  it was producing sound on both on and off settings but no delay.. as others have said it would get quieter and then off when turning mix to the right
works in bypass?it was then when i was trying to use my audio probe it suddenly stopped producing sound when turned on and has full sound when off

[jimitrader]

This might be it. It uses the R5101 at least.

thanks

[idy]

OK, so the original post is replaced with one that makes sense. Looks like that first 4558 there has a short from pin 3 to 4 (not that the pins are numbered in your post).
What about that signal trace? What is going on now? Where does the signal die? Pin 3 of the 4558?

Earlier it seemed like the clean path was working, but no delays.

[jimitrader]

Ok i have been trying the audio probe some more and the pedal is now producing sound again with effects on?

so now i will check that 4558 again
(i have updated the pinouts for the 4558's  i made a mistake reading pin 4 as you mentioned)

[Govmnt_Lacky]

Just as a heads up for this pedal.....

The R5101 BBD chip is notorious for going bad. I was/is horribly susceptible to ESD damage. Definitely do your best to protect against this. Also, this chip is LONG out of production and very rare to find available. Hopefully it is still good.

Good luck! 

[ElectricDruid]

The first op-amp seems to only have seven legs! (only seven voltage readings). This is one reason why it's a good idea to number the pins rather than just give a list of voltages.

Despite the missing reading, it still looks like that first op-amp is far from happy.

[jimitrader]

The first op-amp seems to only have seven legs! (only seven voltage readings). This is one reason why it's a good idea to number the pins rather than just give a list of voltages.

Despite the missing reading, it still looks like that first op-amp is far from happy.

Thanks

[jimitrader]

The first op-amp seems to only have seven legs! (only seven voltage readings). This is one reason why it's a good idea to number the pins rather than just give a list of voltages.

Despite the missing reading, it still looks like that first op-amp is far from happy.

Reticon R5101 (do you have an image of the pinout on this chip?)

[Govmnt_Lacky]

Reticon R5101 (do you have an image of the pinout on this chip?)

Try here:

https://www.mikrocontroller.net/topic/351013

Also, it looks like the schematic for your unit is this one (forgive me if it is above, I cannot see pics right now):

https://www.experimentalistsanonymous.com/diy/Schematics/Delay%20Echo%20and%20Samplers/MXR%20Analog%20Delay%203.png

What you need to do is match up the ICs with the schematic and either re-list the voltages with the IC numbers OR revise your original post with the IC numbers.

[Govmnt_Lacky]

Reference for IC pinouts:

[jimitrader]

i keep changing these to numbers and it keeps reverting back to bullet points? i will see if this works re-typing it out

4013B

   
• 12
• 7.84
• 7.91
• 0
• 7.87
• 0
• 0
• 11.99
• 11.98
• 7.95
• 12
• 7.44
• 12
• 11.99

4001

   
• 8.40
• 8.43
• 0
• 12
• 0
• 0
• 0
• 12
• 7.91
• 7.88
• 0
• 0
• 0
• 12

Reticon R5101 (anyone have a image of the pinout on this chip?)

   
• 0
• 0
• 2.77
• 3.24
• 0
• 0
• 0
• 11.93
• 11.80
• 2.77
• 0
• 0
• 7.24
• 11.93
• 5.34
• 0
• 0
• 0
• 2.77
• 9.17
• 9.17
• 0.04

4558
#1

   
• 11.38
• 11.34
• 0.74
• 0
• 0.73
• 11.36
• 11.38
• 12

#2

   
• 6.06
• 6.06
• 4.10
• 0
• 5.98
• 6.01
• 5.98
• 12

#3

   
• 6.42
• 6.23
• 4.12
• 0
• 5.99
• 5.99
• 3.84
• 12

#4

   
• 11.34
• 11.30
• 0.80
• 0
• 0.77
• 11.34
• 11.37
• 12

[jimitrader]

[jimitrader]

[Govmnt_Lacky]

Looking now at the numbered pins and the schematic, it looks like you are not getting Vs to U1 and U4 (Low voltage on Pins 3 and 5 of both ICs). I would follow that path back to the power section and see if continuity is lost somewhere.

[ElectricDruid]

Does your numbering of the 4558's match the schematic? E.g. #1 is U1, #2 is U2 etc?

[jimitrader]

does anyone know how to add a picture to post ? the "add image to post" is not working?

[Govmnt_Lacky]

Does your numbering of the 4558's match the schematic? E.g. #1 is U1, #2 is U2 etc?

I ASSumed they were 

Even if they are not, my assumption still holds true. Looks like he is not getting Vs (or Vref) to the pins on those ICs

EDIT: Also, where are the voltages for the CD4016?