Old Delay ICs Identification - Faded / Worn Surface Labeling

[sarakisof]

I found an old echo-delay unit from late 70/80s i guess, whith all of its ICs faded and worn out due to age or external conditions. Couldn't find any info about this unit anywhere.
Is there any way i can restore -even temporarily- the labeling by using a liquid (isopropyl?) or smthng?
Most possible those opamps are 455Xs and a MN300X BBD, but how i could be sure?

[bean]

The casing and indentation on the apparent BBD are different from what I'm used to seeing. I would check the voltage readings on pins 1 and 5. If they read higher than +/- 9v it could be either MN3008 or MN3005. If the delay signal is 250ms or more it's probably an MN3005.

[StephenGiles]

Looks like MN3005.

[ElectricDruid]

Looks like MN3005.

+1 agree. The distinctive pinout means there's only a couple of options, and MN3005 is most likely. I'd check by looking for appropriate signals on the clock pins, checking the input goes in where expected, etc.

[Mark Hammer]

The enclosure has many parallels to the table-top delays made by Vantage, Stage, Melos, and several others of that era.  It is more likely than not that the chip is an MN3005.  It's always possible it could be a 3008, but the use of individual input level controls suggests the trailing rather than leading edge of that style of delay which further biases me in favour of a 3005.

[sarakisof]

BBD Voltages:

Pin1: 10.84V
Pin2: 4.86V
Pin3: 5.24V
Pin4: 5.24V
Pin5: 0V
Pin6: 4.87V
Pin7: 5.27V
Pin8: 0.65V

[Mark Hammer]

What the....
A row of dual-ganged pots with only ONE section used?  Who in the blazes does that?
The battery-holders look like they would accommodate 10 C-cells in total (15VDC)/

[ElectricDruid]

A row of dual-ganged pots with only ONE section used?  Who in the blazes does that?

Someone who lives near a surplus store with a barrel full of dual-gang pots at a ridiculous price?!?

I honestly can't see any other reason. But it's been a long weekend and my brain is a bit fried!

[antonis]

I honestly can't see any other reason.

A flat design for stereo unit, perhaps..??

[digi2t]

My money is on the surplus store angle.