Lexicon Delta T 102

[bugbrand]

Hi,
Wondering if anyone may be able to help with this - I've got what may well be a basket case.. Shorted tants on several modules had obviously brought down the PSU and it has been somewhat hacked around (before I got it).
The PSU is massive, badly mounted on mine and currently untestable (despite swapping some parts it still doesn't fully work).

Full schematics don't seem to exist - there's a 4 page PDF floating around (available via Lexicon FTP too) but that is only for a BPO option.
So does anyone either have a PSU schematic or at least info on what voltages and current ratings are required.
The back pin-panel of the unit suggests it should be:
+/-15V supply
+5V supply
Then also has pins for -15 and -12 - those have got me slightly puzzled.. why's there a 2nd -15V line?!

If I could at least rig up a group of PSUs to provide the required supplies then I could move on to the large task of replacing tants throughout.

[yes, I do wonder if it is worth it...!]

Cheers for any help, Tom

 

[JohnRoberts]

The caps may be the easy part.. Digital delay from the 1970s was very early days so replacement memory chips could be pretty scarce.

May have more historical value, than for it's audio path.

JR

 

[bugbrand]

Yup, I hear you for sure - definitely an area where gremlins could lurk - but I can't even get on to seeing if those parts work if I can't power it up for testing!

 

[radardoug]

Are you sure its not a -12 volt rail? Those units could use early memory chips that needed extra voltage rails.

 

[bugbrand]

Yes, the extra two are labeled as -15 and -12.
Could well be as you suggest - and actually I could sometime trace back from the pins on the boards.
Just curious as to why there's a 2nd -15V line - located near the top of the pin field at the back, whereas (what I presume to be) the main bipolar supply is at the bottom of the pin field (+/-15V and 0V).
I haven't really examined all the insides in detail yet - snapping some pics may be helpful. Yes, there's clearly more detective work for me to do!

In many ways I'm curious what power is required for each line. Perhaps something like 1A for each side of the +/-15V, hefty +5V line and ..  not sure for the extra -15/-12V (which only appear to feed a few modules within the frame).