Polysix Rebuild

[Folderol]

I pretty much thought that was the case, but had half a hope I might have been looking in the wrong place.

[BJG145]

How's the jigsaw? I found one of these; untested, but can pop it in an envelope if you want to try it.

[nickle15]

How's the jigsaw? I found one of these; untested, but can pop it in an envelope if you want to try it.

That's very generous of you! Right now we're still stuck looking for a transformer. Not much else we can do until we solve that.

I would be very happy to try out the chip but would also like to pay you a fair price for it. Also, I'm in the US (not sure where you're at) so shipping might be an adventure!

PM is welcome if you want to continue the conversation. Thanks for checking in!

[ajay_m]

Assuming this is a standard linear power supply with a normal E-I laminated core transformer then there are plenty of options. You need to know the secondary voltage or voltages and the VA rating eg 50VA or whatever and then you can probably get an off the shelf replacement. Quite a lot of transformer manufacturers can also make custom voltages. Another option is to find an external PSU with the right DC voltage and just wire that in instead. Since you're rebuilding the case anyway it doesn't much matter if you do that instead.

[BJG145]

Right now we're still stuck looking for a transformer. Not much else we can do until we solve that.

There's one on eBay currently; they might accept an offer.

[jjlonbass]

If you can't find an original transformer, my best guess from looking at the service manual would be that one with 15V-0-15V secondary rated at 30VA or above should do the job; 50VA would be better if it will fit. This is based on the fact that the stated mains power consumption is 25W and that the highest voltage regulated DC rails at the output of the power supply are +15V and -15V. The unregulated outputs from the bridge rectifier and smoothing capacitors will be around +21V and -21V in this case.

You'll need to perform the power supply voltage adjustment procedures after replacing the transformer - I'd recommend doing this even if you fit an original replacement.

Using an external DC supply to replace the missing transformer won't be feasible.

John

[nickle15]

Right now we're still stuck looking for a transformer. Not much else we can do until we solve that.

There's one on eBay currently; they might accept an offer.

Thanks - I tried a couple of weeks ago but they rejected what I was willing to pay.

[ajay_m]

Looks very much like a standard 15-0-15 VAC transformer (sometimes referred to as 30V CT) and it is probably 30VA or so and the full power supply schematic and service manual appears to be at the link below. The fuses are rated 1A so that would confirm that a 30VA unit ought to be about right. The original transformer may have had 115V and 230V primary windings but you do not require them both, obviously, you just want a unit suitable for whatever your mains voltage is (sorry, not sure if you are in the US or not).

http://www.oldcrows.net/~oldcrow/synth/ ... iserv.html

A transformer that size ought to cost about £20 or thereabouts and is a stock voltage.

[nickle15]

Looks very much like a standard 15-0-15 VAC transformer (sometimes referred to as 30V CT) and it is probably 30VA or so and the full power supply schematic and service manual appears to be at the link below. The fuses are rated 1A so that would confirm that a 30VA unit ought to be about right. The original transformer may have had 115V and 230V primary windings but you do not require them both, obviously, you just want a unit suitable for whatever your mains voltage is (sorry, not sure if you are in the US or not).

http://www.oldcrows.net/~oldcrow/synth/ ... iserv.html

A transformer that size ought to cost about £20 or thereabouts and is a stock voltage.

Thanks for the advice! I appreciate it.

[nickle15]

Hey all. Sorry it's been a while. I just got the Polysix home this past weekend and it's up and running. Here's a quick video I made if you're interested. Thanks again for all the help!

https://www.youtube.com/watch?v=xWxbIO4tK4Q

[BJG145]

Fantastic! Glad you got this beauty working again.

[nickle15]

Thanks for everything!!

[Martin Walker]

Ooh, that really does have a distinctive sound - bravo with the renovation

[nickle15]

Ooh, that really does have a distinctive sound - bravo with the renovation

Thanks, Martin!

[Folderol]

Looking and sounding very good. Well done.

[nickle15]

Looking and sounding very good. Well done.

Thanks!!

[Eddy Deegan]

Well done, it's great to see something classic brought back to life!

Bonus points for having a Trinity in the room too

[The Elf]

[nickle15]

Well done, it's great to see something classic brought back to life!

Bonus points for having a Trinity in the room too

Thanks Eddy - you probably don't remember but you sent me the factory sysex for that Trinity. That's a machine I'll never be without!