Voltage mod for Stax SRM-3

[Senes]

Hello!

 

I'm going to acquiere a stax srm-3 wired in 117v (originally 100v)

Could you please tell me  how can I switch it to 230v (France) ?

 

Thanks you un advance!

[Craig Sawyers]

Unless anyone has any specific advice, take the lid off and photograph what you see and post it.  Or try head-fi rather than head-case.

[spritzer]

Here you go:

 

100v:
Gray+White
White wire from the  ACplug+Brown+Green

117v:
Gray+White
White wire from the AC plug+Blue+Purple

240v:
Blue+White wire from the AC plug
Purple+Gray

[Senes]

Thanks you for your answers !

[DefQon]

Actually the SRM-3 has a vertical raiser PSU PCB with the transformer directly soldered. You need to desolder the grey wire from the 100 or 117v position (comes from the switch or fuse) and that goes to the 230v pad and then solder the centre windings from 0 to 120v for dual primary 240v AC input.

I wouldn't be surprised if you have a completely different transformer in the amp though.

Edited March 18, 2016 by DefQon

[Senes]

http://www.noelshack.com/2016-15-1460655465-img-20160414-193433.jpg
http://www.noelshack.com/2016-15-1460655463-img-20160414-193503.jpg
http://www.noelshack.com/2016-15-1460655464-img-20160414-193513.jpg

Here I took some photos, I do not see any "230v pad", only 0; 120 and 100

Could you give me some indications please ?

[spritzer]

They are split primaries so you need to wire them in series or in parallel.  See the wires going from 0 to 0 and 120 to 120?  Remove both and solder just a link between the 0 and 120 in the middle, i.e. change from parallel to a series setup. 

[Senes]

Thanks you a LOT, it works !