I have an SRD7 - which is not working...
It appears to have 3 resistors that have been cut in half (!) - 51k, 100k, 1M - and it is therefore delivering no bias.
It is an early 100V only unit - all the circuit diagrams I have found are for the later multi-voltage units
The other strange thing is that there is no 51k resistor on any of the SRD7 schematics, but it appears on one of the power input lines of the SRD5 schematic.
So it may be that I have an early production SRD7 with a circuit closely related to the SRD5 (I have not traced the circuit... was hoping not to have to !)
Does anyone know a tech in Melbourne (Australia) familiar with Stax headphones and energizers who could help with getting this beastie working again?
bye for now
what about just replacing the resistors and see what happens? Although if you don't feel at ease with a soldering iron and line voltage, better let sb do it.
As for voltage I think they were all capable of up to 240V AC since they use a zener diode to cap the AC coltage at 82V and then double it but some didn't state so on the box... Here's the schematics anyways - http://img99.imageshack.us/img99/6717/srd7ij0.jpg
If you want to play it safe and are in 220-240 country - use a converter - it doesn't draw a lot of power.