[orkney]

Hi,
 
Just received a D.O.A SRM-252A -- suspect it may be a fuse but having some difficulty getting into the case to check this out. Have removed the obvious screws and the volume knob but nothing's moving and not sure how to proceed next. Grateful for any advice from chartered Stax Mafia members.
 
thanks and best,
 
o

 

[spritzer]

There are 4 screws underneath the unit which hold it in place.  Once they and the screws on the front panel are gone then you should be able to slide the amp out of the aluminum extrusion.  

 

[orkney]

^^^
 
Many thanks for the reply, Spritzer! I've opened it up and had a look, and it does seem to be the fuse. Hadn't realized it was soldered to the board but will replace it. Possible to use a slo-blo 1.5 amp to replace or should I stick with the original spec?
 
thanks again,
 
o

 

[spritzer]

Stick with the orignal spec.  Does the unit turn on at all, as in does the LED light up?  

 

[orkney]

Quote:

Stick with the orignal spec.  Does the unit turn on at all, as in does the LED light up?  

Nope. Nothing. No LED when switched on. When I checked the supplied Stax PSU for voltage, it was passing 21 volts (spec'd for 12). The original owner had not been using a step-down transformer (I will be). Wondering if this may be what blew the amp? At any rate, my soldering skills are pretty poor but I'll replace the fuse and see if that does the trick.
 
I really appreciate your help on this, and from others here via PM. Hopefully a new fuse will fix it.
 
best,
 
o

 

[spritzer]

Feeding the amp 21V will fry everything in it, caps and transistors...

 

[orkney]

Quote:

Feeding the amp 21V will fry everything in it, caps and transistors...

Ouch. Well, may be looking at a new amp then. The supplied adapter is obviously defective -- never encountered this before but so it goes. Perhaps I'll put this out there as a fixer-upper and try to find a replacement. Thanks again for your help all and best,
 
o

 

[spritzer]

If you have any 12V/1000ma surplus adapters out then they will work on the Stax amp.  These are often included with routers, switches and other computer gear but you would have to rewire the lead cable.  I for one have only once used the stock Stax adapters and that was at CanJam.  I couldn't bring my 230V units and the amp was modified to handle the extra voltage.  

 

[orkney]

^^^
 
Thanks, Spritzer, and the others who chimed in -- I was able to resolder the fuse and picked up a new PSU and the set now works perfectly. Sounds good too -- not quite in the same league as my dear departed 404LE/T1 combo but pretty darn close, really, in terms of musical enjoyment. This must be one of the biggest bargains going, relative to performance, comfort, simplicity, etc. Great fun.
 
best,
 
o

 

[spritzer]

Glad to hear that it worked out ok.