[autoteleology]

Power on my SRM-Xh is flowing, the LED on the front of the box is lit up, and the red LEDs on the inside are off. What do?

 

[DefQon]

Quote:

you first have to look at the 2 leds in the middle of the board. if both are off, you have
a power supply problem. which you can fix with the 3524 and the 2 switching fets.
 

Good thing KG posted this.
 
Since the culprit is with the PS, the PS stage is the mini trafo with 2 jfets and then you see a JRC 3524-D class semi.
 
The two jfets are in series with a 16v 33uf cap.
 
The TO-92 jfets part code are 2SK940 class 5C.
 
Now I'm not too sure if you need to match the same class (different class different idss/vgs rating) for the switching jfets KG mentioned in the PS but it is very important to match jfets if it is in the signal path of the same class or closest one as it will be saturated, I learnt this the hard way for my SRM1 MK1 amp.
 
The only supplier that I trust and that I know of that stocks the JRC 3524 D class is utsource (HK seller). Genuine stuff, Justin has purchased from them before. 
 
Another one is you can get in touch with Steve at Ceitron electronics and he will source you a replacement. 

 

[kevin gilmore]

actually they are mosfets and they are available at www.bdent.com for $3.53 each
 
this will work for the switching controller
http://www.mouser.com/ProductDetail/Texas-Instruments/SG3524N/?qs=sGAEpiMZZMtEXy65sthk2LbYbUgi0d6clgDzkn30fCI%3d
 
B+ goes to the transformer, and to the cap, the fets switch each side of the transformer to ground driven by the switcher
completely open loop.

 

[DefQon]

Quote:

actually they are mosfets and they are available at www.bdent.com for $3.53 each
 
this will work for the switching controller
http://www.mouser.com/ProductDetail/Texas-Instruments/SG3524N/?qs=sGAEpiMZZMtEXy65sthk2LbYbUgi0d6clgDzkn30fCI%3d
 
B+ goes to the transformer, and to the cap, the fets switch each side of the transformer to ground driven by the switcher
completely open loop.

Thanks for that KG, you learn something new everyday
 
Bdent is never too specific on discontinued parts. No info datasheet or anything on the parts I was looking for. 

 

[DefQon]

Say is there any good modern day substitutes for the 2SC4631 2E3 that will offer a little more sonic improvement? 

 

[autoteleology]

I am totally out of league when it comes to electronics. :eek:

Sorry guys, but I require a bit more hand-holding when it comes to the parts because I basically have no idea what I am doing. What exactly are the parts I need from bdent? Could you give me a link?

 

[DefQon]

Quote:

I am totally out of league when it comes to electronics.

Sorry guys, but I require a bit more hand-holding when it comes to the parts because I basically have no idea what I am doing. What exactly are the parts I need from bdent? Could you give me a link?

You need two of these:
 
http://www.bdenterprisesinc.com/2sk940/
 
And you need one of the 3524's KG linked available through mouser.
 
And a DMM and a solder iron. 

 

[miceblue]

Do electrostatic headphones benefit from "burn-in" as some people claim with dynamic drivers. "Burn-in" in this case meaning playing X noise/music/sounds for Y hours and they magically transform in sound quality.

I know they take some time to "charge-up," and if using a tube amp the tubes need to be "warmed-up."


Oh, also, is there a recommended way to clean the pleather earpads? At the moment I'm just using a tissue to wipe off any excessive oils on it.

 

[DefQon]

Quote:

Do electrostatic headphones benefit from "burn-in" as some people claim with dynamic drivers. "Burn-in" in this case meaning playing X noise/music/sounds for Y hours and they magically transform in sound quality.

I know they take some time to "charge-up," and if using a tube amp the tubes need to be "warmed-up."

No. Burn-in has no benefit's to electrostat's other than weeding out faulty units during the manufacturing process, it is simply a charge up with both the amp and headphones that provides a subtle improvement to sound as it kicks into motion. Like starting up your car in a cold morning, you let it going for few minutes before driving off, beneficial for the performance of the car and the engine itself.

 

[autoteleology]

There's nothing much in mechanical terms to burn in on an electrostat, as far as I know. It's not as if you have to flex a piece of plastic or metal like you do in a dynamic setup.

 

[EveTan]

My 202s have finally returned to their former glory . If they keep this condition for more than a week. I will have successfully overcome the channel imbalance with the "play music" method. Well actually, I just set it to the side for a couple of days. When I plugged them back in after an hour-ish, it started the curing process.
 
If things go well, I won't have to sell em .

 

[DefQon]

Quote:

My 202s have finally returned to their former glory . If they keep this condition for more than a week. I will have successfully overcome the channel imbalance with the "play music" method. Well actually, I just set it to the side for a couple of days. When I plugged them back in after an hour-ish, it started the curing process.
 
If things go well, I won't have to sell em .

Great news, glad what has been said to you worked. 

 

[SquireC]

Quote:

 
Micro Seiki, interesting.  I now remember seeing Micro Seiki electrostatic headphones being sold back then.  Interesting to learn that they were doing some OEM'ing.  Wealth of knowledge here on Head-Fi!

NAD also did some electrostatics. Very similar to the Micro Seiki, and similar on sound to the Stax SR5's.
 

 

[DefQon]

I had those Nad 20's and they are much different sounding to my SR-5's.

 

[milosz]

Quote:

mine is green, and the fuse has already been shorted out.
I don't recommend shorting out the fuse.

Geez, you're no fun....
 
Seriously, though, you're absolutely right.