"Arfa Daily"
The unit has a switch mode power supply (why though?)
** Lower cost and much lower weight - that PSU has to deliver over 500
watts.
I would have thought that if you were going to bother putting a switcher
in a junky piece of hifi that was for worldwide use, you would have used
a design with an efficient PFC front end, that makes it universal in
terms of input voltage.
** That only increases the expense.
Well, if it does at all, not by very much.
** ********.
A 500 watt PFC corrector is a lot of extra circuitry for which and no need
or benefit exists.
Just eliminating a switch is a STUPID reason.
The PSU in that JVC is likely to be of the unregulated kind - ie a
simple square wave inverter.
These are far preferable for audio amplifiers and cheaper to make too.
It's actually not.
** Really ??
How would you know ?
As to them being better for audio work,
** Preferable to either flyback or forward converters and cheaper to make at
the high power levels needed.
Try learning to read what has been written.
Heaven knows, there's enough cheap and cheerful examples out there, used
by the million in LCD TV sets.
** Irrelevant what LCD TVs use.
Well, it isn't irrelevant,
** Fraid it is irrelevant to an audio amp - ****head.
The requirements are very different.
Anyway, that aside, the bridge was ****ted, as were two diodes?? , one
across each of the filter caps. These devices *look* like diodes, and
the symbol on the board is for a diode, and they're called D34 and D35,
but I can't recall having seen diodes in this position before. Voltage
sharing resistors, maybe. The type number on them is R4KL,
** That type is an "avalanche " diode that is specified to zener
breakdown at a particular voltage - like 200 volts.
I too felt that it probably was an avalanche diode. Do you have any data
on the device to support that contention ?
** There is no data on the net, as you well know.
But the R2KS is a similar part.
http://www.datasheetcatalog.org/data.../502475_DS.pdf
Also: R2K, R2KN, R2KY & R2M
..... Phil