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Original Message

GAINCARD DIODES: FE5D 9808 - any info?

Posted by K.T. on May 17, 2002 at 01:29:31:


I got the tweak bug and opened up my 4700s (50 watt) Power Humpty. I'm interested in trying some FREDs of HexFREDs in the circuit, so was particularly interested in finding out what the diodes are.

Inside the Humpty is a very dense and high quality transformer (not a toroidal type). There are two secondary windings, both rated at 23.5V 3.6A. There are 4 diodes which appear to be configured in a standard bridge.

The diodes are labelled FE5D 9808 and are packaged in the grey, round, ballish shaped package with the black cathode band at one end (I forgot what that package is called and am too lazy to look it up). Does anyone have any info and ratings on these diodes? I tried a preliminary cross-reference on the web but had had no luck.

With the discussions on the internet about Gainclones, I surmise that I could use some IR Hexfreds rated at 600v 8A and have plenty margin remaining, but I would like to get the low down on these stock diodes first.

Also, I've read on some posts that the IR Hexfreds are better sounding on higher voltage tube applications (they tend to sound soft at some parts of the frequency range at low voltages), and that the Harris freds are better for lower voltage SS applications. Does anyone have any opinions on this? If this is the case, the Harris ones might be the ticket.

Just to retierate: this is the 50 watt "S" version Humpty, not the 25 watt version.

Thanks in advance,