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Vintage Asylum Classic gear from yesteryear; vintage audio standing the test of time. |
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In Reply to: Re: Caution! posted by Raver on December 30, 2003 at 12:04:20:
I have two Sherwood S-5000 schematics, the one of rather bad quality that's available on the net (http://www.triodeel.com/s5000.gif ) and another from a 1960's copy of a Sam's photofact. I was using this last one because it's a better quality copy and because the other says "Serial No. 959000 and up" while mine is a 5121XX.
But after all these helpful messages that I got from many of you after my request for help, I found that something was wrong in the schematics I was using. So I carefully compared the two and I found that I was following a wrong schematics.
The two schematics, for example, show the the bias supply rectifier with the two "diodes arrows" pointing into opposite directions: the Sam's (that I followed) has them pointing to the filter cap (as I did yesterday), while the "net's schematics" has them pointing toward the power transformer (as some of you told me to do).
Again: the 47 ohm 5W resistor (that is on my amp) becomes a 33 ohm 7W in my schematics.
Another: in my amp the can capacitor C2 (C24 on the "net" schematics) is a two sections (30/20/400V) can, and not a three sections (30/20/400-5/250) as the Sam's parts list states (and as I reported in my post above).
So, if the correct schematics is the one from the net, yesterday I installed the two 1N4007 diodes in the wrong way, and tomorrow morning I'll install them again as per the "net schematics" direction (arrows pointing to the transformer). AS HERE WE NEED NEGATIVE VOLTAGE, IS THIS THE CORRECT WAY TO INSTALL THEM, RIGHT?
Then I'll should be able to see if only the selenium rectifier was damaged from the short or if also the filter cap(s) suffered. However, as there was a low bias also before the accident, I think that I will replace at least also that bias filter can cap.
Of course, following your advices, I will pull the tubes and I'll check the voltages before putting them on again.
Raul
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Follow Ups
- I just realized I have a wrong schematics! - Raver 14:59:00 12/30/03 (4)
- That's it, you didn't read very carefully on my listing below for diodes - koo 16:25:43 12/30/03 (3)
- Re: That's it, you didn't read very carefully on my listing below for diodes - Raver 01:51:52 12/31/03 (0)
- Re: That's it, you didn't read very carefully on my listing below for diodes - Raver 01:50:45 12/31/03 (1)
- My apology too, being too assertive, just want to make things right - koo 16:32:15 01/01/04 (0)
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