Resistor getting hot

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5150loveeddie
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Resistor getting hot

Post by 5150loveeddie » Wed Apr 04, 2012 6:45 pm

Hi guys,

Have an amp (two 6v6, 3 12ax7, one gz34).

Here it goes:

The overheating (actualy failed) resistor is in a bleep type position, between two capacitor (multi can type) ternimals that is feeding the 6v6 screen's, that multican capacitor is fed by the rectifier itseft but there is a 100OHMS high power resistor in series between the rectifier and our multican cap, also there is an other cap (axial) that is in series with that hight power resistor receiving the rectifier DC as well.

Why is that resistor on the multican started to redhot and fail, I removed it replaced it ans the new resistor failed as well, it is pullilng to much watts there, why?

any suggestions will help cheers!! :thumbsup:
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Re: Resistor getting hot

Post by hired hand » Wed Apr 04, 2012 8:12 pm

What amp is this.?
Did you build it.?
Did it work in the past.?
Have performed work on it prior to this.?
Resistors get hot and fail because the are pulling more current than they are rated for in Watts.

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Re: Resistor getting hot

Post by jerrydyer » Thu Apr 05, 2012 11:55 am

that resistor is basically your choke. but it sounds like something else is a little off. whats you b+ voltage there.
if everything checks out good you can try a traditional choke like georges , hes got several to choose from. I use this method on my 100 watters but i use 500 ohms at like 50 watts i think just to err on the side of safety.
vids.
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5150loveeddie
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Re: Resistor getting hot

Post by 5150loveeddie » Thu Apr 05, 2012 2:47 pm

I found my problem. The amp is a Swart 20w (6v6) «Atomic Space tone» amp, sound very nice, PTP, Heybower trannies. The problem with it is that everything inside is glued with electronic silicone and it is difficult to work around, the resistor is actual a screen type resistor, burned because of one 6v6 shorted.....duh!!

Now I have an other problem, with new tubes, new resistor, I though Bingo it is fixed but no I have barely no volume, I recheck all the work, all preamp tubes are good, voltages seems all good everywhere.

There is no HT fuse in that amp and by replacing the «pseudo screen» resistor once and let it burned again maybe the OT or something else got hurt. PT seem ok, have good voltages from primaries& secondaries and from the tube rectifier feeding the rest of the amp.

I can't find a schematic for it so I will have to test that OT and see from there.... :bang:
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