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AUDIO FORUMS >> General Discussion and Support >> Help with CSP3
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Message started by kulafu on 10/25/25 at 14:26:02

Title: Help with CSP3
Post by kulafu on 10/25/25 at 14:26:02

One of my CSP3 stopped working. All tubes light up but no sound comes out. Swapped all tubes and still no sound. I have isolated it to just this CSP since my second CSP3 works on the same system. Before I contact DECWARE, I was just looking to see if anyone can provide some troubleshooting advice.
Bob

Title: Re: Help with CSP3
Post by JHC on 10/25/25 at 14:49:03

You might have blown one of the rectifier fuses. If you open the bottom there are three fuses near the rectifier socket. They are easy to pop out, but it might be hard to see if they have been blown. You can get fuses on Amazon or a local electronics store for very cheap so definitely worth getting some and testing it out. CAJames pointed me to ceramic fuses which I now use and have been great (also very cheap).

Title: Re: Help with CSP3
Post by kulafu on 10/25/25 at 14:53:25

JHC,
Thanks! Do you the rating of these fuses?
Bob

Title: Re: Help with CSP3
Post by JHC on 10/25/25 at 15:26:27

There are three total fuses and two different kinds. The one that has blown on me was 200mA. I picked up a 10-pack of "MECCANIXITY 5x20mm Ceramic Fuse 250V Slow Blow" fuses for under $10 on Amazon. I am sure there are better fuses out there, but that is maybe the one audiophile rabbit hole I refuse to go down. I ended up replacing both of the 200mA fuses. I can't remember what the other fuse is, maybe 5A, but I left that. Regardless, all of the fuses should have their values on the fuse endcaps.

I have blown the rectifier fuse twice, the first time it was clearly blown, the second time I couldn't really tell from the fuse itself, but after replacing them everything fired up and worked as it should. And both times all of the tubes, even the rectifier lit up (even when the rectifier arced).

Title: Re: Help with CSP3
Post by JHC on 10/25/25 at 15:46:05

PS my amps are SE84UFOs. Not sure if they have the same rectifier fuse values. Likely, but it's worth double checking.

Title: Re: Help with CSP3
Post by MikeinMontana on 10/25/25 at 19:47:41

Same here, SE84UFO2.1, 200mA slowblow. The rectifier AND that fuse blew in my case. Some time ago now and all has been perfect since 2 replacements.. The original rectifier looked as if it was working though/ lit up like usual....but a no go until replaced. The second rectifier quickly had lights out, fuse fine that time...lol. Hopefully it is just a fuse. I will not use a Chinese tube in my amp. Some love them and that's all good. Choices. [smiley=icqlite20.png]

Good luck, sounds like an easy fix. These folks here and Decware helped me out on the same situation. Awesome folks! All the best ~ Mike