I was playing my system this afternoon and heard the most bizarre noise that I’ve never encountered.  I was playing my Torii MKIV with the following components attached….ZBIT, ZROCK2, CSP2+, Schiit Bifrost 2, and streaming Roon with my core coming a PC, and the Roon bridge coming from my Raspberri Pi 4B+.  Everything was warmed up and playing music for at least 1/2 hour.  Out of nowhere I heard this loud crackling electrical noise that was reminiscent of like an bug zapper.  I didn’t observe any tubes flashing as I started to power everything down by first lowering the volume on the Torii and then the CSP.  I then stopped the song in Roon that was playing.  The noise was still playing through the speakers at this point.  The Torii was shut down first, then the DAC, then finally the CSP2.  

First off…any insight as to what may have caused that?  The tubes in the Torii are fairly new.   The CSP tubes are a bit older.  My inkling it that the Decware Rectifer in the CSP may be the culprit.

Now the fun part is the troubleshooting?  I could use some help on the process on where to start, and the sequence of a how to isolate the components the get to the bottom of the bug zapping sound.

Thanks in advance.

Dom

Thanks James!  So after some testing yesterday, it seems as though the CSP is the problem.  I put several rectifiers (1 new) and several new input and output tubes into the CSP, and I was getting a low constant hum coming through my headphones, even with the main gain on the CSP all the down.  

Today I’m going to bypass the CSP in the signal chain to see if the weird buzzing goes away.  I plan to setup a phone conversation with Steve this week, and probably have the unit sent in for an evaluation. I’ll probably then do a warranty transfer on the unit with a new tube set.  

I’ll report back later after I do some more testing.

Dom

Well I jumped the gun….I started to isolate components and the noise came back. When I removed the CSP from the signal chain,  I was still getting the noise.

I then bypassed my Bifrost2 DAC and utilized my Audioquest Dragon Red DAC, and the noise was still present. I then isolated my ZROCK2  and removed it from the signal chain and so far everything is quiet.  This component was the least susceptible since I refreshed that tube only two months ago.  

Edit:   Well a funny thing happened as I was playing with the ZROCK2…. I powered it down to remove the tube and then I started hearing the noise again. Now it looks like the culprit may be a bad set of cables somewhere in the signal chain. That’s tomorrow’s project but at least I am making headway.  

I am currently having a noise issue with my ToriiMK5, which I received in June of 2024. It has been dead quiet until a few weeks ago. One day, I forgot to follow the sequence of turning on the tube preamp first and then turn on the Torii. I heard a pop followed by the a loud high pitch sound. I immediately turned both the amp and the preamp off. Since then, I have had a persistent noise, mostly on the left channel. I systematically changed all the tubes from the right channel to the left and the noise persisted on the left channel. The noise is pretty loud and it sounds like a bathroom fan. The amplifier sounds great and the sound is less audible when I play music at moderate to loud levels.

My next step is connect the amplifier to my second system, which has different speakers, different cables, and no preamplifier.

I would appreciate any ideas or suggestions. Thanks!

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Hmm…while I would like to say that I am almost certain that is not the Torii… at this point i’m not ruling anything out.  The noise originated about a week ago when I was using my Zens…It was faint and nowhere near as loud.  So I decided switch over to the Torrii.  With the noise now getting louder, I would hypothesize that it would be a bad tube.  

But… I am getting the noise with the gain on all of the units turned down.  I will try and tap on the tubes to see if that creates the noise.  I think my approach at this point is to start off as basic as possible with the least amount of components in the signal chain.  

James….makes sense.  I guess I was a bit throw off by it happening to the Zen’s as well.  That would mean that that power tubes on both amps would be an issue.  Definitely not out of the question.  I think I kept my old KT66 tubes when I put the 77’s in….so I’m going to do that first.   Let the fun begin for day two.

Well sad to say…it looks like the CSP2 has some sort of internal issue going on. I replaced all the tubes and added the CSP back into the signal chain with no luck.  Going to place a call into Decware tomorrow, obtain an RMA number, and send the unit back to Decware.  I will set up a phone conversation with Steve to discuss if it’s worth making any upgrades or changes to the internals depending on what he finds. The unit already has the 25th Anniversay mods, so I’m hoping it’s something not cap related.  This was Lon’s old unit whom I acquired it from Joe Lazenby.  I never did the warranty transfer, so this may the perfect time to do it.

Now the tough part….listening to music with out a preamp.   Ughh!!

Very true James.  The KT77’s are far superior in its characteristics to the KT66’s in my opinion.  While I would love to buy a new quad of KT77’s, i need to hold off until I fix the CSP.  I think it may be time to go back to the Zen's for a while.

Sorry to hear Dom. Did you happen to look under the hood in the CSP2? Ruling out tubes, the ill sound description could be a sizzling cap going bad.