2. amps-preamps
  3. 191147-148010

Crucial TUBE question

I  placed a KT 150 power tube into a Prima Luna Evo 300 preamp rectifier slot. I know. But what happened was surprising. The sound was, well, magnificent glorious. Nothing burned out. No smoke. No arc lights. I asked Upscale Audio to advise me as to what damage I may have done or could have done to the PL. They only said they would not advise placing anything but the original tubes in the slot. They would not commit to whether or not that power tube could be used in place of a rectifier to tube. So, is it an absolute or not? If so, why?  I’d appreciate feedback (please, no slams) from anyone having any experience with this. Thanks!

128x128audiodidact
invalid
1,180 posts
 

If it was just amount of HV, then why does the sound change even if go from 2 866a tubes to 2 3B28 tubes, same voltage drop. I don’t think voltage drop is a problem in a preamp or Dac, the drop in voltage of an 5ar4 is 17 volts, but that’s not going to happen until higher current.

dogearedaudio
119 posts
 

Like I said, it's a combination of factors.  One way or the other, different rectifier tubes will impart a different sound to the amp or preamp.  A lot of technically-minded folks will disagree with that, but I've always found it to be the case.

audiodidact's avatar
audiodidact OP
79 posts
 

Lots to digest here.  I’m impressed by the depth of knowledge you all bring to this area of audiophilia, and I’m learning a ton.  I will try to tread more carefully and when in doubt—-I won’t without running it by folks with experience.  Thanks to all for helping me better understand how to avoid stepping on my own tail.

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