Just saw your post after my last upload. That’s sounds promising. I’ll definitely look into it. Thanks.
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!
Showing 7 responses by audiodidact
@mulveling thanks for the kind kick in the pants. I should’ve known better. and @czarivey, thanks for that info too. I’ve since pulled the KT150s (cryo and matched for crying out loud!), and I will have to sell them or save up for a powerful enough intergraded tube amp I can use them with that will push 1.7i Maggie’s. |
I know! But everything checks out: the PL is in the signal path alright, volume control for all sources, turn off the PL = no sound and vice-versa. The KT 150s lit up as well (mostly at their tops, because KT105s don’t glow much because of how they are constructed). I’ll say this, not as an excuse, because i should still have checked further: but Upscale promoted the KT 150 as being compatible with “all” of their Prima Lunas. There is no where on there tube info dictating to NEVER place a KT150 into a PL preamp. But, in fairness to them, they probably assume no one’s that stupid. What made me stop to ask them when everything was going great as far as I knew? I couldn’t find any posts, reviews, reports, ANYWHERE about using the KTs the way I did, only with integrateds and amps. It spooked me, so I wrote Upscale about it. Glad I did,and glad I posted about here too. All of you are being super helpful. But, still don’t know how come it worked. |
I did indeed use 2 KTs in the 2 available rectifier slots. The pins actually did fit in the available holes. I had robust, deep bass and sparkling highs for the brief time I had them in. No exaggeration, the soundstage doubled, the sound was tactile. But after all of this great feedback (very positive I might add, and I thank you), I realize I just had impossible dumb luck in not blowing up my preamp. I truly appreciate all your educated ideas to help me understand the “why” of it all. I now have new 5r4gy’s in. Sounds good, but not any way near as good as what those power tubes produced. Thanks all! |
One more thing… What got me started down this dark path was the simple quest to acquire the best (rectifier?)sounding tube I could get for the PL. My PL feeds 2 amplification outputs (Luxman switches between them): 1. Parasound Halo A1+ 2. Two Quicksilver M60s monos (with Zeros, into GR Research outboard crossover) into 1.7i Maggies. (I use the QS for quieter jazz/acoustic, or just for a different flavor, if not great power). So, really I wanted to have the PL kick a bit more juice to the monos. Maybe I should’ve just started here with asking you all what tubes you’d use to get something like that accomplished, if any tube other than the standard PL 5r4gy might do it. |
Just checked-out what’s available for NOS GZs. You’re right, they fetch a hefty price. I’l l just put it out there that since I can’t use them, I’m willing to do a straight swap of the essentially brand new Tung-Sol KT-150s (cryo/matched), for a pair of used good matched and balanced pair of the NOS GZ34s. |
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. |