Siemens EL 34

@pehare Surprisingly to me, the difference appears in the upper mids and highs and not the bass for the KT170s.

pehare, if I may ask, and since you have one of Will’s amps, and your comments about wanting to try a pair of QS Mid Monos - can you share a little more. How is the listening coming along, and what about the upper mids and highs are your hearing and prefer more or less of at this juncture? Does the KT150 or KT170 have more pronounced midrange in your KT Monos so far?

decooney I don't own the KT88's I was forwarding some comments as per my 1st sentence...sorry for the confusion.

FYI, there is a Quicksilver Audio group on face book and an EE audiophile there who used to work for QS about 30 yrs ago remarked this about his new KT monos:

Now back to my comments - I'm enjoying Will's amp - it's the first EL34 amp I've owned besides an original Rogue Cronus Magnum that was tried and sold pretty quickly.

@pehare gotcha, and a forum member colleague here started that QS Facebook forum, I visit there sometimes.  I noticed your comments earlier about mid monos too.   With Will's amps, did you get the pentode push-pull or triode version?  He tends to use the factory Dynamo transformers in his builds and I've wondered if his amps have enough drive for lower sensitivity speakers in the mid to high eighyt sensitivity range. I've never tried one and we conversed some about different builds. Good fun, enjoy! 

Hi decooney I have his ultralinear version and have Tannoy Stirling GR's which are an easy load and are a great combo (rig posted here).  35wpc seems to be plenty.  I still crave more of a triode sound like the Cary SLI-80 F-1 I had years ago and wondering if the mid-monos would provide that since they are 50% triode driven.   

@pehare well, not to rain on the parade, yet perhaps I can share this if it helps, and what I learned recently. You and I have both owned the SLI-80, and have heard what some may refer to as parallel single ended triode switch mode sound in that amp. You also know what UL switch mode sounds like in that amp... did you like the UL setting in that amp? IF so, what you have right now with Will’s amp is similar in UL mode, one might stretch to say - when using the same tubes and caps.

Here is the catch, for the QS Mid Monos, the "50% Triode" caption and unique description is something I asked Mike at QS about directly two weeks go. I don’t think it’s secret or proprietary info. I asked about the circuit function, and what it really means in his words. This was the reply - "It is 50% ultralinear which is half way between triode and pentode operation". A friend has a pair of the QS mid monos and I brought over my Dennis Had Inspire Hot Rod amp to compare. The Mid Monos were classic EL34 sound, a bit more forward stage, midrange was truly present, yet not nearly as recessed or set back type of sound stage as you might hear with one of the little single ended Inspire amps Dennis use to sell or the SLI-80 in triode switch mode. Depends on what type of PSE/Triode sound you might be looking for. As you know, Will also makes a type of parallel single-ended / triode wired version of his amps too, fwiw. I wonder if Will could reconfigure your current 70 amp and get it closer to what you want, instead. I don’t know if that would require a transformer change or anything. He’d be someone to ask. Would be interested in his response back to you.