Are EL34 based amps more musical than KT series based ? Or it's purely a matter of design?

Design. 

Something from the guitar amp world. EL 34s have a different distortion signature to 6L6s - an evolved KT66. 34s clip more quickly but have a smoother distortion - think of a Marshall stack v a Fender Twin Reverb.

However, we use Marshalls because we want them to distort. Not something we look for in a hi fi amp.

300B / SET DHT bug hasn’t bitten me yet - it’s nice but I’ve heard no special magic I "gotta get". To be fair I like to listen louder than most audiophiles, and with more hard rock; the power limitation can cause some nastiness at higher SPLs.

I met Kevin Hayes at Sound by Singer (early 2000s), he opined that the 30/30 might have been the best sounding amp he had ever designed, but it was not a commercial success, he could not sell it for a price that was profitable.

I’ve heard exactly that about the VAC Renaissance / 300B lines, from multiple sources. They’re still sough after. The monos generate more power than most, and might be right up my alley, but I haven’t gone there yet.

But it’s also been a while since those days, and I can say that VAC’s KT88 based amps have come a long long LONG way since the past, even the 2000s (I used to have their little Auricle monos) - in both sound and price :(

RM-9 wrings quite a bit out of EL-34 but Roger was a genius… Like Gordon Gow and the 6L6 MC240… but really no meaningful conversation is possible without also considering the massively important imo ….output transformers….

@tomic601 I’ve always surmised that the MC240 would sound amazing to me. 40 watts is juuust close to enough for my needs :) I might have to try one some day. Yes, output transformers are crucial - avoid the bad ones - a lot of the good-rep vintage amps are renowned for their OPT’s (even Heathkit and Eico used Acrosound, Peerless). I imagine this is where the Chinese tube amps typically skimp. Some of the later Carver amps also got exposed for way undersized OPTs.

KT77 FTW

I use a Grant lumley desgn point to point wired ST70 reference Stereo Power Amp currently I'm using Gold Lion Quad KT88; 2x RCA JAN NOS ECC83 & 2x Gold Lion ECC82.

In this design ECC82 (12AU7) tubes are used as a preamplifier or driver tubs. They are a lower gain compared to the ECC83, making it suitable for applications where a moderate amplification factor is needed.
The 2x ECC83 (12AX7) tubes are used as a high-gain preamplifier tubes providing the a higher amplification factor, making it ideal for initial signal amplification

In the Lumley ST70, these tubes are used in the input and phase splitter stages to ensure proper signal amplification and phase splitting before driving the output tubes.

I can use this amp easily in ultra linear and Triode mode by simply switching them when placng the amp in stand by mode briefly.

Ultimately it depends on my mood and our source material as to my preference but very simply put the amp sounds more incisive and dynamic in ultra linear and just a bit sweeter and holographic in triode mode.

I have completely recapped the amp using Mundorf Mcap Supreme Silver Gold OIL 1200VDC film capacitors for coupling along with top end Nichicon and Audionote elsewhere. Topping off with massive Nichicon reservoirs/ Filter caps. The amp has huge hand wound inputvand output transformers and can now be set to output into 4 ohms or 8 ohms via Rhodium binding posts.

I will never sell it its such a thing of beauty and sounds as good as it looks. I think fir me as long as the KT88's are as good quality as I can afford the major sound changes come via sourcing top quality ECC82  & ECC83 and experimenting although I am so satisfied with how this ampmperforms hooked up to a Tim De Pavaracini designed all tube EAR 912 pre. I just dont feel the need to tinker, its powerful enough to drive my Proac Carbon Pro speakers down low with ease its very holographic and sounds dynamic even at late night listening levels.

I love my tube based system but I don't dicriminate on source I have a much modified LP12  decent digital source streamer about to be made even better by a Chord TT2 & M Scaler a vintage Sony CD player & Tube based CD player too. I'm  not too much of an Audiophile niw that I am listening to music much more than the system. It must beca sign that I'm close to where I want to be gear wise. I just cant see me being without valves in my system.