Ok, got my 5755 adapters in + Raytheon 5755 Black Plates. I'm back in heaven again! These things + the Treasure II's are better than the Raytheon 12AX7 Black Plate + 6414 Black Plate combo I previously had, bettering the Westinghouse 12BZ7 Black Plates. Definitely found the perfect inexpensive valve combination. The other advantage is all valves with the exception of the cheap 5755's are in current production!
Swapped in my 6414's, interestingly not a good match with the 5755's.
The best combo now appears to be Raytheon 5755's in v1 & v4, Psvane Treasure II 12AU7's in v2 & v3 and JJ 6CA7's in the power stage. Spectacular results.
For reference, the stock valves in my version of the MC10T are Shugang 12AX7, 12AU7 and EL34's. The result with the stock valves is very very nice, though some tube rolling has definitely brought some very nice improvements.
You have one of the later ones, so all the changes should be made. I think Yaqin's flirt with the 12AT7 was not a good one.
Not sure why they bothered with 12A7. Everything I've read suggests they're a n noisier tube than 12AX7. NOS tubes are cheaper than 12AX7 though I guess.
Been reading this thread and curious if these tube choices might be worth trying in a Yaqin 30L or not. One reason for my question is the 30L has 8 pre-amp tubes and 4 El-34/6CA7 which would add up to some serious money to try a few sets of what has been discussed here. Some of course in the pre-amp tubes vary in price it just boils down to what would be a solid choice instead of going through rolling several sets.
Thanks I have another thread started specifically on the MC-30L found here:
http://www.audiokarma.org/forums/showthread.php?p=8598170&posted=1#post8598170
I am asking here as this thread has covered a lot of what I am looking to find out, as it pertains to the 10 but might apply to the 30L too.
Thanks
Hermit
Hmmmm, I don't know if the same valve combo's would work really. It's a different circuit. My understanding is that Yaqin haven't really redesigned anything, they've simply used old circuit designs. Sound great to me though. Likewise, speaker choice tends to affect which valves sound good to you as well. I changed from Sony SS-FL6000 speakers to my current B&W DM-16's since I first started trying valve combo's so I could probably roll through some of the valves I'd already tried.
The Sony SS-FL6000's were much more modern sounding with amzing imaging though I found myself listening to the detail rather than just enjoying the music. My current B&W's are much more organic and allow me to enjoy the music far more.
The the 30L uses 6J1's doesn't it? I think you'd need a completely different combination in that. Having said that, I think you find a power valve you like, and then find drivers that compliment that valve. That been the approach I've used that works for me. With power valves I think sticking with current production is a good choice as those are the valves that will wear out fastest, and NOS commands silly prices. I've been tempted to get Siemens NOS valves though I can't honestly imagine audio improving any further from where my system currently is.
The 6414 is very different in many ways to the 12AT7.
The following is explained on the BH forum.
The 6414 has 2/3 the mu and 2/3 the plate resistance, takes 50% more heater current, is rated for no more than 2/3 the maximum voltage and 2/3 the maximum plate dissipation"
I think i have posted this here before.
The internet is like groundhog day the movie, sometimes
Yes I know, though the right tone and sound quality sort of overrode those considerations for me. Irrelevant now. I've a noticeably better sounding combination with the Raytheon 5755 BP's, Treasure II 12AU7's and JJ 6CA7's. I won't be returning to them.
