Just swapped out my NOS Amperex 7308s (previous favorite in the BHK pre) for NOS Cifte/Mazda 12AU7s. I simply have no adequate words to describe the improvement in SQ in my system at least. From top to bottom just right. Detail without analytical harshness. Warmth without mush. Voices have never sounded so real.
These tubes manufactured a year before I was born (1962) are really something. Where does this “hobby” ever end? I suppose it would be boring if we ever felt we reached our ultimate goal and could finally stop all this madness.
I know others have posted some less than ideal experiences with Upscale Audio, but so far so good. I will concur that the 6V tubes are a bit noisier/“wooshy”. The 7308s exhibited this condition after about 500 hours. Will try the 12V tubes for a while.
Has anyone tried the newly manufactured Telefunken ECC82s/12AU7s? Very curious as these are far more affordable.
Glad you love those. I think 12au7s just sound more well rounded in my system. I am using the current production Telefunken 12au7 in my BHK pre. Sounds fantastic!
I found the Amperex 7308 to be really great, at first. After living with them for a couple of weeks, they seemed to be a bit harsh and a tad lean.
I just pulled “The Fisher” Amperex E88CC for a change up and dropped in Mullard RTC E188CC’s in my BHK Pre and changed the jumper setting to 5ma. This combo makes Candace Springs resonate beautifully.
Started the tube rolling phase on my BHK preamp after 500hrs with the stock Psvane tubes.
What an amazing piece of equipment. Congrats PSAUDIO!!!
I decided to stay within 12au7 family to maintain the amplification factor around u=17 by avoiding the 6922 family which has a amplification factor around u=30.
Is it fair to think that the higher amplification factor from the tubes will end into a poorer SNR from the BHK? Or by having a higher amplification factor from the tubes will get more tube flavor from the BHK?
Nevertheless, currently playing on a matched pair of Funkwerk RFT ECC82 early 1960’s with thin dual getter support.
So far I found the following form searching this thread:
Brimar CV4003 NOS
Telefunken 12AU7 New Production, can’t seem to find where to buy these
Gold Lion 12AU7 New Production
Also, the Cifte 12AU7’s from Upscale are very well balanced and quiet as a mouse. So well matched in fact they produce almost no audible clicks when adjusting volume. Really think these are the best overall for my system. Previously in love with the Amperex 7308, but started to hear some whooshing and odd noises. The 7308’s also had some pops/clicks when changing volume, but they do have excellent sound too (maybe a bit lusher).
I’m happy to give my opinion as I’ve had both. But as usual, my opinion is likely meaningless beyond my own system and ears.
I felt the Cifte were very articulate, open, airy, but sterile and maybe a bit strident for certain voices, horns, etc.
The Brimars are neutral and lovely across the range. I thought they had a much smoother, more pleasant mid range.
Does anyone know if a BHK PreAmp can handle the heater current of the 12BH7 family of tubes, they draw twice the amount of current than the 12AU7 tubes. I have some very nice sounding 12BH7s I would to try.
I found that my BHK preamp would accommodate the 600 mA heater current without the heater voltage regulator not dropping out. I tried 6CG7, 6SN7 with octal to 9 pin socket adapter and they all worked and sounded dammed good! So the 12BH7 will surely work. Let me know how they sound,
