from what I read I thought it would be OK and it sure sounded excellent. The company policy is not to endorse such tom foolery
Fwiw...i suspect the tube life may be shortened by the halved heater voltage ...i would think the Cary would be fine...but yeah wait for Mr Haid to reply,that Cary is too nice to risk it.
12AU7 specs Specification and max ratings(*) Filament Voltage 6.3-12V Filament Current 300-150 mA Plate Voltage (max) 330V Plate Current (max) 22 mA Plate Dissipation (max) 3W 6SN7 Specs Specification and max ratings(*) Filament Voltage 6.3V Filament Current 0.6A Plate Voltage (max) 450V Plate Current (max) 20mA Plate Dissipation (max) 5W
I’ll be interested in what you hear back. The curves on the tubes are so similar, it seems that the bias point should have near identical performance regardless whether it’s a 6SN7 or 12AU7. I suppose it’s possible they are running the plates at voltages that exceed the spec for the 12AU7, but that would be really high for a preamp. They also could be using a constant current source for the heater regulator (I’d be surprised though). If that were optimized for the current draw of the 6SN7, the heater voltage would be too high when you dropped in the 12AU7.
no word on the 12AU7, probably best to stick with the 6SN7. Based on the reviews in the Vacuum Tube Valley PDF file I ordered a NOS quad of Raytheon 6SN7WGTs brown base from the 50's. We'll see !
Tried the NOS 50s raytheons, kind of a mixed blessing vs my current sylvania gts. bass is deep and noticeably more powerful without being bloated. a big plus. midrange is slightly more forward, transparent and has a colorful ring to it, very nice. treble is less smooth. gain seems higher, they sound stronger, possibly too much so but could be adjusted via preamp or power amp gain levels. refinement is not as good, there were some turn it down in your face moments. i am not giving up on them and will put them back in to burn in and see if it cures some of the issues. right now i need to enjoy it with the sylvanias because i just got my preamp back from warranty service after about 6 weeks and am not in the mood to wait for the raytheons to burn in. definitely some potential there....
That's a very good description of the brown bases. refinement is not as good, there were some turn it down in your face moments. Yes. Brent Jessee said these need more than the typical 50 to 60 hours burn-in.
Yes, it's a tube with power. One thing I forgot to mention, there's lots of extension in the highs, but they won't be refined like a Sylvania.
Silly question. Does just turning on the gear and leaving it on count for tube burn in? Or do I have to be listening to tunes?
I do both, play music then leave the preamp on overnight, amp turned off. IME, tubes will break in without playing.
Does anyone know much about this Tungsram 6SN7GT or has tried it? There isnt much info I can find on the internet on this tube, please share your thoughts if you do. Thanks!!! 2x 6SN7GT Tungsram NIB Identicall Tube Valve | eBay
I definitely will when they arrived. Just for curiosity sake, I would really like to know more about them like production location and date.
Ah, I see your post now. 6SN7 tubes.Could you please put in order from best to worse these NOS tubes? (Pictures) Yes, I think they have the same design. How is the sound?
