[amandarae]

Hello,

I like to pass on my good experienced with "rolling" the tubes on my Cornet 2.  So far I was getting good results with RCA Black Plates, Tungsram, Telefunken, Matshusita, Sovtek 12AXLPS, Shuguang, Mullard, and Amperex on the 12AX7 positions and Amperex bb, Telefunken, RCA Cleartops, Mullard, JJ, and Sylvania on the 12AU7 positions. 

Lately, I was trying to find a combo that sounds great, and a little cheaper in terms of re-tubing.  I got lucky and I just want to share it here especially to those using the Cornet 2 with SS amp.  I am getting very good results with a GE or RCA 12BH7 on the 12AU7 position and Groove Tube 12AXM in the 12AX7 positions.  On a much cheaper alternative, the Tungsol 12AX7 re-issue, the Sovtek 12AX7LPS, and the Shuguang can take the place of the Groove Tube in the same position as well.  So it seems that the "money tube" is the 12BH7.

To me, the improvements were piano notes becomes so alive and horns have more "air" compared to using a 12AU7.  Vocals sounds like its coming from a very good tube amp in clarity and feeling, and the bass having that "great" kick from mid to the bottom end.  The acoustics of drums and other instruments of the same family have that "snap" that sounded so real.  On guitars, it was very easy to determine wether nylon or metal strings was being use.   These were my observations in my system only of course.   Just want to share my findings and hopefully will work out for others as well.  Of course your experience may vary.


Phono:  Cornet 2
Cart: Koetsu Sugano Rosewood loaded at 60 ohms
SUT:  Tribute set at 1:10
Arm: OL Silver Modified
TT:  Teres 255
Speakers:  Linkwitz Orions

So, a question for Jim.  Is there a thing that I have to worry about using the 12BH instead of the 12AU?  I compared tube specs and everything seems to be fine.  Thanks!


Happy Holidays

[hagtech]

Well, heater current is double for the BH7.  So you're probably running 5.9V or so on the heaters.  That might actually have something to do with the tonality.  It shifts the rp of the X7 at the same time.  You can always change the voltage dropping filter resistor in the heater circuit.  Or just leave it alone.  I doubt the tube is starved at these currents.  Probably last a long time.

I don't see any damage for trying.

jh

[amandarae]

Well, heater current is double for the BH7.  So you're probably running 5.9V or so on the heaters.  That might actually have something to do with the tonality.  It shifts the rp of the X7 at the same time.  You can always change the voltage dropping filter resistor in the heater circuit.  Or just leave it alone.  I doubt the tube is starved at these currents.  Probably last a long time.

I don't see any damage for trying.

jh

Thank you very much Jim!

[Braden]

I'll have to check this out as well. I was using standard new EH 12ax7's, but found they were a little soft sounding in my system. I came across a couple GE 12ax7's that were in a guitar amp and gave them a try. A little bit more forward sounding and a tad brighter, which is probably why they were in a guitar amp. Brought a little bit more life into the system though. The 12au7 I'm using is a nos mullard, but I don't have any other 12au7's around to roll, so maybe I should try the BH7 and see what it does.

[Bill Epstein]

Thanks for the recommendation on the Sovtek 12AX7LPS.
I just completed a complete system change which revealed the EH 12AX7's in the Cornet had a weird tonality. I've had a good Telefunken 12AU7 all along and the Sovteks really let it "sound". Besides a more "correct" tone they have some of the smoothness of Mullards, IMHO.
In the same order I also got a set of New Tungsols and a 12BH7 to try.

New components:
Rogue 66LSR Magnum pre (used; scary quiet and a soundstage monster)
B&K ST-120 amp (used; for those frequent occasions when the DIY 45 amp is being worked on, so nice to push the power button and not have 500DC volts hit the direct coupled circuit! And, yes, I do have the filaments switched.)
Anti-Cable speaker cables (revealed that the Blue Jeans 1506A IC's are too bright for this system)
Heartland 89259 IC's with Eichmann Bullets.
No plans to lose the Cornet or SME arm but I have my eye on a Michell Gyrodec to replace the Ariston. Where's my W-2?

[GRD]

Another opinion.  I tried the 12BH7's (GE and CBS) and prefer the 12AU7 when using the standard set-up.  I think to get the best out of the 12BH7, the filament voltage and operating point for the BH7 would need to be adjusted.  I would think the BH7 would be really nice with these adjustments but I haven't had the time to experiment.

As for the 12AX7's - I've settled on the Sovtek LPS.  I got mine from Jim McShane, who tests before shipping and has reasonable prices. 

As for the AU7, I'm using a Mullard but I've had good results with Tung-sol, GE and CBS - both AU7 and 5814 varieties. 

The 5Y3 is a 6106 right now but I also like the RCA 5Y3.

This is a good phono stage and works well with just about any tube complement you choose.

[rotcoddam]

Currently I'm using a Mullard 5ar4, a Sylvania 6sn7wgta, and I recently switched to a pair of Shuguang 12ax7's after a lengthy period of using the Sovtek12ax7lps. When I put them in I immediatly heard a more realistic presentation of the music over the Sovteks. Even with no breakin time. The Sovteks are actually a nice tube in the Cornet. Very detailed highs with good bass and tone.  I enjoyed them, but I love how these Shuguangs sound. Highly recommended. And cheap on ebay.

[Bill Epstein]

I needed a great 5AR4 to rectify my 45 amp and happened to get a pair of excellent Bugle Boys. This morning one went in the Coronet.
This after I replaced the excellent Tung-sols and a Telefunken with a pair of 7X RCA blackplates and then a Philips/Amperex7U. The RCAs made the image more lifesize and convincing with the same great mid-range as the Tung-sols. Changeing the Telefunken for the Philips/Amperex completely removed some stridency I was hearing on female vocal (the 'let me touch you for awhile' test). Too much difference for mere rolling. I think the Telefunken may be near the end of it's life.
Back to the 5AR4; it extends what the RCA/Amperex combo lent to the sound. Not different, just more of it.
Next I'm going to remove the Rogue Magnum 66 and just use my Goldpoint mono attenuators. It's time to find out how much coloration this pre-amp is bringing along with its wonderful imaging. I expect the Coronet on its own is going to be a marvel with this tube combination.