[Peter J]

Thanks for all the input.

I have a new quad of Black Treasures, as well as a used set of EH on the way. I'll do some comparisions when I have them both here and report back what my half-trashed ears hear. Guess I'm on the tube-rolling train now. I honestly used to assume that was a fools game. I suppose that says something about me 

Roscoe, how did the KT120's do in your Rogue?

[roscoeiii]

Oh man did I panic when I put the KT120s into the Rogue. Just sounded muffled. And they required pretty drastically variable bias adjustment. But after letting the amp warm up more, they really started to sound great. The seller recommended about 10 min for warm-up and I'd agree with that. He also recommended biasing them higher than Rogue recommends, saying they can be biased all the way up to 90mA(!). Not sure how high I will be able to bias in the Rogue circuit, but I will play around with that later this week.

But more pressing is getting rid of this damn ground loop my system acquired as I swapped gear around. Grrrrr. Have an Equitech balanced power conditioner on its way (from NYC, so Sandy delayed sadly). Hoping that takes care of the problem

[Andre2]

Got my quad today at work!     ... but, as I was walking to my office with the quad box my double-e friend happened to be walking to his office, and I opened the box to show off the tubes to him.

And he goes: DON'T touch the tubes with your fingers!  Your imprints will atrack current and your tubes will not last as much or sound as good.

So, there.    I was dressed down, and will have to use gloves to install the tubes in my amp later tonight.  
Listening to great music later tonight on election day!!!

[Andre2]

Gold Lion Cryo set in da house.  All I can say is...








...  WOW - I should've gotten rid of the stock tubes long time ago.!
As much as I enjoyed this system when I got it, it is now sounding much much better.   

[morganc]

Try changing the input tubes and you may be even happier

[Ericus Rex]

And he goes: DON'T touch the tubes with your fingers!  Your imprints will atrack current and your tubes will not last as much or sound as good.

There's some controversy with that theory.  I've heard the glove method recommended by a number of tube manufacturers.  I've also heard Roger Modjeski (perhaps the world's most informed tube amp designer) say it's nonsense.  I personally only use the glove if the tube is hot and I've never had any issues.

[Peter J]

OK y'all, after an empty house, three song comparison here I go jumping on the slippery slope of verbal camparison. The new Black Treasures have about six or eight hours on them, the used EH I don't know...Roscoe? I'll admit my hearing ain't all that good, but at least it's the same ears in both tests. Which is to say; "your mileage may vary".

 I could live happily with either tube set. The biggest difference I hear is what I think is referred to as transient attack. What I'm describing is the front end of a significant musical event...a pick on a mandolin string or vocal beginning...whatever, that's what I'm calling it. The Treasures have a sharper edge on that attack, I found it mildly startling at times. The EHs were a little more rounded, I imagine it as the difference between a razor blade and a sharp knife, if that makes sense.

The other thing that stands out in my mind is just a little more emphasis on the high frequencies with the Treasures, maybe more detail?...nah, it's just got a little more energy up there.

As I said, I could live with either one, but I would give the EHs a slight... really slight edge at least at this point. I'm going to rack up a few more hours on the Treasures and give another go to satisfy my curiousity.

[mjosef]

Umm...yeah way too early to call 
New tubes need some time to 'cook' off the chains of newness before critical assessment.

[roscoeiii]

Yeah, those EHs have about 200 hrs on em I'd guess.

[Ericus Rex]

You should notice the biggest change with the treasures within the first 20 hours or so.  After that, they continue to break in but the difference is slower and more gradual.  Keep us posted

[LeeH]

Im in the process of changing my GL KT88's in the EE M88 amplifier did anyone manage to find out if KT 120's work with this amp? I have sent emails to Bill and Alex Young but had no response.

Also is it ok to uuse 6550 valves? a friend is using Tungsol in his Mastersound amp to good effect and has a spare set for me to try if I want to.

Any help much appreciated

Lee

[Bill O'Connell]

Lee,

 Do not use the KT120, let me check with Alex about the 6550's.
 I apologize for the non answer to your email, I opened it and then was distracted with something else  and then forgot to answer and get back to you with a reply.
 Bill

[Ericus Rex]

That sure is one beautiful amp!

[LeeH]

Lee,

 Do not use the KT120, let me check with Alex about the 6550's.
 I apologize for the non answer to your email, I opened it and then was distracted with something else  and then forgot to answer and get back to you with a reply.
 Bill

Hi Bill

Anything back yet from Alex re the 6550 valves?

Cheers

Lee

[Andre2]

changed the smaller tubes today and I believe that the music has become fuller, strong and more detailed bass/lower frequencies...

[JakeJ]

Andre2,

Despite what your Dubble-E friend says the myth of not touching the tubes with your bare fingers has been debunked by more than one tube circuit designer, including Frank Van Alstine and Roger A. Modjeski.  Vacuum tubes do not draw enough current to cause issues with skin oils on the glass.  However, HID, metal halide, and sodium light bulbs do operate at high current and they have serious issues when the surface has skin oil or other contaminates on the glass.  I have seen the result of this first hand.  Nothin' like the a 1000W metal halide bulb exploding!  Very Fourth of July.

In many amps and preamps the small signal tubes can have a much more dramatic effect on the sound than the output tubes.  This is cool because they are typically cheaper to play with than output tubes.  Woo Hoo!

Have fun,
Jake

[Freo-1]

I had this amp.  From what I recall, I had very good luck with with NOS GE 12AX7 and 12AU7s.  The Japanese Raytheon 12AX7/12AU7s were also nice, a big improvement over stock. 

The Black Treasures were nice, but my favorite output tubes were GE 6550As.  Those made a big difference.  As always, YMMV.

[Bill O'Connell]

Yes, you can use KT120's in the M88.
 You can not use KT150 though.