[Angaria]

I have a couple hundred hours on a quad of GL reissues.  More forward and less lush than the tungsol kt66's I replaced.  More treble detail, but less bass resolution, which strikes me as odd.

My amp also has a pair of 12Au7 and 12Ax7's.  May be amp dependent, but has only one found a particular make of those that went well with the GL's?

Thanks.

[Tyson]

Amperex pairs very well with the GL's (both for 12ax7's and 12au7's).  Tungsol, Telefunken, and (very early) sylvania also pair up with it extremely well.  Finally, you should check with the amp maker to see if you can use a pair of 12bh7's in place of the 12au7's (requires a bit more from the power supply).  The 12bh7's are generally better sounding tubes than the 12au7's, IMO.

[Angaria]

Thanks! - same recommendations for the 12bh7? (they seem to be somewhat scarce)

[Tyson]

Not many companies made them.  Of the ones that did, I really like Brimar and Sylvania.

[Ericus Rex]

Have you tried the GL KT66 reissues?  Sounds like your amp may like that tube better than your KT88.  Comparing different tube types is like comparing apples to oranges, as they say.

[Angaria]

Well, the amp did come with 6l6 tubes stock, but supposedly could handle kt88's which I was assuming would have tighter bass.  You think it could be worth a shot to drop in some high-end kt66's?

[JoshK]

JJ's ECC99 is basically the equivalent of a 12BH7A.

[Pez]

Well, the amp did come with 6l6 tubes stock, but supposedly could handle kt88's which I was assuming would have tighter bass.  You think it could be worth a shot to drop in some high-end kt66's?

Well "can handle" means that if you plug em' in they'll run, that doesn't not necessarily mean they will run well.  The KT66s are easier to drive, and by virtue of that your amp may perform better with them than any kt88s. All of this stuff is very dependant on your particular equipments capability as well as your own personal taste.

[Angaria]

Tried switching between the GL kt88's and tungsol 6l6 - way better bass control on the 6l6 while the GL's sound like they're playing through a very high Qts woofer.  Anyone want a quad of GL kt88's?  Still planning on giving the GL 66's a shot.

[JoshK]

You are probably under biasing the KT88s.  Crank the bias up to the sweet spot and you will probably change your opinion. 

[Angaria]

Sounds like it would do it - but this amp is auto biasing....

[JoshK]

Yeah, then stick with 6L6-oids.  Those sound good too.

[Audioclyde]

Angaria, you might consider trying some of the reissue Tung Sol 6L6 big bottles---pretty inexpensive, I have a quad that I use sometimes in my Cary SLI-80.  I still prefer my NOS TS 6550 blackplates or NOS blackplate 6L6's, but I was actually very pleased with the sound of the reissue TS 6L6 big bottles.  In my system they were in the same league as the NOS RCA blackplates (a great bluesy tube, great for vocals, jazz, etc., IMHO) and I didn't expect them to be so good.  I bought mine from Ron (Cryoset) in California and I consider a great cheap alternative to the NOS 6l6's....

Randy

[Angaria]

Hi Randy, The 6l6's I currently have (and like) and tungsol 6l6gc str's.  Are you talking about their 5881 reissues?

[Audioclyde]

These are the TS reissues I have:  http://www.cryoset.com/catalog/product_info.php?cPath=22_29&products_id=130&osCsid=2c01f3fa8677389f11ed968050cfe437.


6L6G's (big bottle).