 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
108.12.18.216
In Reply to: RE: KT66 NOS Gray glass VS Reissue Gen KT66s posted by Michael Samra on March 30, 2014 at 05:02:18
I know your review is for hifi, and soon I will be building a K&K st70 amp with Magnequest iron (5k impedance) to run KT66 or 6Ps3-e.
But in my Marshall JTM45 and my Bluesbreaker, the Gold Lion equal my clear glass GEC with cleans and clipped and almost as sweet as my grey plate. The grey plate has a little more harmonic content to my ears.
My black base Saratov KT66's that I got from Byrd69 sound a lot like my Gold Lions
My Shug Treasures sounded crummy and muddy.
All of them I rebiased For each pair and ran them for a few weeks at a time. Usually they were biased around around 42ma. A few around 44ma.
I would like to burn the treasures in for a looong stretch, so maybe when I build the K&K I can do that.
When I start building some guitar amps commercially, Gold Lions from Jim will be standard. They are phenomenal tubes.
Follow Ups:
Will you be building an amp based on the original 1961 JTM-45? This I would be very interested in. The best vintage Marshall I played on was an old Bluesbreaker combo. It had KT-66's pushing Celestion Blue alnicos. Crazy overtones. One of the most aggressive sounding combo amp.
Keep us informed!
There are a handful of very good reproductions of both the Bluesbreaker and JTM45 circuit out there (not that I wouldn't build one for someone), but I want to tinker a bit.
I would start with the same Bassman/JTM45 topology and try some different ideas. One thing I am interested in is trying some interstage transformers as the PI and see if there are different saturation characteristics, have adjustable NFB, and maybe use some octals instead of 9 pin in the preamp circuit.
I also want to try out some odd things: maybe a circuit with grid chokes or some plate chokes and see what they do to the sound.
It is hard to come up with something different in a field that has so much history. I love the work George Alessandro has done, and what can one say about Kenny Fischer and HAD that hasn't been said.
As you say in guitar amp it is different and the distortion overdrive is what they look for in those applications..What I have also found is,you can choose the level of distortion you want by the way they test in the new tubes..Higher trans conductance and lower distortion is more for hifi and for guitar you want higher distortion rated tubes or rated different.
I like the Saratov KT66 and that was actually designed by Aspen Pitman of Groove tubes built on his tooling in the Reflektor plant..I like the GL reissues better but they do sound similar as you say.
Honest amplification is better than excessive 2nd order distortion anytime.
Yeah, aspen got it right with those.
The other hard part is so much of biasing for guitar amps is done by ear within a few ma and one can always be suspect of biasing to get similar tone with different sounding tubes.
Best of all, my original pair of Gold Lions from Jim are still going strong in my Bluesbreaker since '08.
Mike, just to anal, what most guitar amps shoot for is harmonics & OD in the pre-amp and input stages. Harmonics in the output stage. OD in the output = very, very loud. Some output bottles have that magic overtones, even at moderate volume levels.
Edits: 03/30/14
In the driver stages? I was wondering because Apsen Pitman and Myles at Groove Tubes were always telling me about distortion ratings and what I need for hifi vs guitar applications.
Honest amplification is better than excessive 2nd order distortion anytime.
Mike, I've found that a clean output stage, not pushed too hard can yield pleasant results. Most vintage 6L6GC Fender amps run around 65% rated max dissipation. Large percentage of the tone is derived from setup of the gain stages and feedback parameters. I use the toughest, cleanest sounding output stage tubes that most hi-fi guys are after. Except for SET amp tubes.Even with this setup, you can really hear the difference between makes, types, and era of output tubes. Every tube has its own characteristics.
Edits: 03/30/14
Marshalls and others based on Marshall's take on the Bassman can have a lot of clipping in the Phase Inverter. It is one of the reasons I LOVE smooth plate Telefunkens in the PI, as well as bp Raytheons and RCA long plate 7025s.
Grey glass mov genalex are such bottles for sure. Swirly, 3d, rich and all other sorts of adjectives.
I have two new quads of reissues and I was going to try a quad and see if they are better than 2007 reissues. I was surprised you didn't like the Treasures..Of course the only ones I heard were the KT88 and 6CA7 and both of those were fantastic.
Honest amplification is better than excessive 2nd order distortion anytime.
Edits: 03/30/14
I was surprised by the treasures also. I like their KT88 too. I am definitely going to break them in further and maybe by another pair to try.
Plus, I was even more surprised because the dragon Shug 66's sound great in Marshals.
Post a Followup:
| FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
||||||||||||||
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
