riffmeister: To my ears a "true" KT66 (certainly the original Genelex and for the most part the Shuguang KT66's) have a stunning clarity about them, (especially in the mids) that would not have been present in your amp when you were using 6L6's. The sound/tone seemed sweeter and more "alive" as well. The overdriven tone is quite "thick" (yet with clarity) and it also has a REALLY nice "growl" to it. I found the KT66's perfect for blues and light to medium rock. In comparison, the GT-KT66-HP's seemed QUITE blurry in the mids, and had a LOT more gain (not in a good way to my ears) than the Genelex or the Shuguang KT66's. When overdriven, the GT-KT66's seemed "mushy" and nondescrip by comparison. IMHO Chuck
Riff, What tubes were in the amp before the change? I find that generally, it's a more 'English' sounding 6L6. A little different character to the mids, a different low end in that it's more fat, with a unique character to the compression when driven hard. I've had experience with both Valve Arts (Shuguangs) and GT KT-66HP's. I thought the VA's sound more like the NOS Genelex than the GT's.
I think the latest GT iteration of the KT66 is quite good. Not as good as a Gold Lion from Britain. I can do direct comparisons on the Ganesha with a flick of a switch, EL34's are brasher, more trebly and sound to have higher gain. The KT's are richer and darker overall with a smoother treble. My favourite tubes alongside 6V6's or 6K6's. Best, Pete.
That sounds like fun! I own and love a Classic 45. I did a quick swap a while ago from KT66 to EL34 with a re-bias which was an interesting and useful variation. If you have time on your hands , would you compare the Club 40 to a the Classic 45 when loaded with EL34? I'd love to hear the similarities/differences as the Club40 has me gassing too! Thanks Chris
Been thinking of putting them in my tube rectified '67 JTM 50. Any idea what that will sound like in comparison to the EL84s? Will it make it sound like a JTM45?
I've had the Classic 45 for the better part of a year now, and early on I swapped out the KT66s (Valve Arts) for EL34s (Siemens) because the KT66s sounded too bassy to me......the EL34s improved things.....but I still run the amp with the bass control "off". So the comparison I will do when the Club 40 arrives is C40 vs C45 with EL34s thru the same cab, then C40 vs C45 with KT66s thru the same cab. Always fun to do the shootout thing.....
I've never liked KT66's, that grainy type of distortion bothers me. But, when it comes to KT77's, KT88's and EL37's, I'm all over them.
Yes, I did. Basically, the C45 (with EL34's) is a warmer more laid back "1960s Marshall" and the C40 is a brighter more agressive "1970s Marshall". And with a little fiddling with the tone controls it is possible to make one sound fairly close the other (the C45 set up for a brighter sound is close to the C40 set up for a darker sound). I had fun with the C45 for about 9 months.....now it's time to have some fun with the C40.
I can't say for sure, but I'm guessing it'll get you 2/3 of the way there (you'll have the KT66s, the tube rectifier, but I think the plexi circuit has a little higher gain?). I also think the old RCA 6L6G (not the GC) is a great sounding tube in a JTM45, and very similar to the KT66.