Hi oldhvymec. (And others...thank you!)
Yeah, I was wary of that one number being extra high. That comes from a replacement tube. I'd bought two matched quads, but one tube turned out to be bad, and I guess that's the best replacement the proprietor could find.
Another thing: I'm surprised at the nature of the change in sound this brought to my amp.
Up until how I'd stuck with whatever CJ recommended at the time, which 6 years ago where the modern Tungsol 6550s. So that's what I'd used until recently. I started hearing creeping grain/distortion in my system and figured it was likely tubes. I've had the CJ Premier 12s since the late 90's and never replaced the small input tubes either! So I figured it was time just in case. The original were GE tubes, one 5751
two 6FQ7 per amp.
I ordered the Svetlana Winged C 6550 NOS tubes, and wanted to try tube rolling for the input tubes. Bought these:
5751 super low noise:
http://www.tubeaudiostore.com/57suplownois.html
And these Mazda 6CG7 / 6FQ7:
https://upscaleaudio.com/products/mazda-6cg7-6fq7
My research on the Svetlana Winged C 6550 NOS tubes suggested they had a rep as a linear-sounding tube, tight bass etc, not overly tubey.Which I was kind of going for.
The results have been, first off, a total lack of distortion and grain, so that problem was fixed. Utterly gorgeous, smooth, velvet texture and tone.
BUT...an increase in the "tubey-quality" - the bass is less defined, bigger, a bit woolier, less air on top, a teeny bit thinner upper midrange. And most of all a mellowing of dynamics, punch and density. In effect it now sounds more like a slightly underpowered tube amp - gorgeous in tone, but lacking some drive and aliveness. That part is a bummer.
So I'm wondering if it's the 6550s or the input tubes changing this character. I've heard input tubes can change an amp even more than the bigger output tubes.
Thoughts? (Anyone?)
Yeah, I was wary of that one number being extra high. That comes from a replacement tube. I'd bought two matched quads, but one tube turned out to be bad, and I guess that's the best replacement the proprietor could find.
Another thing: I'm surprised at the nature of the change in sound this brought to my amp.
Up until how I'd stuck with whatever CJ recommended at the time, which 6 years ago where the modern Tungsol 6550s. So that's what I'd used until recently. I started hearing creeping grain/distortion in my system and figured it was likely tubes. I've had the CJ Premier 12s since the late 90's and never replaced the small input tubes either! So I figured it was time just in case. The original were GE tubes, one 5751
two 6FQ7 per amp.
I ordered the Svetlana Winged C 6550 NOS tubes, and wanted to try tube rolling for the input tubes. Bought these:
5751 super low noise:
http://www.tubeaudiostore.com/57suplownois.html
And these Mazda 6CG7 / 6FQ7:
https://upscaleaudio.com/products/mazda-6cg7-6fq7
My research on the Svetlana Winged C 6550 NOS tubes suggested they had a rep as a linear-sounding tube, tight bass etc, not overly tubey.Which I was kind of going for.
The results have been, first off, a total lack of distortion and grain, so that problem was fixed. Utterly gorgeous, smooth, velvet texture and tone.
BUT...an increase in the "tubey-quality" - the bass is less defined, bigger, a bit woolier, less air on top, a teeny bit thinner upper midrange. And most of all a mellowing of dynamics, punch and density. In effect it now sounds more like a slightly underpowered tube amp - gorgeous in tone, but lacking some drive and aliveness. That part is a bummer.
So I'm wondering if it's the 6550s or the input tubes changing this character. I've heard input tubes can change an amp even more than the bigger output tubes.
Thoughts? (Anyone?)