2. amps-preamps
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Help with VTL TL 5.5 Preamp

I recently acquired a Vacuum Tube Logic TL 5.5 preamp. It utilizes 6 tubes: (2) x 12AX7 and (4) x 12AT7. In trying to get to know this preamp, I've rolled several different combinations of tubes, BUT I cannot get the highs to sound smooth and "sparkly."

The preamp images well, has air and texture, is great sounding in the mid-range, good bass slam, etc., but the highs are driving me a little nut... sharp, edgy and too much grain. The highs can get in your face and blow you back a bit.

I've used various combinations Mullard, Telefunken, Mazda and Brimar. Right now, my set up is: (2) Mullard 12AX7A and (4) Brimar 6060 (T-Logo). All the tubes I've tired have been matched.

Any thoughts, suggestions or experiences?
bside123
bside123 OP
21 posts
 
Istanbulu Ed: Thanks for your suggestions. I've got great cables throughout my various systems. I know the sound of those cables very well. For the Tranquility SE DAC, I am using dB Audio's own Essential Cable, but I am certain that the cable and the DAC are NOT the source of my high frequency grudges. I've tried the VTL 5.5 in 3 different systems and have toggled between Analog, CDP as well as the DAC. I have changed configurations, etc. I am certain that I have narrowed down the sound of my complaint to the preamp itself. I am hoping to find a better tube combination and not to just "tame" the high-end with a cable. Anyway, sound is subjective. Many, I am sure, would disagree with me. Again, thanks for chiming in.
desmondjim
67 posts
 
I currently use a VTL TL5.5 with a McCormack DNA 125 while my ST-150 is in for service :( I have had great results with the old American Made Tung Sol 12ax7s. The highs were extended and sparkly but not etched or forward. They integrated very well with the glorious mids these tubes had. I also have had good results with the new issue Mullard 12AX7. I didn't like Telefunkens I tried.

On I side note looking at Steve McCormack's email above I do have the gain issues he wrote of. It is especially apparent using the mc phono input that I feel has excessive gain.

Cheers,
Jim
johnjohn
42 posts
 
Get a Classe CA200 or 300 - much smoother than DNA without giving up bass or resolution. Or just replace the 5.5 with a 2.5 which uses smoother 12AU7 tube.
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