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Looking for 5AR4 rectifier tube most like solid state

I have the Cary SLP-05 preamp (with the Ultimate Upgrade), which sounds exceedingly good in most respects. Unfortunately, it's sorely lacking in rhythmic excitement (what various British companies call Pace, Rhythm and Timing, or PRaT).

I suspect that the 5AR4 tube rectifier is at least partially to blame. In general, tube rectifiers exhibit "sag". This helps some aspects of the performance, but is likely dulling transients that are needed to create faster dynamics (e.g. percussive envelopes).

Cary has told me that I cannot insert an equivalent solid-state rectifier, as it would require a power supply redesign. Instead, I'm hoping to find a 5AR4 tube that mostly closely behaves like a solid state rectifier. I don't want it to be warm, or smooth, or anything like that. This preamp already has an overabundance of those qualities. Instead, I want it to be fast, dynamic, rhythmic, and exciting, with a real sense of "boogie".

Any suggestions?

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blisshifi
1,164 posts
 

I’m just re-reading and seeing this is about the SLP-05. I owned a similar unit with the ultimate upgrade and actually paired it with Ralph’s Atma-Sphere S-30 on a high efficiency system for a little while. Unfortunately, the preamp wasn’t a keeper for me due to the characteristics you describe. Regardless of the tubes and cables I put on the SLP-05, it felt slow and sluggish. It is colored is a very pleasing way, but I couldn’t live with what it did to the timing the way it over-colored the presentation. Best tubes I used with it to speed it up as much as possible were Sylvania VT-231 for all the 6SN7 and the EML 5U4G in rectifier position. 

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danager
923 posts
 

Different take but you should investigate the Space Tech Labs STR. (super tube rectifier). I’ve heard it and it’s the real deal. The HIFI cave and the Decware forum talk about it with both giving very positive results.

gs5556
1,229 posts
 

The sonic signature of your preamp is mostly the 6SN7 tubes. Voltage sag is not an issue (I think) because those tubes maybe draw 5mA each idle and maybe swing to 10mA on full signal. So the highest plate current is about 80mA for all 8 tubes which you do not hit unless playing full volume.

The 5AR4 drops the least amount of voltage for a given plate current than other standard issue rectifiers. At that plate current it's only about 5 volts, which should not really affect the linearity of the 6SN7 tubes. Rectifiers are more carefully chosen for power amplifiers, but in preamps I don't think will make much of a difference.

 

knotscott
882 posts
 

Another different take, or perhaps in addition to....have you done much tube rolling with the preamp tubes?  They can be quite different from one to the next.  

invalid
1,142 posts
 

@danager +1 on the space tech lab super rectifier, I own one and it makes a profound difference with my preamp. I don't know exactly why it makes such a difference, but it does, if I want it to sound more like solid state I just roll in a couple 3B22 or 3B28 tubes, if I want more tube sound I just use 300b or 2a3.

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