Supratek Tubes and Tube Swappin' for Everybody

Fiddler - I'll give the 6106 a week at 24/7 and see how it does. The actual articulation of the notes from start to finish is fine and this is the most important thing. There is no question that it is a very good rectifier, but at this point it hasn't destroyed the competition.

I have a dual-getter metal-base amperex bugle-boy gz34 that goes in after the 6106

The cabernet only uses a single triode out of the dual-triode 6SN7GT. The other triode used is the we101d. Which might explain a difference in bass output between my preamp and yours.

I might give the tungs-sol round-plates a place in the hot socket one day. But for now I am working on finding the best rectifier and regulator. I am trying some alternative regulator tubes including the 6f6g and we'll see how it goes. One thing I can already say based upon my experiences. That is that the higher plate dissipation of the regulator will increase the operating point on the rectifier causing the signal tubes to distort more. So for the cleanest and most natural sound and highest resolution the 6f6g is going to smoke the 7581, 5881, el-37, kt-66, el-34, 6l6gc etc. And I am not really concerned with freq response for my system although I will note it. What I am after is the best execution of the note from start to finish and including the harmonics. I want maximum resolution of the music and for the preamp to still perform without a hint of strain.

Hi Whoopadeedoo - I really don't want to argue about it so... I'll take your word for it, printing means nothing, the construction is the same, and they all sound the same and we'll leave it at that.

How many KR's have I owned? I don't remember exactly but I have owned many. As I am sure you know, the ratio of good "pre-amp" quality 6SN7's (low microphonics / quiet) to not-so-good is relatively slim. Depending on the tube manufacturer/type/vintage, its often very difficult to find a nice vintage 6SN7 which is adequate for use in a line stage...Particularly the Supratek which is quite sensitive to tube quality. Having said that, for several years, I purchased numerous KR Black Glass tubes from various sources and maybe, at best, 1 in 10 tubes were quiet enough (no squeeks, no microphonics, no crackle) to even be considered as usable. Of the KR tubes I purchased during that time span, I kept about 20 (10 pair).

Also during that time, I was cycling through various amplifiers, cables and digital components. I discovered that I could "tune" my system with the various "flavors" of the KR black glass tubes. Initiallly I didn't know they were sonically different but after swaping back and forth tubes and matching with various components, I soon realized that they were all similar but very different. Certain marked Ken Rads were totally unusable with certain component combinations while other KR's were seemingly perfect.

Using the KR's in a line stage preamp produces a much different effect than in an amplifier. So for those people who use these tubes in amps and hope to obtain various sonic results, I don't know what to say because I would expect the results to be much more subtle and possibly less noticable in that application. It is when the tubes are used in a line stage - particularly the Supratek - that the difference in sound is obvious.

The 6SN7GT marked Ken Rads are noticably dark, and rolled off. The VT231 marked tubes are the most even/neutral of the bunch, the NAVY tubes are far more extended in the highs than the other types...but still maintain the KR signature.

Well.. your descriptions of the other tubes when used in a Supratek are weird, particularly the CV181 description. I know that CV181's do not work in Chardonnay and Syrah preamps (for whatever reason).

The "midrange" on a 350B is more-or-less quite neutral. In fact, the 350B is oddly one of the least "involving" or romantic sounding tubes available when used as a regulator in the Supratek. Where it stands out and what makes it the best, is what seems to be the most brute force and blatant accuracy of all regulator tubes. Which may be why they do not float your boat -as you put it. You state you like what they did to the midrange and that makes me a bit curious as to what else is going on in your system that you'd identify the 350B as having a particular midrange quality (vs. everything else) in your system that was good.

The 350B really comes into its own when used with a Bendix 6106.

Fiddler,

IME, the Sylvania Bad Boys is comparitively "dry" sounding versus the Tung Sol's more liquid, "wet" sound. For clarification's sake, I am not using the adjective "dry" with any negative connotation. It's a matter of perference. I like the Bad Boys; they've got better control of attack and decay then the Tung Sols, and the Sylvania 6SN7GT '52 have more spatial seperate and thus sound slightly more resolved. The high frequencies have an uncanny air to them. However, the Tung Sols simply reproduces harmonics that is extremely beautiful to my ears .... a bit more full and palpable. And they sound more balanced from top to bottom.

I confirm the problem with the 6106 regulator when use for the Chenin. There is no problem on CD source. In fact you can crank up the volume to the max (no music playing) and you will not hear any hum at all or tube rush sound. Not for the phono section though! With the 6106 as a rectifier, using the same test method, there is a loud "chugging" sound when the volume pot reached about two O'clock.

So for the Chardonnay, the 6106 will work without problem since the one that is affected is the phono section.

I was using 6F6G on my Chenin. But I am now enjoying a GE 7518 as regulators. It adds a little "muscle" to the already superb phono section (not that I am complaining!). I like the RCA 6L6GC'a also.

It seems to me, after reading a lot of comments and experiences about regulators and rectifiers, that the Syrah, Chenin, Chardonnay and the other preamps have a different voltage requirements. I think as far as the tube rolling issue is concern, the only tube that is "universally acceptable" based on others experienced to everybody is the 6SN7's for the Suprateks. The others vary and should be specific to each model only.

I think....