yeah. I was recommending the Ken-Rad's 6SN7GT/VT231 or Sylvania 6SN7GT as signal tubes. I think Raytheprinter was looking for some suggestions on that also. |
I have an extra pair of TJ101D which I cannot use in my cabernet. So any cabernet owners who can use this tube are welcome to them. Its a freebie, I don't won't any money for them. Send me an email. |
Jes45 - If you have an axe to grind with Mick then tell him about it. There is nothing we can do to correct any problems you may have. From my past experience with Mick he has always taken care of things that needed fixin. |
Whoopadeedoo - So tell me more about your impressions of the tung-sol 6SN7GT round-plates. How do they compare to the RCA grey-glass and Sylvania vt-231. I have a few pair lying around but I haven't had them in the system for a couple of years. So I can't really recall what they sounded like. |
Whoopadeedoo - Are your Visseaux 6L6G's the ST glass or tall skinny glass? I got quite a few of the latter but I've only seen picturers of the former. I rolled them in my Sauvignon a long time ago. I used Sylvania 5932 dual plate for about 18 months. First in the Sauvignon and then in the Cabernet. It is IMO a real sleeper as regulator. I think the unique dual plate structure is what sets it apart. It gave me a rock-solid soundstage with neutral freq
response. Regulator tubes are a different lot when it comes to judging sound. Some of the regulator substitutes have an unusually high heater current and will place a larger demand on the power supply and also affect the current draw through the rectifier hence the voltage sag on the recifier and ultimately the operating point on the signal tubes. I wonder sometimes if that load is adversely affecting the expression of the music or maybe it's just getting everything in its sweet spot.
Sylvania VT-231 has excellent top-end extension, tight bass but could be lean for some tastes. Sylvania 6SN7GT 1952 tall boys are very similar to Sylvania VT-231 but with a bass boost below 100hz. RCA grey glass have maybe the best midrange of all 6SN7GT's with very nice harmonics. |
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. |
I got the Bendix 6106 in the Cabernet. It is more than a little tipped-up. The bass is even less than that of the Sylvania Vt-231 with a gz34 or gz33 rectifier. And I have the Sylvania 6SN7GT 1952 tall-boys, which are well known for their bass, in the preamp right now.
For example, when playing "poco a poco" performed by fourplay the drums are normally featured prominantly and there is a tension in the music between the bass section and the melody. With the 6106 the bass and drums become an accompanyment to the melody.
What bass is present is at least well controlled but that has never been a problem in my system. I seem to have lost some pitch resolution in the bass also. For the rest of the audio spectrum the detail and resolution is very good, even excellent. There is a slight incoherence in the soundstage depth. Mainly due to the reduced bass output.
So does the bass ever get bigger with the 6106 as it breaks in? |
I just measured my system with Tact RCS. This is in-room response and no my room is not an anocheic chamber. Previous rectifier was a gz33. The current rectifier is a bendix 6106. Output below 300hz is reduced by a few db. There is a hump in response from 3-5khz by at least 2-3db. From about 8khz on up it just climbs a mountain. I am up at least 5-6db at 20khz. I can't consciously hear anything about 17khz but somehow I can percieve a 20khz test tone. |
Amandarae - Are you sure that you are using the 7518 or is it the 7581? The 7518 only has a 2.5v heater and if that is what you are using you might want to get the fire extinguisher handy. You are right about different voltage requirements but the difference is mainly between the linestage only versions and the full-blown preamp with phonostage. SupraTek owners with the phonostages will have higher current requirements that will restrict the use of some of the lesser rectifiers and pentodes.
Anyone who has a phonestage in their SupraTek preamp might want to check with Mick before rolling power-suppply tubes. |
Here are my listening impressions of the 6106, GZ33, and GZ34 rectifiers in my system. These listening impressions were with the 6F6G in the regulator position. Beefy regulators with high plate dissipation may tend to reduce the audible differences between the rectifiers. In my system the differences between rectifiers were easily recognized. The Cabernet sounded great with all of the rectifiers I listened to. It all comes down to personal preference.
6106 - Some leanness from about 300hz on down. The rectifier WAS detailed and very good but gave up some pitch resolution in the bass compared to the GZ33. The 6106 required 24 hours continuous use before it even started to open up.
GZ33 - The warmest of the 3 rectifiers in terms of freq response. Excellent low-level resolution. I've used this rectifier for about 18 months. The GZ33 required about 4 hours use before it opened up.
GZ34 - This is the Amperex BugleBoy metal-base with double-getters. The measured freq response in my system was similar to the 6106. There was the same leanness from 300hz down. This rectifier gave me the highest resolution of the 3 rectifiers. It was very airy with excellent harmonics and the best pitch resolution in the bass. The GZ34 required about 4 hours use before it opened up. |
When I asked Mick about what tubes I could roll in the regulator position he said the heater voltage has to be 6.3v and the heater current can't be more than 1.5a.
According to the western electric datasheet for the 350b it says the heater current is 1.6a. I recall someone in the "preamp deal of the century thread" said that using 350b's damaged their SupraTek powersupply.
http://www.westernelectric.com/spec_sheets/350B.pdf
Yall might want to check with Mick to see if the 350B is ok to use.
I was interested in using the 350b myself but this kind of put me off a bit. |
Bwhite and Fiddler - my intent was only to bring the heater current issue to the attention of SupraTek owners at large. However they act on that info is up to the individual. We are talking about a small amount of power. Less than 1 extra watt DC for both heaters combined. But design specs normally exist for a reason. |
Raytheprinter - the 5881 is one of the worst regulators. Better to go with 6L6G, 6L6GA, or 6F6G and they are less $ than 5881. Ken-Rad's 6SN7GT/VT231 or Sylvania 6SN7GT Tall-boy have the best weight. Email me if you need pictures of examples. |
Ecclectique - it is great to see you active on the thread again. I tried the 6106 in my preamp for a week and it was very good. It opened up a bit after the first 24 hours but I didn't notice much change after that.
Are we dealin with a breakin issue or is it an operating temp problem? If you take your 6106 out and let it cool off, how long will it take to open up again when you put it back in?
Is that the heater element in the middle of the 6106? Looks like they ran it through some ceramic. Maybe that attributes to some of this.
On another note. I have some 6K6G on the way. Mick said they would work in the regulator position. The plate dissipation is real low so I am hoping for some magic. |
Slowhand - I used the dual-plate 5932 in the Sauvignon and Cabernet for at least 18 months. IMO it is probably the most underrated of the regulator tubes. My SupraTeks were always at their quietest and the soundstage most stable with the 5932 in place. Regarding impact on the sound qualities the 5932 is between the 6F6G and 7027a/KT-66.
bass output/fullness 7027a/KT-66>5932>6F6G
harmonics 6F6G>5932>7027a/KT-66
detail retrieval 6F6G>5932>7027a/KT-66 |
Raytheprinter - 6SN7 quality starts to decline in the early 50's. This is just a generalization. There are very noteable exceptions like the Sylvania 6SN7GT of that period. 6sn7gta and 6sn7gtb are not as good for audiophile applications as 6sn7gt and vt-231. In 1952 6sn7gt's were still being manufactured and I don't think the 6sn7gtb had been designed yet. To the best of my recollection the 6sn7gtb has the same higher plate voltage of the 6sn7gta but with a slower startup. I stay away from GE tubes until there are no more Sylvania/Ken-Rad/RCA left in the world. |
Wc65mustang - Mick's comments have a lot of merit. Esp about the different rectifier/regulator combo really only serving to change the operating points on the signal tubes. I still recommend rolling all the tubes, but I would use some auditory/budgetary discretion along with a clear plan of action. I suggest rolling the rectifier first, regulator second, and signal tubes last. |
