I’m surprised that this thread appears to be running out of steam at a time when more and more Horizons are being delivered, which means folks are now getting more time to become familiar with the numerous tube choices for their units. I therefore thought I’d provide an update on my tube preferences and the rationale for their use.
The British are coming, The British are coming.......The British are here!
TRIODES
I might as well start with the most controversial choice, the legendary Tung-Sol Black Glass Round Plates (BGRP). This tube has an ambivalent following. I was curious to learn whether it is the highly revered tube that many have praised, or whether it is a tube that deserved some of the pans such as those by the well-known 6SN7 user and reviewer Robert Hutton from a few decades ago. In my view, the truth lies somewhere in between, but is mostly favorable. It is certainly an excellent tube with an interesting story. According to Hutton, the tube became enormously popular many years ago when Upscale Audio touted them heavily, which caused their prices to escalate dramatically, until Upscale ran out of inventory, at which time they dropped them like a hot potato and moved on to something else leaving only their high price in its wake (which Hutton thought was entirely undeserved.) More damning perhaps is that Hutton thought the tube was somewhat sibilant sounding on top hence he became a very vocal naysayer. While I can understand Hutton’s concern about the sibilance issue (easily demonstrated on Patricia Barber’s wonderful cover of “The In Crowd”) it is a relatively minor misgiving that doesn’t detract from the tubes wonderful assets which most prominently is a very beautiful midrange. Although I enjoyed this tube, it has not become my triode of choice for two reasons. The first is that the bass, while well defined, is rather polite. Having just returned from Carnegie 2 nights ago hearing Scheherazade and some assorted Victor-Lobos pieces, it is the 40-80Hz range of the tube that just plays too light for me in my system. The main liability of this was the sonority of lower brass, which for me, just doesn’t provide the correct “weight” of the orchestra that is more like the real thing. Secondly, the entire treble range while good, doesn’t have the definition and clarity of some other triodes in this range such as the Sylvania 6SN7W/B65 or the fabulous Mullard ECC32/31. In short, the BGRP, while very good, just didn’t have any magic for me to the point that it was a keeper. I ended up selling mine a while ago. But that midrange is truly gorgeous.
Almost but perhaps not quite as controversial as the TS BGRP is the Sylvania metal base B65. Most who have heard this tube are impressed with the top end for good reason. It’s performance there is exceptional. There are parts of the frequency spectrum that are so extraordinary, it translates to genuine impressions of being fooled by thinking you are hearing the real thing. This is the magic that everyone comments on when hearing these beauties. The tube is just outstanding down through the midrange and lower. It’s liability, which is just to say that it is not a perfect tube, lies in the bass range, particularly in definition more so than extension. There, it’s good, but not great. Having tried a number of Sylvania 6SN7’s I can relate to dminches when he says the bass on Sylvania’s are like Forrest Gump’s box of chocolates- you never know what you’re going to get! I agree. For example, I found the bass on the VT 231 6SN7 GT to be very big and almost overwhelming, while the 6SN7W black base had noticeably atrophic bass. Still, I found that if you mate the B65 with a compatible rectifier with strong bass, the combination can be thrilling. There is just so much that the B65 does exceptionally well that virtually no other tube does, which is why it always turns up in the top echelon of 6SN7’s by audiophiles. It may have some minor weakness in the bass, but I’ll share it is a tube I will never sell. It’s a reference tube in so many ways because it’s more than a great tube for listening to music. Rather, it’s a great tool for comparing other tubes to in order to assess their performance to see what they bring to the table.
Finally, there is the Mullard ECC32/31. I might as well just say it. This tube is simply beautiful. It does the entire frequency range so well and is so musically balanced that it just stands out among its peers. The articulation, frequency response, tonality and sense of “rightness” is exceptional and most importantly, delivers that one thing that we all aspire to, which is listening to music while letting the gear or component get out of the way. With the Mullard, that is what it does extraordinarily well. You just don’t think about what the tube is doing. You just end up listening to music. This tube has genuine magic, but here it is almost everywhere not just primarily in one frequency range. But if you want to start with accolades somewhere you might as well start with the midrange, which is stunningly good, low in distortion and harmonically rich. The top end is very pure and sonically wonderful. It would be a fool’s errand to try and compare it’s top end to the Sylvania B65. They are both excellent yet but different (but each is a light year better defined for me than the TS BGRP). The bass is also very well defined, well extended and has the right balance which renders the orchestra floor very believable to me.
It should be mentioned that while the ECC32 is very expensive (even if you don’t buy from the whore in Hanoi), there is a far more accessible alternative which is the ECC31. As has been mentioned a few times here the ECC31 is identical to the ECC32 but it has a common cathode grid and therefore requires an inexpensive adapter (eBay) to use in the Horizon. Both have Lukasz' approval which is very important since the ECC32/31 is not considered a drop in plug and play for a 6SN7.The Mullards have 50% higher current draw and grid voltage, gain and transconductance are all different than a 6SN7. Again, Lukasz assured me that the Horizon is very over-engineered so the Mullards are easily handled in the Horizon. While ECC2’s can go for over 2K/pair, the ECC31’s are generally a few hundred bucks per tube if you shop wisely. In fact, there was a new in box Mullard ECC31 advertised recently for $75 which just drove me nuts as I would have bought it in a heartbeat if a pair were available.
PENTODES
As many have discovered, it's best to think of the 3 individual tube types not only individually but as cast members of a larger sonic consortium. Regarding pentodes, nothing has given me the same sonic enjoyment as the Mullard EL34 xF2 made in Blackburn. The main attribute of the Mullards, which is why they are so revered, is not only their sonic beauty but their resistance to overload. This is true whether its solo piano gone Yuja Wang berserk or Mahler in Warp 9 overdrive. In the history of high end audio it may not be hyperbole to say the Mullard EL-34 may be one of, if not the most consistently praised tube ever made. It's popularity waned a few decades ago when massive wattage tube power amps were made which utilized the greater power available of 6550 or KT88 valves. But bigger doesn't necessarily mean better and in the case of the Horizon, power is not the primary consideration for Lukasz's unique hybrid octal design as it might be in a full blown powered amplifier. Some reviewers have simply said that the key feature of NOS Mullard EL34's is that they just sound more like music than any other equivalent pentode.. I would agree and for that reason, it’s my keeper. I sold my KT-170’s a while ago. One advantage of the KT-170’s however, is that they are very obtainable and that’s worth great deal as the Mullards are not a dime a dozen. It also doesn’t hurt that the KT-170’s sound very good so they are a very solid choice. I could easily live with them, but for me, the Xf2’s are in a different league and bring another small level of sonic truth. Piano, voice and strings are exceptional and simple tracks of these can be used to easily hear the merits of this tube. I read an old comment on another blog where one listener said that after listening to a piano on the Mullards, it wasn't worth hearing a piano on any other tube. A bit of an exaggeration perhaps but I understand why he made that comment. They aren’t cheap, but they’re generally obtainable for about $250-300/tube, which considering the price of the Horizon, seems like a modest investment to me.
RECTIFIER
Previously, I wrote that the Takatsuki 274B was my rectifier of choice for the Horizon (and the GG2). Post #2845
https://www.whatsbestforum.com/thre...ling-review-thread.26478/page-143#post-819130
However, I voiced a minor concern that as good as it is, it is a somewhat dark sounding tube (“bottom-up” or “yin” sounding). Yet its strengths are so good, particularly in the bass through upper bass, that it remained my recti of choice. Until now. The reason for exploriong my new recti reference was the comment I made previously regarding my sense that a Steinway piano recording sounded a bit like a somewhat darker Bosendorfer through the Tak and this remained a legitimate concern. What put me over the top in re-opening the rectifier exploration was the uncanny midrange of the Mullard ECC32. The Mullard, combined with the Tak was just not able to nail Steinway Grand with openness the way I had hoped due to some aforementioned darkness. Enter the incredible MOV/GEC U52. This rectifier is no secret.
To be continued...
