6V6 Overview 6J4 6P6P Preamp

With the 6V6G's the Preamp looks like an SEAmp!

Talk Tube: 6V6

6J4/6P6P Preamp, Part III

6J4/6P6P Preamp, Part I (basic info), Part II (cable mod)

As mentioned previously, these days I cross over to Hong Kong every week or two, and sometimes bring back things to test out in SZ. I had mentioned WE tubes, and I've brought back a few more since, but that's not the focus of this article (a later one maybe).

Overview: 6V6

Regular readers shall know that I'm a great fan of the 6V6. Tube enthusiasts should read this excellent Wiki entry on Beam-Tetrode. As mentioned in the article, aside from the rare MOV prototype, the US 6L6 was the first of this family to be released - and, I may add, to become one of the most famous tubes ever. First released right after the 6L6 (likely in 1936), like its bigger brother the 6V6 has been in continuous production (worldwide, if not the US). 

Push Pull Its use in PP (about 6-8 watts) vintage radios and amplifiers was ubiquitous. With the emergence of vinyl (7", then LP), when audio gradually became well domesticated, many manufacturers offered modestly powered PP 6V6, EL84 and 6L6 in their catalogue (in increasing power, to be joined by more powerful EL34, 7591/7868 and 6550 later as loudspeakers got more inefficient). First in Consoles, then Stand Alone's. This lasted many years (about 2 decades) from the early Mono era to when Stereo was well established. This blog has covered Bell and Grommes (mono integrated) amps and even, recently, the relatively recent ANUK Kit 4! They sound absolutely great with the cheapest and most ubiquitous of straight bottled 6V6GTs. Due to the limited power on hand, your loudspeakers cannot be too inefficient and your room cannot be too big, and head banging music is a no-no). Due to the way home audio developed, when it comes to vintage, there were few 6V6 Stereo amps. In the modern era, there have been very few commercial 6V6 amps, the tube mostly relegated to the domains of DIY and boutique amp makers. One can understand why. The smaller sized EL84 can offer more useful power in a smaller footprint, whereas 6V6 would take up as much space as EL34 etc. And so, we have quite a few EL84 PP amps out there (Leben, Manley, just two that popped into my mind; this is not to count the large number of cheap [but good] Chinese 6P14 amps, more if you include the closely related 6P1 [different pin-out, for which convertors are readily available]). In comparison, there is almost no Western commercial 6V6 amp (the only one I can think of is Swissonor; not counting the [worthwhile] Chinese 6P6P amps, less in number than 6P14 but still a worthwhile presence).

SE There were earlier vintage ones that were Single Ended (used in radio etc), but they are not commonly seen now. Aside from boutique offerings The hybrid Elekit TU-8150 is a rare one. I see now there are cheap Chinese Boyuu ones). It is really not recommended for anyone other than efficient horn users.

Guitar Amps As you can see, today there are not many 6V6 Audio users out there, not much of a market. The only reason why current manufacturers still make modern versions of 6V6s is because they are in great demand from Guitar Players (true for many other tube types too). Many famous Guitarists swear by the tone of the 6V6. BTW, many of the tube rolling opinions on the net are from Guitar players and, despite the overlap, they are quite different from tube audiophiles really; so read with that in mind.

Variants There are many almost forgotten relatives in the immediate family, like 6F6, 6K6 and 6H6, among others (not 6L6, which is much higher power). Among these, the 6F6 has an underground reputation of being closest to the very expensive WE349A. Mind you, none are exact equivalents, but WE349A has always been regarded as the "best" 6V6. Indeed, the sound of the WE133, which is 349A PP, is mesmerizingly great! Exact Equivalents like 7408 and Bendix 5992 are much more expensive and IMHO not necessarily better in sound (more rugged in built for sure). 6AQ5 This is a much smaller tube, even smaller than the EL84, that has the same electrical properties of a 6V6. However, in sonic terms, I regret to say it's just a little behind the larger-enveloped 6V6, as documented in the Elekit report cited above.

"Best" 6V6? GT The sheer number of working old-stock 6V6GT Pull's is pretty amazing. There are so many different types of constructions, it's like 45. I myself have a large box of them. The most ubiquitous (and easier to pair up) seems to be the smoked glass RCA's, very fine sounding and what I usually use. But there are black glass Ken-Rads, and an endless variety of latter day clear glass GT's. G

There are many fewer ST ones are they command higher prices. I'd not bother with the over-priced European NOS ones. Also see below. Russian, Chinese and Current Tubes My old ANUK Kit 4 came with Russian tubes, and they all failed very quickly (no problem with RCA)! I once had a SINOVT/Raphaelite 6V6 amp that came with extra tubes, including "Tung-Sol" Russian tubes. Nothing to write home about and not as good as any old-stock. As for the Chinese 6P6P, black bottles, they are OK, but old-stock better still. Message? Forget about current tubes; just plug old-stock ones into your amp and you will be guaranteed great sound. The 6V6 is that good. As usual, I'd buy used but test strong old tubes from reputable sellers.

 

Tube Lore Among older HK tube audiophiles, the 6V6 has always been regarded as 琴王, King of the Violin (just as the LS3/5A, Ensemble Reference and Sonus faber Guarneri were regarded as best transducers for the instrument). I'd say, even if there's an element of truth there, it's too categorical as to be laughable. But an element of truth is that the 6V6 has very good treble purity and transient speed, and these are beneficial to violin replay.

Also, the similar 6F6 is used as driver in two of my Wavac amps, the 811 and 300B. The stock uses GTs and they are more detailed and have more oomph, whereas the 6F6Gs I acquired later bring a more solid texture at the loss of a little detail. In my systems I prefer the Gs but I can well imagine the GTs doing better in other systems.

Although I subscribe to the view that for most tube types in general the larger the envelope the better the sound (e.g. earlier Globe and ST better than GT), Years ago, some tube idiots hosted a poorly set up shootout of 6V6 types. I think it was a Radio Craftsman RC_ amp. That's where I heard the British 6V6G tube, thick, sluggish and altogether lacking in resolution. Well, that was favored by some of the "experts" and I decided then and there to part ways with them. Mind you, 6V6 has only minimal presence in the UK (or Europe), being mostly an American phenomenon.

While searching for WE tubes I came across three 6V6Gs (which I've not used) in one of my boxes. What the hell, I brought two back to SZ. They are not the same, one a smoked glass (Sylvania) and another a "Delco". 

6V6G in 6J4/6P6P Preamp, Part III

I plugged them into my 6J4/6P3P Preamp, which since I had been going to HK had used RCA 6V6GTs. I had also brought over a Hytron (black plate) 6X5, which surprised me by how superior it is to the Raytheon I had been using. A much clearer and more incisive sound!

Surprise! They 6V6G sound just as detailed and have just as good transients as my RCA's! What I gained were a larger sound envelope and an even cleaner sound. As this has not always been the case with G tubes, I was very pleased. These are staying in this preamp!

These improvements, though incremental, are still significant.