What are the best tubes for the Little Dot?
This is a question often asked in this forum, and if the person asking doesn't want to mess with 9-pin sockets, Vector socket testers, and external heater power supplies, the best we could do was suggest the 6HM5, which are not all that good compared to even a mediocre double triode.
However, due to the pioneering work of Hypnos1, I now believe we can make a much stronger recommendation:
C3g
If someone doesn't want to mess with double triodes, these are "endgame" tubes. Even if they eventually decide to try double triodes, they will not find them to be better, just slightly different.
Pairs of C3g are going for around $70 on eBay. And I should point out that this is what top-tier double triodes often cost. It is possible to take the black metal sheaths off, but as Siemens designed this tube to last 10,000 hours with it on, it is perfectly fine as is.
A pair of adapters is needed to convert the 8-pin loctal C3g base to a the Little Dot's 7-pin 6AK5 socket. A pair will run about $60.
http://www.ebay.com/itm/301131714830?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
And finally, if one is using a stock Little Dot, the above adapters will not fit within the gold rings surrounding the driver sockets, so a pair of small "Test socket 7 pin miniature" for about $16 will be necessary.
http://leedsradio.com/parts-sockets.html#savers
And this is the result, shown next to a nice Tung Sol 6AK5 for scale. Yes, these are BIG! But the sound is GLORIOUS!
Ok, $146 is not cheap. But then again, this an "endgame" recommendation. Moreover, rolling different brands of C3g is not necessary. As best as I can determine, every C3g was made by Siemens, even those labeled Telefunken and Valvo. And further, these are 10,000 hour tubes. It is likely that the tubes will last longer than the amp! lol
In the end, if someone is willing to spend $146 in this way, they won't have to spend another dime on driver tubes for the life of their amp. And perhaps even more impressive, they will have an amp that can easily match amps costing considerably more.
Further observations on 5687 v C3g...given my gear and ears, of course!
As the Tung Sols were also used tubes, I think I now have enough time on them to get a good idea of what they do...
Although they are far better than the Raytheons (mine, at least), I think I am getting - coupled with others' findings - a fair impression of the 'house' sound, and it looks like a definite emphasis on the bass and lower mid-range frequencies. This gives a really nice 'lush' sound, and fair blows the mind (if not the head off!) with music where this part of the spectrum dominates - like 'The Battle' on the soundtrack to Gladiator...VERY exciting...
However, this is at the expense of some of the higher frequencies - they are there, but are somewhat overpowered by the lower ones, most noticeable when the upper strings come in, on this particular track.
This tendency I also found with music combining acoustic, electronic and vocals...a nice rich, 'full' sound on the whole, but again the more subtle tonal ranges of the upper mids and treble, eg. strummed strings, treble woodwind/percussion, female voice etc. weren't resolved to quite the same degree as managed by the C3g. Coupled with the slightly less note decay (especially in the treble), this aspect - of my 5687s - results in not quite the same degree of 3D, holographic spatial rendition (as I have mentioned previously). The C3gs also seem better able to position different elements of a REALLY good recording engineer's mastery of "surround sound" - front/back; top/bottom; left/right - in fact, sometimes I could swear there's a FOURTH dimension going on in my head, lol!
Once again, these differences are only very subtle ones, and so much is going to depend on the rest of the set-up in question of course. My own findings are through HD650s (with pure silver cable, and said silver wherever I can manage to fit it! - right down to my own-made adapters) connected direct to the amp; mains power conditioner etc. etc.
Anyway, these are just my own observations - but I feel there must be a modicum of truth somewhere in how I find the C3g ...viz a question recently put to maestro Glenn (of Glenn amps, of course), ie. when asked if he had an amp "to rule them all", Glenn's reply was..."C3g > 300B with Lundahl transformer... rules everything". I cannot imagine a better vindication of the qualities of the C3g, lol!..
ps. Mind you, these 5687s sure are mighty tubes...and a lot cheaper - IF you are prepared to do some modding, that is!
Hi JV.
Glad the guys have put you right re. the C3g...you are in for one REAL treat - they are brilliant even straight out of the box, and they just keep getting better and better up to 50hrs or so burn-in. If you fancy having a go at releasing them from their metal prison, I posted a tutorial some good while ago (if you do, and you can't find it, just post 'help'! and I will search it out for you).
An added bonus of the MKIV and SE is we don't need the extra extenders...GREAT!
HAPPY ROLLING...
1) It has been so long since I have listened to EF91/92 and 95, that I cannot give a detailed answer. I will say that in my opinion, the C3g is several orders of magnitude better than any of the traditional tubes.
2) No, I have never heard any additional noise due to using adapters, and I use lots of them.
3) First, I have an LD 1+, so no power tubes.... However, you might have noticed that many of our group have used 6SN7's as power tubes, and believe them to be better than the traditional Russian tubes. In that the 5687, as a driver, is as good or better than a 6SN7, I would expect them to be better as well. However, if anyone is using these tubes as powers, they haven't gone public, so I don't know..... Could I interest you in being a guinea pig?
4) Yes, the adapter is designed to convert from 8-pin Loctal to 7-pin EF95, so you would set your LD accordingly.
