Best current 845 Tubes

TJ and Sophia (and Full Music) are the same tube, yes, but Sophia tubes are specially culled, i.e., they are the best of that factory's production.

KR makes an 845 tube and I would expect it to be the best of currently available tubes. KR had a bad U.S. distributor for a few years, which resulted in KR's reputation in the U.S. taking a hit, but their new Ann Arbor-based distributor is fine. E.A.T. and Emission Labs, the other two Prague tube manufacturers, don't make 845's.

While I don't want to say that all Chinese tubes are crap - the Black Treasure stuff out of Shuguang and the TJ / Full Music / Sophia tubes can be quite good - I believe that KR and E.A.T.'s production tends to be a lot better. It can vary by production run, however, as tube manufacturing is largely artisanal and like everything else that's hand-made, a worker has good days and bad - there can be bad quality production runs from the more prestigious manufacturers, and good quality runs from the crap manufacturers - you have to have a reputable vendor to ensure that you don't get the "runts of the litter". Why are there two different prices and two different warranties offered by some vendors for what appears to be exactly the same tube? The more expensive ones with the longer warranties tested better.

I'm not sure how relevant this is to the 845's, but I just had a monster quest for PX25 tubes, which are much more scarce.....

I heard from a couple reputable sources that the KR tubes are not of the same quality now that Dr Kron has died. This was confirmed when I went ahead and bought a new pair of their PX25's - they're pretty much the only game in town for new production on these. It turned out that they weren't as robust in construction, and they didn't sound as good as my pair from a few years ago.

I'd be interested to hear if the 845's are also on the decline...

I've only had my 845 amp a bit over a year, and haven't heard that many different 845 tubes. My amp came with the basic Shuggies stock, and I also got a pair of the Psvanes with it. To me the Psvanes were better across the board, but I'm now using Shuguang 845B's, which sound better yet to me, a bit warmer, more depth & dimension to the sound.

I'd love to try the Create 845 tube, as my prior amp was a 300B, and as much as I liked the Black Treasure 300B's, I preferred the Create 300B tubes in that amp--better extension on both highs & lows, but still with a magical midrange.

Randy

Please take a look at the KR 845 specifications, they do not conform to the Amperex 845 standard, therefore, most amplifiers will need a modification to reduce the filament current to run KR845 tubes.

As with any task to designate a "best," a best 845 tube doesn't exist. First, it depends on your amp. One of the touted advantages of tube amps is the ability to "roll" or change tubes from one brand or build variant to another. Now, I say this as a lifelong tube audio devotee: if tube changes alter the sound of an amplifier, then which produces the accurate or highest fidelity sound? It becomes quite subjective. In some respects, audiophiles use tubes, like cables, as fixed parametric tone controls to tune the sound of their systems to personal preferences.

For example, nearly all of today's 845 amps ship with the cheap and ubiquitous Shuguang 845A commodity tube. It's super cheap and reasonably tough, and sounds fine out of the box. But I've not heard a single 845 amp that sounds its best with this tube, no matter how many times the maker says "the best tube is the one we ship with the amp." For most amps, the Shuguang 845B will improve everything over the 845A, at a modest increase in cost. The B tube will prove long-lasting and both electrically and physically durable, able to handle amplifier circuits that run the 845 aggressively.

But the Shuguang 845C has some interesting qualities. Its transparency, high frequency extension and transient speed are remarkable, though it produces about 20% less power than the A or B tube. It also is rated for less plate dissipation than normal spec (~75w v. ~100w in the A and B tubes) so in many amps it will have a short life and run borderline runaway, but that's a separate matter. Point is, in an amp like my Audion Black Shadow monoblocks, the 845C sounds shrill to the point of unusability unless paired with a speaker with a rolled-off top end. But if used in a Tri amp, which is voiced more like Shindo for a too-soft top end, and undynamic with rounded transient character, it *can* be an asset, depending on your preferences.

For most, the 845B is the "best" 845, because it is neutral, toneful and delivers good bass control, plus it's affordable, reliable and predictable. Some people prefer the Psvane 845-T to the Shuguang B tube, but the sonic advantage is not large and the newer T shows indications of being less reliable. It certainly hasn't established the long-term track record for reliability yet. But it's worth a try for someone restless.

The standard TJ tube has lower-than-spec plate dissipation, so it isn't universally compatible. The TJ Carbon plate that Sophia sells claims full RCA spec, so it should be fine. I haven't heard it. Nor have I yet heard Canada Fuller, Create and Synergy.

The KR 845 is the outlier. It is an interesting design innovated by Kron and it's off spec. It's dynamic, transparent, vivid. The initial version had serious reliability problems due to the ribbon filament shorting. This has allegedly been corrected though I can't personally vouch for current reliability. The maker of my amps, Audion's owner, says it's a drop-in replacement with no problems and it's his favorite way to listen to the amp. Prices are nearly at NOS levels in the US. In some other amps, some modification to the filament supply may be needed.

What's the best 845 tube? Tell me your amp, your speakers, your room characteristics, your tolerance for risk and expense, and your general sound preferences, and we can narrow that down to a "most likely to be best" for you.

Phil