Tube shootout – 5965 types
5965 - GE, Brimar, Edicron, Pinnacle
12AV7 - Sylvania
7062 – Amperex Bugle Boy
E180CC – Philips ‘’Special Quality’’ (SQ)
E180CC – Mullard
6829 – GE (badged United Electron 7062)
6414 - Sylvania
Not tested: CV8431
These tubes are double triode small signal tubes, usable in preamps like the Conrad Johnson PV5 or in the input stage of amps (Bottlehead amps used them before they changed over to the 6N1P which has superior smoothness and detail). They are a useful choice for phase-splitter and their clean bright sound seems to have a good synergy with the 6N1P preceding it, which is smoother and more detailed. These tubes have a medium mu and a heater of 0.45amp at 6.3v:
Tube mu Va(max) Pa Ia Ra S Rk
12AV7 41 300 2.7 18 4.8k 8.5 56
6414 43 200 2 8 7.6 5.5
5965 48 275 2.2 8.25 7.2 6.5 220
6829 47 275 2.2 8.5 7 6.7 220
7062 48 275 2 8.5 7.2 6.4
E180CC 48 275 2 8.5 7.2 6.4
All the above are noval (9 pin) tubes. The base is the common 9a, as found in the 12at7, 12au7, 12ax7 and the rest of the 9a family where pins 4 and 5 are connected to one half of the 6.3v heater supply and pin 9 to the other half (12.6v can also be used as another option with appropriate rewiring). Note that this is not the same base as the 9aj where 6.3v goes to pins 4 and 5 (6922/ECC88 types, and the 6N1P). See www.duncanamps.com for details of tube bases.
All the 5965 types had very similar internal structures. The GE and Brimar were identical, and the Edicron and Pinnacle were very close cousins. The 6414 has a very similar internal structure in a slightly taller bottle. The 7062/E180CC has a similar size internal structure though of a different build, and the bottle is taller still than the 6414. The 6829 shares the taller bottle but has three mica spacers. The Amperex 7062 has a rather attractive small knee half way up the glass, the Mullard, United and Philips are in a straight glass. The internal structure of the 12av7 is smaller than any of the above, in the same size bottle as a 5965.
Country of origin
Of the 5965 types, the GE was made in the USA, the Brimar in Great Britain, the Pinnacle and Edicron unstated. The Sylvania 6414 and 12av7 were made in the USA. The Mullard, Philips and Amperex were made in Holland. The 6829 (United 7062) was made in the USA.
5965 - GE, Brimar, Edicron, Pinnacle
These tubes shared a clean balanced sound with good tone. The best for resonance and dynamics was the Edicron. The GE was pleasant with good tone. The Pinnacle had slightly more detailed treble but suffered elsewhere, the Brimar was the least interesting, tending to sound the most wooden. The differences, however, were small. Generally the 5965 was a flatter sound than the 7062/E180CC, with less micro detail and dynamics.
6414 – Sylvania
The 6414 was close in sound to the above, and this sample pair had a slightly smoothed and rounded treble. Not an improvement overall. The Edicron or GE would be at least as good or even slightly better.
12AV7 - Sylvania
This tube had a little more life and dynamics than the above types, with good tone and treble. The difference was not great. This is a useful tube, and there are stocks about from which good examples could be selected.
7062 – Amperex Bugle Boy
The Amperex, Philips and Mullard betray their common Dutch origin by looking pretty much identical in internal construction. With these larger Dutch tubes, things got more interesting. The sound became more dynamic, and more inner detail starting to reveal itself. On recordings of grand piano the overtones and harmonics were more evident, giving more information to the sound. There was greater low-level ambiance in general. Of the 3 Dutch 7062/E180CC the Amperex tested were the brightest and most etched, with the most identifiable soundstage and instrument positioning, and the most immediate vocals. Grand piano tone was bright and percussive. Violins and cymbals were clear and clean.
E180CC – Philips
The Philips were close to the Amperex, lacking only the last ounce of etched clarity and bloom. General tone was crisp with the most clean and defined treble of all, though maybe with a suspicion of hardness. This tube more than any other captured the steely treble quality of the Steinway piano. Possibly the most ‘solid state’ in tonal flavour. At any rate, another good and perfectly viable choice.
E180CC – Mullard
The sound of the Mullard was again close to the Amperex. Grand piano was a touch more resonant. The general sound was fractionally richer, and less percussive than the Amperex. Outright winners in the Dutch group would probably depend on the particular tubes tested. Another pair of Mullards tested after the main body was better again, with excellent detail and clarity.
6829 – GE (branded United Electron 7062)
This tube was made in the USA and has a different construction. It is a touch shorter than the long Dutch tubes, and has a double mica spacer on the top in place of the single one. The plates are darker and vary between mid grey and charcoal according to sample. Sound was again in the top group for overall detail and tone quality. Low level detail was probably the most apparent of all the tubes tested, and it had a particularly subtle tonal presentation, distinguishing between some hues and colours missed by the others. On the other hand, the grand piano was a touch disappointing – slightly wooden and rounded and not equal to the Mullard, Philips and Amperex. Strings in the orchestra were less etched than the Amperex and had more fragility and reediness. Soundstage, though benefiting from some subtle details and placements, was a little more recessed and overall less clear and defined than the Amperex. Overall tone was softer and more mellow, less percussive, with gains in the midrange and losses in the upper treble. If the Amperex was Mid-Summer, the Philips might be early Summer with clean refreshing air and the Mullard might be Spring. The United would be more like the hues and colours of autumn when the brightness had diminished and mellowed.
All the above tubes are NOS and tested good for strength and balance of the two halves. They were auditioned in a Leak Stereo 20 amp modified by Chris Found to use this tube in the phase-splitter position. The input tube was the 6N1P which provided a good initial tone and plenty of detail. Output tubes were a pair of EL84 per side in Ultralinear configuration. Makes used were a mixture of Mullard or Sovtek. Source material was from CD – ‘Roots’ by Cedar Walton for jazz instruments, Tony Bennett with Bill Evans for piano and voice, The Nightfly by Donald Fagan for beat music with inner detail, and Debussy’s La Mer (3rd movement) by New Philharmonia/Boulez for orchestral detail.
The most exacting test of the tubes turned out to be the grand piano recording of Bill Evans, where there was a clear difference in piano tone and in the richness of the harmonics, the 7062/E180CC being a level better than the rest and showing subtle individual differences within the four types tested. The 12AV7 was good, the rest slightly flatter in tone, with the Edicron being the best of the 5965s. Inner detail on The Nightfly and the Debussy confirmed the superiority of the 7062/E180CC, which in addition had more life and interest to the sound in general. This is a good tube by any standards. It must be emphasized, however, that the differences in sound were subtle though clearly identifiable. The 12AV7 and Edicron 5965 were satisfying to listen too on a variety of material, and the others not too far behind.
Once the 7062/E180CC were auditioned, however, they became the tubes of choice. The overall winner would depend on sample - the Amperex had brightness, bloom, pace and dynamics, the slightly richer piano harmonics of the Mullard were very persuasive, and the clear treble of the Philips on cymbals was appealing. Given that the Dutch tubes are so similar in construction, we may be talking differences in batch or year of production rather than badging. But again, by choosing one of the Dutch valves one would regret the subtle tones and hues of the 6829.
None of these tubes are currently made, so all are NOS or pulls. They are not as universally stocked as the commoner 12a(*)7 types, but stocks are about, and in the case of the 5965 and 12av7 may still be quite plentiful with certain retailers. Since the 5965 was used widely in computers they were often not matched for audio applications, and the halves are often out by up to 30%. Prices for 5965 and 12AV7 should be cheap – around 5 dollars, and 8 max. If you want the halves matched you should request selection by testing and consider paying a little extra – it will be worth it.
The 7062/E180CC and the 6829 are superior tubes. Stocks in the USA favour the 7062, which some retailers have in hundreds but most only in quantities of up to a dozen. Many retailers are out of stock of this tube. The E180CC is commoner in Europe, though stocks are uneven. While over ten thousand are known to exist, most retailers will again only carry up to a dozen. The 7062/E180CC is at least double the price of the commoner types, but since demand is not great its price has stayed very reasonable, and it can be bought for as little as 6 to 8 dollars. One or two suppliers have started charging 12 to 15 dollars (and in rare cases more) so it pays to purchase sooner rather than later while there is a choice of cheap suppliers. If you buy this tube for 10 dollars you should be satisfied with your purchase. The 6829 is typically between 9 and 12 dollars at time of writing.
This is not a collectible tube - it does not have cult status, does not feature in admired esoteric designs (the Japanese seem to have ignored it), and is often passed over in favour of other alternatives like the 6072 which has a similar medium mu of 44 and is found in the legendary Audionote Ongaku. In the right place and in the right circuit, however, it is a good performer and can add a useful flavour to the final sound. It is being phased out of Bottlehead designs in favour of the 6N1P but is still found in some of the Machmat tube products (they are known for their range of amps and active tube crossovers).
~ Andy Evans ~
November 26, 2000