Don Allen 6BX7

June 2026

Don Allen is a tube audio legend of yesteryear, a name you find in the back rooms and long lost forums of this hobby, and who is famous for his silver lightning bolt signature and a reputation for fine sound. A TV repairman in Phoenix Arizona, in the 90’s and early 2000’s Don built many single ended and push pull tube amps and a variety of other hifi gear. He seems to have been an unconventional character who followed his own paths, and his builds are often a little unusual in power tubes and other choices. I really like that. Don Allen amps are not things you find every day, they are rarely seen now on the used market, so when one comes along I pay attention. And in this case I couldn't let it pass me by.

I’ve owned one of Don’s creations in the past, a huge single ended KT88 that was superb sounding and featured a physically gigantic transformer set. And here we have my second Don Allen amplifier, a push pull 6BX7 circuit built into Don’s classic chassis; Ford Model T black with the jaunty rear illuminated Lightning Bolt logo. This is a simple looking piece, but it still manages to stand out in the room with some personality.

In this amp, the push pull 6BX7 are fed by 6SF5 input tubes and 6J5 phase splitters. The amp is tube rectified by the 6BY5, and these choices all add up to plenty of tube rolling possibilities to tailor a preferred sound profile. I haven’t experimented much here beyond a small variety of power tubes, and everything has sounded fantastic. I’m not sure about power ratings for this amp, its not documented, but I’m guessing somewhere around 3-4 watts per channel.

Sound-wise the amp is extremely good. Like many of the TV tubes, the 6BX7 is wonderful sounding, and can be one of the best imagers I’ve experienced. Apparently Don appreciated this simple little TV triode a long time ago, and in his circuit the 6BX7 has got a ton of depth, and a grounded, deep-hitting presence that is delightful to listen to. With both Jazz and intimate singer songwriter stuff the amplifier places performers well and sounds solid and nicely convincing. Bigger music is no sweat for this one either, with dense African and large-scale ensembles sounding thick and deep while still being spread out. It has perhaps slightly less image and “air” than I remember from my small single ended Columbia chassis 6BX7, but overall this feels like typical push pull tending to blur that last little snippet of air in exchange for power. As I’ve said elsewhere I wish builders would pay more attention to the modest little 6BX7, it’s got a lot of potential.

The Don Allen 6BX7 below is as far as I know a completely unique and one-of-a-kind amplifier, so I don’t have any real recommendation for the reader other than to once again endorse Mr. Allen’s builds. I don't know how many of Don’s creations are still out there, and they are quickly becoming antiques, but if you come across one of his Lightning Bolts it will definitely be worth your time. Highly recommended!

Clean and classic lines on this amp.

6SF5, 6J5 and 6BX7.

6BY5 rectifier.

The binding posts are a bit unconventional. Black is common, white is 4 ohm and grey is 8 ohm.

In the room, the amp looks cool and has some presence.

This amp drives all of the wide band drivers on hand to satisfaction. It has plenty of power for realistic volumes well exceeding my threshold.

Although I like the Allen 6BX7 best in my small room on open baffles with vintage wide band drivers, this amp does have enough power for my Altec speakers in my bigger space. And while not as solid feeling as typical performance with the McIntosh 240 or Lance Cochrane’s PP EL84, the little 6BX7 lit the speakers up with emotion and warmth using a passive Luminous Axiom pre.