Tubes that everyone should own, or at least hear

prime minister

Site Owner
Staff member
Not just to be contrarian, but aside from @Ernie s Almarro, and perhaps the Leben, I've never heard an EL84 amp that I've loved. They range from dull to awful (My Stingray). Yes, they have nice mids, but they just seem overly soft and lacking in sparkle up top. Give me a 7591 any time.
 

Andyman

Junior Member
Keg loved top capped 6BG6G tubes in his modded ST70 with adapters; he posted that combo as his "best sounding amplifier" at one point years ago. It was so Keg using inexpensive tubes to get great sound.
I haven't figured that out yet, so I am running some Chinese Valve Art 350B tubes in it now that he liked alot too. And had some JJ KT-77s in it too.
He was also big on 12BH7s as replacements for 12AU7s IF your PT can handle the extra draw. I use them too in his ST-70 with the VTA-ST70 board.

Aforementioned tubes at work. Note Keg's bias values on the right for them.

20220219_190651.jpg20220219_190626.jpg
 
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mhardy6647

Señor Member
Site Supporter
Speaking of that cheap & cheerful Chinese ValveArt brand...
Way, way back when, our Paramour kits came with ValveArt 2A3s.
They were, way back then in the 20th Century, very inexpensive (20 bucks a pop, if memory serves) and had zero cachet -- but they sound good and look very nice when doing their directly heated triode thing.






Unlike most 2A3s (or even tubes that aren't really 2A3s but have 2.5 V filaments and are sold as 2A3s ;) ) the filaments in these - for whatever reason - light up nice(ly) and bright(ly).

I always like to point out that my son took both of the (IMO) superb photos reproduced above with his first DSLR way back when. The metadata @ Flikr says 2008, but they may be even older than that... I'd have to Czech. ;)
 

Redboy

Knobophobe
Site Supporter
Has anybody mentioned the fiddy yet?
@Redboy -- gonna put in a good word for the fiddy?
(he and I got to hear a nice pair of single-ended fiddy amps a couple-three years back, at an undisclosed & unverifiable location...)

;)
Ooh yeah, the Type 50 makes an impression! I heard 'em and haven't been able to stop thinking about 'em...

Ima build some Type 50 monoblocks soon... very soon.

I do like the EL84, triode strapped. And of course the usual DHT suspects, but also a little up-and-comer called the 46. Y'all oughta check that one out!
 

Redboy

Knobophobe
Site Supporter
I’ve got a lonely 46 here. I think.

A 47 as well.

Any word on the 47?
A 47 sounds quite similar to the 46, at least when used as a drop-in sub for a triode-strapped 46, in my amps. I have several pairs of them and on occasion I'll roll them through. I like them.
 
interesting that you guys are talking about the 47.

on Friday I mentioned to a guy who lives near me that I was putting together a push pull 2a3 amplifier. He said to forget that and lower the b+ a bit, change the sockets and cathode Resistors then use the 8r taps on my 16r speakers so the output transformers primary is 12k. All this so I can use old tubes. He thinks I’ll get about 5 watts which should be fine, or more if I were to use in pentode mode.

I admit the idea of being able to use nos tubes is appealing, does it sound like a good idea?
 

Thermionics

Post Whore In Training
Site Supporter
Keg loved top capped 6BG6G tubes in his modded ST70 with adapters; he posted that combo as his "best sounding amplifier" at one point years ago. It was so Keg using inexpensive tubes to get great sound.
I haven't figured that out yet, so I am running some Chinese Valve Art 350B tubes in it now that he liked alot too. And had some JJ KT-77s in it too.
He was also big on 12BH7s as replacements for 12AU7s IF your PT can handle the extra draw. I use them too in his ST-70 with the VTA-ST70 board.

Aforementioned tubes at work. Note Keg's bias values on the right for them.

View attachment 45307View attachment 45308
Are those TO-300 OPTs, pray tell? I've got a pair of those sitting on the shelf for an eventual PP 6B4G build.
 

Redboy

Knobophobe
Site Supporter
interesting that you guys are talking about the 47.

on Friday I mentioned to a guy who lives near me that I was putting together a push pull 2a3 amplifier. He said to forget that and lower the b+ a bit, change the sockets and cathode Resistors then use the 8r taps on my 16r speakers so the output transformers primary is 12k. All this so I can use old tubes. He thinks I’ll get about 5 watts which should be fine, or more if I were to use in pentode mode.

I admit the idea of being able to use nos tubes is appealing, does it sound like a good idea?
@joe83 is he suggesting you use Type 47 output tubes instead of 2A3 in a PP design? That could be interesting, indeed! Let us know how it works out. :-)

Oh, and while NOS tubes are nice I would not hesitate to buy used tubes that test as new... right? ;-)
 
@joe83 is he suggesting you use Type 47 output tubes instead of 2A3 in a PP design? That could be interesting, indeed! Let us know how it works out. :-)

Oh, and while NOS tubes are nice I would not hesitate to buy used tubes that test as new... right? ;-)
That’s exactly what he is suggesting, he is adamant that old tubes are where it’s at… I’ve noticed a few sets of 47 tubes on ebay that are waaay cheaper than 2a3.

from what I’ve read so far I should be able to get about 5 watts out of them in PP when wired triode so that sounds promising.
 

Salectric

Site Supporter
Site Supporter
Regarding the 47:
A couple years ago my son and I compared three amps he’d built—PP 47, PP 46 and his regular SE 46. To my surprise the PP 47 sounded very, very close to the SE 46, so close I wasn’t sure I could tell them apart consistently without a lot more listening. Also surprising was the PP 46 didn’t sound like the others at all. Each of the amps had similar parts and build quality.

When all was said and done, my son gave up on the two PP amps and now uses the SE 46 exclusively.
 
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