Thought I recognised that insignia... Its strange seeing a RF beam power tube on diyaudio.com, then again...
http://www.diyaudio.com/forums/tubelab/173622-6146-simple-se.html
http://faculty.frostburg.edu/phys/latta/ee/6146amp/6146b/6146b_big.pdf
Beware though that there are significant variations between brands of this same model, this does affect RF performance though you would have to ask one of the other smarties wether or not it would affect AF performance...
http://www.diyaudio.com/forums/tubelab/173622-6146-simple-se.html
http://faculty.frostburg.edu/phys/latta/ee/6146amp/6146b/6146b_big.pdf
Beware though that there are significant variations between brands of this same model, this does affect RF performance though you would have to ask one of the other smarties wether or not it would affect AF performance...
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Ha! That's funny, but I google for hours before I will post something like this. I asked how they sound subjectively. I can find circuits
Regarding the other post with the Acro iron, they use the proprietary windings for UL. It's not easy to replicate.
Thanks!
Thanks,
That's more less what I'm looking for. I notice that it handles highish plate voltage, and thought it looked like a decent candidate for my Bogen overhaul.
I've seen the Acro and an old theater amp schematic with them, but your point is probably why the schematics are few and far between.
Blair
That's more less what I'm looking for. I notice that it handles highish plate voltage, and thought it looked like a decent candidate for my Bogen overhaul.
I've seen the Acro and an old theater amp schematic with them, but your point is probably why the schematics are few and far between.
Blair
Over 20 years ago Ned Carlson told me that 6146 was a bad sounding audio tube and, along with a lot of other useful advise I received from him, I have respected his opinion.
i agree, it is not the tubes per se, but what you do with it that matters....
these are a pair of monoblocks done by a local diy'er in Manila:http://www.wiredstate.com/forum/viewtopic.php?f=53&t=22509
An externally hosted image should be here but it was not working when we last tested it.
Nah you just have to pay attention to the CCS vs ICAS ratings. Most people consider it a "ham" tube so it gets little attention.
My understanding is that they were strongly marketed by RCA for both ham and audio use. When they were being flogged for audio, the UL connection was also becoming popular, with most companies switching to it from a pentode connection. The problem that arose was that the 6146 couldn't take a lot of voltage on the screen so they were failing miserably, and soon abandoned for UL audio use. I think the only concern for audio is that they need to run as pentodes with a regulated screen supply.
Why not capacitively couple the UL tap to the screen grid and provide an R to drop the screen voltage to something safer? It sounds do-able, but I haven't tried it.
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It's tough to decide to commit to a tube that has such a spread of opinions. Tony, I've seen those, and they look nice! I wonder what they sound like.
It just seemed like a good, inexpensive candidate to try for good power. They can be had on eBay for $20-30pr in the states.
if i were you, i'd try tv tubes instead, they are cheap also.....the 6FW5, 6AV5 for example is $4 a bottle....the 6GV5 is just a $1....
It's tough to decide to commit to a tube that has such a spread of opinions...
6146B is fine for pentode connected push-pull amplifier, but not suitable for UL-connection.
The reason is that the screen voltage must be essentially lower that the anode voltage.
One opinion can be found from RCA data sheets and follow their suggestion.
With: Ua = 600 V, Ug2 = 200 V, Ug1 = -47 V (fixed bias) and 5k6 output transformer the expected output level is 96 W.
This means that, say 50 W can be taken from a pair of 6146B with VERY good linearity and low distortion.
Such amplifier do not "sound" bad.
These tubes are very similar. Both have designed for low screen voltage operation.
Therefore these are not suitable for UL-operation, but work fine as pentode connected with 150 to 200 V at the screen.
As for how 6146Bs sound, it's a matter of loadlines and the resulting harmonic "personality" of the type. If these tend to produce hots of H5 and above, they may need some local NFB to clean 'em up, as does the 807. If that's the case, you have the choices of parallel NFB or cathode NFB. The low screen voltage spec pretty much precludes UL operation. In that case, regulated screens and local NFB (if required) will probably give excellent sonic performance.
Otherwise, expect the usual pentode performance: under damped bass and "edginess".
Otherwise, expect the usual pentode performance: under damped bass and "edginess".
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