The 1626 definitely is not a "downsized" octal 45, it has about half the power generating capability, and the operating characteristics are significantly different, as were the intended RF uses for these tubes.
If you want to try a cheap "45" alternative, the octal 6DN7 or duodecar compactron 6FJ7 power triode comes very close, at least in sound quality, and the VA triode is close to being half of a 6SN7.
These tubes are significantly different from 6EM7, so it is not a direct drop-inreplacement, and the power triode is happiest with a B+ around 315 to 325VDC, a 620 ohm, 2W RK (bypassed) and an 6K to 8K OPT primary (which is about 3X the RP). 5K will work, but there will be a tad more THD.
With these conditions, the cathode/plate curent will be about 27 mA, and the RK will see about 16-17 VDC across it, so it needs about a half to a third of the 6EM7's grid drive signal voltage.
The VA triode has a mu of 22.5, the power triode, a mu of 15.4.
These 6DN7s are the same tubes that Doc Bottlehead uses in his "Single Ended eXperimenter's" (S.E.X.) amp, and I can vouch, they sound very good, indeed.
There are no Russian or European equivalents, and no alternate filament voltage versions. These were used for TV vertical deflection, and were made by the millions, near the end of the all-tube TV era.
Interestingly, there is little or no difference between the various manufacturer's pproduction, so tube-rolling will not yield much of any real interest. These tubes come in both the standard octal base, and the newer "coin" octal base versions. These, like the 6EM7, have the commonly used octal
8BD pinout.
If you want to model it with TUbe-CAD< treat the VA as 6SN7, and the PA as 6BL7, that will get you "in the ball park", close, enough is good enough, just like with horse shoes and hand grenades
Nice ST envelope tube line-up
. Add in a 2A3 or 6B4G, then they would be displayed in four ascending sizes
/ed B
Posted: Fri Aug 05, 2011 6:21 pm
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