Chorus II � 2a3 or 300B?

[paully]

Oh yea. I have gone back and forth. The 2a3 had no problem whatsover running the Chorus II. I just put the amp on the 4 ohm tap and converted it to 2a3 and let it play. Never had any problem acheiving volume levels that were much too loud for comfortable listening without clipping. I have enjoyed it very much. I am back to 300B right now, not due to any power level requirements, just for fun and listening to different tube types. I really liked the Shuguang 2a3c and picked up some Shuguang 300B to try so I converted the amp back. If I pick up some old stock 2a3 I wouldn't hesitate to switch it back to 2a3.

[Erik Mandaville]

This is kind of funny -- not the 2A3-300B conversion, just the fact that the thread is two years old if a day. As if there were no gap in time.

Paully: To make this change are you just changing the filament voltage between 2.5 and 5V and leaving the rest of the circuit the same? I really love our SET amps, both the 2A3s and 300Bs. I also can't help but admit to be being very impressed by the sudden and scarily realistic snare and kick drum cracks and thwaks that heavier hitting amps can provide. I can't deny that something CAN be said for high power. It's just that for the long haul, I keep going back to what seems to 'fit' best -- big, single-ended triodes that aren't nearly as strong in terms of output wattage as their comparatively impressive physiques might suggest. What they are able to do sounds right to me.

[Dmannnnn]

What were your impressions, as far as differences between the two tubes? This is still a Paramount that is being switched back and forth, correct? I am contemplating switching myself.

[paully]

It is the Paramount (Erik, I don't know exactly what we are changing. We are going from direct to indirect coupled and all sorts of things I am not sure about. Three is a set of directions on how to change the Paramount from 300B to 2a3 on the Bottlehead Paramount page. If you read that you might get a better idea of what we are up to).

I have used more 2a3 tubes than 300B. But the interesting thing is there was a much larger difference between, say, RCA old stock 2a3 and the Shuguang 2A3C than there was between the Shuguang 300B and Shuguang 2A3C. The Shuguangs sounded about the same to me. And since I really liked (I mean really liked) the Suguang 2A3C I figured might as well have the extra power so I have left the 300B in. At least until I buy a new pair of 2a3 again and feel the need to switch back, but that could be a while. Truth be told, in my very limited experience, I don't hear the big differences that people talk about with 2a3 and 300B. The finesse (2a3) versus the great mid range but tubby bass (300B). It just isn't like that for me.

I do think about going back to 2a3. There just seems to be more options for tube rolling in my price range. 300B, lots of options, most terribly expensive. We'll see.

[Erik Mandaville]

Paully: A very honest answer. I recently finished a pair of 300B monoblocks that also incorporate direct coupling, so I have an idea about what you (might) be talking about. The 'tubby' bass said to be sometimes associated with the 300B was not something I experienced, in fact, at least with the Sophia 300Bs I'm using, it's quite the opposite from 'loose' or over-ripe bass response.