2a3 or 300b

[jrebman]

Ken,

I think you'll find that that is an integral part of the bottlehead experience and dare I say it,sometimes even more fun than the listening (depending on the individual, of course).  How many other audio manufacturers would not only encourage you to try different configurations for their gear, but also supply you with the how-tos?

-- Jim

 

[RPMac]

As a side note, you can operate the 300B in direct coupled mode, by changing the audio circuit but leaving the filament power alone. This will give you a good part of the nuance available with the 2A3 in this amp, and the 300B will have a longer life when loafing at 15 watts. Many prefer the JJ 2A3-40, which is basically a 300B with a 2.5v filament.

I'm confused...aren't you saying to build in direct coupled 2A3 audio circuit and changing the filament power to 5 volts to operate the 300B in direct coupled mode?

Ken, don't worry about it, either way it's going to be good!

 

[Grainger49]

A last piece of advice.  As Paully's system went down in power I perceived it increasing in detail and a natural sounding midrange.  So I'm for the 2A3 or 45 if you can.

IMHO the question you should be asking is How Much Power Do I Need, that is a link to the FAQ thread and the question is question #3.  There are a number of factors.  Once you get a grasp on your power needs I would suggest the lowest power you can get away with.

 

[Paul Joppa]

As a side note, you can operate the 300B in direct coupled mode, by changing the audio circuit but leaving the filament power alone. ...

I'm confused...aren't you saying to build in direct coupled 2A3 audio circuit and changing the filament power to 5 volts to operate the 300B in direct coupled mode?...

You are not confused, you have understood it exactly. Except for filament voltage and maximum plate dissipation, a 300B is nearly identical to a 2A3.

 

[Reap]

I'm new here and new to tube amps but not new to system designs. I think I have the perfect solution that Doc should love.

Use 2 pairs. Run one with 2a3's for a tweet and small mid running @4k and up. Run the other pair on mid bass/sub bass on frequencies below 4k. Voila!

LOL, I know, you didn't want to spend that much.

 

[ssssly]

Could also build one of the two in 300b form and one in 2a3 form. Then compare them, decide which you like, and convert the other one to match.

I ordered a bee-pre and paramount kit on black monday. I will be building mine in 300b form to run the bottom end of my tri-amp setup now being powered by a modified paramour II. So I'm looking forward to the increased available power. While a 2a3 will move a Altec 416 quite well, it can run out of gas a bit when played at high volume.

 

[Reap]

Could also build one of the two in 300b form and one in 2a3 form. Then compare them, decide which you like, and convert the other one to match.

I ordered a bee-pre and paramount kit on black monday. I will be building mine in 300b form to run the bottom end of my tri-amp setup now being powered by a modified paramour II. So I'm looking forward to the increased available power. While a 2a3 will move a Altec 416 quite well, it can run out of gas a bit when played at high volume.

You going to use active crossovers to the amps?

 

[Reap]

I used to think I was indecisive but now I'm not so sure.  :-\

 

[denti alligator]

Would pairing the Paramounts with the BeePre make the decision of 2a3 vs 300b more obvious?

I 'm leaning toward the 2a3, in parts because my speakers are highly sensitive. But then will hum be more of an issue?

 

[Paul Joppa]

Generally speaking, 2A3 hum has half the voltage (6dB lower) than 300B hum. But Paramount has a DC heater supply, so hum is usually not a problem in either case.