Any optimizations for 2a3 paramount?

Jim R. · 4420

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Offline Jim R.

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on: December 28, 2009, 06:14:38 AM
I was wondering if there is anything in the circuit, such as parafeed cap, plate choke, etc. that can be further optimized if one only wants to run 2a3s in the paramounts?  Is the MQ iron upgrade equally suitable for 2a3 and 300b configurations?

Sorry for all the questions, but the year-end bonus was much less than in the past and I have one chance this year to find the right amp to live with long term.

Thanks,

Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline Paul Joppa

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Reply #1 on: December 28, 2009, 08:59:33 AM
Right now the Paramount 2A3 runs at a target 55mA which is too much for the Paramour BH-6 upgrade plate choke (rated 50mA), so the standard BH-7 (rated 70mA) remains the best choice. The BH-5 output transformers are identical. While you would get a few more mW of power with an EXO-35 transformer, the BH-5 is such a superior design that I strongly recommend it. Get a partial or full nickel core if you can afford it; to my ear it is a little more clean and transparent - the same sort of virtues that 2A3s usually have over 300Bs.

IIRC I've recommended 5.6uF for the parafeed capacitor, especially with the upgrade iron. If anyone has bookmarked this, please post a link!

Paul Joppa


Offline Jim R.

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Reply #2 on: December 28, 2009, 11:01:59 AM
Ok, sounds good.

Thanks,

Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)