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Goodbye Type 45 ....... hello JJ 2A3-40

Hello,

After a YEAR of building and listening to two superb Type 45 DC two stage amps, I have GIVEN UP on Type 45s, ... STs or Globes !! No more !!

Yes, friends, I hear ALL the "nice" things a Type 45 does, in the ranges where it plays well. Its fine for a radio.

But what I can't stand is ...... and CERTAINLY what NO ONE EVER talks about, ...where the tube does NOT play well.

******* There is a HUGE mid range SUCK OUT, a BROAD non-linear power-delivery-deficiency in the mid range, ( as I say, NEVER discussed ) that has been driving me NUTS the last year on my well set up ALTEC A7-800s. ******

As soon as I put in a pair of JJ 2A3-40s, a few days before RMAF, biased as a Type 45, only 27 mA.!!!, ******* the suck out was GONE, and the amp and SPEAKER played with power, authority, and LINEARITY into my listening room.********

My 515Bs and 802Ds came to life - scared me.

Raised the JJ's bias up to 44 mA. where I want to run the tube, and it all came into better focus.

I WASTED a full year of my life, since these 45s were the ONLY amp I used - and had on-hand in my home.

Now that the RMAF show is over , I will re-do my SET DC amp into a "proper" JJ 2A3-40 amplifier, likely use a conservative op point ....44 mA. and 250 VDC P-K.

The JJ 2A3-40 tube, when well implemented ( as I JUST heard it for 3 days at RMAF ), can ROCK. Heard it versus an EML mesh 2A3 this past weekend. I'll take the dem JJ's for MY listening tastes, in my amp, thank you !!

Jeff Medwin

NOTE, I have NOT heard an EML Type 45 tube, which MAY easily out perform a standard Type 45, due to the EML's large LINEARLY SPACED filament structure.

The JJ 2A3-40 HAS the EML's similar shaped and superior type of filament structure to begin with.

NOT a tiny radiating " V " or a " W " - shaped ( NON-LINEAR-spaced ) filament structure, as do ALL old-stock 45 tubes !!



Edits: 10/10/16

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Topic - Goodbye Type 45 ....... hello JJ 2A3-40 - drlowmu 11:34:51 10/10/16 (53)

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