ELROG ER300b tubes

P

patm

New member
I have a pair of the new Elrog 300b tubes on order to try in my Paramounts. I saw in a post on the Bee Pre thread that Paul Joppa recommended increasing the Cathode resister to 1200 ohms from 1000 ohms. I know very little about electronic circuits, my Paramount manual saya the cathode resisters are 2 2000 ohm resisters wired in parallel. I'm confused.

Thanks,
Pat McSween
 
When wired in parallel you have to calculate the equivalent resistance (Req) with this formula:
1/Req = 1/R1 + 1/R2 (where R1 and R2 are the value of your components).
So, doing the math, Req=1000ohm, that is the cathode resistance.

 
Thanks, I knew there was some math involved. I looked on line for a formula but was unsuccessful. I knew that this Forem would come through. This is the best group I have had the pleasure to encounter.

Thanks
 
When you get them, just plug them in at first so you can listen - they are supposed to work OK that way, worth giving it a try. Then if you would post the voltages on the 300B socket, I'll compare them with the predictions based on the very limited data available so far.
 
So, just to make sure I got this right as far as the math. I would replace the two 2k ww resisters with Two 2.4k ww resisters (25watt).
 
Saw on the Vinyl Savior blog site today the official data sheets & plate curves.
I left my house for 20 min on Friday and of course that's when USPS came to Delever my pair. Didn't see the notice untill late Fri. So my tubes will sit in the Bronson Fl Post office untill 9:30 Monday morning. Fate ha ha.
 
Excellent news - thanks for the timely post!

Looks to me like they will work well in a Paramount, making about 5 watts with a damping factor around 2.4, compared with 8 watts and 3.0 damping factor for the regular 300B. I would not make any adjustments. Distortion spectrum should be very similar.

According to the curves they should also work well in the BeePre, with about 10 volts more at the plate (110v instead of 100v - this parameter is subject to plenty of tube-to-tube variation).

Looking forward to listening comparisons. Expect a bit of bass bloom from the decreased damping factor - speaker dependent of course but try to listen past that. I don't see any other gross technical differences - it's down to the subtle stuff plus the stuff we don't technically understand yet.
 
My listening impressions of the Elrog ER 300b

First my system. Paramounts with Mundorf silver/oil caps, Magnaquest full nickel. Unextended FP III with Goldpoint attentuators and Mundorf Silver/oil caps. I am using a pair of Amprex 12AU7s in the FP III and the Elrog 300b are driven by a pair of Telefunken 12AT7s.

The first thing I heard is tight wonderful bass that I have never heard in my system. There is almost no bloom. It seems that the base player and drummer have been invited on stage with the rest of the band and it's wonderful to have them join the party.

These things have ATTACK. The screens I have been enjoying for the last three years ( Emmission Labs 300b mesh) were so smooth and warm except at the top where the treble seemed to blow through the top and sound to bright and there was very little bass and what there was was soft and quiet. The Elrogs don't slam me out of the chair but the bass sounds proper. They love to play out on the leading edge and they are so effortless in there presentation.

There is just more of everything. The notes seem to start sooner go farther and wonderfully fade into blackness.

I am in heaven. I have heard them described as a 45 that makes 5 or 6 watts. I have never heard a 45 amp so I can't do that comparison. They are just the most completely satisfying 300b I have heard. 

Patrick A McSween
 
johnsonad said:
Mine are on order now. Thanks Patrick for the review.
Click to expand...

Same here!  Two pairs - one for the BeePre and one for the Paramounts.  Given their limited availability and wait time, I figure I can sell them at about cost, if they are not as good as the reissue WE 300Bs I'm currently using.  I'll be sure to post a comparison of the two.

Gerry 
 
I was considering doing the same thing Gerry.  I'll try my pair in both and see if I can justify a second pair. I'm worried about microphonics in the BeePre.
 
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