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Sophia 274B (finally) bites the dust (Read 2537 times)
erimille
Ex Member



Sophia 274B (finally) bites the dust
07/20/06 at 14:20:52
 
Ok,

I love the sound (and the looks) of the Sophia 274B mesh in the Zen.  After about a 2 years of almost daily listening it finally died on me.  Running a 274B in a stock Zen doesn't hurt the amp, but does shorten the life of the tube.  While I pleased with past 2 years performance with this tube, I knew it couldn't last... ah well.

For those out there thinking of running the 274B, seriously consider modding the amp before hand. Once you start using this, its tough to stop Smiley

--e
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chrisby
Ex Member



Re: Sophia 274B (finally) bites the dust
Reply #1 - 07/21/06 at 18:19:45
 
By "modify" you mean at least reduce the first cap to less than 10mF? (good place for a film!)  - a lot more room inside the stock chassis to change that part than to try an redesign for a choke input supply!

Doesn't the same caveat apply to the 5R4 "potato masher"?  not quite as gorgeous a shape as the ST, but definitely a nice sounding   piece.  
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erimille
Ex Member



Re: Sophia 274B (finally) bites the dust
Reply #2 - 07/24/06 at 19:36:19
 
[quote author=chrisby  link=1153405252/0#1 date=1153502385]By "modify" you mean at least reduce the first cap to less than 10mF? (good place for a film!)  - a lot more room inside the stock chassis to change that part than to try an redesign for a choke input supply! [/quote]

Yes.  The Zen has too much capacitance for this rectifier - I believe its 40uf in the Select. Again, it doesn't seem to harm the amp, but may shorten the life of the tube. As I recall, the 274B wants a first cap value of 10uf or less.  (Caveat... working from memory, so I'd suggest getting a confirmation on these numbers before chancing anyting!)

Quote:
Doesn't the same caveat apply to the 5R4 "potato masher"?  not quite as gorgeous a shape as the ST, but definitely a nice sounding   piece.  


Yes I suspect so, but haven't tried one of these... er, yet. Smiley

--e
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