5AR4/GZ34 Tube Wanted

[Multi-Volti Devices]

My second comment on this matter.  I know of a couple audio-heads who
are perfectly happy with SS rectification and even regulators with tube
audio. Of course, there are many who hate the above becuase they do
sound different. It depends what you like I guess. SS rectifiers are
inescapable if you want to beef up the power supply capacitance; the
tube rectifiers won't handle the peak currents charging the increased
capacitance, and will fail earlier than they would with an 'in spec'
capacitance. Many new amps use SS rectifiers; they just were designed
properly, taking to account all the effects. It's the retrofits where
the consequences have not been anticipated and planned for.

The only 5AR4/GZ34's I have seen at the outrageous prices you refer to
are the ultra-audiophile ones. Unless your tastes have elevated beyond
the garden-variety ones, I suggest pursuing the cheaper ones, with a
bias (no pun) towards the Russian tubes from a reliability perspective.

If you search enough magazines (try Glass Audio), and post on
rec.audio.,tubes you'll find reasonably priced parts.


Murray
Multi-Volti Devices

Dave Edwards wrote:

> At 03:50 AM 7/28/97 -0700, you wrote:
> >At 09:38 PM 7/27/97 -0700, you wrote:
> >>> >Subject: 5AR4/GZ34 Tube WantedTo:  Denny, WB7EGG/6
> >>From:  Bob Groh, WA2CKY
> >>
> >>I, personally, do not try to replace vacuum tube rectifiers directly
> but
> >>simply replace them with silicon power rectifier diodes.
> >
> >Be careful with this.... the forward drop is significantly less
> >than hollow state equvalents, and the immediate conduction
> >is not what the designers were aware of when designing the
> >circuit involved. Both can cause serious issues.
> >Best 73
> >/John
> >
> >Don't even consider the solid state replacement.
> Besides the electric problems they bring to the rest of the circuit
> with
> there instant-on operation, you will kill the re-sale value of the
> unit.
> While I am skeptical about this, audiophiles cringe at the sonic
> deficiancys
> of solid state rectification.
> Get the Chinese or Russian GZ34s, and use them. Then keep your eyes
> peeled
> for a carcass that uses an RCA or GE or just spend the money and buy
> one at
> the high
> price. You should not have to replace it again. (unlike the output
> tubes)
>
> ...Dave
>
> Dave Edwards  WB2TBB
> ____________________________________________________________________
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