Modern SS devices in the 8877 power class are are not ready for prime time
in linear service.
IMD, gain/bandwidth, and derating for our use are still a problem.
Ive been playing with a couple of Freescale devices at 6M that are close to
promising but only at 250W.
Carl
KM1H
----- Original Message -----
From: "Joe Subich, W4TV" <lists@subich.com>
To: <amps@contesting.com>
Sent: Sunday, April 29, 2012 9:58 AM
Subject: Re: [Amps] Tubes vs. Solid State (was) Expert Amps 2K-FA: Any
Opinions ?
>
>> I'm an ardent "tube" amp man for this reason. They're significantly
>> more robust and bullet proof in the longevity stakes.
>
> I don't believe that for a minute if you compare apples to apples.
>
> Most of the tube designs have been significantly "over engineered".
> That is, the tubes have excess plate dissipation for the power output
> and grids that will take a significant beating.
>
> If one looks at amplifiers like the MLA-2500 or Alpha 76 series with
> tubes that have grid dissipation in the 10 watt range and no grid
> protection ... tubes that have become unobtainium ... there are plenty
> of owners that have been reduced to tears at the cost (or lack) of
> replacements. Even the 8877 is not exactly an "unforgiving" tube
> when used in designs that lack proper grid protection and the 3-500Z
> are not safe in an unmodified TL-822.
>
> Given proper design and protection, modern solid state devices will
> last a lifetime unlike tubes that *will* need to be replaced due to
> filament/cathode aging. Transistor amplifiers don't suffer from
> catastrophic arcing and certainly don't represent the electrocution
> danger of tube amplifiers.
>
> There are pros and cons on both sides of the solid state vs. tube
> debate but choose the appropriate amplifying device, operate it
> within its design parameters, keep it cool and provide the proper
> protective circuits and either will provide years of trouble free
> service.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 4/24/2012 9:32 PM, Leigh Turner wrote:
>>
>> It's a pity vendors of solid-state QRO amplifiers don't offer purchasers
>> an
>> accompanying low-cost insurance policy to cover them against the
>> inevitable
>> day when the finals blow up for whatever reason and reduce the owner to
>> tears at the huge expense of carrying out out-of-warranty repairs.
>>
>> I'm an ardent "tube" amp man for this reason. They're significantly more
>> robust and bullet proof in the longevity stakes.
>>
>> Leigh
>> VK5KLT
>>
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