[ARC5] Somebody is Still Building 832's?

[Dennis Monticelli]

Hi Bob,

Well we have already done that at the California Historical Radio Society.
We have a 1950's recreated broadcast studio with a commercial AM
transmitter.  Rather than burn the filaments of the massive 833 triodes all
day just for show, we put LEDs under the envelopes. The tubes don't light
up quite the same but visitors don't know that the glow is supposed to come
from within the plate structure.

Dennis AE6C

On Wed, Mar 3, 2021 at 7:39 AM Bob Groh <bob.groh at gmail.com> wrote:

> Well, ignoring the totally bogus claims, having an 832 'anything' sure as
> heck looks cool.  I've got the 832's in my stash and having some form of
> 'art' using them would be so neat. Not even sure I would power it up - I
> have always wanted to try a few LED's hidden close to the base and shining
> up into the bulb. Put that on a nice walnut base with a sexy variable cap
> and dial - now there is some serious fun!  And, yes, I am being serious
> here!
>
> 73
> Bob Groh, WA2CKY
>
> On Wed, Mar 3, 2021 at 9:28 AM Dennis Monticelli <
> dennis.monticelli at gmail.com> wrote:
>
>> A colleague and I did an armchair analysis of the 832 in the stereo
>> headphone driver product.  The ridiculously low plate voltage (12V)
>> translates into very low though measurable gain with a high output Z.  Gain
>> is not really necessary for this application but driving 32 ohms is.  The
>> circuit also uses a venerable op amp with 600 driving capability.  So the
>> circuit is probably using the 832 for the glowing input stage and the op
>> amp for the driver (after taking a loss via a series output resistor to
>> avoid driving the op amp into current limit).
>>
>> Nobsound makes other great stocking-stuffer audio tube products.  You
>> KNOW you WANT one so you can plug in a real NOS 832 for audiophool bragging
>> rights!
>>
>> Get yours today!!
>>
>>
>> https://www.amazon.com/Nobsound-Little-Vacuum-Headphone-Amplifier/dp/B07R7PL7YM
>>
>> Dennis AE6C
>>
>> On Wed, Mar 3, 2021 at 5:22 AM Doran Platt <jeepp at comcast.net> wrote:
>>
>>> I see these tubes for less than $15 each.  Maybe the word is not out to
>>> the (with all due respect) Audio Gnomes, yet.
>>> K3HVG
>>>
>>> >
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