From John.Fisher@utah.edu Tue Jun 26 08:37:45 2007
Subject:RE: Motion Pro 3Tm question

I can add that the filament in the Electro harmonix 12AX7EH that Motion
Sound uses is mostly covered by the cathode cylinder and thus not easy
to see. The filament is operated at 12.6 volts DC.

John Fisher



________________________________

From: CloneWheel@yahoogroups.com [mailto:CloneWheel@yahoogroups.com] On
Behalf Of Bruce Wahler
Sent: Tuesday, June 26, 2007 9:22 AM
To: CloneWheel@yahoogroups.com
Subject: Re: [CWSG] Motion Pro 3Tm question



Hi All,

The glow in a tube is from both the filament heater and the gasses in
the tube. Bear in mind that any glow is essentially wasted heat -- the
heat adds nothing to the sound or performance -- so the tube
manufacturers don't *try* to make the tubes glow, it just *happens* as
part of the physics of how the tube works. The heat and tube glow
actually contribute to the tube's eventual demise; i.e., if the tube
didn't get warm, it would last longer. (Starved-plate tubes almost last
forever.)

As a general rule, the more energy that a tube is transferring, the more
it glows. Power tubes glow more because they *have* to, in order to set
up a physical condition where they can transfer large amounts of power
to the output. By comparison, preamp tubes are very lightly loaded, and
so glow very little, especially if the preamp in question also uses some
solid-state devices as buffers and such.

Unfortunately, musicians have come to expect a glow from their tubes,
because "that's the way it's supposed to be." Thus, manufacturers stoop
to silly tricks like backlighting the tubes.

Regards,

-BW

--
Bruce Wahler
Online Music Sales
AshbySolutions.com_ http://music.ashbysolutions.com

978.386.7389 voice/fax
bruce@ashbysolutions.com

At 11:06 AM 6/26/2007, you wrote:
>I'm not sure if "cheapness" has anything to do with how much it glows.
I recently acquired and Hicox tube tester and started checking all of
the tubes in my B3, XK3, and Leslies. I noticed they all seem to have
that dull faint glow, except for the 6550's which definitely have a
brighter glow. I am not an tube expert at all, but that's my observation
anyway.
>
>jblann1 > wrote:
low-voltage tubes give a very faint glow, I guess its a cheaper build
>and less noise interference, so you can cram all that in a small
>light-weight package, as compared to a large expensive heavy-weight
>6550 dual tube setup. you could do what H/S does and stick a red LED
>behind it, and really make it glow.
>
>--- In CloneWheel@yahoogroups.com
, Dan A wrote:
>>
>> You should be able to see a very faint glow of the tube.
>>
>> bellows22 wrote: Hi cloners,
>> I am just curiou about ny Motion Pro 3Tm. Should I be able to see
>the
>> tube glowing? I do not.I bought this cabinet about a year ago and
>just
>> got around to using it. I am using a JBL EON G2-15 for the low
>end.I
>> realize the rotor cabiet handles a small part of the sound but it
>seems
>> to not be very loud but altogether it does sound great. I can dial
>in
>> the distortion all right.
>> Any coments would be appreciated,
>> LooseBruce
>>
>> PS any idea of how to measure if the output of rotor is correct?
>>
>> ---------------------------------
>> You snooze, you lose. Get messages ASAP with AutoCheck
>> in the all-new Yahoo! Mail Beta.
>>
>> [Non-text portions of this message have been removed]
>>

[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]