[Mr. Finsky[_2_]]

Does anyone have any feedback on the various online sellers of tubes
(i.e., Tube Depot, The Tube Store)? Are these places reliable and
trustworthy? In addition, does anyone know if the description and
quality of the various new and old tube makers matches the description
provided by the online retailers? Are the NOS tubes really worth the
big bucks?

I am curious since I had 2 Electro-Harmonix 12AX7A tubes go bad in my
Conrad-Johnson preamp after 4 years. The other tubes seem just fine. I
am now concerned if E-H tubes can be trusted.

[Sonnova]

On Fri, 1 May 2009 13:35:52 -0700, Mr. Finsky wrote
(in article ):

Does anyone have any feedback on the various online sellers of tubes
(i.e., Tube Depot, The Tube Store)? Are these places reliable and
trustworthy? In addition, does anyone know if the description and
quality of the various new and old tube makers matches the description
provided by the online retailers? Are the NOS tubes really worth the
big bucks?

I am curious since I had 2 Electro-Harmonix 12AX7A tubes go bad in my
Conrad-Johnson preamp after 4 years. The other tubes seem just fine. I
am now concerned if E-H tubes can be trusted.


I had 4 of the 6 Electro-Harmonix 6922 (6DJ8/ECC88) tubes that I re-tubed my
trusty Audio Research SP-11MkII with go bad (gassy, noisy) over a period of
less than a year. I would NOT recommend Electro-Harmonix tubes to ANYONE.
However I have good luck with JJ/Tesla* brand from Tube Depot, who seem to be
very reliable and honest.

* If your preamp uses 6922/6DJ8/ECC88 tubes, its best NOT to buy NOS for this
tube type. The reason is because the 6DJ8 was designed originally as an RF
tube for FM front-ends. For that reason, any 6DJ8 made before about 1985 will
have no internal mechanical supports to damp-out microphonics. Because this
tube was an RF-only dual-triode, the type of internal element support needed
for hi-mu triodes for audio was deemed unnecessary in an RF application.
Compare, for instance, the mechanical structure of a NOS 6DJ8 with a 12AX7
and a modern 6DJ8 from Sovtek, Svetlana, Tesla, etc. and note the structural
differences. The new tube will resemble a 12AX7 more than it will resemble an
older 6DJ8. A NOS 6DJ8 will ring in an audio application, and a newly
manufactured tube will not.

[[email protected]]

On May 1, 4:35*pm, "Mr. Finsky" wrote:
Does anyone have any feedback on the various online sellers of tubes
(i.e., Tube Depot, The Tube Store)? Are these places reliable and
trustworthy? In addition, does anyone know if the description and
quality of the various new and old tube makers matches the description
provided by the online retailers? Are the NOS tubes really worth the
big bucks?

I am curious since I had 2 Electro-Harmonix 12AX7A tubes go bad in my
Conrad-Johnson preamp after 4 years. The other tubes seem just fine. I
am now concerned if E-H tubes can be trusted.

In general, I would not purchase any tubes on-line, especially any
that made claims to be matched. This is _NOT_ casting aspersions on
any particular seller, just that I have reasonable local opportunities
to purchase tubes and the capacity to test and match correctly myself
those very few times when that is necessary.

Otherwise, Tube Depot is honest and reliable as Sonnova suggests.

Stay away from Chinese Tubes would be my only other advice.

Peter Wieck
Melrose Park, PA