Review of New 12AX7 Design: TechTube E813CC

[212Mavguy]

I was surprised to listen to a lower-transconductance E813CC that I'd burned in for over 40 hours, and hear what seemed more bass than I originally estimated. I've yet to compare the burned in tube to one that is not burned in, to see if there are tonal changes.

- T

After I burned both of mine in, one normal and one higher gain, both seemed to exhibit a fuller tone in lower mids and bass than the tones I remember hearing before burn in FWIW. To my ears that is a good thing!

 

[Timbre Wolf]

To my ears that is a good thing!

Me too! Thanks for the confirmation, though. I just want to be sure I'm hearing what I'm hearing - the fuller lows came unexpectedly.

- T

 

[212Mavguy]

There is a newer version coming out very soon to evaluate that is supposed to be less microphonic...

 

[Timbre Wolf]

There is a newer version coming out very soon to evaluate that is supposed to be less microphonic...

Yeah, yeah YEAH! :mrgreen:

 

[Timbre Wolf]

I was surprised to listen to a lower-transconductance E813CC that I'd burned in for over 40 hours, and hear what seemed more bass than I originally estimated. I've yet to compare the burned in tube to one that is not burned in, to see if there are tonal changes.

I was wrong

After subsequent listening sessions, and comparisons with a non-burned-in version, I've found that there is no significant change to the bass, when comparing the two. My initial impressions of this tube were that it had thinner bass than many 12AX7. But on careful listening, it is the reduced low-mid body that gives this illusion. The bass is fine - I'm just not as used to hearing it without support of fatter low-mids.

Low-mid body is an important element of an overall tone, to me (for my taste). There is a certain richness and impact that it provides.

Another point: I've been able to try samples from the ends of the gain range TechTube offers. They have four graded gain ranges, from G1 (lowest gain, basically a 12AX7 spec) to G4 (highest gain, with transconductance at nearly 150% of the G1). In sequential listening tests, these both maintain the same tonal character. That is, the frequency ranges emphasized (or de-emphasized) remains consistent. They sound like each other - in case anyone was wondering.

- T

 

[Timbre Wolf]

:shock:


I read the news today - oh $#@^%*!

http://www.lancashiretelegraph.co.uk/news/blackburn/4642860.Historic_Blackburn_firm_in_administration/



Is this the end of the road for TechTubes? I sincerely hope not, but it does not look good, at all.

- T

 

[dodger916]

That really stinks...