guitar with built in tube?

[Heviink]

Does anyone know anything about this:

eBay Australia: Buy new & used fashion, electronics & home d

appears to be a tiny tube that runs on a 9v that you can put in your guitar as a preamp... any thoughts?

I might buy one and see how it goes in my strat.

[Tom Phillips]

Typically tubes run at very low plate voltages do not instill tube like warmth or crunch as they are advertising. Surplus miniature tubes such as the one shown have been available for a long time. I have not heard people bragging about audio applications for these tubes. Before jumping in I suggest you look for user reviews that you can trust. IMO this tube pre-amp in your guitar is probably not the path to improve your tone.

I'm not saying that you should give up the investigation but the offer just looks like a kit product made up to use the surplus tubes they found. They don't even disclose the part number of the tube.

Cheers,
Tom

[J M Fahey]

Agree. Sounds like snake oil to me.
Maybe they don't disclose the tube model specifically so you don't find that the 100 hour battery life claim is impossible.
It *should*work with 1.5V (so far so good) but impossible low 7mA.

[Enzo]

On the other hand, perhaps an EL84 could be used as a bottleneck for slide playing?

[J M Fahey]

Just checked WA2ISE sub-miniature tube page
The lowest filament consumption is 40mA and goes up to 100/300mA.
Even low 40mA would mean up to 12 hours.
And they need B+ *at least* 22.5V , with most needing 45 to 90V.