Opinions on this tube

[pucho812]

O.k. this is for the guitar amp guru's out there. My buddy and myself are building an amp. And as our pre-amp tube we looking at using a 1629 tube.

Based on this test chart is it a good choice. Most amps I have seen are using a 12ax7 as a pre amp tube but we don't really like them sonicly. So this magic eye tube comes to mind as it is a triode, looks real cool and based on the chart I like the results. so any thoughts?

 

[ioaudio]

http://members.aol.com/sbench101/Preamps/1629amp.gif

and i have seen a hifi preamp working with the em84.
(not as indicator..)
maybe its not suitable as a first stage(maybe it is...),
better for interstage after the eq.

 

[pucho812]

well it is a triode so 2 of them would work as the 12ax7 is a duel triode. I am sure it will work my question is more do you think it will sound good based on the chart above? I am thinking yes as the more voltage you push The better it gets and is almost a log curve.

 

[ioaudio]

i´m not experienced enough to say how it sounds by looking an these curves... the sound from the hihi preamp was described as coloured.

 

[pstamler]

Looking at the distortion data, this looks like it's at least worth trying. Might want to experiment with different values of resistance in series with the grid when you build the amp.

Peace,
Paul

 

[CJ]

this is one of the more original ideas, i can say that.
you will have a gain stage and vu meter, all in the same package!
i do not know about noise, are you plqanning on lighting up the target?

 

[Butterylicious]

I have a pair of EM71's I've never messed with for fear of burning them up.

Here's a good read about eyeball tubes:
http://www.vacuumtube.com/eyetubes.htm

 

[pucho812]

[quote author="CJ"]this is one of the more original ideas, i can say that.
you will have a gain stage and vu meter, all in the same package!
i do not know about noise, are you plqanning on lighting up the target?[/quote]

In short. Yes. But in reality based on the distortion data the sound will just get better as the amp gets louder. And totally a VU and gain stage in 1 package. Because of the 12AX7 being a duel triode will use 2. Maybe gain pot for the nose and cut out a smile and fill it will speaker mesh? seriously though the thought of using 2 for the pre-amp has been entertained and the more I see that chart the more we are going to do it. Apex trip this weekend and we go from there. :twisted:

oh and buttery I read that already for research but thanks though. :thumb: