SPAX7-A Are they worth the extra cash?

[kungfujews]

Hi - I was thinking of replacing the V1 tube in my MkIV as my amp's getting a little noisy on higher volumes. I've been told to try a SPAX7-A premium tube instead of the usual 12AX7. These tubes are more expensive...are they worth the extra or shall I just stick with the 12AX7? :?

 

[KH Guitar Freak]

It does reduce noise for sure. On the other hand, perhaps something else is causing all that noise? Personally, my rigs run quieter with a good power conditioner...

 

[kungfujews]

Hey thanks for that - I hadn't even thought of using a power conditioner - at least it might stop me picking up radio signals. I think I'll go for the SPAX7- A and the conditioner! :idea:

 

[KH Guitar Freak]

Well, if those two can't reduce noise, then something else is wrong...

I have the SPAX7 preamp in V1 of my Roadster. Compared to stock, it had less noise, floor noise included. Perhaps just a tiny bit tighter and range of gain has increased. This is all very marginal though. It's mostly about reducing noise...

 

[mikey383]

It's all about the rubber sleeve.


Try putting some O-rings over a regular 12AX7...they will reduce noise too.

 

[dodger916]

It's all about the rubber sleeve.


Try putting some O-rings over a regular 12AX7...they will reduce noise too.

Great Avatar mikey! 8)

 

[droptrd]

Like these?

http://www.tubedepot.com/dctuberings.html

It's all about the rubber sleeve.


Try putting some O-rings over a regular 12AX7...they will reduce noise too.

 

[mikey383]

Like these?

http://www.tubedepot.com/dctuberings.html

It's all about the rubber sleeve.


Try putting some O-rings over a regular 12AX7...they will reduce noise too.

Those would work, although they're a bit pricey.

You could always take a tube to a hardware store and find some plain rubber O-rings that will fit it for a couple bucks.

 

[droptrd]

Brilliant! should you do that to all of them or just V1

 

[212Mavguy]

...on the rubber sleeve thang, it's just heat shrink tubing. I use one inch size and do two layers. Works great and costs a buttload less than the rings.

 

[domct203]

Right on Mav. I can't believe the money people pay for "tube rings".

P.T. Barnum sure got it right!

 

[aaronlyon]

I want to put this new SPAX7 in V1 of my Mark IVa head, but the black shrink tubing won't fit inside the silver collar around V1. Should I trim off enough of the tubing to make it work?

I also notice I have a microphonic EL-34. But it quiets up immediately if I put light pressure on it with my finger. Can I put an O-ring or something on it?