SORTED....PRE-AMP TUBES/VALVES

Castro

Hey guitar people

I am re-valving my recently acquired Two Rock Crystal 40w combo. 

The first step was to replace V1 as there was noticeable hum at gig volume. I pushed the boat out and bought a 1963 Blackburn factory Mullard. It removed the hum and 'wow' what a special tube it is. The amp was already incredible but the old Tung-Sol was clearly holding it back musically.

I'd appreciate some thoughts on my next step which is to replace the remaining valves; they're all getting old.

V2 is the reverb send 12AX7
V3 is the reverb drive 12AT7
V4 is mixing stage 12AX7
V5 is the phase inverter 12AX7

The reverb is very good but I primarily use an Eventide H9 Max for reverb anyhow so I'm guessing I don't need anything special in V2 and V3....is that right?

I've not seen the term 'mixing stage' before. Anyone know what that is and whether a good quality tube is essential for it?

Finally V5 and I've read that this tube 'does' make a difference so I will invest in something decent unless I'm wrong and it doesn't matter.

I will probably go the Genalex Gold Lion route as I used those in three previous combos and they were always very good.

You experience and comments will be much appreciated.

rico

I'm a fan of TAD premium selected valves

Castro

Cheers @rico

mbe

I'll go along with TAD. Get mine from American Musical Supply in New York cheaper than from TAD in Germany.

SunDevil

I don't know the topography of the Two Rock, but I'm assuming the 'mixing stage' is the driver after the EQ assuming it's a Blackface topography?

Caveat - all the below is personal opinion and you're experience will depend on a host of variables..

V1 is the most critical, indeed
You don't say whether the Mullard is an I63 or I61, but a lot of folks apparently like an I63 in the driver - they tend to be a little more compressed than the 61

Form suggests a black plate RCA or similar gives you the classic Fender tone in V1, bit you're ears and prefs are what count and if you like the Mullard then who's to disagree

Driver - less prone to microphoics - that Mullard or a Sovtek LPS is a good new choice

The PI does make a noticeable difference too, especially if you swap in a 12xt7 - very Blackface again.

I'm not a reverb guy, but I believe the Reverb driver / return just need to work

Castro

Thanks @SunDevil that's really helpful.

Castro

Cheers @mbe ;