What tubes do you use in your Bottlehead Crack?

[seanrr]

I know there are several threads on this at head-fi, but I was wondering what Audiokarma owners of Bottlehead Crack headphone amps use for their tube compliment. Right now I am using a Sylvania Gold Brand 6080 as a power tube and a Mullard CV40003 as the driver tube. It sounds quite nice, but what are others using? I could have put this in the headphone section, but I was thinking there is more traffic in the tube audio forum, and it is a tube audio question more than a headphone question...

 

[captouch]

Tung Sol 5998 for power tube and I switch between Telefunken and Mullard 12AU7's

 

[tjste]

Tung Sol 5998 and a CBS 12BH7A on mine. Best sounding combo on my system so far.

 

[mhardyman]

RCA 6080 & RCA 12AU7A cleartop (I think!) w/ side getter - both came with kit so we can clearly say "stock" what ever that means!

 

[seanrr]

Do people think the Tung Sol 5998 is a definite upgrade? I recently had the Speedball installed, which is great, but as always, one always wonders if things could get even better...;-)

 

[tjste]

I've run the 5998, 6080 and a 7236 and have the best results with the 5998 on my setup. There are countless threads over on the Bottlehead forum discussing every possible tube combination imaginable. I'm planning on adding the Speedball to my amp as well, what was your initial impression of the upgrade?

 

[seanrr]

The speedball added a lot more detail. Initially, the detail almost sounded "solid-statish," but with time (maybe a week) and the right tubes, it sounds much better than before. I think it is well worth doing. I will shop around for one of those Tung Sol 5998s - it sounds like there is pretty much a consensus that the 5998 is the best power tube for the Crack (short of some very exotic ones like the GEC and the WE 412).

 

[seanrr]

One more question for all of you 12BH7A users - is this a direct drop in to the crack if you already have the Speedball upgrade, or do you need to still do something to change the circuit?

 

[keithpgdrb]

My BH Crack w/speedball is also sporting stock tubes. but its time for a change. I will also look for the Tung-sol 5998, but lets hear more about the driver tubes! those are supposed to make the most difference in sound.

 

[seanrr]

Well, I am using a Mullard military stock CV 4003 that sounds excellent, but I just ordered some 12BH7 tubes to try. People say the 12BH7 is generally better than 12AU7 variants, but I also hear conflicting information about whether you need to make a circuit change to use them. Some say you can just drop them in with the speedball; others say you should change something in the circuit.