Herbie : removing tubes ?

[mininoyz]

Is it possible to remove one or two pairs of tubes in the Herbert ? I just don't need this power. I suppose it will affect the sound, but in wich manner ?
Anyone already tried other tube combinations, to get a more 'vintage' vibe, like tw KT66 ala JTM45 ? I currently own a VH4 and could swap it for an Herb'... just to taste another flavor.

 

[duesentrieb]

a) from 1,2,3,4,5,6 you can pull 1,6 or 2,5 or 3,4 - even two pairs. Run the amp one step lower when you pulled one pair (16 Ohm cab to 8 Ohm speaker out). Or two steps lower with two pairs pulled (16 Ohm cab to 4 Ohm speaker out).

b) think about your speakers first, then tubes. Of course 6L6GCs sound different than EL34s, but IMO swapping speakers can have a bigger change than swapping tubes.

c) if you want a more loose type of sound you can snip/cut two of the filter caps, thats what I did. Peter (or I) can you teach you how to do that. Its fully reversable . . .

Olaf

 

[mininoyz]

Thanks Olaf,
so, just to be sure I have well understood :
- Herbert will run under 8 ohms with a quartet
- 4 ohms with a duet ?
So you can't use any cab you want when you have less than 6 power tubes, right ? For instance, I don't have any 4 ohms cab, so I won't be able to run only two tubes.
Thanks.

 

[duesentrieb]

Yup. If you have a 16 Ohm cab, you can pull 2 pairs.

1 pair pulled, 16 Ohm cab to 8Ohm speaker out
2 pairs pulled, 16 Ohm cab to 4Ohm speaker out

1 pair pulled, 8 Ohm cab to 4Ohm speaker out

You won't notice a big volume difference, the amp gets a bit smoother though . . .