HALF POWER ROCKET

[RCGPNY1]

I probably missed it but has anyone done a 1/2 power Rocket? I would rather have that power level...more useful to my particular needs.

[gktamps]

I think many have done so, either with 2 power tubes, or switchable 4-2. Here's one I did:
https://tubeamparchive.com/viewtopic.ph ... highlight=

[eniam rognab]

i converted a hammond AO-43 into a half power rocket too! it rocks.

https://tubeamparchive.com/viewtopic.php?t=24959

[cbass]

4 el84 sounds better and isn't that much louder than two.

[gktamps]

I agree, CBass - I like the VVR approach better.

[Paultergeist]

4 el84 sounds better and isn't that much louder than two.

As a point of reference, the Ceriatone "Rock It" kit has a half power switch -- so operated by dropping out two power tubes and adjusting the cathode resistor value accordingly. Having heard this mod played in both the full power and half power configuration, I have following opinion:

Using only 2 power tubes does not sound "half" as loud to our ears. If the amp was too loud with all 4 power tubes when cranked up to the sweet spot, it is probably still going to be too loud with only 2 power tubes engaged.

As cbass notes above, something is lost -- all other things being equal (OT, etc) just dropping out 2 tubes. Normalizing volume via an attenuator, the amo just sounds and feels better with all 4 tubes working up a sweat, in my opinion.

[Paultergeist]

Delete duplicate post.

[KellyBass]

I've built both 15 and 30 watt rockets, and the standard with 4 el84's sure did seem to have more "swirl"...no matter what changes I made. Very little volume difference.

[naciketas]

I agree that a quad of 84s give a fuller and rounder tone, but nobody where I live but me seems to appreciate it, so with my Liverpool (former ac30/4) I use VVR to set the appropriate level (around half at rehearsal, even less at gig) for the situation and the 2/4 switch to boost the solos: Heaven is only few db away.

[sliberty]

2xEL84 amps are generally very different from 4xEL84 amps, even when the preamp is the same or similar. I'd also do the full Rocket, and install a VVR. Actually, I have done that - twice And the results are really good that way.