Transformers

[SteveCPerrino]

So I bought the ax84 P1 Octane Guitar Amp Kit. (AX84.com - The Cooperative Tube Guitar Amp Project)

It's a beginner amp kit, on account of the fact that this will be my first amp build.

It's only 5 watts, and I'd like to have it be louder to have more headroom/make it louder for playing shows/etc.

In order to make it louder, could I just replace my output transformer with a greater wattage one, or would it be more complicated that than/impossible?

Thanks!

[SteveCPerrino]

***It's actually just called AX84 P1 Tube Guitar Amplifer, not Octane.

[defaced]

It's sufficiently more complicated that that. You're looking at replacing both transformers, adding/enlarging tube sockets/holes, and seriously modding the amp. I'd opt for a microphone and running it through the house PA or buying a different kit - P1 extreme maybe. That said, 5 watts is pretty loud. Depends on your band situation/room size if it'll be loud enough to gig without more power.

[tedmich]

its possible to run the pre output into a bigger tube power amp or even a cheap chip amp at 60w or more. The so called "fire zog" mod allows you to take a pre line out and there are other options too, check ax84.com!

[Chuck H]

In order to make it louder, could I just replace my output transformer with a greater wattage one, or would it be more complicated that than/impossible

Yes, it's more complicated than that. A lot more actually. I had trouble finding an accurate P1 schem, lot's of alternate versions though. But in order to increase output appreciably you would need to increase plate volts (different power transformer). Since there is a limit to how many volts an EL84 can manage in class A I don't think that just higher plate volts (different power transformer) and bigger (different) output transformer would make a useful difference. The actual volume difference from 3 to 4 watts is really tiny. You would hear more volume increase by changing to high efficiency speakers. A 3 to 4 watt amp isn't really useful for gigs anyway, unless your band plays the local library and the Shady Acres rest home

If you want the P1 tone at gig volumes there are a couple of ways to do it. One would be to add a speaker driven line out to the amp and plug that into a bigger amp or the bands PA and adjust volume with the second bigger amp. Another would be to plug the P1 into a dummy load (eliminating the speaker all together) and use a similar "line out" type circuit to make the whole P1 circuit, power tube and all, into a preamp. THEN re-amp with a bigger amplifier just as you would with a preamp. You could also just mic the amp as it is.

Your only other choice would be to build a P1 "type" circuit with some big bottle power tubes in parallel. Four 6L6's parallel in class A would have an output around 25 or 30 watts. You would need an extra triode stage in the preamp to drive the bigger bottles to the same OD level as the EL84. It wouldn't sound exactly the same either because 6L6's don't sound the same as EL84's. I'm sure the chassis you got with your kit wouldn't accomodate a circuit like this. So you'd be scrapping MOST of your already purchased kit to build an amp like this.

If you need an amp loud enough for gigging, why did you buy a P1 kit???

Chuck

[SteveCPerrino]

haha i thought it would be more complicated i was just checking.

and I don't NEED it to be louder, I have another head, I was just wondering. I'm just gonna make this and use it for recording and practice for building louder, more complicated heads.

That's everyone so much for the info! I greatly appreciate it!

[J M Fahey]

Shortest practical answer: you can't.

[Bruce / Mission Amps]

I like Chuck's, spkr/output transformer tapped line out method... assuming you would be playing out with a PA too...
It will cost you; 10" of wire, two 25 cent resistors and a $2.00 mono, or non-switching, jack... plus a decent guitar cord to plug into your unbalanced input jack on the PA.

[Chuck H]

And it sounds better than you might think.

If you build a really simple voltage divider (with no cap to ground for high end roll off) the mixer will usually handle any EQ anyway. This method works for bunches of players that want to use thier "Champ" type amps on stage.

Chuck