tube preamp PCB?

[AdamB]

Hey,

I just sort of got donated a 4x10 cabinet and a 4-rack head and want to do something with it. As I'm a poor student and currently play through a 30W solidstate laney combo, I want to build my own amp with it, but don't want to jump into the deep end...

The amp in it at the moment is a 150W mosfet poweramp and some crap solid state preamp that is a seperate module that plugs straight into the poweramp (it was being used as a bass amp). I was thinking to start with I'd just build a vavle preamp to drive the poweramp that's already in it as I don't feel condident enougth to fool around with high voltages yet, but where can I get a good layout (vero or PCB) for a valve preamp for guitar that would sound good driving the mosfet power amp and doesn't require me to tangle with death to build?

-Adam

[Joecool85]

As far as I know, even tube preamps use high voltage.  I could be wrong though.  There was a site about making low voltage tube amps that go up to around 1/8w, that type of power would be fine for a preamp.  Don't remember the site though.

[bancika]

Don't be scared of voltage. Make real McTube, there's PCB project on tonepad. I started with Firefly tube amp and nothing happened. Just use common sense and you're safe.

[gez]

A lot of solid state preamps involve op-amps and are therefore run at relatively low voltages compared with valve preamp stages.  Bear this in mind - you don't want to blast the hell out of the power stage!

Find out what voltage the preamp is run off first, then start making decisions.

[dano12]

Is retaining the original solid state power amp important to you? If not, why not go all tube?

Rich at www.guytronix.com sells small wattage tube amp kits that are just wonderful. I build the 8 watt Ardmore head and did not kill myself in the process. Sounds great and at 8 watts is it easily loud enough to keep up with my drummer.

FWIW,
-dano

[AdamB]

hrm, that real mctube preamp looks good from tonepad, that way I could get tonepad to make the PCB for me to save effort and it's only 12V.

Retaining the original poweramp is pretty important, as I'm very poor. I don't have much to spend on parts so I wanna keep the building down to a minimum. I really do want a valve-like sound tho. Plus I don't really wanna do anything high voltage yet, I will do eventually but not now.

I haven't actually got the cab/head yet as I should be getting it sometime next week, as soon as I do I'll check out exactly how it works and post some images of it. It's a custom-built amp tho (my friend built it, he's giving it away coz he's moving country and can't take it with him).

-Adam

[AzzR]

Jaycar electronics has a tube preamp kit which has its own power supply which you buid. it steps the power up from 12 v i think

[bancika]

McTube isn't 12V. I mean, you can make it to work with 12V DC input, but you need one more transformer inside that will give 120V back...