DIY Valve Guitar Amp Head

[DrNomis_44]

Hi Everyone, I thought I would start a thread about a Valve Guitar Amplifier Head I've been working on since I was working as an apprentice Fitter and Machinist in my Dad's workshop back in 1997 (it was a 3-year apprenticeship) before I moved from Kununurra to Darwin in 2000, anyway, the Amplifier itself started out as a Mesa/Boogie Mk I and Marshall Super Lead 50 Hybrid, the preamp was the Mk I circuit and the power amp was the typical 50 Watt Marshall power amp design, but I could never get it to sound good in both the clean or overdriven modes, I could get the clean sound to have a good tone but the overdrive sound always lacked tonality no matter how I set the tone controls, it turned out to be due to where Mesa/Boogie put the tone controls in the preamp circuit.


I decided to rebuild the amp so that it was like a Soldano SLO 100, I've had to shelve the project for a while so I could put my money towards other things, but decided to post a pic of the amp in it's current state just in case you're interested in checking it out, here's a pic of the amp "as is":

[wokkaboy]

nice one Doc, you must have a fair bit of knowledge to attempt mods to an amp head.
If you have any queries you could always ask Lozza (Lawry) has a very good knowledge of amps circuitry.

[DrNomis_44]

nice one Doc, you must have a fair bit of knowledge to attempt mods to an amp head.
If you have any queries you could always ask Lozza (Lawry) has a very good knowledge of amps circuitry.

It's actually not a mod, it's a complete scratch build, I made the chassis myself from a piece of 2mm thick sheet Aluminium which I marked out and then cut off the excess material with a jigsaw with metal cutting blades, I got a local Kununurra Engineering company to Mig-Weld each of the corners for me after they bent the metal up in their metal-bending machine, the wooden cabinet was made from half-inch plywood covered in green pool table felt I bought from an upholsterer, the clear front panel is just some clear Perspex, I made the power transformer from a power transformer I salvaged from an old movie projector if my memory serves me right.


Cheers for that, I'll definitely have a yarn to Lozza when I get the chance to mate.

[wokkaboy]

good stuff Doc, you must have learnt alot putting the amp head together. I wouldn't know where to start and would end up electrocuting myself !

[DrNomis_44]

good stuff Doc, you must have learnt alot putting the amp head together. I wouldn't know where to start and would end up electrocuting myself !

I think I did learn alot as I went along, most of it was just doing alot of internet surfing for Amp schematics, checking out websites and trying lots of different circuits and stuff, I also learnt alot about electrical safety in the process too, if you follow some simple safety procedures amp building can be relatively safe as long as you know what you're doing.


I've been looking for a good Australian supplier of Guitar Amp-building components and materials for a while, one that I can order stuff from online relatively easily.


Here's a pic of the underside of the Amp's chassis:

[wokkaboy]

well done Doc I am impressed. That's a big step to learn as you go build an amp head. Think I'll start building FX pedals and working up to an amp head !

[DrNomis_44]

well done Doc I am impressed. That's a big step to learn as you go build an amp head. Think I'll start building FX pedals and working up to an amp head !

I'll be happy to give you some pointers about building FX pedals if you like mate.


If you're after a good diy valve overdrive pedal, I know one guy who lives in Christchurch New Zealand who sells a set of professionally etched circuit boards to build a pedal he designed called the Baja Real Tube Overdrive, I bought a set of the PCBs and built one, it worked first time, it runs off a 16V AC plugpack and uses a real 12AX7 valve, here's a link to the thread he started on the Freestompboxes.org forum of which I'm a member of:


http://freestompboxes.org/viewtopic....38b21e1f1f5e6c

[wokkaboy]

thanks Doc, when I get my guitar hanging rack a bit lower I might ask for some tips

[DrNomis_44]

thanks Doc, when I get my guitar hanging rack a bit lower I might ask for some tips

No worries at all mate.

[stan]

nice work Doc. hopefully you will get it going how you want. Another vote for Lozza, he knows his stuff...

those valve OD pedals sound awesome, does he have a site or direct contact?