WHEN I'M NOT MAKIN' DOPE ADS, I'M MAKIN' DOPE GUITAR AMPS


Building these things is like playing a high-voltage version of Operation. But it's relaxing. And it feels great to plug in a guitar and breathe life to something you've built with your bare hands.

This build is a clone of the Soldano SLO100. It's a high-gain design from the '80s. It paved the way for pretty much every modern hard-rock/metal amplifier ever since. It's been used by players like Eric Clapton, Eddie Van Halen, Warren Haynes, and Stevie Ray Vaughan.

I hand-wired everything with painstaking detail.

Click the below image of the finished amp for a larger view.

 

slo_stack_by_haftelm-d7spotx.jpg

The finished amp sitting atop a Bogner 4x12 speaker cab. It's LOUD!

 

I made it with my hands! And a soldering iron. And some pliers... a drill helped too.

 

The drilled and punched chassis.

 

Signal capacitors are mostly Sprague 716p, made from polypropylene film.

 

Super fancy blue ceramic disk capacitors.

 

I used Vishay CCF60 metal film resistors for low noise. 1% tolerance, rated for 500 volts.

 

Panasonic filter capacitors.

 

Preamp PCB (printed circuit board).

 

Preamp PCB is now populated with all the various components.

 

Boards mounted in the chassis.

 

Masking off chassis to do some metal work before mounting the controls.

 

Controls (Pots), front-panel switches, and the vacuum tube heater/filament circuit wired up.

 

Power transformer, output transformer, and choke. All by O'Netics.

 

Power transformer and choke wired in.

 

Power board populated and mounted in the chassis.

 

This is a modification I implemented to "elevate the heaters." The amp runs off vacuum tubes. They're kinda like big, glorified light bulbs. Like the filament in a lightbulb, tubes have an element that heats up when the amp is operating. But this element causes noise. By referencing this part of the circuit to an elevated, DC voltage instead of ground, you can reduce that noise. That's all these parts are doing.

 

loop_switch_by_haftelm-d7sadfr.jpg

The impedance selector, footswitch jack, and FX Loop jacks all wired up.

 

Wiring up the preamp jumper wires. These will loop down to the preamp vacuum tube sockets.

 

Almost done! This is the home stretch.

 

Finished! Powered it up and no smoke or explosions... sounds pretty damn good too.