DIY Discrete Solid State Guitar Amp

[Kaz Kylheku]

Also, this schematic has no short circuit protection so shorting the output could damage the output transistors. I have newer versions but they are a little more complicated.

Have you thought about a dual supply version, DC coupled to speaker?

[Loudthud]

Have you thought about a dual supply version, DC coupled to speaker?

It's the simplicity of a single Voltage gain stage without global feedback that makes the amp sound more like a tube amp. Cap coupled outputs just sound better. DC coupled outputs are why transistor amps sound bad.

MEF is back. Check this thread:
https://music-electronics-forum.com/forum/amplification/guitar-amps/theory-design/49294-

[Loudthud]

I forgot to mention: There are 48V power supplies that can be used to power a 59W @ 4 Ohm guitar amp.

Example: https://www.jameco.com/z/PSA120U-480L6-R-Phihong-120W-48VDC-Output-Desktop-With-C14-Inlet-and-4-Pin-Din-Connector_2670879.html

Some have a barrel connector like used on effects pedals. I'd stay away from those because you don't want to plug 48V into a 9V stompbox by mistake Choose one with the 4 pin DIN connector. Most have a Universal Mains input so it can be plugged in anywhere on earth. All you need is the right Mains cord for wherever you are. The minus side of the 48V is usually connected to the Mains safety ground inside the brick. For a 50W amp you need something like 125W power supply.

[J M Fahey]

I'm relatively new to electronics so would like to use this as a learning project. I've restored a number of early transistor & tube audio amps and one SS guitar amp. Have dmm, oscilloscope, sg, soldering station, etc.

Are there any amps out there I can clone or are there any tried and true schematics available that I can use?

My goals are:

all discrete circuit (no op-amps, IC's, etc.)

10-20 watts (+-)

treble & bass controls

capacitor coupled output

thanks in advance

You will find lots of discrete 15-50W power amps , specially before the 2000s.
Peavey, Marshall, Crate, Laney, Vox, Ampeg , Fender, search , lots of possible amps to copy.

Now Preamps started using Op Amps very early, late 60s Kustom amps already used them.
I remember ONE 70´s Marshall discrete preamp, I´ll post it here if I find it.
Here, I found it, discrete end to end.
Unobtainium MJE3001/2501 must be replaced by TIP142/147

That said, not much "learning" from them, beyond hand dexterity and build practice which is not bad at all.
if you don´t study theory first, and run some textbook experiments yourself, you´ll be "painting by the numbers", just blindly following printed instructions.

[J M Fahey]

A few modern-ish (70s 80s) Roland , Yamaha ibanez preamps are discrete, but use FETs which are in a quite different league. Same with original Randall preamps.

Want to experiment and learn?
Then follow and copy Forum member "saturated" posts, he´s doing a  very good job at that.