Just got a msg from my local shop. The amp I ordered has arrived and the main guy there, who is a diehard tube amp guy, says it is amazing and he has ordered one for himself. You can't get a bigger endorsement than that.
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I was thinking it's really a great idea for novice amp builders because they don't have to deal with Mains wiring. With one of those switchmode supplies that are common now, they don't even have to worry about Mains Voltage. They work on anything from 90 to 250 VAC. Just get the power cord that will work in your country.

Interesting that it uses an external power supply. The jack on the back looks like the same one used on pedals.

Check for DC on the speaker output and DC Voltages around the preamp. Something must have changed.

Quote from: Enzo on April 11, 2022, 12:54:41 PMIt is like an electrical appliance in your home.  If double insulated, no need for earth.   Just my opinion.

All you need is a double insulated guitar and you're set. Without the safety ground, you can get hum and mild shocks when you touch microphones or other guitar players

The clipping LEDs make the amp a little more bedroom friendly. When operated with the Master Volume turned down so as not to allow the power amp chip to clip, the LEDs give the effect of more preamp gain and allow the Master Volume to be turned up a little farther past the point where the volume jumps from nothing to too loud.

A low cost amp such as this is probably not capable of driving an additional speaker. The power transformer and power output chip are carefully chosen for low cost. It may be possible to drive two speakers, but they would need to be twice the impedance of the stock speaker.

Quote from: Jazz P Bass on March 04, 2022, 01:12:43 AM
Did you search the web?
I found this.
Not sure of the particulars.

In the upper right Notes section it says PCB: JMP27A

Quote from: phatt on February 25, 2022, 06:33:06 AM
Mean time all the older analog stuff (SS or Valve) which are mostly simple designs will still be repairable.

That assumes you can find someone to repair it and they can find the parts. If you can find somebody, they may be half way across the globe.

I think the big limitation will be that the package will limit the power dissipation. Apparently the chip comes in a 16 pin dip and there are no options.

That resistor looks like 1/8W. At 180K it would take 150V to reach 1/8W. If it is 18K ( multiplier looks like orange to me ) it would take 47V. E=Square root (P*R)

Is there that much Voltage in that circuit ? If it were me, I'd unsolder one end of the resistor on the good board and measure it.

Huh ? Those schematics look like wireless transmitters.

Here's where DiscoVlad stole the idea for the MC14506 replacement.

https://forum.sunnstillshines.online/index.php?topic=6864.msg29374#msg29374

The link you posted does not download completely for me. From what I can see, the death cap is C2, .02uF 600V. One side goes to ground, the other to one side of the power switch.

Pin 3 of your pot symbol appears to be the clockwise terminal, therefore, the Mid, Treble and Bass controls are backwards.