All transistors are installed on a heatsink with thermal pads.(Complementary pairs TIP31\32 or 41\42, BD911-912, BD243-244)
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This was designed outside mental hospital and was tested and works great. You may drop the diodes alltogether, but include some biasing control. This is buffer and will drive any speakers. If you need more current, add outputs.
https://www.diyaudio.com/community/threads/output-bjts-for-buffer.386324/
https://www.diyaudio.com/community/threads/output-bjts-for-buffer.386324/
I'm sorry I really don't know what I'm doing yet this entire idea came from not knowing that ground was between + and - voltage on a AB class amp I seen a diagram for and turning it into a bridge to solve that. I build drones transmitters and 3d printers and all kinds of electronics that I hook up premade chips too. What I'm trying to do with this is build a very small guitar amp that runs on battery so guys still in the hospital can play electric guitar in their rooms. I'd also like to move into copying old tube amps to sell. I'm great at soldering and making electronics as soon as I know how to hook it up and I've made a few functional preamps and this amp a few times. I have no idea about things like impedance and how to choose resistors and for power supply **** I just use the biggest caps I can find. So my electronics knowledge is all hooking **** up till it works. Right now I can get good sound out of my little 4 ohm 5w speaker. So what I need now is to get a preapm made and I was thinking I could use the preapms feedback resistor and a potentiometer to control volume since I was just going to use another LM741 for that. I was then going to add a Arduino to allow a few effects. The whole thing is going to be powered by a lithium battery in a 3d printed case using the little rca speaker I've been using for this. This doesn't have to be perfect. When I start building with tubes I need that perfect.
Better to have the preamp op amp with fixed gain, and a standard passive volume control after it.
The transistors as shown in the drawing are bipolar junction transistors, (BJT's) not MOSFETs.
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A bipolar transistor, NPN or PNP, cannot be directly replaced with a MOSFET without serious circuit modification. The bipolar and the MOSFET are two completely different animals.
can be fun to imagine circuits.
if you have computer access
be easy to test circuits
and explore other topologies
using spice.
it is interesting circuit.
seems different way of doing bridge / floating
load.
for guitar circuit maybe more simple
known topology.
either way is interesting to think
how to make this circuit work.
depending if BJT or mosfet.
still needs current to drive power transistors.
Maybe simple Darlington , or use Darlington
output transistors.
and constant current / bootstrap for
R1-4
could use dual opamp, or full diff package
to have feedback loop /gain.
if you have computer access
be easy to test circuits
and explore other topologies
using spice.
it is interesting circuit.
seems different way of doing bridge / floating
load.
for guitar circuit maybe more simple
known topology.
either way is interesting to think
how to make this circuit work.
depending if BJT or mosfet.
still needs current to drive power transistors.
Maybe simple Darlington , or use Darlington
output transistors.
and constant current / bootstrap for
R1-4
could use dual opamp, or full diff package
to have feedback loop /gain.
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