Hybrid Class A / Class B design.

[GK]

The schematic MKII:

Scaled down to 500W with some very fancy bias current regulators added for the class A stages........

An externally hosted image should be here but it was not working when we last tested it.

 

[Ultima Thule]

Großschmidt Audio Inc.?

Glen,

do you have any better picture perhaps?

Cheers Michael

 

[Wavebourn]

Glen;

your design reminds me: "You are tired. Give me your backpack. I'll carry it. You'll carry me".

 

[GK]

Großschmidt Audio Inc.?

Glen,

do you have any better picture perhaps?

Cheers Michael

Oh c'mon, this amp is only a baby!
No better picture yet. That schematic is only very preliminary and contains a few wiring errors and omissions (That I can see now). The component designators are currently all over the place and most of the component values and part numbers aren’t properly entered yet. That picture is just a ‘print screen’ of where I got to last night.
I’ll be working furiously on it over the next couple of days though, as I want to get start laying out the PCB’s soon. Stay tuned to this thread…..

Glen;

your design reminds me: "You are tired. Give me your backpack. I'll carry it. You'll carry me".

Cheers,
Glen

 

[GK]

Just fixed a couple of glaring boo-boo's in that second schematic with my red pen.........................

 

[GK]

Here's the latest schematic....(in case anyone is interested)......
After much procrastination I've decided to change the class B floating supply drivers to class AB. Now I can start laying out the PCB's..........

An externally hosted image should be here but it was not working when we last tested it.

Cheers,
Glen

 

[suiraMB]

Reminds me very much of patent # 4,115,739, Sano, et al.
Alternatively you can consider # 5,343,166, Pass (et nobody).

Entertainingly enough, I think Dynamic Precision were awarded a patent for this as well. They're a Norwegian company, with amps in the 800W-1500W @ 2ohm range unbridged, with all current models based on this idea of a class B amp driving the ground of the floating class A amp. Depending on the speakers, I find it gives an equivalently rated X series amp a run for its money, usually with no clear winner.

One wonders what the USPTO is thinking about, sometimes... kind of like the patent on the XOR logical operator and the multiply linked list in the IT sector: obvious to the tons of people not bothering to patent it, and apparently Ancient Greek in Tengwar fonts to the people reviewing the applications.

I haven't tried comparing the patents (legalese is not exactly greek to me, but I don't want to read it unless there's money involved), but it would be rather embarassing if there are three people that all hold a patent on the same technique.

 

[unclejed613]

try designing a small scale (maybe 50-100w) version for proof of cocept first..... i'd hate to see you let the magic smoke out of that much silicon........

look at what's used for AM transmitter modulators, since modulators are very high powered hi-fi amps, their loads being modulation transformers rather than speakers (more reactance to deal with).

with an AM transmitter, the output power of the modulator has to be the same output power as the transmitter for 100% modulation (i.e. for a 1kw transmitter, the audio amp needs to be a 1kw amp).