https://www.ebay.com/itm/195785024138
This uses k1058/j162, the circuit diagram looks like a goldmund clone.
But why does this kit have a vbe multiplier? Does it work?
I'm new to vbe multiplier on an amplifier using lateral MOSFET.
In general, sort of. The trail starts with the Hitachi application note circuit: differential input, differential driver, source follower output, then the Maplin exact clone, Maplin like clone and countless hifi and PA clones with various part substitutions, then the Goldmund circuit adding follower drivers and then individual follower drivers and finally the Chinese clones .... well doing their thing on cost saving clone designs (cheaper unmatched part substitutions etc.) that at times don't sound or behave anything like a Goldmund. Some sound really good, others not and some are dangerous. Caveat emptor.
So far, I haven't had any problems with the G29 Hm3s. However, I have made a few modifications. This isn't an amp for beginners. There are other amps that are less difficult. I recommend the Maplin GA28F. It sounds just as good and is significantly cheaper and easier to build. It starts with the fact that the components are easier to acquire than the Goldmund clone.
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Fundamentally, I don't think the circuit is any worse than the original g29. The VBE also serves as a temperature compensator and counteracts the negative temperature coefficient. That's why the bias transistor is located directly on the large heat sink. I think that's a good idea by the Chinese. However, the savings on components that belong on the board are unfortunate. Probably just to make something cheap. Examples: input capacitor, fuse holder, drivers, the Zobe winding...
