My Amplifier Design - Comments?

[WuYit]

Kanwar,
I`m so very worried, I need something stronger.

 

[jaycee]

IMHO: You can try one more approach in triple OS, configure pre-driver + driver in CFP fashion and output stage as EF, it will give you best of both worlds.

This arrangement can actually work pretty well if carefully compensated. I designed and simmed an amp using exactly this topology - just never got around to building it.

 

[WuYit]

jaycee,

I designed and simmed an amp using exactly this topology - just never got around to building it.

Then you don`t know.

 

[ontoaba]

May be he has some reasons, to still using 3 stages with that arrangement, when 2 stages are more than enough to get the rated power output with its gain.
I am still suggesting as my previous post with 2 stages.
Now please check its stability by adding about 50uH to 500uH inductor in series with that 50V batteries, the supply will start to vibrate but the amplifier should still stand with few distortion or no distortion. I usually doing this trick to my simulation.

 

[jaycee]

jaycee,

Then you don`t know.

I dont know 100% for sure, but it worked extremely well in simulation using all the accurate models. 5th Element built a similar circuit to mine and had good performance with it too.

 

[WuYit]

jaycee,
there are several severe problems with that configuration (in Amplifier-Triple OPS.PDF), please believe me.

 

[kASD]

jaycee,
there are several severe problems with that configuration (in Amplifier-Triple OPS.PDF), please believe me.

WuYit,


CFP+EF is no where in that PDF.

 

[AndrewT]

I think he meant NPN for the first half of the CFP and a dual PNP in darlington configuration for the second half of the CFP.

One could consider the last PNP as an EF for the first PNP.

 

[WuYit]

Kanwar,
right, the CFP as a driver compound is easier to accomplish, but is also much less exciting.

 

[kASD]

I think he meant NPN for the first half of the CFP and a dual PNP in darlington configuration for the second half of the CFP.

One could consider the last PNP as an EF for the first PNP.

Andrew,

In that way the output still is CE not CC, thats why i pointed it out.

Using CFP as driver and EF generates many benefits, one of them is Bias is one VBE less drop for each half.

 

[Bigun]

Kanwar,
right, the CFP as a driver compound is easier to accomplish, but is also much less exciting.

The CFP doesn't like switching on/off and therefore, has additional problems when used for the Output.

But using a CFP for the driver to the output avoids this since it operates in Class A.

The low output impedance and improved linearity of the CFP has a huge benefit on the performance of the OPS starting with reduced H3.

It also provides an effective buffer for the VAS, another benefit to sonics.

As far as I can see, it's an almost ideal topology.

I built one and it sounds very good: http://www.diyaudio.com/forums/solid-state/167369-designing-tgm3-output-triples.html

 

[WuYit]

Hi Bigun,

The CFP doesn't like switching on/off

Very true.
The high distortions occur in the output devices.