♫♪ My little cheap Circlophone© ♫♪

[terranigma]

Ok it seems, I should expect an answer like "it doesn't matter of how you add RC filter at Circlophone's output as principle".

[danielwritesbac]

Originally Posted by Elvee

Here is a suitable buffer to match the Circlophone, clever enough not to degrade its performances:

Oh thank you! That looks very elegant.
And, I have a bit of shopping to do.


Edit:
Does it do wide range voltage, such as from 18v rails to 39v rails?

[Elvee]

Originally Posted by danielwritesbac

Edit:
Does it do wide range voltage, such as from 18v rails to 39v rails?

Yes, it works from +/-15 to +/-42V, the zeners do not actually regulate, they serve to keep the voltage within safe limits for the FETs.

If a very good matched pair of FETs is available, or if one of the 220ohm source resistor is made adjustable, the non-polar 4µ7 could be discarded.

Ok it seems, I should expect an answer like "it doesn't matter of how you add RC filter at Circlophone's output as principle"

Basically, the order in which series elements are connected does not matter, except in cases of high impedance levels or religious issues.

[danielwritesbac]

Originally Posted by terranigma

I think Daniel means that could we get similar affect like Elvee's new CFP implementation if using aka 700 Hfe LTP transistors rather than 250 Hfe ones. I may wrong but it sounded like me that.

BC560C, 50v, HFE=420~800 (Fairchild datasheet specification)
Your idea, and it is a good idea. I wonder about the more orthodox approach of fine tuning both resistors of the gain divider. This much gain is easily sufficient for 90w to 8R size amplifier and you might not need to use up as much gain if your source is capable of pushing hard enough without blaring or distorting itself.

Taking steps towards very stiff rails, such as high amperage transformer, thick cable and a sturdy schottky at D4, D5 (see previous discussions), plus the addition of a soft clip circuit, could make the 90w to 8R size amplifier compete with 150w to 8R size amplifier and require output devices suited for the 150w to 8R size amplifier, especially when soft clip circuit is added.

The only thing you need to ask yourself is if you would like to turn up the influence of your amplifier or if you would rather push it with a preamp. I think that both options are well worth an interview.

[danielwritesbac]

I am grateful to see the new CFP "Circlophone 200" but applying it confuses me. Since the compensations and simulation is very specific, I would like to see it specifically (re)tuned for easily available parts capable of the target voltage.

high output power on 8 ohm (~150W), with a high input sensitivity

Can it have a new simulation with specific compensation fine tuned for either Hitachi 2SD669a (available, 160v, 12pF), Or Toshiba 2SC3421 (available, 120v, 15pF) for phase inverter?, And also maybe with a conveniently matching complimentary partner for driver (since they are stocked together)?, And a widely available output device capable of target voltage and current?

[Elvee]

I cannot find reliable models for these transistors; anyway, that is something that needs to be tested for real, a sim alone is not able to tell the complete story.

[kenpeter]

I should quit weird topologies to focus upon rolling parts. Vastly more irritating.

[terranigma]

Originally Posted by kenpeter

topologies to focus upon rolling parts

I'm sorry, I didn't understand what do you mean. Do you mean that Circlophone is one of them?

[Tony]

Originally Posted by kenpeter

I should quit weird topologies to focus upon rolling parts. Vastly more irritating.

IIRC, the tubeophiles started the trend with tube rolling, then came the IC rollers replacing the NE5532, with types like OPA2134, OPA627 et. al......and now transistor rollers....

not as easy to do as tubes, transistor rollers do it thru simulation.......

and why not? this is DIY, a DIY'er has lesser constraints than a commercial designer....

sorry for the OT.

[kenpeter]

Originally Posted by terranigma

I'm sorry, I didn't understand what do you mean. Do you mean that Circlophone is one of them?

I'm merely suggesting that Elvee has the patience of a saint.
Wish as many questions were asked of how and why it works.
Understand first, throw darts later...