This morning, I tested the amp and here are the results:
- The square wave at 10k has practically zero ringing. There is no phase compensation except for an 82pF cap across the feedback resistor.
- The test load was an 8 ohm 225 watt resistor.
- Input sensitivity is 2VPk (1.414 volts RMS) for 138 watts.
- THD is around 0.25% at 138 watts out, at most frequencies every octave.
- Attached are my published test results.
I never even looked at the eiclone circuit or heard much about it for that matter. I guess me and Shannon happened across very similar circuitry. After all, tubes circuits are very simple. The LM334 is a semiconductor and has popped on me under certain conditions. That is why I shy away from it. I thought I would have to sacrifice some performance for a resistor instead of an LM334. But no, a phase compensation pot does the same job. Why use semiconductors where they do not belong? Furthermore, adding a cap places another pole in the system, rendering it coherently less stable. Why would you make a circuit less stable for a CCS (especially for PPP circuits)?
Questions:
- I was blown away by the numbers with the amount of feedback I am using. Did anyone else think without an LM334 low distortion was possible? Has anyone done this with such high power, or at all, without a CCS?
- The distortion increases exponentially and becomes really apparent after 10k. This happens in all amps I have worked on, even solid state. Why is this? Harmonics > 10k are inaudible anyways, so I guess they are moot.
- With a simpler circuit, I am producing comparable numbers to the figures McIntosh and Audio Research produce. Why do they use more complicated circuits and carefully selected tubes, where with run of the mill parts, I can produce similar numbers? What is with their high prices for what is really nothing special, or in some cases, inferior?
- I asked Heyboer for a 130 watt power handling transformer. Why is it still producing low numbers at 138 watts?
- What is up with the square wave? Is it low leakage inductance?
- What do you think of the wiring job (see above)?
-Ice cream is irresistible.
-Spaghetti and salt is irinductable.
-Artichokes are ircapacitable.