Are there THD measurements for Le Monstre?
Not just 0.xxxxxx% THD, like, specific harmonics or spectrum analysis?
Not just 0.xxxxxx% THD, like, specific harmonics or spectrum analysis?
formal THD high (as for all amps with small feedback or without feedback), in spectrum lastest harmonic is 4th.
I can't find spectrums of THD.
As I remember:
Harmonics:
2nd=-60 db
3rd=-85 db
4th=-102 db
no other harmonics
bias=0,5A
4V to 3,5om+6,8uF
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!!
Ah, but how about the "highest spike" in the fifth harmonic? Is the spike -126 dB or the average?
If it's ALL -126 dB then "it should not be audible at jet engine volume"
If it's ALL -126 dB then "it should not be audible at jet engine volume"
You don't even need to put resistors, simply install an inductor.
If you can't then a CRC should work but will be noisier unless you add TONS of filtering capacitors.
A CLC filter has a lot more ripple reduction than a CRC one without losing too much voltage and generating too much heat. To further lower the noise floor, simply use a CLC filter, rather than a CRC filter circuit.
Try a CRC and if your set-up is a bit noisy replace those resistors by an inductor.
BR,
Eric
It has not harmonics after 4th.😀😀😀😀😱Ah, but how about the "highest spike" in the fifth harmonic? Is the spike -126 dB or the average?
If it's ALL -126 dB then "it should not be audible at jet engine volume"
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Here is some measurements taken on my le monstre,
note the bias is deliberetly set low to get the steep increase of THD with output power like one would get with a 2A3 / 300B amp.
I did have a photo of the distortion waveform in realtime (captured with a HP 339A showing it to look rather similar to a pentod driven 300B, indicating not only the amplitudes of the distortion components shows similarity but also their phase relations.
note the bias is deliberetly set low to get the steep increase of THD with output power like one would get with a 2A3 / 300B amp.
I did have a photo of the distortion waveform in realtime (captured with a HP 339A showing it to look rather similar to a pentod driven 300B, indicating not only the amplitudes of the distortion components shows similarity but also their phase relations.
Attachments
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Tazzz, thank you.
It looks like 0.057 THD+N, but 0.000000 at sixth harmonic and higher, is this rare?
It looks like 0.057 THD+N, but 0.000000 at sixth harmonic and higher, is this rare?