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WolfX700 Measurement of DIY Firstwatt F6 Clone

WolfX-700

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#1
In the AHB2 thread, I said I've been obsessed with making different types of power amplifiers for myself. In this thread I will measure one of the units.

If I didn't get it wrong, Nelson Pass's FirstWatt collection is a public release design and encourages DIY. I think DIY Power Amp based on the design released by this series for myself use will not involve infringement of intellectual property rights.

This is the finished product of DIY:

Photo.jpg

Rear.jpg


It is based on the design of FirstWatt F6, and I made some efforts in the selection of components during the production process.

I knew before production that this was not a high-performance unit. From the few Firstwatts I chose to make, I'm just curious about the characteristics of some special circuit architectures.

Let's take a look at it now:

4R5WDash.jpg

8R1W.jpg

8R10W.jpg

Noise.jpg


Dynamic-Range---NoWt.jpg

8R1W-THD-Ratio.jpg


8R-THD+N-Ratio-vs-Measured-Level.jpg

8R-THD-Ratio-vs-Measured-Level.jpg

8R-SMPTE-Ratio-vs-Measured-Level.jpg

8R1WGain.jpg


Recently I have also been thinking about some measurement issues. The following Multitone is a result of my thinking: Take a multi-tone measurement with pink noise attenuation and read TD + N. I personally think that the characteristics of music sounds are closer to the distribution of pink noise, and polyphony is closer to the actual situation of music sounds.

WolfMTDN.jpg


Summary: The result of DIY should be to or even exceed the Spec on the Owner's Manual. From a DIY perspective, it should be successful.
 

JIW

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Nov 11, 2019
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#5
Recently I have also been thinking about some measurement issues. The following Multitone is a result of my thinking: Take a multi-tone measurement with pink noise attenuation and read TD + N. I personally think that the characteristics of music sounds are closer to the distribution of pink noise, and polyphony is closer to the actual situation of music sounds.
Have a look at the signal with EIA-426B spectrum and 12 dB crest factor used by Dr. Anselm Goertz for Sound & Recording and Fidelity Online.

Test signal is a multi-sine wave with 60 excitation frequencies and a weighting according to EIA-426B was used for an average music signal. The signal has a crest factor of 12 dB. The graph in Figure 15 shows, the spectrum of the excitation signal (green curve), the measured spectrum of the radiated from the speaker signal (red), and the extracted distortion components thereof (blue).
Source: https://www.fidelity-online.de/2015/12/16/neumann-kh-420-messungen/
 
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