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Component Measurements

As there are clear audible differences between different components, Korneel and I chose to measure a bunch of inductors and capacitors, to see if any conclusions can be drawn.

The list of inductors is:
5.6mH:
- Intertechnik air LU92, 1.4mm, 0.83Ohm (€17.60)
- Intertechnik air LU92, 2mm, 0.47Ohm (€47.10)
- Intertechnik core HQ58, 1.4mm, 0.22Ohm (€12.10)
- Intertechnik trafo FE130, 3mm, 0.09Ohm (€80.40)
- Monacor trafo, LSI-56T, 1.4mm, 0.15Ohm (+/- €15.00)

5.1mH:
- Intertechnik copper foil, CFI, 3.29mm, 0.5Ohm (+/- €75.00)

0.82mH:
- Intertechnik air E130, 3mm, 0.09Ohm
- Intertechnik Tritec 3.51mm, 0.15Ohm (€27.40)
- Visaton air, 1mm

The list of capacitors is:
82uF
- AudynCap MKP
- Intertechnik bipolar

88uF (4x 22uF in parallel)
- Mundorf Supreme

Measurement

Two types of measurements have been don. One measurement has been performed with a Stanford Research Systems Model SR785, measuring the magnitude and phase as a function of frequency. The second measurement has been performed by an HP 4263B LCR at 100, 1.000, 10.000 and 100.000 Hz. All measurements have been performed at 1 Volt.

Inductors

Intertechnik 5.6mH, air LU92, 1.4mm, 0.83Ohm


Intertechnik 5.6mH, air LU92, 2mm, 0.47Ohm


Intertechnik 5.6mH, core HQ58, 1.4mm, 0.22Ohm


Intertechnik 5.6mH, trafo FE130, 3mm, 0.09Ohm


Monacor 5.6mH, trafo, LSI-56T, 1.4mm, 0.15Ohm


Intertechnik 5.1mH, copper foil, CFI, 3.29mm, 0.5Ohm


A summary of the inductors (with the 5.1mH transposed with 0.5mH for comparison reasons) is given by the following measurement, performed with the HP 4263B:


Intertechnik 0.82mH, air E130, 3mm, 0.09Ohm


Intertechnik 0.82mH, Tritec 3.51mm, 0.15Ohm


Visaton 0.82mH, air, 1mm


The summary of the 0.82mH chokes:

Capacitors

AudynCap 82uF, MKP


Intertechnik 82uF, bipolar


Mundorf 82uF, Supreme


The summary of the capacitors:

Conclusions

As expected, it is hard to draw any conclusions from these experiments. There a clear differences between the measurements. The extreme bad ones (e.g. Monacor trafo) explain why they don't sound very well. It seems that the copper foil choke has a nice response. The Intertechnik transformer choke based on 3mm wire has a low internal resistance, and therefore its -3dB point is reached at a very low frequency, and the phase shift in the operating range is low compared to the other chokes. Maybe this accounts for its good sound?

The capacitor tests are a bit limited in frequency, and unfortunately we couldn't measure up to 1MHz. All capacitors become inductive at higher frequencies (which is normal behavior due to the law of physic of rolled plates). The Mundorf shows a nasty second resonance. The bipolair elco shows some larger phase shift in the audio band already. We have bunches of other caps to test, which we might do in the future.

These measurements are based on steady state signals, and don't reflect what happens if large differences in voltage swings occur, implying transport of large charges or saturation of cores.

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