Helikon LOADING

Dear Neil: Thx for your approval about my post.

Btw, " should point out that cartridges are really current producing devices, but there are very few current amplifying phono preamps, " ,

well I don't know any out there. Our phonopreamp design is a CURRENT one.

Regards and enjoy the music.
Raul.

Raul, I did not realize your new phono pre was a "current" device. I think that is wonderful. I did see another one recently, and if I can find it again ;~)) I will send you the link.

N

.

Raul:

I think your point that the load recommend by the manufacture is a fixed value, which is independent of the “system”, is indeed an oversimplification of the intent of the recommendation and cannot be sustained by any reasonable technical analysis. I agree with Nsgarch that the recommended load is simply a “ball park” figure. Ultimately one needs to experiment to determine the optimal load value for the particular “system”.

The load is “system” dependent. The impedance of a MC cartridge is not purely resistive, it contains a reactive component. The system in which the cartridge is used will impact the transfer function of the cartridge (flat frequency response, etc). The “system” here includes tone arm, turntable, phono interconnect cable and the input characteristics of the phono preamp, etc. For example, the cartridge impedance may be impacted by stray impedances due to the presence of external interferences, the interconnect has nonzero impedance and the input impedance of the phono section is not infinite thus it impacts the value of the loading impedance. In summary, one needs to experiment, using the recommended load as a guide, to determine the load value that gives the best-perceived flat response.

If you wish I can go into more technical depth.

I think, most of us are on the right track, Raul with his opinion and Gmorris with his explanations. When the wire in the arm is silver or copper, you can choose different loads, next is the wire from the termination box to the preamp, same story. I agree, that you can go the one and only way with the manuf. recommendation, but do you think, that all of them use a 1.class phono preamp? Or step ups? Or tubes? Or transistor? Even the tonearm material has different damping influences ....

Dear Gmorris: This is only to clarify: when I speak about manufacturer load impedance recomennded I'm speaking not about the very wide impedance value range that usually comes on the manual I'm speaking that I ask directly to the manufacturer for his advice about, so that wide range scale it converts in a single value or a very short value range. Normally the load impedance that " see " the cartridge is: the one from the tonearm internal wires, the one from the tonearm interconnect cable and the input impedance of the phonopreamp that in a well phono stage design is the resistor at the input: the one that we can change it for modified the load impedance value.
These three impedance stages are the ones that we have to taje in count fo to have the right load impedance value where the frequency response is flat. There are others subjects about like what you say: " by stray impedances ", but those other subjects does not affect signify the frequency response. And yes we can go in deep about any time you want: welcomed!!!

" is not purely resistive, it contains a reactive component. ". Btw, is inductive and capacitive.

Regards and enjopy the music.
Raul.