The range of input loads for MC

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Firstly, if any of you frequent the Audio Asylum (Bernhard) then my apologies for the cross posting...

Can you folks please tell me what MC you use and what input load it seems happiest with?

I'm in the process of designing/building an MC phono amplifier for a friend and wanted to know what range of impedance options I ought to make available for cartridge loading. If I'm building in flexibility, I might as well design to allow for all the likely MC contenders.

The gamut seems to run from AudioNote Io at 10R through to Benz Micro at 1K. These appear to be the extremes with most (Clearaudio, Dynavector, Wilson Benesch, Denon) falling at the 100R point. Some (Ortofon) seem happier at around the 33R point. I've seen very few cartridges requiring loads between 1K and 100R, (200R to 750R loads seem almost non-existent).

Does the info above correspond with your experiences?

Thanking you in advance for your inputs (pun intended)
Drew
 
Drew,

it depends if your MC input is a transformer or an active stage withan input resistor.

For resistive input your info is quite correct. Ii is long ago that i used resistive input for MC and my impedances were:

Supex 1000, 30R
VdH DDT, 100R
Elac EMC2, 100R
AT OC9, 100R
Spectral Reference, 1k
ShinonRed, 600R->1k
Koetsu Rosewood Sig.MkIII, 100R
Koertu Urushi, 100R
Ortofon X3-MC, 100R
Ortofon Rohmann 30R resistive. 47Ohm inductive.
I use a Jensen JT-346-AX input trannie, loaded with 6k8 at the secondary, ratio 1:12 reflects 47 Ohm at the trannies primary.

not yet tried out or hearsay:
Accuphase AC3, 100R
Denon DL103, 400r->1k
hearsay:
Clearaudio, 40R
vdHul Kolibri, 500R
Allaerts, 100R
Ortofon SPU, >100R
 
Thanks Bernhard. Looks like I'm on the right track then.

at present the plan is to fit an 8 bank dip switch with the following values:
27R
39R
56R
110R
180R
330R
470R
1K

All in parallel will give 9.8R which will suit the A.N. Io 1K//330 is 247 1K//180 is 150.

This should give a pretty wide range of matching options such that we're not locked into a dead end.

The help is appreciated

Drew
 
Are these are high output MC's similar to Sumiko BPS?

Just to set the record straight, the 47k input impedance will be standard for MM as will the lower gain setting. The extra 10dB of gain and the lower impedance values will come into play as and when selected by the user

Thanks for the heads up.

drew
 
Drew,

Why don't you take a look at the X-Ono Owners Manual.
I'm sure you'll get all the answers you need.
BTW:
my Jubilee is happy with 40R load.
my MC7K5 with anything between 80R and 100R
Haven't tried my v.d.H. WB/SPX with my Ono yet, anyway it's custom made with 0,25 mV output and should work with 100R instead of 500R as recomended by the "Dutch" for the standard version.
Anyway, cartridge loading is not going to be a problem if you go for something like the thresold M1.

Regards,
Nick
 
DrewP said:
I'm in the process of designing/building an MC phono amplifier for a friend and wanted to know what range of impedance options I ought to make available for cartridge loading. If I'm building in flexibility, I might as well design to allow for all the likely MC contenders.

I'm very interested in your ideas, can you present them. Sorry for the threadjacking. Please start a new thread if/when you will answer me.
 
Don't forget the capacitive load

When I had the Denon 103 and was using an active MC stepup, I tried a lot of values, and got the impression, that 100R gets fine treble, but overdamps the basss, and that 1k gets free and powerful bass, but a bit harsh treble. So I then tried an RC-combination of 1k and parallel to that a series combination of 10nF and 100 Ohms. Bingo.

If you have a look at ad pages of Swiss company FM Acoustics (they sell very expensive phono stages, their top of the line model even with adjustable EQ), or their manual, you see, how you can influence the frequency response in treble and overall region when setting resistive and capacitive load independently. Very interesting.

regards,
Hartmut
 
peranders said:
Lots of info so far but I still wonder how the frequency response is for a MC pickup with different R and C and a high impedance input (like my monster amp). Anyone who knows? I'm interested technically, not just how it sounds.

dice45 has given a long answer in the "twin" thread. http://www.diyaudio.com/forums/showthread.php?s=&threadid=6283 Thanks once again.
 
Prerpetually Puzzeled lPeranders

"Lots of info so far but I still wonder how the frequency response is for a MC pickup with different R and C and a high impedance input (like my monster amp). Anyone who knows? I'm interested technically, not just how it sounds."

I believe several references gave source impedances of a few moving coil cartriges. Go plug the numbers in a Spice model and stop being such a pest! I thought you were an engineer.:no:You are stating to remind me of a vampire.:vampire: Why don't you go suck the life out of some other forum.:vampire3:

"I'm very interested in your ideas, can you present them. Sorry for the threadjacking. Please start a new thread if/when you will answer me."

You mean getting free design advice.:xmas::Present: Maybe he will sell it to you so you can sell PCBs to others.
:rain:
:umbrella:

Art
 
Re: Prerpetually Puzzeled lPeranders

artnyos said:
Go plug the numbers in a Spice model and stop being such a pest! I thought you were an engineer. You are stating to remind me of a vampire. Why don't you go suck the life out of some other forum.
..
You mean getting free design advice. Maybe he will sell it to you so you can sell PCBs to others.

Thank you artnyos for you kind words.
 
Well, Art must have very very high expections for the level
of competence of newbies on this board. To really understand
theoretically what you were asking would probably require
double masters degrees, both in EE and Mech. eng.. Probably
Art has a PhD in each, an expects everybody else to have that
to. Unfortunately I've only got one PhD, and not in either of
these subjects, so I cannot help you. ;) ;)

BTW, I am also interested in the answer to your questions, but
at least Bernhard has shed some light on the issue.
 
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