MC cartridge loading

[drrd]

I've been experimenting again with resistor values for MC cartridge loading and I wondered if anyone would care to comment on some recordings I made from vinyl:

Original CD track (for comparison)
http://www.mediafire.com/?z35zmwr368n5pp9

Resistor value 1
http://www.mediafire.com/?luya75zbbpzc6p7

Resistor value 2
http://www.mediafire.com/?bj6p7ehkf69jk4w

Resistor value 3
http://www.mediafire.com/?ehhznwutajnn8d1

All files are 16 bit 44.1 KHz FLAC. I'll keep the resistor values to myself for now and I won't comment on what I hear just yet so as not to influence things. I'm interested to know if people think they sound different and if so which sounds best, which sounds most like the CD version, if there is a perceived change in frequency response, that sort of thing.

[oceanobsession]

I have just downloaded the four tracks, i cant tell a difference between them.

[sq225917]

Check the frequency response in Audacity, it'll quickly tell you if there is a difference worth trying to hear, if a quick listen leaves you wondering if there is any difference.

[drrd]

Don't necessarily concentrate on frequency response (they don't measure that differently), if they sound tonally similar it's ok to say so. The sound of transients, low level resolution and just general 'sound quality' may be difficult to measure, better to listen instead. Just to reassure you though the resistor value range is by no means small, this isn't a trick or something :) Also the tracks have just been normalised to give a similar level to the CD, I haven't EQ'd or processed them in any other way.

[Artifolk]

UMMM... I had to play with my Superline to get the best Resistive load match for my DV 20X2L, Resistive loads in my system made a hell of a difference, I'm finding it hard going here but no2 to me sounds a little better in the bass end and slightly more open overall.
No doubt i'm wrong though. :lol:

Listening through: Laptop,Dacmagic,Pioneer A-400 and Mission 754s

[drrd]

Thanks Charles :)

By the way my cartridge internal impedance is 38 ohms. How would people usually load this? I'd read roughly 10x that quoted, one reviewer thought 500-1000ohm, Benz themselves recommended 'anything under 100 ohms'.

[sq225917]

I'd probably start at 200 and work my way up in 50 ohm intervals to 1k. With 38 ohm impedance I'd expect sweet spot to be close to 400 ohms, though this depends on what lies upstream and your own prefs.

[drrd]

Hi Simon, yes that's just what I did when I first got the cartridge. One of the recordings above was done with 500ohm loading, there's a 50-fold difference between the highest and lowest resistor values I used though. Did you think they sounded very different or that one stood out as sounding better or worse?

[sq225917]

Honestly, i haven't downloaded them, i find vinyl rips worse than pulling teeth... sorry.

[drrd]

Ah shame, we use almost the same cartridge, the A->D was done with a dCS converter and you've got a decent DAC, I thought you'd be an ideal pair of ears :)

[sq225917]

Oh go on then.

[drrd]

Cheers :)

[Reid Malenfant]

Do you know if WINamp happens to play FLAC files when it's never seen them before? :eyebrows:

[sq225917]

Ok, i prefer Z2.

Z1 seems to come in late on the drums, if that makes sense, and Z3 seems a little muddled/congested in the upper bass.

All 3 sound significantly less dynamic and lighter in the bass than the cd version and there sounds like there might be some low level wow on all 3 of the vinyl versions- slightly off centre pressing maybe?


Which cart do you use?

[drrd]

Cart is a Benz LP-S

z3 is 500ohm
z2 is 33ohm
z1 is 10ohm

I agree all 3 sound less dynamic than the CD. Now one reason may be that to make the comparison with CD fair I did reduce the original 24 bit files to 16 bit (with appropriate dither), when listening to the 24 bit files it's not quite so obvious. To my ear though there is a definite trend from z1->z3 of increasing sloppiness of the bass, less defined higher frequencies, softened leading edges, a sense of loss of dynamics essentially. I don't hear much of an EQ effect tbh which is sometimes how loading is talked about, that surprised me given the range of loading here.

I've uploaded one more recording to highlight the effect further, 6.5ohm
http://www.mediafire.com/?67gaw4s0p42275p

Same file again but left at full 24bit resolution
http://www.mediafire.com/?a5345s4v6pgn4vh

The downside with very low resistor values of course is worsening S/N but even at 6.5ohm noise wasn't actually an issue and there seems to be obvious benefit to the SQ.

I'm wondering if having a very short run of cable from the arm to the phono amp would be another good way to better damp the circuit?

[sq225917]

What capacitive loading do you have on the cart?

[drrd]

None that I know of.

[drrd]

I think I may have solved it, I belive the M-Audio unit I use to capture the digital signal introduces a small amount of digital DC off-set. I made a test recording with no analogue signal and zooming in on the waveform there is a block of DC on both channels at about -97db. Running DC off-set removal I'm then left with a nice random waveform at about -110db. So I ran DC off-set removal on the recordings, I wasn't expecting a big difference but it's quite audible in the higher frequencies and sense of dynamics. I think my vote also goes for z2 now, lower than that starts to sound a bit weedy and 500ohm sounds too soft.

z1 (10ohm loading)
http://www.mediafire.com/?bsa6yykqd276uge

z2 (33ohm loading)
http://www.mediafire.com/?g2pego0l72gdp1e

z3 (500ohm loading)
http://www.mediafire.com/?8h47111sg1hd5uz

[sq225917]

digital- perfect forever eh? ;-)

[drrd]

Yeah :) 'tweakable forever' maybe, a good reason to stay away from post-processing and lossy storage.