Phono Preamp Help - 47K Ohms - 100 Ohms .. Huh?

I am relatively new to analog and therefore have little experience matching a cartridge with a phono preamp. I currently have a Shelter 901 which the user manual specs at "within 100 Ohms" as the recommended load impedance for the head amp. I've been shopping for a new phono pre and find that many top phono pre's are all rated at 47K Ohms and are not switchable.

This got me thinking that maybe 47K Ohms was the right setting for ALL phono stages and sounds the best... So since I currently use a Black Cube which IS switchable between 47K Ohms and 100 Ohms I decided to play around.

When in the 100 Ohm setting, I feel the sound is crystal clear - nearly perfect - yet the midrange seems recessed ever so slightly causing some recordings which I know should have heft and body to be somewhat recessed sounding and maybe thin. Also, at 100 Ohms, the sound is not quite as involving as I like. It's not exactly bright but quite close.... really close - in fact, as extended as I've ever heard a system be without being able to confirm it as being bright.

Switching das cube over to 47K Ohms gives a dynamite midrange. Very impressive vocals. Solo instruments seem incredibly lifelike - highs are ever-so-slightly rolled when compared to the 100 Ohm but during complex music, and even not-so-complex music the mids seem somehow congested as if the notes are bumping into one another slightly - perhaps muddy - more or less "confused". This sucks because everything else seems to be close to perfect.

Each setting has its virtues but I feel the 47K Ohm setting would be ideal without the midrange confusion.

Now for the questions...

If my Shelter 901 is designed for "within 100 Ohms" what the heck does that mean? Within? Does this mean I need to stay at 100 Ohms for the best match to the cartridge?

When switching to 47K as I said above, there are some advantages and clearly a few disadvantages. Are the downfalls more related to the phono preamp, the cartridge or even the impedance match? I mean, could the congestion be a result of the black cube itself vs. a direct result of the impedance settings?

What's more important - the preamp or the impedance setting?
What you are hearing is pretty much the tradeoffs related to loading. One thing to keep in mind is that changes in loading affect the Q of the generator system and, in many cases, VTA should be readjusted to compensate. Many find loading at around 1000 ohms to be the best tradeoff between attack/detail and body/presence. Why not try this with your Black Cube?
Bwhite, I personally think that you should try a slight raising of your VTA, and leave it at 100 ohms. Recessed mids are a trait of a too-low VTA. Raise it up, a little. If there is a percieved brightness, it's probably in the Cube. Running the cart "unloaded" at 47k is just compensating for other errors, that are causing the problem. I know that raising the VTA can cause some brightness, but in this case I think you need to. The Shelter could not be considered a "bright" cart, so if you are having "brightness" problems, it is somewhere else. You might try a little self-stick black felt, from the crafts section in Walmart, on the headshell. The Ittok could be "ringing" a little. That is a high-energy cart, and sends alot of energy back into the arm.
Hi Twl, Okay.. now.. the VTA is that the adjustment I can do with the hex bolt? or is that the knob on the arm? I think if I remember correctly its the hex bolt... So I'll try that.

My Ittok is the BLACK Ittok which is/was released right before the Ekos and is essentially an Ekos without the integrated arm rest. This Black Ittok is damped unlike the silver Ittok arms and it does not ring like 'em.

The brightness I referred to is not actually "bright". It is however, as close to being bright as I've ever heard without being bright.

I'll try to raise the VTA slightly and see what happens.
47 Kohms is the typical "correct" load for MM cartridges.
You can optimize MM cartridges by changing the capicatance, but this is not relevant to your question.
There can be interactions as to the prefered settings between VTA and cartridge loadings. In general low output MC cartriges specify a low impedance loading. You may prefer the sound at a higher impedance which generally gives more air but is less focused in the bass. If your sound is bright at the lower impedance loading you should definitely try to adjust the VTA by lowering the rear of the arm until the sound is "focused". If you go to far the bass will become "wooly". Then go back and raise the impedance setting until you get the sound you like best.
This takes a lot of patience, but the results are rewarding.
Okay... I messed with the VTA. Quite frankly I don't know if it went up or down but the bass is better, the highs are nice and the mids are much more accurate. This is what I was trying to acheive.

Thanks all who helped!

This brings me to the phono stage question regarding various loadings. I guess from what I've read, its best to match the output of the cartridge however it is difficult to find a better phono pre (the kind without the toggle switches) that is at 100 Ohms. The Linn Linto is at 150, the LAMM is at 40, Jadis is at 47K, The Joule's are at 47K, the Lukaschek is at 22K.... I cannot find one at 100 Ohms What gives?
As Oldears notes, fixed 47k is usual for MM phonos. For Mc carts, most phonos allow a variety of settings; mine goes from 25-1000. I would very surprised if Jadis et alia don't allow variable settings nowadays -- even if changes are not user friendly (i.e. involve finicking with solder). I assume you've checked that those loadings refer to low-output MC phonos... Cheers
Gregm, I was looking at getting a Jadis and the guy told me, "It is fixed at 47K. Every modern moving coil is optimized for 47K". That was VERY confusing for me and the catalyst which sent me into my latest fervor regarding my analog rig.

All my research tells me that his comment, "Every modern moving coil is optimized for 47K" is asinine. Perhaps he blundered by saying moving coil vs. moving magnet but given we were discussing the DPMC I presumed he knew what he was talking about. The name DP"MC", kind of implies its for MC cartridges but I could perhaps be wrong.
Bwhite, many of the better MC phono stages have plug-in resistors to match the value that you want to load your cartridge to. This is the type of phono stage to get. Selector switches are ok, if they have the right values for you, but as you found out, they often do not. The best ones also allow capacitance loading, which is another can of worms, but can give even better results if you are willing to mess with it. My MFA Magus preamp has a plug built into the back for plug-in resistors, for cartridge loading. Do some more research on different brands of phono sections, and you will find some that have the plug-in resistor feature.

The guy who told you that all MC carts are designed to work into 47k was either confused, or doesn't know what he's talking about.
I have found that the recommended loading can be pretty useless as a guide to what sounds best. It seems to me you would probably prefer a loading somewhat higher than the low 100 ohm setting, but not essentially unloaded like 47k ohms. The correct setting could prove to be in somewhere in the low to mid hundreds, or even up to a couple of thousand ohms, depending on both the cart and the rest of the system. Since you don't have the ability right now to easily test many values in order to find your favorite before wielding the soldering iron on your Black Cube (unless it has socketed resistors - I'm not familiar with it), you might want to try giving your cart's importer a call and see what they recommend using. BTW, if you do install custom value loading resistors, be sure to look into getting premium quality replacements - this might run you $20 instead of $2, but the improvement is well worth the small difference.
Bwhite I, too, think that the sales rep was thinking of MM or hi-output MC. Zaike gives good advice on choosing quality resistors & Twl's tip on capacitance loading is a valuable trick... But do focus on resistance for now!
Aah, TWL suggests raising the VTA, Oldears suggests lowering, some think 47K and other lower. Is there any better illustration of why so few new converts are being brought into the analog fold and why so many have defected to the silver disc?
Viridian - analog rigs seem to be a wee-bit tweeky to set up correctly but the sound is for the most part, exactly what I always hoped digital could be. And it was easy to get to that level vs. spending 10's of thousands on digital + associated cables and stuff. Analog is so good that I haven't listened to a single CD since I got my TT.

However, as much as I like the TT and vinyl, I am leaning toward using my digital system for classical. I am a bit frustrated with the quality of classical recordings (at least those that I've listened to on vinyl, they just don't seem to be as fulfilling). The crackle/pop at lower levels is very, very distracting for this genre - not to mention the "short" play time of a single side of an LP.

As I am finding out, it seems that many newer LPs from the late 80's through current were recorded digitally. The advantages of an analog version of a digital recording are debatable. Also during this time period, it seems the vinyl was a bit "rough-cut" and cheezy. So this may be a time period where I prefer digital as well.

Pre 80's music (all the way back), and some early 80's analog recordings are outrageously good sounding. So for this era, I will certainly use my analog rig.
Viridian, we can't help unless we post what we think, right? There are conflicting posts on just about every thread on the forum, including the Digital page. It's not just analog that is suffering from this problem of conflicting answers.

Bwhite, at least with the TT, you CAN adjust something to change the sound. With a CD player all you can do is buy a new one.
Agree with Twl, except I wouldn't even call 'conflicting' answers a 'problem' (unless they're posted by the same individual!). If there was no sincere difference of opinion or experience to be found in this hobby, we wouldn't really need this forum, would we? Vive la variety! :-)
Shelter says the loading for the 901 should be less than 100 Ohm, with different phonos I had good experience with 100, 150 and 1000 Ohm so it depends on the phono amps. VTA for the 901 is also important that different settings produce different presentation, I ended up slightly tail up. I have heard other users spent up to 3 months in getting the right VTA. I don't think tracking force is as critical, I am tracking at 1.65g.
I have had various vintage of LP12s over the last 20 years, I feel it is paramount to have proper support for the LP12, the best result I had is a Sicomin platform and I think other light and rigid platforms will also do.
The Coph Nia is factory set at 100 ohms, but, pop the cover off and there are a series of dip switches that allow adjustment from 40 to 47k Ohms. I found that 100 Ohms is the "best" setting for my Dynavector 17 D-II, Karat. Any higher and the upper registers become progressively more "pinched."
Consttraveler - how is the Coph Nia??? I've read a bit about them and I'm curious to know what you've compared it to. Care to share?

I am reservedly happy with the Coph Nia. I have not had it very long (maybe 40 hrs. play time), and I am relatively new to analog. I just got back into LP's about a year ago after a layoff of about 25 years, so a review by me probably will not be very useful.

However since you asked, the Coph Nia is replacing a Rega Fono MC unit (at about 3 times the price) that sounded very nice, but I felt I was missing some detail and extension, as well as volume. The Coph provides much more extension, better bass, and a bit more gain.

I am only reservedly happy, because I was expecting more gain, and still feel I want/need it. My cartridge is a low output MC (Dynavector 17D-II, 0.23mv) that provides the signal to the Coph, from there through a Mark Levinson 380S pre, to the amp. With such low signal strength, the 380S must be adjusted to very high volume to get the music to a good listening level. As a result, I am getting speaker noise (actually, Preamp Noise) along with the music, which bothers me on quiet passages. By the way, I have tried several amps and the noise stays, also when in digital mode, I can duplicate the noise but I have to turn the 380S up to a nose bleed, paint peel, level.

Back to the Coph Nia; I like it, it is very musical and very detailed (which I like). I have not been able to identify a "signiture" that it imparts, that is, I don't hear the Coph. I was not able to audition other units so I purchased it after reading all the reviews I could get my hands on, and after talking with a couple of dealers who's opinion I trust. I guess, I can sum up my impression by saying that I still trust the opinion of the dealers.

If there are any other questions I can reply to, I will be happy to answer to the extent of my knowledge/experience.

This is one of those "holy grail" issues that has no set answer; it is all so personal!

My Goldring Excel VX is rated at 100 ohm and is a low- to medium-output MC cartridge (0.5mv) Using an EAR/Yoshino 834P tube phono stage works very, although I don't know its specs.

However, the Blue Circle solid state BC23 phono stage, like many other makes, has DIP switches and adjustable gain that can make a huge sonic difference. Setting the BC23 to anything other than 100 ohm is a waste. For one thing, I have to turn up the volume on my amp to almost 2 o'clock! Setting it to 100 ohm sounds better. Adding the extra 10pF DIP switch clears things up a little more. Then, setting the toggle switches to 61db results in magic!

With these setting, the results are wonderful. I must say, however, that although I'm happier with the BC than with the EAR, both are very fine for under $1000. With the BC, one must remove the cover and set the switches (no big deal), whereas the EAR simply has a button on the rear that changes from MC to MM output (much easier, but does not allow for tweaking).
Consttraveler, with a cart output so low as .23mv, many (most?) phono preamps will need the assistance of a phono step-up transformer to provide a sufficient amount of quiet gain, and that sounds to be the case with your system.

That's what I was afraid of, and where my next purchase will be. Do you (or anyone else) have a recommendation? I've been reading about the EAR MC3, which seems to be the likely candidate.

Ortofon sells a step up transformer (it's in their website). Pretty beefy unit and it can be purchased through Hong Kong for less than $500. You'll save so much it will be worth to send it to vapor cryo treatment...
You have to always properly optimize input load according to the type of cartridge (MM/MC) or you either baffle the signal too little or too much. You should'n forget to add a interconnect capacitance and deduct this value on the phono stage settings if you want to have it optimized accurately. The standard setting are 47k/220pF for MM and 100ohm for MC. MC type cartridge gives less output voltage and due to low resistance you don't need to use any capacitor, it's recommended to bypass the cap. if possible. A lot of manufactures don't allow you to change all values, they allow you to choose between MC or MM type of load, and they rely on luck that it's gonna be suitable. It will be suitable in most cases, but if you have some unusual or special type of cartridge, you will probably loose the low or high sound edge and that's the problem if you can not set it accurately.
Guys, unfortunately, I have to disagree with step up transformers used in phono preamp. Yes, it's possible to use them but it won't give you the best resolution. There are semiconductors those are suitable for this kind of applications (to amplify low level signals),and believe or not they do their job much better. Using of step up transformers in phono stage (nowadays) is a marketing trick or lack of knowledge when someone tells you that it's gonna give you better sound.
Mamba, I don't think you are entirely correct about the step up transformer thing. We don't like semiconductors in our signal paths. About the lack of knowledge part, maybe you should discuss this with Kondo, who specifies only step up transformers be used in his pickup systems. I personally use a step up transformer with a tube phono section, and it gives me better sound than any "semiconductor" would hope to give.
Consttraveler - Sorry, I'm not going to be of much help for specific recommendations, as I've never owned a super-low output MC that required a transformer (though I have read that Wright Sound offers a decent one for about $350). Maybe do a forum search on the topic 'phono step-up transformer' or such. The other option would be to just switch to a very high-gain capable phonostage that doesn't need transformer assistance (or has one built-in) to provide adequate gain (probably >66dB I should think), rather than keeping the one you own and also investing in a separate trannie, but I can't suggest which approach would potentially give better sound or be more cost effective for you (not forgetting the extra set of IC's you'll need for the stand-alone option). Best of luck, Z.
Consttraveler, if you can find a used Cotter Mk2, that would be your best bet, but they are sometimes too expensive due to demand. Alternatives are a Peerless, or Jensen, or more expensive ones like Audio Note, Shelter, or ET SU-1. Or a head amp like the Denon, etc. Mimimum will be about $100, if you are lucky. The SU-1 is about $3.5k used.
I just bought a Denon 103R cartridge from Audiocubes out of Japan, I opened the box and read the instructions included with the cartidge, it strangely read among other things the LOADING WAS 47K, uh, what, this is supposedly a very low output Moving Coil cartridge. I have not emailed them yet to bring this to their attention.

I proceeded to adjust the Jeff Rowland Concentra II to 100 ohms as well hook up the Denon step up tranformer I got from Audiocubes as well.

This all done and the cartridge installed, and tweaked for about an hour or so and surprise surprise, not bad, open airy. my table is light in the bass anyway, its a tweaked Well Tempered.
Tomorrow night I will take out the Denon transformer then listen and see what happens. Any pointer's would be extremely helpful.
it strangely read among other things the LOADING WAS 47K
Have you checked the shunt capacitance? Is it 100mF? Don't sweat, the 47k could be OK. Try it, and lower and check out how the hi frequencies sound.