Cartridge incompatibility, Soundsmith and Luxman

The gain should be ok, but the load is way off and you can clearly hear it. The highs are rolled off and I need to crank up the volume to be acceptable level.

@audiojan 

Are you using the 'MC' setting on the front panel of the Luxman?

but I'm not going to add SUT with additional cables and all that complexity.

It's the best option and makes your system future proof. It's not that complex and you can stash the preamp anywhere. 

Just get a Puffin and don't look back. It is adjustable to any and all carts.

@atmasphere Yes, MC setting. The load is not variable however, I think this is what's causing the issue.

@russ69 Which then means yet another piece of equipment, another set of phono cables (Cardas Clear Beyond sounds amazing, but they're not inexpensive...). Completely defeats the purpose of going with an integrated to simplify things...

Yes, MC setting. The load is not variable however, I think this is what's causing the issue.

Based on all I've read, I think you are correct.

Dea @audiojan  :  I think that before you pull the trigger for a different cartridge put in contact with Luxman and ask if exist a posibility that they can change the impedance to 400-500 ohms. You can try and maybe find out the solution.

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

I can't recommend a particular cartridge but the right outboard phono preamp will give you the adjustments you need to keep your current cartridge or any future cartridge. Perhaps a high output MC will work better for you. Personally I would not have a low output MC without an outboard phono preamp. Talk to your dealer or the manufacturer about matching a cartridge to your amp. 

Per Raul, get some in-line RCA resistors to try.

I looked at the specs for both the Zephyr Star and the Luxman 590. There is no obvious reason why this pairing cannot be made to work well. First, I don’t understand quite why SoundSmith recommends a 470 ohm load for this cartridge. It’s internal DC resistance is only 10 ohms, so in theory it should be able to drive the 100-ohm load of the Luxman MC input stage. The problem might be that this is not actually an MC cartridge; therefore it has an inductance much higher than that of a typical MC. (About 100X higher, if a typical LOMC cartridge has an inductance of about 25uH. Inductance of Zephyr is 2.75mH.) Maybe Atma can comment on how that would be an impediment, but perhaps that is also why SS recommends a 470 ohm load. We also know from specs that the output of the Zephyr (0.4mV) is not too low for the MC inputs to handle, because Luxman tells us that the MC gain (NOT stated on the Luxman website but can be calculated) is adequate for a cartridge with an 0.3mV output. Before doing the research, I had assumed that the MC gain of the Luxman is derived from using a SUT placed ahead of the MM stage, but the website, while very lacking in phono-related info, suggests that MC gain is done by an active stage. For one thing, in their many photos, I see nothing on the PCBs that looks like a SUT. OK, so if there is no SUT, then there is no problem to replace the 100 ohm load resistor with a 470 ohm load resistor. Any skilled technician can do that. I would do that way before throwing either baby out with the bathwater. I am a big fan of MI or "fixed coil" cartridges.

Oh, by the way, this problem cannot be fixed by paralleling an external resistor with the 100-ohm input resistor, net parallel resistance is always lower than the value of any one resistor in the bundle.  So paralleling an external resistor can only lower the net input resistance, not increase it.

@lewm Greatly appreciate your knowledge and input!!! In theory, it should work, but it's clearly rolled off (quite a bit...). The only logical answer I can see is the mismatch in loading. Gain should indeed be no issue. And I do really love the Zephyr Star, so I want to make it work if at all possible.

It seems like the options are either modify the Luxman or get an SUT... since I can only imagine is going to be pretty close to a wash cost-wise, I might just as well accept that I will need to go down the route of an SUT..

So with that said, any recommendations for a SUT? Don't want to break the bank (let's try to keep it less than $1k used), but sound is much more important than cost, so if that's the path...

Also, no experience with SUT's, I assume I should use phono cables out of it into the MM, but not just "regular" interconnects. Is this assuming correct?

When you use a SUT you should use short, low capacitance cables. Under 1m for sure, ideally 0.5m or as short as you can go. It has to be low capacitance - for example, the Audioquest LP / phono cables, and their Bridges / Falls IC cables are good, but their higher end Elements interconnects are BAD for this. Cardas interconnects typically have extremely low capacitance and are good for this.

I’ve done the 10x SUT thing for a Benz LPS with 0.34mV and 470 ohms MINIMUM recommended load (it seems like it wants a higher number), not too unlike your SS but MC based. Tried a few SUTs, 8x - 10x. It was an OK result, not stellar. I feel like this kind of cart is a tough match to a SUT (all my other carts love a SUT). With the LPS, I got a slightly better result from a Hagerman Piccolo2 which is a JFET headamp that has amazing gain & loading options and only costs $289. But the best result I’ve gotten from the LPS so far is on a Hagerman Trumpet MC, which only costs $1100 new and has an improved balanced Piccolo built in. The MM stage is tube based and (mostly) balanced circuitry. It’s not as quiet and refined as my VAC phono stage (which is SUT based), and the chassis & wall wart are clearly built to its low price point, but for that tough-match LPS it gave a better result than the ~$16K of phono stage & SUT.

The resistor mod to you Luxman sounds like it might be a great idea though.

Dear @audiojan : " need to go down the route of an SUT. "

Well, due to what you have in the Luxman that’s the bad move ( is up to you. ) that degrades the higher the cartridge signal against a " simple " internal modification below Luxman advise. Maybe I have to say SUT is the wrong way to go for the quality level of the cartridge you own, can’t benefit you in anyway but the other way around but as I said: is up to you.

" there is no problem to replace the 100 ohm load resistor with a 470 ohm load resistor. Any skilled technician can do that. I would do that way before throwing either baby out with the bathwater.  "

R.

Purchasing I rather inexpensive dedicated capacitance meter 

with zeroing lead capability can be quite handy for confirming

cable suitability.

@audiojan You might want to take a look at this website

http://hagtech.com/loading

Since your cartridge is a low output, scroll down to where the low output calculator is.

I dropped the values of your cartridge (2.75mH) and input load (0.1KOhms or 100 Ohms) and it spits out a rolloff value of only about 5KHz. That might sound rolled off 🙂

So you either need a different cartridge or modify the input load to be something higher. I put in the the 470 Ohm value as recommended and the rolloff changes to 27KHz!

So I think we found the problem.

@atmasphere Greatly appreciate it! So at least I'm not going mad (although my wife would disagree with that statement...).

It seems that every other solution but to replace the cartridge has quite a bit of drawback... going to an SUT adds complexity and additional cost; modifying the Luxman limits my ability to use something different in the future; standalone phono preamp adds more cost, more cables, more complexity.

Easiest solution seems to be a different cartridge.

The fact that the sound seems rolled off in the treble to you suggested that the relatively high inductance of the cartridge, compared to that of a typical LOMC, is causing a loading issue, as Atma-sphere just showed us. This was mentioned in my previous analysis as a possibility. SS do recommend a higher than minimum load resistance, and now we have confirmatory evidence that this is to compensate for the inductance. But I repeat, all you have to do is open the chassis and change the phono load resistors to any value equal to or above 470 ohms. I believe it would be a mistake (or at least an unnecessary expense) to go to a SUT, but if you do, be sure to consult Peter Ledermann who made the cartridge and probably has a deep understanding of how to match a SUT to it. Of course, then you use the MM inputs. I don’t understand why changing the phono load resistors, the simplest solution imaginable, incurs any more of a limitation in the future than the 100-ohm resistors constitute in the here and now. Worst case scenario: you switch back to 100 ohms for some future hypothetical cartridge. There really is NO cartridge that requires a 100-ohm load, actually. A cartridge that works well with a 100 ohm load will also work well with a 470 ohm load, but the reverse is not the case, as you now know. Good luck.

Please note CHANGING the internal resistors does NOT inhibit you in the least from other cartridges in future; it is totally the way to go (assuming the simple  change works for this circuit).  If you go to 470, or 1000 Ohms, you can ALWAYS use an external metal short RCA Y adapter ($12) with two female/one male RCA and insert RCA plugs with resistors soldered inside. Parallel resistors will bring it down to what ever you  need in future.  (product of values divided by sum of values). We have seen this ONE load value in this model before, and it is very short sighted in my NSHO.  The proper way is to have 1000 -2000 internal and at LEAST some open RCA females jacks on the rear apron, allowing you to put loading plugs in at will. If someone who knows circuitry can verify this circuit allows the 100 ohm resistors to be changed, let him know.....OR send ME the schematic. That is the lowest cost way to make this unit flexible like almost all models of MC preamp designs. Our high gain MCP-2 phono preamp ($1199) has a variable control to go from 10 Ohms to 5K Ohms. Another option. 

Peter Ledermann/Soundsmith

Great post! Thanks.

Unfortunately the specifications on the phono section are sparse so it is unclear what the input configuration is.  The fixed 100Ω value is an odd choice unless there is an internal SUT for the MC input.  To further confuse things the E-250 phono has an internal SUT and lists gains of MM: 38dB, MC HIGH: 57dB, MC LOW: 66dB and input impedances of MM: 34kΩ/47kΩ/56kΩ/100kΩ(switch selection) MC HIGH: 40Ω, MC LOW: 2.5Ω.   When I do the math the numbers do not add up without some overly complex switching and loading arrangement.   The MC high setting it adds 28dB of gain which suggests a 1:26 step up ratio.  That means that the impedance ratio is 1:676 so if the 2.5Ω value is indeed the actual value then the secondary of the SUT would need to be terminated with 1700Ω which is highly unlikely.  Looking at it from the other direction and assuming the 1:26 and a 47kΩ load the input impedance would be 70Ω.  If you work out the same numbers for the MC Low they are equally confusing.  This leads me to believe that 2.5Ω and 40Ω numbers are not the actual input impedance but rather the suggested cartridge impedance which is how many Japanese companies specify phono inputs.  The E-500 lists that it uses 4 SUT's rather than the tapped unit in the E-250.  

Since the specifications of the phono section of your integrated do not list the MM and MC gain, it seems the only way to find out for sure is to measure the DCR of the input of the phono and see what you get.  If it is 100Ω then that is likely your actual impedance value and it may be possible to change that to a higher value.  If it is around 1Ω then it likely has a internal SUT with a step of ratio of ~1:20.  My guess is it is the later at which point while increasing the load value is possible it may lead to less than desirable results.  

dave

Dave, the Luxman website page on the 590ax2 ( not the 250 or 500) indeed gives very little useful information regarding the phono section, but the many photos of the many PCBs reveal no evidence of a SUT anywhere. Furthermore the unit seems built with discrete components rather than op amps and SMDs. So I am guessing it would be easy to remove the putative 100R load resistors and replace them with 470R or higher. I’d use 1000R or even higher, unless PL has a preference for exactly 470R. I knew that Luxman use a SUT in their flagship 500 phono stage, so my a priori expectation was to find there is a SUT also in the OP’s unit, but that doesn’t seem to be the case so far as I can tell from the scant information.

@intactaudio ​​​​@lewm Thanks guys. The information is indeed very limited... all the website gives is this:

PHONO (MM): 2.5mV/47kΩ
PHONO (MC): 0.3mV/100Ω

Basically no information expect that the loading for the MC is very low, which explains why the Soundsmith Zephyr Star MIMC is not very happy. The sound is really wide and you can clearly place each performer in their space, but there's no highs at all.

I'm not much of an DIY guy and the prospect of opening up the L-590AXII to replace a resistor is not something I feel comfortable with. I sold all the separates to simplify things and having to modifying a new amp isn't very appealing. I think changing the cartridge is the easiest and best solution.

I also have an MIMC Star, and have found the loading of 1,000k works best for me (wish I had the option of around 850 though, and 470 lacked a bit of 'sparkle'), and my gain is set at 60 dB. My setting on my Hagerman Trumpet MC provide a variety of setting for MC, and these are what I have settled at. 

Provided as an example from another MIMC user.

Dear @audiojan  :   I already told you that before ant thing else you can contact directly to Luxman to have a better know about that 100 ohms resistor and if  it can changed by a technician . 

You don't have to distress at all before doing that and after Luxman answer you can now what to do.

Normally the change of that resistor could be simple for a good technician, don't have to do it by your self.

You like the SS quality level performance, well at least make the intent by email to Luxman for know if you can follow enjoying the cartridge in the future or not.

Sorry @lewm  but you made a very high bad " noise " here with the SUT when the unit has no SUT . You gave an explanation of MC cartridge and SUT impedance and the like with out any necessity to do it. Sorry but no sense of what you posted down there about. Even in the same post you said the need of a good technician to change the resistor. Makes sense to you? because  the OP does not needs that kind of mix-up/confusion for something that's simple to solve even that till today the OP just does not email Luxman , obviously is up to him. Never mind.

R.

I have no idea what you’re talking about. I never advocated a SUT to solve this particular problem. I really think you ought to reread whatever previous post of mine has got you confused, and maybe then you will understand better what I was trying to say. Anyway, I think you would agree that a clear pathway to a solution has been agreed-upon by just about everyone who has commented in the past 48 hours. So there really is no need to bring up whatever it is you don’t like about me or my previous comment.

If you cannot find a technician to switch out the built in loading resistor (assuming this IS the issue), and you are against using an external SUT feeding the MM input, you will be in the still troublesome spot of finding a cartridge that works.  Do you have a dealer that is willing to allow you to audition cartridges or allow you to bring in your integrated amplifier to see if sounds okay with particular cartridges the dealer has to offer? 

I would hate to hazard a guess as to which cartridges might be compatible, not only with your integrated, but with the rest of your system and your particular taste.  The 100 ohm fixed load suggests a cartridge with a low impedance of the coils in the cartridge itself-at most an impedance of 10 ohms, and much lower would be better still. 

Most low/medium output cartridges with a typical 0.4mv - 0.6mV output and ~ 5 - 10 ohms coils should work well with that Luxman MC phono. The carts like the SS Zephyr and (I'm guessing) Benz LPS / Ruby / SLR are the outliers that have any trouble. There are a number of MC phono stages that only offer a 100 ohm load, since it's a very typical value in this range. 

@lewm is right, he never advocated a SUT here. I don't think anyone was suggesting that, except OP. I touched on cable requirements for a SUT, but to be clear I definitely wouldn't try to throw a SUT on this thing (the JFET headamp is another deal entirely). 

It was me who pondered that there might be a SUT inside not Lew. I realize that many MC inputs offer a 100Ω option but I found 100Ω as the only option to be a bit odd particularly for something likely to be paired with a 40Ω denon 103.  Add to this that there are many who insist that a MC cartridge should be loaded at 47kΩ and the single 100Ω option seems like a very limiting choice for any active circuit but a perfectly logical one for an internal SUT.

dave

Cardas Clear Beyond sounds amazing, but they're not inexpensive...

Cut the cables in half, add 2x extra terminals and put the SUT in between?

There seems to be one easy thing to do and many crazy solutions. Umm.....please don't take the top off and modify or tweak your amp. There are a zillion excellent cartridges. Buy the one that fits the phono stage and have a great time.

Changing the phono load resistors is neither a mod nor a tweak in my book. But why do you hold the opinion it shouldn’t be done?

Finding that load resister is not hard. It will be right off the phono input @retipper has already joined this conversation and is obviously loath to give himself business by making this suggestion but, I would suggest acting as an obvious shill for Soundsmith that you send him your amp and he will be happy to make that modification and sell you some loading plugs for a very reasonable cost.

How does the Luxman sound when playing other sources, such as CD player or streamer, as compared to your prior rig?  It would help to know if the basic sound of the Luxman is to your liking.  If you like the sound, then it is the phono stage that is an issue (either not very good, or incompatible with your particular cartridge or other aspects of your set up).  How much have you experimented with other aspects of your phono setup--have you played around with VTA, for example?  A higher VTA (pivot of tonearm elevated more) will tend to shift the tonal balance more toward the high end.

Larry, If you read the responses, you will know that the problem is almost certainly the fact that the fixed value of the load resistance at the phono inputs of the Luxman is 100 ohms.  The Zephyr is a rare low output MI type, which has high inductance compared to a typical LOMC type.  Thus it needs a higher value load resistor.  The high inductance cartridge into a 100 ohm load would be expected to exhibit all the characteristics that the OP is not happy with, and justifiably so. That issue would have to be dealt with before one could fairly evaluate other elements in this system.

First, I'm not going to open up the amp and modify it. By the time I do that, I might just as well spend the money to get a different cartridge. Yes, I do like the Zephyr, but there are other good ones out there.

Larry, yes, I do love the sound of the 590axii. It's ONLY the phono that sounds extremely dark. Switching to a different cartridge (I have a spare MM cartridge) opens up the highs to be just like my streamer (or CD for that matter). It's a compatibility issue between the fixed load and the cartridge.

I have read the responses, and in fact, I suggested a cartridge with a source impedance below 10 ohms, in acknowledgment that that might be a way to avoid the incompatibility problem.  I just wanted to be sure that the OP did not get off on the wrong track.

I hesitate to offer specific recommendations because cartridge preference and system matching is so personal.  If I were to hazard a guess, a Lyra cartridge might be a good match--most have quite extended highs, a very clear sound, and have a fairly low source impedance that would be compatible with the 100 ohm loading of the phono stage.  I own an old Lyra Titan and I like its sound, although these days I run a Transfiguration Orpheus L.  

Larry, The low output Zephyr already has a low internal DCR of 10 ohms.  That's not the problem.  The problem is its inductance, which, at 2.5mH, is about mid way between a typical LOMC (about 50 microhenries) and a typical MM (500 millihenries, or about 10,000X more than the LOMC).  If the Luxman was mine, it would have been "modified" last week. I don't really view this as a modification in the usual sense that we use it, because the change does not alter the circuit or alter ("upgrade") the parts content.  I'm envious of your Orpheus, BTW.

audiojan, I realize the die is cast, but to say you "might as well spend the money to get a different cartridge" indicates money is not an object. Because changing the resistor, even if you must hire someone else with the expertise to do it, is bound to be the less expensive alternative.  Anyway, your problem is solved one way or the other. 

Yes, I agree completely.  I made the recommendation for low impedance cartridge because I thought the OP is set on finding a MC replacement for the Zephyr and I was trying to suggest staying with low impedance cartridges to avoid the same sort of loading issues.  
 

That's for sure. If he wants to let the tail (the 100 ohm resistors) wag the dog, then he must acquire a LOMC with typical LOMC inductance.  But also gain must be high enough to work well with the inherent gain of the MC section (plus the linestage gain) of that Luxman. (I don't know what that is in db but evidently it was not a problem with the 0.3mV output of the Zephyr.)

Any good technician should be able to unsolder the old resistor and install the new resistor for under 100 bucks easily. I don't get where the OP thinks it's a 1000 dollar mod, sounds like someone was blowing smoke up his arse.

BillWojo

@billwojo where do you get $1000 from?! By the time I sell the cartridge I have and get a different one, it’s pretty much a wash.

I think am guessing that the $1,000 comes from the amount you are willing to spend on a SUT, such that paying for a modification would have to be at or above that amount to be out of the running as an alternative.  Most repair places will charge for the modification by the hour, with one hour at a minimum.  I would expect that one hour’s labor would be charged, and the lowest charge I would guess is $120 per hour.  I would guess $160 per hour is more realistic, so expect $180 as the total cost. For future versatility, you should consider a very high value resistor (meaning LOW loading), with the use of loading plugs to set the particular value for your cartridge; that might mean paying the technician make loading plugs. The ideal approach would be having cheap plugs of various values (e.g. 80, 160, 320, 1,000), and after ascertaining the correct value, I would hard wire a quality resistor between the positive and ground of the back of the input jack (easy to do and safer than desoldering the resistor on a circuit board which may accidentally damage a trace).

The SUT approach would require not only the SUT, but also a decent interconnect (shielded interconnect to minimize noise pickup).  This is an expensive approach and you run some risk of noise problems that are hard to resolve by finding the right location of the SUT, but, I personally like the sound of them.

If the OP wants to sell his Zephyr cartridge, I am interested. Just saying. I don’t advise it, but I’m interested.

Let me repeat the option of buying a $289 Hagerman Piccolo2 as a "stopgap" for use with the Luxman MM stage - it will properly load the SoundSmith, and it will allow OP to discern if he likes the cartridge enough (I mean REALLY likes it) to keep pursuing its options. It can be sold to recoup funds at the end of experiment. Or it might sound good enough to keep in place for a while.

I used one on my Benz LPS and it handily beat SUTs which couldn’t optimally load that cartridge into my VAC Renaissance SE phono stage. No, on even ground its circuitry isn't gonna match the refinement of OP's Luxman or my VAC, but it will beat the crap out of any loading mismatch!

Mine arrived in a week from Hawaii. Like British Mullard tubes, it might not be what you settle on, but it’s a handy addition to your audiophile toolkit.

@audiojan , the finest 1% metal film 47K resistor costs maybe 75 cents. If you lived anywhere near me I would be happy to do it for you. I live in NH. Cost you a bottle of scotch. Lagavulin please.

Lewm would do it for you also but, he would charge you 2 bottles. One for before and one for after the job🤪

i am a buyer for the used Hagerman! lines are forming left and right…..

PL was astute in asking for a schematic BEFORE the Scotch…it may matter what comes just after that oh so easy to change input R..

And Mijo, where are you buying laser trimmed Vishay R for $.75 ? 

The finest Vishay nude resistor costs more like $13. Caddock TF030 costs about $7 each and is nearly as good, maybe indistinguishable. For phono loading, quality counts but the watt requirement is tiny. The change in load resistance is compatible with any MC cartridge. There are no cartridges that “require” 100 ohms. So there’s no need to determine in advance whether one likes the Zephyr. And of course the change is not unreversable anyway, if one ever felt the need.

Audiogon, the land of “ nearly as good “ but with a penchant for Lagavulin. I prefer Talisker, small sliver of ice….

What is right after that input R ? Some dude who invented the cartridge in question seemed…interested in that…

Tomic, your point, other than the notion about personal preference, is lost on me. Can you be more explicit? Do you really not know what comes after the load R? I’m guessing that was rhetorical.