While I am not familiar with the Rothwell attenuators, Rothwell is a good company and since you already have them on order you certainly should give them a try. They can't hurt anything and you should give them a listen and make up your own mind. If the sound is OK to you then your problem is resolved. If not then a low output MC cartridge is your best alternative and of course there are a lot of options there. Ortofon just introduced a new low priced line that are getting good reviews that are worth considering. Audio Technica also offer MC that are excellent that are well under the price you have been quoted.
Do I need a MC cartridge now? Or an attenuator?
Hello folks,
I am turning to this network of smart folks for help in an area i don't know too much about.
I have a MoFi Electronics StudioDeck+ turntable, and a MoFi Electronics UltraTracker MM Phono Cartridge. Previously, this MM cartridge output went to my McIntosh MA252 integrated amplifier using its phono input. The range of volume was fine and I could play it at a low volume - it sounded terrific.
I now have set up a mostly Laiv Harmony system and the signal goes to the Laiv L-Ext for phonographs, and on through to the Laiv HP2A preamplifier and then to the Laiv GaNM Monoblocks.
The sound volume control on the HP2A ranges down to minus 59 dB and then it shows an infinity sign and there is no sound output. However, the sound coming out at -59 dB is still rather loud. There is no volume control on the monoblocks; the HP2A does that entirely. In discussions with Laiv Harmony help (which is really responsive and helpful) has provided me with a couple of options.
He wrote: "The MoFi UltraTracker is a high-output MM cartridge (~3.5 mV), while the LExt Phono is a dedicated MC phono stage with a fixed 70 dB of gain — optimized for low-output MC cartridges (around 0.3 mV).
"Using them together results in excessive gain — similar to feeding a line-level signal into a mic preamp — which causes the signal to be overly loud, distorted, or clipped. This is likely the issue you're experiencing.
"One option is to replace the current MM cartridge with a compatible low-output MC cartridge. You can also reach out to MoFi for recommendations on suitable MC alternatives that pair well with your setup."
A second alternative we discussed was to place a signal attenuator between the HP2A and the monoblocks - I have ordered Rothwell balanced in-line attenuators (minus 10dB) for about £71. I figured that can't hurt and is affordable enough to try.
Replacing my ultratracker with a moving coil from them is an about $1,000-$1,500 experiment.
My questions:
1) Are Rothwell attenuators OK to place in the line? Possible effect on the sound?
2) I am pretty pleased with my TT - I think it is very underestimated for its quality, out performing its price point in general. But would an UltraGold MC Phono cartridge for $1500 be wasted on that turntable? I am just not well enough versed in the differencs between their top TT and the one I have, to know if this makes sense.
Tim
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I think one of the issues you are going to encounter is proper cart loading, using the MC input on a MM cart is not going to give the proper loading the cart wants to see. 47kohm is normal for MM but MC rarely exceeds 1kohm. If the Rothwell allows for this then you’re fine, but if not you are not going to get an optimized sound from the MM cart into a MC stage. You may be better to buy an inexpensive phono stage (MM) for now until you can upgrade to an MC cart. Even something like a Denon 301 MC is an option untill you can affored beter. |
This sounds to me like the old (Henny Youngman) joke about the tailor who made one leg of your pants too long. So when you complain, he tells you to "limp", in order to make the pants appear to fit. If you are only a very casual listener who is not that interested in ultimate sound quality, then sure, the Rothwell ought to work. But it is a kludge that will compromise your sound quality no matter how good it is. Also, I have to wonder about cartridge loading. If you are using an MM into an MC input, it not only affords far too much phono gain but also you may be loading the cartridge excessively. (High "load" here means that the input impedance of your phono stage is too low in impedance which here is another word for resistance.). There is no way to get around that, and that will really compromise the sound quality from any MM cartridge. The standard load for an MM cartridge is 47,000 ohms (47K ohms). Typical load for an MC cartridge is 100 to 1000 ohms. There is no easy way to fix that with your phono stage. Furthermore, because your MM cartridge has a much higher signal voltage output than any low output MC cartridge, your cartridge is undoubtedly also overloading the phono input, which causes further distortion. It's a mismatch any way you look at it. So you need either an MM phono stage or a new LOMC cartridge. The Rothwell will only solve the gain problem. |
I think trying to make that combination of cartridge and phono preamp work well together is going to be an exercise in kludgery that will result in you not getting the best out of either component. You’re likely to get better sound by replacing either with a properly matched component, even if it’s a budget model. |
The Laiv Harmony HP2A, using their L-Ext (phono input) allows me to change the input impedance via their "selectable input impedance" at 22Ω / 47Ω / 100Ω / 470Ω / 1kΩ / 47kΩ. I am currently set up at 47kΩ (which matches the TT MM output) but the gain cannot be changed. I have reached out to MoFi for help in determining if their MC cartridge will work with their Studiodeck+ turntable - I suspect it will. I think I then select the 100Ω input impedance, as the MoFi site tells me that their two replacement cartridges specs are "Recommended Load: ≥ 100 Ohm" My phono experience with this TT/MM stylus into the McIntosh MA252 (into either of my speakers) has sounded superb. I cannot discern too much distortion in the new setup (though I suspect there is) - just too high a dB volume. It does not have a MC phono input however - I suppose I could go with their MA12000 which has one of each phono inputs. I think I could put some other form of phono pre between the TT and the L-Ext but that seems like kludgery to me as well. I will likely get the better MoFi MC stylus. I have slacked off in overspending lately anyway, and I can't have my wife getting used to that!
Tim |
Attenuators can't fix your problem. Its just that simple. You need to understand the difference between gain and volume. You have a gain issue, and that means you have to fix the problem with gain. The high output of your phono cart is overdriving the input on your phono preamp. If you use volume/attenuators, the distortion will still be there no matter how much you lower the volume. Anything involving gain is on the input of a component, and anything involving volume/attenuation is always on the output of a component. They are 2 separate things. You can only damage the signal with excess gain. Volume/attenuation can't alter or damage the signal in any way (aside from whatever slight coloration that may happen when the signal passes through the it). Its like having a record with a lot of scratches. If you lower the volume, the scratches are still there. You need to get a different phono pre or a different cartridge. Its your only option. As always, sound quality is subjective. That said, a LOMC cart should make a significant difference in sound quality. And its the type of difference I think you'll be very happy with. I can't make any guarantees, but I think there's a far greater chance you will like a new cart, than not like it.
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MM phono preamps aren’t meant to run LO MC with it, you will need a SUT to use that type of cartridge into a MM phono preamp. You should invest in a LO MC and there are plenty of options listed in the previous reply’s that are less than the MoFI option. Good luck and if truly want to be in the vinyl world with LO MC’s than do it the right way and invest in a cartridge. |
Thanks to all for this helpful advice. Seems that the only path forward is to bite the bullet and get a new MC cartridge on my current turntable, change the impedence setting on the L-Ext for my preamp to 100Ω, and all shall be good. I suppose someday I will find something to do with the attenuators I have coming to me! Researching which might pair well with my current setup will require some fun research. Tim |
Most manufacturers will recommend a range of input impedance. For example, “>100ohms”. Such a LOMC cartridge will also drive any impedance up to and including 47K ohms. I don’t agree at all that an LOMC cartridge is categorically superior to any MM cartridge. In fact, on a bang for buck scale, I prefer MM or MI vs LOMC. So don’t feel that you must dump your MM just to make your phono stage happy. Consider also an inexpensive MM phono stage. |
The Laiv Harmony L-Ext phono extender for their HP2A preamplifier is proprietary in design with a "LE-LINK" cable providing the power to the extender and the pathway for the signal to the preamp in one cable. I suppose I could place a MM pre in line from the TT to the L-Ext, but that seems less helpful than changing the cartridge itself. I will explore more affordable options. I am waiting to hear back from MoFi, but i strongly suspect they will recommend using their stylus. I can also check with Definitive Stereo in Seattle (from whom I bought it all) to see what they recommend. |
The L-Ext is a Moving Coil phono preamp with 70db of amplification according to the Laiv site. You need to change either the phono preamp to MM with approximately 40db amplification for your 3.5mV cartridge (not using the L-Ext at all) or acquire a low voltage MC cartridge compatible with the 70db amplification of the L-Ext. If you were to keep your current cartridge a separate Moving Magnent phono preamp would be needed that plugged directly into the HP2A Laiv preamp not using the L-Ext in any way. If you want to use the L-Ext phono preamp you purchased then you need a low output Moving Coil cartridge. The 70db amplification will handle most cartridges from 0.2mV to 0.5mV. |
Thanks again to all. To Glenn, I am not at all "stuck" - I came here for ideas and recommendations. The recommendations I have rceived so far (here and elsewhere) are to check out Hana and Dynavector models. as well as the low priced lines Bill mentioned (from Ortofan and the Audio Technica) and the Denon 301 Glenn mentioned. I was not too concerned about the absolute cost, but more about the issue of possibly buying a cartridge that was too much better than the turntable that any possible benefits from its quality would be lost due to limitations of the TT itself. MoFi did finally get back to me and suggested that the UltraGold MC Phono cartridge might be too much for my turntable but that the StudioSilver would be a good fit. He who sold and set up the turntable for me, said that the Hana SL MKii was a "killer bang for the buck", at $850. Since he will install and calibrate the table and weight for me if I buy it from them, I think I shall go that route. https://www.hanacartridges. Tim |
