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Moving Magnet on Moving Coil Setting?

spazus

spazus

Active Member
Howdy Folks,

I have a Outlaw 2160 receiver with MM or MC settings on the phono stage and am curious if I would hurt anything by running a MM on the MC setting? Based on the calculator I used, it recommended 38db of gain for my cartridge (.4mv)

From what I understand my phono stage gain settings are 33db (MM) and 48db (MC)

Reason I'm asking, is my phono stage on MM seems too quiet for me. Like to give this a try before shelling out for an adjustable preamp.

Thanks
 
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You won't hurt anything but the cartridge loading will be FAR OFF as the MC expects a low (typically 10-1,000 Ohm) impedance whereas the MM is typically in the range of 47 kOhm, perhaps with variable capacitor loading. What cartridge are you running?
 
spazus said:
Howdy Folks,

I have a Outlaw 2160 receiver with MM or MC settings on the phono stage and am curious if I would hurt anything by running a MM on the MC setting? Based on the calculator I used, it recommended 38db of gain for my cartridge (.4mv)

From what I understand my phono stage gain settings are 33db (MM) and 48db (MC)

Reason I'm asking, is my phono stage on MM seems too quiet for me. Like to give this a try before shelling out for an adjustable preamp.

Thanks
Click to expand...
so you're saying you can't get enough volume even with the volume maxed out? or is it just not as loud as your other sources at the same volume setting.
 
I can get the volume....Just have to turn it up quite a bit more (Approx 15db difference).

Just wanted to know if I could cause damage by trying it at the higher gain setting.....
 
johnfalc said:
You won't hurt anything but the cartridge loading will be FAR OFF as the MC expects a low (typically 10-1,000 Ohm) impedance whereas the MM is typically in the range of 47 kOhm, perhaps with variable capacitor loading. What cartridge are you running?
Click to expand...

Thanks for pointing out the cartridge loading......Had to go read up on it!
 
spazus said:
I can get the volume....Just have to turn it up quite a bit more (Approx 15db difference).

Just wanted to know if I could cause damage by trying it at the higher gain setting.....
Click to expand...

Not hurting anything turning it up, the other sources being louder is quite the norm
 
musichal said:
The cart's output is 4.0 mV, not 0.4. So even ignoring the impedance loading issue, that output is too high for the MC input. That's why it sounds bad.
Click to expand...
That's not quite true. The output is 4mV into a 47k load, but it will be less into a lower impedance. Let's assume for argument's sake that the cartridge has an impedance of 1k (Audio Technica's specs say 485 ohms DC, 3.3k at 1kHz, 550mH inductance), into a 100 ohm is will only give 0.36mV. That means it won't actually be any louder on the mc setting than the mm setting. Of course, the impedance on the mc setting is totally unsuitable for an mm cartridge so it sounds terrible.
 
rothwellaudio said:
That's not quite true. The output is 4mV into a 47k load, but it will be less into a lower impedance. Let's assume for argument's sake that the cartridge has an impedance of 1k (Audio Technica's specs say 485 ohms DC, 3.3k at 1kHz, 550mH inductance), into a 100 ohm is will only give 0.36mV. That means it won't actually be any louder on the mc setting than the mm setting. Of course, the impedance on the mc setting is totally unsuitable for an mm cartridge so it sounds terrible.
Click to expand...

Many years ago I put a MM cart with a very similar output into a MM/MC switchable input. You could switch on the fly. The 4.0mV cart was way, way louder (at least an order of magnitude) - and very highly distorted - when switched to the MC position (which included appropriate loading for each position) Seemed the high output overloaded the input.. My experience differs from yours.

The gear in question was an NAD integrated amp, Signet cartridge, Denon DP-23F TT and ADS speakers.
 
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musichal said:
Many years ago I put a MM cart with a very similar output into a MM/MC switchable input. You could switch on the fly. The 4.0mV cart was way, way louder (at least an order of magnitude) - and very highly distorted - when switched to the MC position (which included appropriate loading for each position) Seemed the high output overloaded the input.. My experience differs from yours.

The gear in question was an NAD integrated amp, Signet cartridge and ADS speakers.
Click to expand...
It would be quite possible to have an mm/mc phonostage that switched the gain but kept the same load impedance, or switched to an impedance much higher than 100 ohms. In that case an mm cartridge on the mc setting would be much louder.
spazus said:
Well....I tried it and nothing blew up...but it sure sounded like crap.
Click to expand...
Did it sound any louder?
 
Whatever. Don't claim to be expert. Did do as explained, and did hear what I described. Don't know how NAD designed their input. IIRC, it offered two or three different loadings for the MC setting (different switch, both back panel beside the phono input). Standard 47K for MM.

In the audio shop where I worked, we jokingly called it the Turbo switch because of the high output level when switched, which we only did twice. Initially, I did it alone, then demonstrated it to another salesman a few minutes later. (Both times for about five seconds since it sounded so bad)

That's when I dubbed it a turbo switch, "Hey, Dave! Check out the turbo switch on this NAD amp!"

By then, a young college student had entered the store, and just had to buy one, based on my remark. I explained the true function several times, pointing out that distortion was high, but he still insisted on buying, so I quit trying to talk him out of it, but did explain the switch again - he claimed he understood.

And that's the rest of the story.
 
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musichal said:
Whatever. Don't claim to be expert. Did do as explained, and did hear what I described. Don't know how NAD designed their input. IIRC, it offered two or three different loadings for the MC setting (different switch, both back panel beside the phono input). Standard 47K for MM.
Click to expand...
Do you remember the model number of the NAD? I'd be interested to look up the specs.
 
rothwellaudio said:
Do you remember the model number of the NAD? I'd be interested to look up the specs.
Click to expand...

I've been trying, but am not certain. Also, not completely certain that optional MC loadings were on that integrated - I could be confusing that with an NAD preamp.

It was the era of the 3020 and 3040 integrateds, and we also had some 3155s that were discontinued by then, iirc. The 7220 and 7225 receivers were around and I think the 7225 was new and may have had the switch, as well. Memory can play tricks on me, but that gives you the general era.
 
rothwellaudio said:
It would be quite possible to have an mm/mc phonostage that switched the gain but kept the same load impedance, or switched to an impedance much higher than 100 ohms. In that case an mm cartridge on the mc setting would be much louder.

Did it sound any louder?
Click to expand...

Yeppers - Way Louder!
 
I have noticed that my turntable output (running through a Cambridge Audio phono preamp) is a bit quieter than what I get from digital sources (CDs, DVDs and TV). It would be nice to have a bit stronger signal to run into my amp, but it's not the end of the world...
 
According to the specs both on the Outlaw web site and in the the user manual for the RR 2160, that model doesn't use a lower input impedance for MC, but just the same 47 kOhm as for MM. So in this case the bad sound quality would likely be due to phono stage overload.


spazus: According to the specs, your Outlaw should provide an MM gain of not quite 35.7 dB and an MC gain of not quite 50.5 dB. And while AT specifies 4 mV (@ 1kHz and 5 cm/s) for the AT-MV95E, it actually delivered 7.7 V at DIN 0 dB level (= 8 cm/s in 45°/stereo modulation) in the review of the German online magazine LowBeats (*), so that would rather be ca. 4.8 mV at 5 cm/s in 45°/stereo modulation.


Greetings from Munich!

Manfred / lini


*) Lab testing performed by Peter Schüller, who has several decades of experience in measuring hifi equipment.
 
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