I have a B&O RX2 that we bought over 20 years ago along with a "low-end" NAD receiver.  A trusted friend in an audiophile store sold us this pair, and it performed very well for our needs.  We really don't understand most of the audiophile terminology, as will probably be evident by this post.  The NAD died awhile back and I inherited a receiver that didn't have a phono input section.  By that time, we were well along into the CD era, so we didn't miss playing vinyl.

Over the past few years I've had a hankerin' for some / a lot of the treasure that we have on vinyl.  So, I've been shopping for a new receiver, and am finding that I need to know whether my turntable cartridge uses an MM or MC type.  So, imagine my surprise when I dig up some manuals online and find that the B&O RX2 uses an MMC "Moving Micro Cross" cartridge!

One receiver I am looking at specifies to use an MM cartridge and, if using an MC cartridge, a "separate head amplifier or step-up transformer" should be used.

I'm guessing that, since we were able to directly connect the RX2 to the NAD, we won't need "separate head amplifier or step-up transformer", but I'd appreciate any advice from others here who can answer definitively.

Thanks!
- Dan

It is a Moving Iron design  which of course sounds confusing! Treat it as a Moving Magnet though it does have a very slightly lower output than normal.

Doctor:

It is a Moving Iron design  which of course sounds confusing! Treat it as a Moving Magnet though it does have a very slightly lower output than normal.

Indeed but it still requires a phono (RIAA) preamp which is not always present nowadays on integrated amplifiers...

Do make sure there is one on your amp, or else you could buy a separate box like these: 

http://www.amazon.com/Cambridge-Outboard-Audiophile-Phono-Silver/dp/B00106JE1E

http://www.lifestyle-av.co.uk/details.asp?sectionId=4&productId=2972

Oh, and welcome to Beoworld Dan! Where do you live then?

Thanks Doctor and Jacques,

I'm in mid-Michigan here in the states.  Snowing at present.  ;-)

So, Jacques, you are saying that a preamp is required for the MMC?  I checked the Amazon link, $179 blows my budget.  (Times are tough, eh?)  At the risk of embarrasing myself, the receiver I am looking at is a Sherwood RX-5502 which will set me back about $140.  So you see I'll have a hard time justifying more than doubling my expected investment.

Let me just ask the devil's advocate question: What can I expect if I try to directly connect the RX2 directly to a receiver that specs an MM cartridge?

Victory!

The Sherwood HAS a phono input so it'll work right out of the box!

http://www.sherwoodusa.com/prod_rx5502.html

chartz:

Victory!

The Sherwood HAS a phono input so it'll work right out of the box!

Yes, but...    (confusion reigns)

As mentioned in my OP, the user manual for the 5502 specs that a turntable with an MM cartridge can be directly connected to the 5502, whereas an MC cartridge requires "a separate head amplifier or step-up transformer."  So I guess the question is, where does the MMC cartridge fit in this scenario.

In case it helps, I'm pasting the amp specs on the 5502 below:

• Power output, 8Ω, THD 0.7 %, 20 Hz~20 kHz, only a pair of speakers driven ..... 2 X 100 W
• Total harmonic distortion, 8Ω, @ -3dB, 20 Hz~20 kHz ...... 0.05 %
• Intermodulation distortion
      60 Hz : 7 kHz= 4 : 1 SMPTE, 8Ω, 100 W ........................ 0.03 %
• Input sensitivity, 47 kΩ
      Phono(MM) .................................................................... 2.5 mV
      Line(CD,DVD,TAPE,AUX) ................................................ 220 mV
• Signal to noise ratio, IHF "A" weighted
      Phono(MM) ................................................................... 75 dB
      Line(CD,DVD,TAPE,AUX) ............................................... 98 dB
• Frequency response
      Phono(MM), RIAA, 20 Hz~20 kHz ................................. ±0.3 dB
      Line(CD,DVD,TAPE,AUX), 10 Hz~100 kHz ..................... ±3 dB
• Output level
      TAPE OUT, 2.2 kΩ ......................................................... 200 mV
• Bass/Treble control, 100 Hz/10 kHz ................................ ±10 dB

DanDaMan:

 

• Input sensitivity, 47 kΩ
      Phono(MM) .................................................................... 2.5 mV

I think, but am not sure, that the specs I just posted answered the question.

Under Frequency Response, there is this line:

    Phono(MM), RIAA, 30 Hz~20 kHz

Now, I don't know whether that implies that the receiver has the RIAA pre-amp, or whether an external one is assumed.  If the latter, it seems to conflict with the other statement in the user manual re the requirement of "separate head amplifier or step-up transformer."

I think I'm about ready to call Sherwood for info.

BTW, Jacques, thanks for the quick reply earlier and all your help!

- Dan

chartz:

DanDaMan:

• Input sensitivity, 47 kΩ
      Phono(MM) .................................................................... 2.5 mV

It will fit alright, go ahead!

Sorry, you were too fast for me to see this reply before I sent that last one!

Hi Dan and welcome from me as well!

Have you given any consideration to an older BeoMaster and be done with it?

You don't need to call Sherwood at all. It WILL work, I guarantee!

I take it for granted that your RX2 has RCA (Cinch) plugs for the amp of course, since you had an NAD.

burantek:

Hi Dan and welcome from me as well!

Have you given any consideration to an older BeoMaster and be done with it?

Thanks!

No, I hadn't done that, it really wasn't on my radar.  I trust that by "older", you mean "pre-owned"?  I'd have to consider price, the condition of a used unit, and going without a warranty.  The latter two items being a major deal for me.

All B&O stereo cartridges work on the same principle and all cxan be treated as moving magnet. The output is however slightly lower than an average moving magnet cartridge so you will need to turn the volume up an extra notch compared to the CD player! But I dare say that this will not be a problem! Ortofon use the same system in some of their moving magnet cartridges as do Decca.

chartz:

You don't need to call Sherwood at all. It WILL work, I guarantee!

I take it for granted that your RX2 has RCA (Cinch) plugs for the amp of course, since you had an NAD.

Good question! I am nearly absolutely certain the RX2 has the RCA plugs, but it's been a few years since I looked back there.  I'll check when I get home tomorrow night.

Hey, one more quick question:  In addition to the aforementioned Sherwood RX-5502, I am also looking at their RX-4109 which has similar specs, the big difference is that the 5502 has connects for two pair of speakers, and the 4109, only one pair.  But the specs had one seemingly significant difference under Frequency Response that I am wondering about:

RX-5502: Phono(MM), RIAA, 20 Hz~20 kHz ................... ±0.3 dB
                Line(CD,DVD,TAPE,AUX), 10 Hz~100 kHz ...... ±3 dB
RX-4109: Phono(MM), RIAA, 30 Hz~20 kHz ................... ±3 dB
                Line(CD,TAPE,AUX), 20 Hz~100 kHz .............. ±3 dB

First, I'm wondering if the "±0.3 dB" on the 5502 is a typo.  If it isn't, is the difference significant?

Second, I noticed that the range spec'd is different between the two units.  Is there a reason for that?  Or would you generally expect the spec'd range to be the same across all of a given manufacturer's units?

Finally, I am overwhelmed at the quick and frequent responses I've received in this forum!  It really has boosted my confidence that I am making a purchase that will work well for me.  Thanks to all!

Yes but most probably the ±3 dB is a typo error though! ±0.3 dB sounds more like it from 20 Hz to 20 kHz, the useful bandwidth. 100kHz is irrelevant anyway, because we can't hear much past 15 kHz, and 10 Hz is also anecdotical!

I'm sure the lesser model will be fine as well.

Jacques, you were right about the typo; a Sherwood salesman verified that for me.

I ordered this today, hope to have it within a week.

Thanks again, everyone, for all of your help!

You're welcome! Do keep us informed please!

The Sherwood came, I read the manual as I was setting up, and it says:

For safe amplifier operation, use the speakers with impedance of over 8Ω when you use only SPEAKER A or B terminals and use the speakers with impedance of over 16Ω when you use both SPEAKER A and B terminals.

Both sets of speakers I own have 8Ω impedance.  I wasn't expecting this.  How does using speakers with 8Ω impedance cause usafe amplifier operation?

Hi,

Don't you worry. When using the two sets at the same time, just don't push the amp too hard... Leave the bass at the zero setting and the loudness disengaged and you should be fine!

Merry Christmas!

Actually, I use only one pair of speakers.  It's just that both pairs are 8 ohms.

So, if I use only one pair of the 8 ohm speakers, does that reduce the risk of harming the receiver?  (As opposed to using two pairs?)

I'm not at all familiar with impedance, although I did read up a bit on the subject online today, it's still not clear to me how it all fits.  I just want to play music and not be worried that I'm going to blow the amp if I play something.  I'm a 50-something and I'll play just about anything but wall-jarring type music.  Like John Denver, Journey, Asia, Elton John, etc.  No Metallica, and nothing that will make the windows shake. 

I guess it comes down to subjectivity.  What's loud to me might not be loud to you, and vice versa.

Are there any warning signs that will tell me that I'm pushing the receiver too hard?

I spoke to support person at Sherwood this afternoon and got a short lesson on impedance.  He basically put my mind at ease and pretty much repeated what Jacques offered.  The receiver has a safety shutoff if it ever overloads.

I got everything hooked up, and we christened the unit with "the" Boston album, and followed that with REO Speedwagon.  And, yes, I pushed it, and it responded just fine.  Bliss!  BLISS!   Just going through the collection to REMEMBER what we have.  Jackson Browne is up next.  Can't find my "Captain Fantastic and the Brown Dirt Cowboy" though, and I am majorly bummed by that.  Gotta be around here somewhere.

The nicest surprise?  My 15-year old daughter is just amazed at the great music we had in the 70's and "why don't they make music like that now?"

Oh my, I think my Christmas was just made. 

And on that note, I'd like to thank all of you who held my hand through this entire thread, and wish all of you a very blessed and Merry Christmas!

chartz:

Don't you worry. When using the two sets at the same time, just don't push the amp too hard... Leave the bass at the zero setting and the loudness disengaged and you should be fine!

By the way, I should also mention that I had the bass turned all the way up.  I admit I was a bit worried when you said leave the bass at zero.  Hello?!?!?  Bass at zero?!?!?  Incomprehensible!   But it responded fine, and I could not discern any distortion.

It's all good.

Thanks again!

- Dan

DanDaMan:

Hello?!?!?  Bass at zero?!?!?  Incomprehensible!   

You're most welcome, my friend. Any time.