Need Help with a Mono cartridge set up

Hello all,

So i have an Audio technica AT-LP1240 Turntable going into a Marantz Pm6005 Amp. I purchased a At-mono3/lp cartridge to play my dillon/beatles mono box sets and just realized the Marantz doesn't do MC Cartridges. The manual refers to a MC Head amp or step-up transformer. I really have no idea what this is, whether i should pursue it, what I should buy, or if I should just return the cartridge. Any help would be appreciated

Thanks,
Mike

 

Your amp doesn't have an input for a low output moving coil cartridge which your cartridge is. I'd send it back and buy a mono switch that a gentleman sells in the "hardware for sale" forum on this site. Much less inexpensive.

 

Moving coil carts produce much less output than moving magnet carts and therefore need a different type of pre amp. Step up transformers (sut) boost the signal of the cart before it reaches the amplifiers phono stage. You can get them from less than £50 used over £1000+ for artisan designs. You can also make your own.

 

thanks for the info!

 

Take the cartridge back, Buy a Shure M78S(already jumpered for mono from the factory) and a genuine Shure .7mil diamond stylus. These re-issue mono LP's are cut at .7mil just as stereo records are cut. The original Dylan, Beatles, etc. records were cut at 1mil. Compared to an original mono pressing in excellent condition, these new "audiophile" mono re-issues just don't measure up. Consider the age of the master tapes and their deterioration. Remember all the articles about the trouble they had re-mastering the Beatles tapes?
Also remember that all the Beatles early mono recordings were fold downs from a 2-track master. Even when they started recording with 4-track, they mixed many like old 2-tracks. When you get up to the mono "White Album" it is well know that it was a fold down from the stereo mix.
The Dylan mono recordings, most of the later ones were fold downs from stereo, except for the singles. Outside of Dylan's first couple of mono albums, the rest, including the singles, were compressed mono. Love those Dylan color vinyl DJ 45's.

 

Without going to the expense and trouble of getting a step-up or a headamp to boost your cartridge's signal, it would probably be best to try another mono cartridge, preferably one with greater output. Utahhusker's recommendation would work pretty well for your current stereo cartridge if you don't have a mono button on your preamp.

 

My Arcam Delta 290 integrated amp has a mono switch....never tried it!
Most high gain mc cartridges will work perfectly well with a mm phono input/pre-amp.

 

That cartridge is a high output MC and can be used like a MM cartridge with a MM phono stage. There should be no need for a step up transformer.

 

The "mono button" does some seriously altering effects from the source material. It is better to play it with a dedicated mono cart or to just play it through a stereo amp.

 

Totally disagree with your statement. With the new mono records he's talking about, a stereo cart with a mono switch is all that's needed. Old monos, a dedicated mono cart is better.

 

Huh? Mono is mono. The difference between "old" monos and the new re-issued monos, is the groove width, 1mil compared to .7mil, plus the "old" monos were closer to the original masters. Just as the difference in different generations of masters, when you do your coupling at the cartridge stage, it is better than doing it at the amplification stage. You need to stop the phasing from a stereo cart at the source.

 

Here's a large thread dedicated to this topic. http://forums.stevehoffman.tv/threads/one-more-time-true-mono-carts-vs-mono-buttons-y-cables.330790/ . The double y, that's being discussed is the same as a mono switch.

 

It all depends on how far you want to take this. It's not as simple as "mono is mono". If you have a wide variety of pressings from the '50s to the early '60s, the groove width differs, even after the supposed advent of standardized, agreed-upon cutting widths and equipment. If most of the OP's mono records are recent, and he has a mere few of them, the easiest thing to do is either use one's stereo cartridge with the mono switch engaged, or barring that, the method utahusker is talking about. It may not be absolutely ideal, but you can go to a lot of expense here if all you're wanting to do is play a few mono LPs.

If your phono stage can boost your cart's signal sufficiently, that AT3 mono will probably do a fine job on the "Beatles in Mono" or "Dylan in Mono" boxes.

Have a look at this thread on "LencoHeaven.net": http://www.lencoheaven.net/forum/index.php?topic=18098.0

 

It is actually so that modern vinyl has a groove width of one mil, mono or stereo. On older records this can vary significantly, from 2-4 mil sometimes wider.

The advantage in summing to mono, or to use a dedicated mono is noise reduction. Vertical movements are either cancelled out or not read.

 

Summing to mono at the amplifier stage is definitely a noise reduction, so good in fact that it cancels out sound that you want to hear. That is why when you push that mono button, sound level is reduced and certain instruments disappear or fade into the background. Jumpering a stereo cartridge doesn't effect sound levels. Jumpering a stereo cartridge incorrectly and out of phase will only reproduce the verticle movements. This is how you play an Edison Diamond Disc or any other vertically cut records on modern equipment.
Some jukebox manufacturers and home stereo manufacturers wired their stereo cartridges out of phase into stereo amps to give a wide-stereo effect, and to reproduce the common information, like vocals, always had a center speaker. Similar to how Dolby Surround works through phasing.

Back at the radio station, when we started getting stereo records and converted to stereo cartridges, we installed a pair of AR3's, running the stereo carts into a stereo pre-amp, then to a stereo power amp going to the speakers and summed the auxillary line output to a single channel into the transmitter. Well, it didn't work, for the AM radio listeners that is. The best broadcast effect was to jumper the cart.

 

You are talking about needle tip radius, that isn´t groove width. Groove width at contact points is 1 mil on modern records, then needle tip radius has to be 0.7 mil. 1 mil / Sqr2 = 0.7 mil

Summing to mono is cancelling (or reducing) out of phase movement, when using a stereo cartridge to play a mono record that is cut laterally. That is the whole point.

 

I just want to add that the reason summing to mono works as perfectly as it does, is that the coils in a stereo cartridge is out of phase for a 45deg motion.
Also when summing we keep the same resonance as before, as the capacitance is doubling and the inductance is in half.

 

Thanks, I'm going to try that. Looking at the shure stylus choices could you recommend which one to use with the M78s cartridge.

Thanks for all the help,
Mike

 

Probably anything in the N25 or N35 series, whichever matches the kind of record you are playing. These are DJ stylii. For the higher end audiophile mono records, maybe you would be better off using a Shure stereo M97xe and jumpering it at the cartridge. I believe Shure sells the brass jumper strips separately. I use a separate headshell for each different cart I use. I just swap the headshells w/carts mounted and re-balance the tone arm.

 

What now? Don't measure up? None of them? Pffft, glad you don't succumb to sweeping generalizations.

Remember all the praise for the Beatles Mono LP Box Set?

And once again for good measure: The AT-Mono3/lp is a high output MC and can be used like a MM cartridge with a MM phono stage. There should be no need for a step up transformer.

 

That's for 78's, not albums. The only thing wider is RCA pre-grooved home recording discs from the 1930's at 8 mil.

"Modern" mono issues are cut with a stereo cutter head, so 0.7 mil is the correct stylus.

 

Yes a 0.7 mil needle is the right one for a groove width of 1 mil.

 

For a groove width of 1mil, a .7mil stylus is too small. If you play the older original microgroove records, the only advantage to playing them with a .7mil stylus is to get down below the surface wear. Because the modern audiophile mono records are cut with a .7mil stereo cutting head, so have a .7mil groove width, it is acceptable to play them with a .7mil stylus. There were some commercial ultra-fine groove mono records cut at .5mil which were to be played with a .5mil stylus. DO NOT play a 1mil or .7mil groove record with a .5mil stylus, it will damage the record. In the past, there was a compromise 2mil stylus which was meant to play both the 3mil later 78rpm records and the 1mil microgroove records. This 2mil stylus will NOT play a .7mil stereo or modern mono record. I have tried this 2mil stylus personally on some recent audiophile mono releases and it skips. It plays well on the 1mil mono records through the mid-60's.

 

The groove width is of course only a relevant measure if the width is measured at the contact points. A needle tip with a radius of 0.7mil will contact the groove at a groove width of 1mil. So I really don´t know what You are trying to say.

https://dl.dropboxusercontent.com/u/39225261/Groove_width_1mil.jpg

 

Post 1968 mono releases are cut on Stereo cutting heads, and have some vertical component. Their playback demands Stereo safe cartridges (Denon's DL-102 is a mono cartridge which is that). Exception is labels like Electric Recording Company's classical issues and a few like them cut on period equipment.