SH Spotlight If you have a turntable you need to play your mono records in true MONO. How to do it cheaply..

Discussion in 'Music Corner' started by Steve Hoffman, May 14, 2006.

  1. qwerty

    qwerty Forum Resident

    I have read some posts on this topic (or some of the other topics on the subject on this forum) where people have responded to this.
    Any extra length of cable, sockets, switches has the potential to degrade the sound quality, even if only in a minor way. First, a disclaimer - I don't have a box, and it's been years since I've used a double-y connector (and enjoyed the benefits them). I'm in the process of reconfiguring my system and will incorporate some mono capability for vinyl.

    The box appears to use reasonable quality sockets, and I assume that the wire is of reasonable quality, the length of wire used is very short. So I would expect the impact to be minimal, which has been reported by some who have bought it. However, it does require another set of interconnects, which is introducing extra length into the system, so it would be wise to ensure that both sets of interconnects used with the box are of at least reasonable quality and have an overall minimal usable lenght (as always, higher quality cables assist with good sound).

    A double-y eliminates the requirement for another set of interconnects keeping the signal path shorter. They do introduce another connection into the system. People have reported that using cheap+nasty double-y's have substantially improved the quality of listing to mono vinyl compared to listening in stereo. One person reported changing the cheap+nasty double-y's for a set of Monster y-cables, and found they provided higher quality sound compared to the cheap+nasty's. It was acknowledged that while Monster products can be a step up from cheap+nasty, that they are not regarded as high-end audiophile products. We can conclude that using double-y's made from audiophile-quality cable and connectors would provide higher sound quality, however, these don't appear to be commonly made by high-end cable manufacturers.

    If I were to make one, I would have a box with one set of input sockets and a switch to accept the phono cable. Rather than having another pair of rca sockets, I would have a short length of audiophile-grade phono cable with quality rca plugs to go into the amp.

    Of course, it all depends on the quality of your system. I doubt that much difference would be perceived on a consumer-level stereo, whereas differences would be easier to notice on a very high-end system.
     
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  2. ABG

    ABG Member

    Location:
    Sydney, Australia
    Thanks qwerty. Gotta love the convenience of being able to listen to true mono with the push of a button. And writing a name that runs with consecutive keys on a keyboard...
     
    qwerty likes this.
  3. PeteFior

    PeteFior New Member

    Location:
    Rosendale, NY
    Yes, Steve, you are absolutely correct! A mono switch or L+R patch should only be used when playing a monophonic vinyl recording cut with a true monophonic (horizontal) groove. As I explained in a previous post - all stereo cartridges were (and still are) designed with their two output coils 180 degrees out of phase so as to make them backward compatible with monophonic disks. As a result of this original design, stereo record (45 degree) channels are also cut 180 degrees out of phase to compensate for the mis-phase of the cartridge coils.

    A great side benefit of this coil phase difference is that all signals generated by vertical movement of the stereo cartridge stylus will be cancelled out by combining the two cartridge outputs. This will result in a significant reduction in any surface noise or distortion stemming from vertical stylus movement. That is why most vintage pre-amps and receivers were equipped with A+B or L+R switches! When playing a monophonic disk, the sound output will thus be virtually identical to a true monophonic cartridge without the need for a separate turntable or cartridge shell.

    Consequently, the electro-mechanical factors discussed here are unique to stereo cartridges and do not apply to monophonic CD's - whether commercially produced or home copied from a vinyl disk. Therefore, prior to archiving any monophonic records to CD - or any other digital medium - it is important to combine the L and R channels . Doing, so after the fact, will not work well - as Steve has pointed out above!
     
    Last edited: Sep 17, 2016
    qwerty and Steve Hoffman like this.
  4. HGN2001

    HGN2001 Mystery Picture Member

    Right Steve. There are cases where you would end up with phasing problems and we wouldn't want that.

    I was referring to cases like the following: There were some very old 45s and acetates that Richard Carpenter put out on the Carpenters box sets - FROM THE TOP and ESSENTIAL COLLECTION. These were very early recordings when Karen was recording for Magic Lamp. I believe these mono recordings are properly "in-phase", but were transferred to CD using stereo. The result is that if you listen to them, there's a tiny bit of left-right noise associated with it. This is most heard if you use the OOPS method to phase out the center. All you're left with is noise when you shouldn't be left with anything from a pure mono recording.

    One can reduce this ambient noise by combining right and left. This collapses the errant ambient noise that was introduced by the stereo reproduction of the mono record just the same as if you had the rare record at home and played through the mono button or y-cable.

    Basically, whenever I work with mono, I listen to it through the OOPS method first. If I hear anything odd, I'll then try it with the y-cable or collapsing the track to mono on the computer. Assuming the phasing is OK on the main audio, this method works wonders on those kind of tracks.
     
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  5. PeteFior

    PeteFior New Member

    Location:
    Rosendale, NY
    Please note that "combining right and left" when playing a monophonic CD, or other monophonic digital media, is not at all equivalent to combining the channels when playing or archiving a monophonic record. The phase difference inherent in the output of a stereo cartridge (see my previous post) does not exist when playing other media. Therefore, the same rules regarding vinyl noise and distortion cancellation do not apply to these other situations and any noise reduction, therefore, would be extremely minimal. The only scenario where this might help - if the noise is concentrated in one channel - would involve exclusively feeding the lower noise channel to the output. Since the source material is monophonic anyway, there should be no degradation of the sound output using this method.
     
    Last edited: Sep 17, 2016
  6. lukpac

    lukpac Forum Resident

    Location:
    Milwaukee, WI
    Not sure what you're getting at. If you record a mono LP to CD in stereo, summing that CD to mono will be no different than summing to mono while playing the LP itself. The same two channels are being reproduced, whether or not they've been digitally archived.
     
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  7. PeteFior

    PeteFior New Member

    Location:
    Rosendale, NY
    Thanks for responding! This point was explained in my second paragraph. A mono LP should always be recorded to CD in mono, not stereo. That way, the noise cancelling action of summing the two channels will be fully utilized. This is because the two output coils in the stereo cartridge are opposite in polarity so that the two signals due to unwanted movements of the stylus will be largely cancelled out. On the other hand, once the music plus noise are transferred to the CD in stereo with both channels again in phase - the noise cancellation effect will not occur when summing the CD to mono.

    Please keep in mind that stereo LP's are the only sound medium where the two channels are originally recorded in opposite polarity - but the opposite polarity of the cartridge L and R coils again reverse the polarity to produce a final output with both channels again in phase. Think of the principle: "two negatives make a positive"! Actually, the main original reason for setting the stereo cartridge coils to opposite polarity was to make it possible to play monophonic records without cancelling out the two signals resulting from the strictly horizontal movement of the stylus. But, it is precisely this polarity difference that also makes this useful noise cancellation technique possible.
     
  8. lukpac

    lukpac Forum Resident

    Location:
    Milwaukee, WI
    That is untrue. If a mono LP is transferred to CD in stereo, summing to mono when playing the CD has exactly the same effect as summing to mono when playing the LP. Recording to CD (or any other medium, analog or digital) does not change the phase relationship of the channels.
     
    HGN2001 likes this.
  9. PeteFior

    PeteFior New Member

    Location:
    Rosendale, NY
    Your point is well taken - any phase difference between the noise component in the two channels should be carried over when a mono LP is transferred to CD in stereo. In theory the summing effect should be the same in either case. Practically speaking, however, some forum members have encountered problems doing the summing from the CD. Personally, I have not experimented with summing in this manner - but the question still remains - why not make a proper monophonic archive in the first place and be sure that the final result will be optimal?
     
  10. lukpac

    lukpac Forum Resident

    Location:
    Milwaukee, WI
    My posts mainly concern what can be done in particular situations, not what should be done.

    That said, when doing needledrops of mono records, I *always* record in stereo and do any conversion to mono later. Sometimes it is preferable to select one channel rather than summing, and declicking is usually more effective prior to summing to mono.
     
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  11. 68Mustang

    68Mustang Member

    Location:
    UK
    Hello everyone!

    New to the forum after scouring for tips and info for a while! I was looking for a stereo - mono switch box and came across this and many other threads! I couldn't believe there wasn't one commercially available as I'm not too savvy with electronics, apart from the ridiculously overpriced one on Kabusa, for what I gather is a fairly simple excercise (if you know what you're doing!)
    I decided to try the double Y cable method, and went to Maplins yesterday (UK equivalent of Radioshack I guess), and thought I could do it with two adapters rather than the cables, to save space.
    Well, like an idiot I bought the wrong ones, to a degree. I bought a 1 female - 2 female and 1 male - 2 female adapter. All that meant was that I had to use another interconnect to complete the connection to the phono stage. I suppose it meant that I could use one of my decent ones to retain sound quality! Just another way of doing it I guess, and it worked beautifully for older records, but as I've seen mentioned didn't seem to improve much on newer mono pressings.

    Does xmas111 still make and sell the boxes as eventually I'd prefer adding one for the convenience of not crawling round the floor unplugging stuff just to listen in mono? Being newly registered I don't think I can PM anyone yet! ;)

    Anyway just thought I'd share and say hi! Thanks for all the tips and advice all! :)

    Cheers
    Lee
     
    timnor likes this.
  12. dbsea

    dbsea Well-Known Member

    Location:
    Seattle, WA
    Oh my god. I just tried this and it is amazing how much noise just went away. Thanks a lot!
     
  13. qwerty

    qwerty Forum Resident

    - Lee, if you continue with the double-y it would be best if you took the 1F-2F back to Maplin and got the 2m-1f, so the signal path is kept short.

    - You will be able to PM if you make some more posts - this should be easy to do on the Music forum - don't be afraid to share you opinions! I think the member who makes the boxes is in the US, so you will be likely to pay prohibitive postage for the box. The diagram and pics to making this box is available on this site (I'm not sure if it's on this thread or another one on the same topic, there are a number here). You should be able to cut+paste the relevant info and have someone handy with a soldering iron make it economically for you in the UK. The parts are cheap, and it only requires some holes drilled in a box and a few wires soldered - easy!
     
  14. dbsea

    dbsea Well-Known Member

    Location:
    Seattle, WA
  15. Fishoutofwater

    Fishoutofwater Forum Resident

  16. AnalogJ

    AnalogJ Forum Resident

    Location:
    Salem, MA
  17. dbsea

    dbsea Well-Known Member

    Location:
    Seattle, WA
    It sounds correct and there is the expected reduction in noise. I may pick up an additional connector to test, but the results I'm getting seem to indicate that it is working as expected. I've listened to the same album with and without the y connector combo and there doesn't seem to be a loss of detail or other problem, just a dramatic reduction in noise.

    Edit, below are the connector details from the product descriptions.

    C2G / Cables To Go 03181 Value Series One RCA Stereo Female to Two RCA Male Y-Cable-6 Inch Black

    Convert the signal from dual RCA jacks (stereo) to a single RCA jack (mono)
    Connector 1: (1) RCA Mono Audio Female
    Connector 2: (1) RCA Stereo Audio Male

    ---

    C2G / Cables To Go 03181 Value Series One RCA Stereo Female to Two RCA Male Y-Cable-6 Inch Black

    Convert the signal from dual RCA jacks (stereo) to a single RCA jack (mono)
    Connector 1: (1) RCA Mono Audio Female
    Connector 2: (1) RCA Stereo Audio Male
     
    Last edited: Jan 12, 2017
  18. dbsea

    dbsea Well-Known Member

    Location:
    Seattle, WA
    Is $10.50 expensive for two y connectors? That price seems trivially low.

    Edit: is the quote showing up? If not, this is a reply to Fishoutofwater regarding the cost of the connectors.
     
  19. AnalogJ

    AnalogJ Forum Resident

    Location:
    Salem, MA
    No. I probably paid $14 for my pair.

    But I can hear a degradation in sound. Although I have subsequently purchased a dedicated mono cartridge, I would have loved to have a high end company such as Cardas make those cables. I distinctly heard the top end roll off a bit as well as heard a bit of a veil over the midrange detail. It certainly solidified the mono sound, but I lost some of the qualities of my Benz-Micro wood body Glider.

    Depending on your own system, you may not hear the deterioration in sound, but it bothered me.
     
  20. dbsea

    dbsea Well-Known Member

    Location:
    Seattle, WA
    I'll have to do some additional tests regarding the degree of noticeable detail loss. I've probably been so floored with the noise reduction to be objective in that regard. My testing of this configuration has been limited to just a few album sides this evening. Thank you very much for your feedback.
     
  21. qwerty

    qwerty Forum Resident

    In one of these threads someone posted that the cheap+nasty Y's were tried, with an improvement in sound (as expected). He then bought some more expensive Y's (possibly Monster, maybe something else) and noticed an sound improvement compared to the cheap+nasty's.

    The switchbox has very short signal paths, so providing decent cable and connectors are used I would expect it to have negligible impact on the sound quality.
     
  22. qwerty

    qwerty Forum Resident

    Here is the wiring diagram:

    And here is how one person made it (there are other examples with slightly different layouts posted on the site):

     
  23. lukpac

    lukpac Forum Resident

    Location:
    Milwaukee, WI
    No they don't. It's stereo female -> mono male -> mono female -> stereo male.
     
  24. AnalogJ

    AnalogJ Forum Resident

    Location:
    Salem, MA
    That's not what is advertised.
     
  25. lukpac

    lukpac Forum Resident

    Location:
    Milwaukee, WI
    That's what is shown, both on Amazon and in @dbsea's photo.
     

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