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Using a double Y Cord for mono recordings

Discussion in 'Audio Hardware' started by sberger, Jan 5, 2005.

  1. The FRiNgE

    The FRiNgE Forum Resident

    I have found IME the double Y as suggested by Steve H (our host) does enhance the mono listening experience as advertised. This is by comparison to the same mono record played in stereo. The Y connection lowers the noise floor, and reduces harmonic distortion produced by any differential mistracking, or difference artifacts introduced during stereo play.
    The reason you did not hear any difference, your comparison was single channel mono to dual mono. Single channel mono (the left or right channel at the cartridge Y'd to both channels on your amplifier) vs dual channel mono (both channels strapped across by selection of mono mode on your preamp) ... both versions produce clean mono reproduction with lack of sibilance and distortion, plus a lowered noise floor.

    My above comments apply to an unworn record.

    Records with wear will require varied mono hookups to achieve the cleanest play with the least fidelity loss, ie: left channel only, right channel only, or both channels strapped. The most practical mono setup is the double Y in my opinion, since this covers the majority of situations, new record or worn record and achieve greatly improved results. This is the most practical setup, sometimes as simple as flipping the mono switch on your preamp.

    Improved results does not mean best results. The best results are achieved through spot plays, in the trial of different mono playback methods. In my opinion, there is no convenient setup for this, which requires a time and patience, probably best left to preservation of a vinyl record to a lossless digital storage medium.

    Since all stereo cartridges produce a sum and difference signal, and that the stylus is free to move in all planes, the stereo cartridge is not the best solution in the reproduction of a mono record. There are painfully few true mono cartridges available, and many of them limited in frequency range. A true mono cartridge reproduces only the laterally cut portion of the groove, no sum signal, no difference signal, only ONE mono signal. The sibilance and distortion produced by a stereo cartridge are almost non-existent in a mono, given the same compliance and stylus shape. Since sibilance and harmonic distortion artifacts in stereo are almost entirely difference, and out of phase distortion, and created by vertical mistracking (venturing into the twilight zone of pinch effect) This same vertical mistracking of a mono cartridge will not be converted into an electrical signal, by virtue of the single pickup coil in a lateral alignment.

    A stereo cartridge strapped to mono is subject to any channel imbalance at the coils, any imbalance in the signal path before the Y strap. Again, 45/45 aligned coils are sensitive to vertical movement of the stylus, which in a mono record is pure noise.

    Just an afterthought, the sibilant issues in stereo playback occur mostly by vertical mistracking of the mono component. In other words, the stylus mistracks vertically in a laterally cut groove. An experiment to prove this point, play a sibilant record, switch to mono. The sibilance and/or distortion should go away almost entirely (in most instances) For everything, there is a season (meant to say reason) turn, turn, turn ... As a stereo cartridge is strapped to mono, all or most of the difference signal combines or sums, halving its output. Noise and distortion are also reduced by a factor of two or more.
     
    Last edited: Nov 1, 2014
    GerryO and ghost rider like this.
  2. ghost rider

    ghost rider Forum Resident

    Location:
    Chicago
    Thanks for explaining it does make some since. So if I'm going to all my listening from the computer via needle drop. I can keep it simple and do as I have done and to set the preamp to mono and record to a single channel and play it back like that.

    If I do take to mono pressings I would consider a MM mono cartridge for my Project debut. I would assume that I would use a single cable to the preamp MM phono input and set it to mono. I’m not using it at all.
     
    The FRiNgE likes this.
  3. The FRiNgE

    The FRiNgE Forum Resident

    I use the same mono setup, one channel, usually the left since that's usually the least worn groove wall. (switched to mono on the pre-amp) This simple setup preserves all of the fidelity pressed in the groove, so I prefer it. But it's not perfection since it's not quite as quiet as both channels strapped.

    Most older mono records have been previously played on vintage record players which were unkind to the record. The heavy tracking ceramic cartridges soon scored the groove walls, if not right away on the very first play. The groove wall on the label side tended to score first, since the skating forces were also great. (the arm wants to skate in) This is why most (not all) worn records play cleaner on the left channel, since that groove wall (the wall away from the label) was not subject to any skating force.
     
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  4. ghost rider

    ghost rider Forum Resident

    Location:
    Chicago
    I'll remember that when I buy an old mono record.
     
  5. soumac

    soumac Forum Resident

    Location:
    Orlando
    I've been using this technique for a while now, and just posted about this method over at another forum. Someone there suggested that this could possibly damage your system doing this?

    They argued that outputs, which are low-impedance, should only ever 'see', or be connected to, the high-impedance presented by a properly designed input. They then posted this link as supporting documentation.
    Why Not Wye? »

    I certainly haven't had any problems using the double Ys. Is there anything to the statement/claim that one could potentially damage equipment due to summing channels? It sounded dubious to me....
     
  6. Tony Plachy

    Tony Plachy Forum Resident

    Location:
    Pleasantville, NY
    I think I know what is wrong with the analysis in the link that you posted, but I am not a EE so someone who is should check it. I think what the person in the link is not taking into account is that the double Y goes between the tonearm and the phono preamp. The tone arm is not an active device with powered output devices that drive the output signal. The little generator in the cartridge produces a tiny signal (0.2mV to 4.0mV) that causes an equally small current to flow in the cables to the phono preamp where it is amplified by a factor of 1000 or so. The phono preamp actually has to present an electrical load to the cartridge to get a signal out of it. I think the idea that one side of the cartridge can drive to other side of the cartridge when you sum them together with the Y connector is not valid. But again, I am not an EE, someone who is should comment.
     
    2xUeL likes this.
  7. The FRiNgE

    The FRiNgE Forum Resident

    There is always "back emf" when any two coils are connected in an active circuit. Speakers produce "back emf" (the double wye aside for a moment) as the voice coil is driven. The amplifier's damping factor and low output impedance helps to control voltages produced by the speaker. As a speaker "motor" is driven by an AC voltage, it also acts as a transducer, producing voltage of its own. In other words, the speaker is also a microphone, and could be used as one, although inefficient.

    I have abandoned the double Y having discovered fidelity losses. I am not an EE as well, so I can not offer a technical explanation for this. I think it is reasonable to assume each coil in the cartridge produces voltages of its own as it is excited by the stylus. Normally connected to a single input, this probably has a minimal or perhaps an inaudible effect. However when connected together, one coil could conceivably drive the other coil. Without any amplification connected between them there is no gain, so the effect should be so small, that the effect may not be audible, or is it?

    Summing the L+R channels does cancel the difference signal, including noise which is largely L-R artifacts, theoretically leaving the mono L+R signal alone. Perhaps groove wear factors in, which then the part of the summed mono signal could be compromised, probably mostly in the higher frequencies.

    Most importantly, the double Y connected at the cartridge presents a higher load to the phono input. The cartridge coil resistance will be halved, since two are connected in parallel. If a double Y is employed, maybe it's better to insert at line level. Some preamps may not like this either, beware of fidelity losses and/or distortion artifacts, such as the "fuzzy trail offs". (I may have invented a new term here.. but they do exist, a low level distortion artifact.. ie: a "fuzzy trail off" can be a "fuzzy" sound at the very end of a reverb decay or voice or musical instrument. I once owned an Ampeg guitar amp that developed a "fuzzy tail off". It was only audible at very low signal levels, as a plucked string tailed off to zero, but was very annoying. Store techs failed to find the problem, even denied there was a problem.. I ended up selling the amp)

    I've had much better results recording to mono, by simply using the L or R channel, no double Wye. Just a single Y connects one channel at line level, ie" "rec out" Left to "mon" L+R. Just flip the tape monitor switch, you have instant mono, and can select the L source or R source by changing the single end to the L or R "rec out" jack. (keep the volume control down when connecting the single wye.)

    Just sharing my experience with this, I am an experienced bench tech but not a degree in EE, thoughts please?
    Steve VK
     
    Last edited: May 1, 2016
  8. bizzle

    bizzle New Member

    Location:
    France
    Hi everybody,
    I'm new here (from France, so sorry for my English...)
    I just bought the 2 Y cords, to listen to my MONO records. And while I noticed the amelioration, I have a hum (just like if the ground connection was not connect)
    Can someone help me ? I think I did it right : phono cord of the turntable -> Y cord 2 female to male -> Y cord male to 2 female -> phono stage of my amp ....
    Thanks
     
  9. AnalogJ

    AnalogJ CMO (Chief Musical Officer)

    Location:
    Salem, MA
    Make sure the plugs are solidly connected to each other. If that doesn't do it, I'd wonder if one of the grounds in the cable plugs is not connected properly. You might try replacing them with another pair.
     
  10. Adam9

    Adam9 Senior Member

    Location:
    Toronto, Canada
    That hum happened to me too occasionally with the Y cord. I found if I used tape monitor input s and outputs (I know new equipment doesn't have that).
    The hum is worse than any improvement using the cable.
     
  11. Tony Plachy

    Tony Plachy Forum Resident

    Location:
    Pleasantville, NY
    As mentioned above first try removing the "y" connector. If the hum goes then it is due to the " double Y" connector or a bad connection to the "double Y" connector. So first check all five the connections (two to the TT. two to you amp and the Y to Y connection). With everyting connected and the volume up enough that you can hear the hum wiggle each connection and see if the hum stops. If you cannot get the hum to stop then it is possible to test each half of the "double Y" to see which half causes the hum. If you need help doing that please post back.
     
    AnalogJ likes this.
  12. The FRiNgE

    The FRiNgE Forum Resident

    In my opinion, a better place for the double Y is line level, the tape monitor loop. (or at the output side of a phono preamp) The double Y at the cartridge changes the impedance and sound of the cartridge.
    Adapter cables can be finicky, or defective. If you have an Ohm meter (VOM) see that the cables do not have an open ground. Sometimes an RCA plug can be loose. Some types can be carefully pinched in needle nose pliers for a more secure fit.
     
    marcb and AnalogJ like this.
  13. Isaac K.

    Isaac K. Forum Resident

    Instead of double Y-ing every time you want to listen to a mono LP, why not quadruple Y? That way you can run a stereo feed to one input and a mono feed to another available input on your amplifier. Or would that degrade the signal too much?
     
  14. The FRiNgE

    The FRiNgE Forum Resident

    Hey Isaac K., That's just too convoluted, and would not benefit in any way, just more adapters and potential connection problems. The double Y does the job, simply and efficiently.

    As mentioned in my previous post, the Y connection at the cartridge will impose an increased load to the phono inputs and change the frequency response, usually for the worse. (different cartridges and inputs will respond differently) Place your double Y at the output jacks of the phono pre-amp. At line level, the difference in impedance imposed by the double Y connection has no effect on frequency response.

    For those using a vintage receiver or integrated amp, bridging across the L & R rec-out jacks accomplishes the same result (one cable jumps across both rec-out jacks) This is very simple and has the exact same result. The mono switch (if equipped) is wired internally the same way in the audio path, simply jumps across the L & R channels. (the rec-out jacks tap directly in the audio path... they are "hot" all the time)

    rock on
     
    Last edited: May 29, 2017
  15. Isaac K.

    Isaac K. Forum Resident

    I don't see how it is convoluted. It's a pretty simple thing to do, and the clear benefit would be not having to always plug and unplug the rca cable and risk wearing out the jacks. From the preamp out, you put a Y on both the left and right cable and run one pair to input one and then double Y the other pair to input 2. Easy.
     
  16. 33na3rd

    33na3rd Forum Resident

    Location:
    SW Washington, USA
    Once you tie the two sides together for input 2, the whole thing is mono, even the set going to input 1.
     
  17. Isaac K.

    Isaac K. Forum Resident

    You're imagining the set up wrong. The white output of the preamp has its own Y and the red output has its own Y. You take the white cable from each Y and connect them to one input on the amplifier. That connection will be in stereo. Then, you take the two red cables of the Ys and then double Y that combo to input 2. Ergo, one line for stereo, one for mono.
     
    Last edited: May 29, 2017
  18. 33na3rd

    33na3rd Forum Resident

    Location:
    SW Washington, USA
    It makes the whole thing mono. Once you join the signal on the one side of the Y, the other side is joined too.
     
  19. Isaac K.

    Isaac K. Forum Resident

    But that isnt what is happening. One Y is splitting into two left signals. The other Y is splitting into two right signals. You are only joining one of the two from each side. The ones that you don't join together are going directly into the amplifier the exact same way they would be if you weren't using Ys.
     
  20. 33na3rd

    33na3rd Forum Resident

    Location:
    SW Washington, USA
    Try it.
     
  21. 33na3rd

    33na3rd Forum Resident

    Location:
    SW Washington, USA
    I don't know if you've seen these, http://forums.stevehoffman.tv/threads/stereo-mono-switch.386061/

    They are made by one of our own members, @xmas111

    This would do what you want to do without the Y cords. He has newer models that you can see further down that thread.
     
    Harbins_Grave and xmas111 like this.
  22. Grateful Ed

    Grateful Ed Forum Resident

    Location:
    Vermont
    Will this work if done after the phono preamp on the way to the integrated? My phono pre-amp is built-in to my turntable.
     
    AnalogJ likes this.
  23. Adam9

    Adam9 Senior Member

    Location:
    Toronto, Canada
    Yes, because it will sum the 2 stereo channels into mono.
     
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  24. Grateful Ed

    Grateful Ed Forum Resident

    Location:
    Vermont
    Cool. Just wanted to make sure the level of the signal (phono vs line) didn't have any effect on this method :righton:
     
    Adam9 likes this.
  25. AnalogJ

    AnalogJ CMO (Chief Musical Officer)

    Location:
    Salem, MA
    It should ALWAYS be done somewhere after the phono preamp.
     
    qwerty, The FRiNgE and Grateful Ed like this.

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