True Mono from a Stereo cartridge - switchable !

[Coffee Phil]

Slowly read my last post again and try to get what I am saying.

Do you suppose that there are many on this forum who were not aware that it is possible to play mono records on a stereo system before you informed them?

Do we not know that hooking the channels of the phono cartridge in parallel is fairly standard?

Are any of us telling you that you are not free to listen to your records that way?

You have been saying that we can't know as much as Stanton engineers have forgotten.
That could be so but you don't know that. If we want to eek a bit more performance out of our systems to play our mono Lps, lateral cut 78s, and vertical cut records by departing from what you see as Stanton's stone tablets, what is that to you? Are we compelling you to do the same?

Again I ask, If you have no interest in the subject of this string, why are you bothering us?

Now if it is not that you are saying what we are doing is just not worth the effort for any possible gains we may achieve but rather that there no gains to be achieved, fine, prove it! Draw the equivalent circuit of the parallel cartridge working into a preamp load and using Kirchhoff's laws write the equations and show us.

Phil

what is actually your problem? all I said basically that there was a simpler way of playing mono records,and you in various posts have resorted to kind of veiled personal attacks on me,if anybody already has a phono stage the method I suggested is simpler than going ahead and building your pre(well I think it is)and has you have said riaa eq is adequate.
If a thread is started is nobody allowed to have a different point of view or suggest anything alternative to your or lds ideas?Its as though all expect from any poster is adoration and if that isn't forthcoming you take offence,why?

[Ldg]

The point of this string is to investigate methods to play mono records with stereo cartridges with the performance of mono cartridges.

If you really don't think that the subject of this string is a worthwhile pursuit (it is hard to tell with the gibberish which you write) why are you bothering us with your prattle?.....Now if it is not that you are saying what we are doing is just not worth the effort for any possible gains we may achieve but rather that there no gains to be achieved, fine, prove it! Draw the equivalent circuit of the parallel cartridge working into a preamp load and using Kirchhoff's laws write the equations and show us.

(my emphasis)

Yes, that's exactly the crux. It's one thing to miss the point, but no excuse to trash a thread with perfectly good original content on the strength of it. Especially when the point has been clearly made, and advantages explained.

Ironically, it seems to be Stanton's engineers who are being most insulted here, by any suggestion that parallel wiring is somehow their best shot ! No, parallel wiring's only merit is its simplicity, and if one is skilled in the art that's pretty obvious. And, for the reasons already set out, it is compromised. Quite heavily so, IMO. As to mono buttons, devil's in the detail of how it operates. Nothing very useful can be known simply from there being one.

[steve195527]

The point of this string is to investigate methods to play mono records with stereo cartridges with the performance of mono cartridges.

If you really don't think that the subject of this string is a worthwhile pursuit (it is hard to tell with the gibberish which you write) why are you bothering us with your prattle?.....Now if it is not that you are saying what we are doing is just not worth the effort for any possible gains we may achieve but rather that there no gains to be achieved, fine, prove it! Draw the equivalent circuit of the parallel cartridge working into a preamp load and using Kirchhoff's laws write the equations and show us.

(my emphasis)

Yes, that's exactly the crux. It's one thing to miss the point, but no excuse to trash a thread with perfectly good original content on the strength of it. Especially when the point has been clearly made, and advantages explained.

Ironically, it seems to be Stanton's engineers who are being most insulted here, by any suggestion that parallel wiring is somehow their best shot ! No, parallel wiring's only merit is its simplicity, and if one is skilled in the art that's pretty obvious. And, for the reasons already set out, it is compromised. Quite heavily so, IMO. As to mono buttons, devil's in the detail of how it operates. Nothing very useful can be known simply from there being one.

If trashing a thread in your opinion is caused by reacting to some childish jibes then perhaps I have

[josephazannieri]

Yo Seekers of Mono:

There is one additional method of obtaining mono that nobody has talked about, and it is the method I am currently using. I have 2 channels of a stereo cart plugged into 2 channels of a stereo preamp. (Hafler DH101) When I want mono, I use the mono switch on preamp, which parallels the channels, but does it at a later (high level) stage in the preamp. I'd have to look at schematic to determine exactly where, but it's not at phono preamp because the mono switch affacts all inputs, both phono and line level.

This takes care of the problem with the cart channels loading each other that is the stated reason for putting the channels in series. It also gets rid of the problem with the suggested series circuit in my system, which is that with the number of arms I have (3 arms and 3 carts on 2 inputs), I cannot common ground the cartridge grounds as is apparently required for the series stereo/mono switching system to work. If I do that I get hum out the wazoo. I need a star pattern ground where all the grounds come together in the preamp chassis. But that is my problem, and maybe the other users of the series system don't have that problem.

At some point I will cobble up a head and take a shot at series wiring, but I am currently satisfied with the system set up as it is, and I get a nice solid mono on both 78's and mono LP's.

There seems to be a great deal of passion being generated here, and I confess that with the cartridge loading reservations, which may diminish impact when the cart channels are tied together at cart, I tend to go with parallel. I sent a CD of a clean 78 and another CD of a rough 78 to Coffee Phil, recorded in the manner described above, stereo channels parallelled after the phono stage, and I think the result was pretty good. The problem was taken care of without the cartridge loading issue. Phil said it didn't stink. Seems to me that parallelling after the phono stage may be a good answer for lots of people.

Luckdog's comments about those early Beatles stereo remixes are well taken. When you try to break those records out into 2 channels, everything is misplaced and off size. Also, there are places where singers are singing different lyrics at the same time. During the period when those were made EMI did not have pan pots on their mixing board. They put all the channels together, with appropriate volume adjustment for a solid mono mixdown for mono 45's for AM radio. They did not think in terms of 2 channels until much later, after they turned into "artists," and George Martin started speeding up the tapes. By that time, they had pan pots on the boards. I have a mono mix of "Sgt. Pepper," that I bought in 1969, that is much different from the stereo mix, including sound effect wowups.

And good luck from that agitating old guy, now wearing his Kevlar jacket and hiding in the bunker to dodge the blasts from the faithful,

Joe Z.

[Coffee Phil]

Hi Joe,

I think I went well beyond "it didn't stink". They are very good and your use of "clean-up" software was very tasteful.

By the way folks, If Joe offers you copies of his records, take him up on it. Not only are the copies excellent but his ability to annotate the music is outstanding.
If vinyl ever gets back to where it was he could have a career in writing liner notes. My English Major wife saw the note on the table and started reading them.
Her comment: "This guy writes pretty well".

Phil



There seems to be a great deal of passion being generated here, and I confess that with the cartridge loading reservations, which may diminish impact when the cart channels are tied together at cart, I tend to go with parallel. I sent a CD of a clean 78 and another CD of a rough 78 to Coffee Phil, recorded in the manner described above, stereo channels parallelled after the phono stage, and I think the result was pretty good. The problem was taken care of without the cartridge loading issue. Phil said it didn't stink. Seems to me that parallelling after the phono stage may be a good answer for lots of people.

[satanfriendly]

When someone such as LD shares with all something simple and effective which can only add to betterment of this small community, then it should be met with open arms, not a kick in the balls.

I am in no way technically minded to the same level as many out there, but when a subject is put over in a 'simple to understand' layman type manner then my own wisdom (or lack of) is suitably expanded and it all adds to my own little world.

Those of you who explore vinyl reproduction to a level beyond the 'bog standard user' such as myself, then please continue to keep the outside world informed. It is much appreciated by many out here. It all helps to understand and keep vinyl reproduction alive.

Threads such as this don't deserve to be publically executed.

[Coffee Phil]

Hi Satanfriendly,

Thanks for those words.

Phil

When someone such as LD shares with all something simple and effective which can only add to betterment of this small community, then it should be met with open arms, not a kick in the balls.

I am in no way technically minded to the same level as many out there, but when a subject is put over in a 'simple to understand' layman type manner then my own wisdom (or lack of) is suitably expanded and it all adds to my own little world.

Those of you who explore vinyl reproduction to a level beyond the 'bog standard user' such as myself, then please continue to keep the outside world informed. It is much appreciated by many out here. It all helps to understand and keep vinyl reproduction alive.

Threads such as this don't deserve to be publically executed.

[hi_torq]

Excellent post and very neat switching arrangement. But I have to ask: Why not parallel the coils?

Thanks ! Parallel wiring's not bad, it's just not optimal. And doesn't sound or measure anything like as good/well as series wiring to me..... Because in parallel wiring, unless L&R channels have exactly identical signal, then one coil will load the other in an odd and undefined way. Consider the extreme case of pure L signal with zero R signal. With parallel wiring the R coil loads the L coil, in series wiring it doesn't. This is obviously relevent for stereo summed to mono, but is also relevent for true mono when non-ideals aren't identical.

Not only does this sound right playing true mono recordings to me, but the noise improvement on stereo summed to mono is useful for those stereo records where one is unlikely to find another copy, but surface noise is a distraction. Then the noise reduction and overall sound improvement can sometimes be worth losing the stereo image, IME.

I would be a little uneasy about having any extra set of contacts in that part of the chain.

I used a sub-min toggle switch under the armboard near the pivot, where the tonearm wiring terminates anyway. Nothing I'd attribute to contact noise, hum etc.

In series wiring, the cartridge is always loaded properly and in a defined way. The output is always a simple voltage sum, not a shunted undefined.

ld,
Thanks for reply to my comments. Sorry if I missed your original point about parallel wiring (but this thread is getting a bit long-winded)! I should have stated that I only strapped the two coil outputs (as a quick fix) when transcribing mono discs, obviously the rules change if the intention is to derive mono from a stereo disc. I'd be interested to compare noise measurements for the series/parallel approaches. I think that the parallel approach might have a theoretical advantage in so much as any non-laterally-induced output would be effectively shunted. Just to add some food for thought, some cartridges have a L-R imbalance of up to a dB!

[Ldg]

When someone such as LD shares with all something simple and effective which can only add to betterment of this small community, then it should be met with open arms, not a kick in the balls.

I am in no way technically minded to the same level as many out there, but when a subject is put over in a 'simple to understand' layman type manner then my own wisdom (or lack of) is suitably expanded and it all adds to my own little world.

Those of you who explore vinyl reproduction to a level beyond the 'bog standard user' such as myself, then please continue to keep the outside world informed. It is much appreciated by many out here. It all helps to understand and keep vinyl reproduction alive.

Threads such as this don't deserve to be publically executed.

Thanks, SF

[Ldg]

....I think that the parallel approach might have a theoretical advantage in so much as any non-laterally-induced output would be effectively shunted. Just to add some food for thought, some cartridges have a L-R imbalance of up to a dB!

Hi hi torq.

Yes, parallel wiring is effectively useless for stereo summed to mono.

Parallel wiring indeed works by shunt loading for certain non-ideals, and it has two disadvantages. Firstly, coil impedance is being used as the shunt, and that varies significantly with frequency. For example it has magnitude c 16kohms@5kHz, versus about 1kohms @100Hz. Secondly, coil impedance always has a finite minumum value, determined by coil resistance, and this sets a fairly low limit for rejection.

Series wiring works by voltage summing, and does not have these disdvantages. It's good for stereo summed to mono too.

It's the non-ideals of true mono replay which best highlight series wiring advantages. Unfortunately, not all signal is ideal and lateral, and not all noise is ideal and vertical - but even ideally, series wiring has the advantage.

HTH !

[LeeS]

Unfortunately, it can't be done without rewiring at the TT armbase, though.

Why is this LD ? Surely a simple box with a pair of "phono ins" and "phono outs" and DPDT switch as in your diagram would be simple to build and allow switching between stereo and serially summed mono at the "plug" end of wiring?

Good thread by the way (shame it was marred by some useless, unhelpful ramblings). I am tempted to build something along these lines for my system. I have had to change to an auto LT (SL-QL1) and p-mount monos are hard to come by and a bit of a PITA to swap out, so your method is very simple and looks easy to try out.

Cheers...

[Ldg]

Unfortunately, it can't be done without rewiring at the TT armbase, though.

Why is this LD ? Surely a simple box with a pair of "phono ins" and "phono outs" and DPDT switch as in your diagram would be simple to build and allow switching between stereo and serially summed mono at the "plug" end of wiring?

Hi Lees. The problem is the blue cartridge wire. Sometimes it is connected to ground in the armbase termination. But even if not, this is not a ground when wired in series, yet one of the coax shields would connect to it - hence effectively it would be unshielded. And lastly, cable capacitance would be different across the two coils.

It's possible to wire correctly at the headshell, as per b_50's post and my follow up though.

[LeeS]

Yes.... I see now, what you're saying. Of course. It's obvious when pointed out.

Well with my TT being a p-mount, there is no head-shell or opportunity to wire at the arm base (there isn't one), but I guess a switch could be added near to the PCB where the arm-leads exit the arm, before they go on their way to the arm-leads proper. I will have to do a bit more research I think.

Thanks for the response though...

[josephazannieri]

Yo Coffee Philand other mono seekers:

@ Phil: Thanks for kind words.

@ Phil and everybody else: My use of mono switching is primarily for playing mono records. If the record is in stereo I don't parallel it. I can see where there would be additional issues caused by having 2 different signals on the different channels, as you have with a stereo record. Of course in that case there would be major isues with cartridge channels loading each other, because of the amplitude and phase differences between the channels. Summing stereo records for mono is a completely different game.

And good luck from that grateful, but stereo-fried old guy,

Joe Z.