I have a handful of mono LPs in my collection, too few to justify a dedicated mono cartridge or listen with only a single channel active. My phono stage does not have a mono input. Assuming normal listening to dual channels, I can think of a few ways to configure the phono stage input:
1. Stereo cartridge outputs to to dual phono input (normal stereo).
2. L or R cartridge output identically to dual phono input (single channel mono)
3. L+R summed cartridge outputs to dual phono input.
I have only used option 1 and the drawback is very audible. The occasional surface noises/pops/clicks can appear to be in the L or R output and are a distraction when all the signal is meant to be dead centre. The vertical out of phase component can cause a spread to the central image. With option 2 the vertical component will appear mixed with the mono central signal. With option 3 the vertical component should be cancelled, assuming perfect gain and phase matching of L, R channels. What are the opinions on the pros and cons of these options and are there any others I have overlooked?
1. Stereo cartridge outputs to to dual phono input (normal stereo).
2. L or R cartridge output identically to dual phono input (single channel mono)
3. L+R summed cartridge outputs to dual phono input.
I have only used option 1 and the drawback is very audible. The occasional surface noises/pops/clicks can appear to be in the L or R output and are a distraction when all the signal is meant to be dead centre. The vertical out of phase component can cause a spread to the central image. With option 2 the vertical component will appear mixed with the mono central signal. With option 3 the vertical component should be cancelled, assuming perfect gain and phase matching of L, R channels. What are the opinions on the pros and cons of these options and are there any others I have overlooked?
Hi,
You can of course simply use Your stereo pickup and amplifier to replay mono LPs.
The real problem though is, that before 1964 a multitude of different EQ-Curves existed which in part deviated considerably from the RIAA standard .. see attached list.
Especially the old 78rpm LPs differ by as much as 14dB from RIAA.
Those will sound seriously wrong replayed after RIAA regardless of a Mono or Stereo setup and its qualities.
I´d suggest You try to figure out after which EQ-Curve Your LPs have been pressed and then decide if it´s worth the effort to invest in a real mono capable preamp that allows to adjust to the required EQ-Curve.
An example of such an preamp is the AS Monophonic that I designed.
jauu
Calvin
You can of course simply use Your stereo pickup and amplifier to replay mono LPs.
The real problem though is, that before 1964 a multitude of different EQ-Curves existed which in part deviated considerably from the RIAA standard .. see attached list.
Especially the old 78rpm LPs differ by as much as 14dB from RIAA.
Those will sound seriously wrong replayed after RIAA regardless of a Mono or Stereo setup and its qualities.
I´d suggest You try to figure out after which EQ-Curve Your LPs have been pressed and then decide if it´s worth the effort to invest in a real mono capable preamp that allows to adjust to the required EQ-Curve.
An example of such an preamp is the AS Monophonic that I designed.
jauu
Calvin
Attachments
@gigigirl
I use mono LP's as a set up tool for my stereo cartridges. When the mono image is central, narrow and stable, I know that the stereo set-up is near optimal. I assume any apparent stereo width on a mono LP is an unwanted artefact. Of course local acoustic asymetry and reflections will spread the mono central image. I don't have a mono switch, and don't even know if it is the best option. I recall that older japanese amplifiers often had L, R and L+R mono settings. This would settle my concerns but sadly it is no longer commonly seen on todays electronics.
I use mono LP's as a set up tool for my stereo cartridges. When the mono image is central, narrow and stable, I know that the stereo set-up is near optimal. I assume any apparent stereo width on a mono LP is an unwanted artefact. Of course local acoustic asymetry and reflections will spread the mono central image. I don't have a mono switch, and don't even know if it is the best option. I recall that older japanese amplifiers often had L, R and L+R mono settings. This would settle my concerns but sadly it is no longer commonly seen on todays electronics.
On my Rogers HG88 Mk 3 stereo amplifier the mono switch connects both disc input channels in parallel and feeds both the L & R amplifiers in parallel.
This works well and, to me, makes sense as the preferred method.
This works well and, to me, makes sense as the preferred method.
Unfortunately, "settling your concerns" isn't in the interest of stereo equipment manufacturers any more, you're right.
The era of "simplicity", along with the dumbing down of the population, is more important.
Bare-Bones amplifiers are all the rage, convenience features lacking.
But indeed, that lowly "mono switch" is the proper way to go, to filter out those nasty noises.
I guess they assume people would not choose to play such "old crap" on their stereos.
Apparently, the best option is using mono speaker. Stereo Speaker only causes phantom cantor issue, comb filtering mono source.
@plasnu, as explained in OP, my small collection of mono LP's don't justify altering my stereo set up. I just want to get optimal results within the constraints of dual channel downstream from the phono stage. I think comb filtering is still a factor in single speaker replay, due to reflections. I am aware that LP's mastered in mono will not sound as intended when replayed dual channel. It occurs to me that some early stereo LP's mastered with hard left and right channels (e.g. early Sonny Rollins) may be preferred as L+R mono. Another benefit to using a stereo cartridge is that the stylus may contact pristine areas of the groove, untouched by previous conical stylus'.
Bon, I totally understand your situation, but I'm always listening to mono recordings with just one side of the stereo speakers. No special mono setup is used. I had a little strange feeling at first, but once I accustomed to it, I can't go back to stereo speakers for mono source. Please try it if you're interested. It's a one minute's experiment just disconnecting a cable from one side. I love mono recordings, and I even always play stereo version of Beatles with one speaker (only L or R is playing at a time).
A lot of rather misguided advice here...
Mono records are backward compatible with stereo equipment so you can in fact reproduce them with the same degree of fidelity as a stereo disc by simply playing them back with a stereo cartridge on a stereo system.
However, you can bring the noise floor down by over 3dB my paralleling the two channels together. Phono preamps used to have mono switches that did this (and rumble filters!) but you seldom see these any more nowadays. A big benefit of summing the two channels together is that you cancel any vertical components of stylus movement (the difference between the left and right channels) which will only contain distortion and noise. Some people like more distortion, but I certainly do not...
As far as the rest of your hifi goes, as long as it's properly set up for stereo playback, you do not need to modify it to listen to mono recordings in any way.
I would not waste my money on special 'mono cartridges' which in many cases are simply stereo cartridges with the two channels paralleled internally with a price markup to match. All LP records made post 1955 (not 1964) will use RIAA equalisation and many cut before this will be fine to use with an RIAA preamplifier as they were cut with fairly similar equalisation curves that will generally resolve to a within couple of dB of the RIAA curve. This is satisfactory given the fact that the fidelity contained on such pressings generally may not be too good in the first place and the RIAA curves treble rolloff occurs sooner than the curves that preceded (2.5kHz, 3.18kHz, 4kHz very rarely), so reduces surface noise any any harsh distortion generated by program material in the 2-3kHz range...
If you don't have a mono switch, then you could build one into your flyout cables by having a switch that connects the two cartridge outputs together before they go into the preamp.
Take care.
Mono records are backward compatible with stereo equipment so you can in fact reproduce them with the same degree of fidelity as a stereo disc by simply playing them back with a stereo cartridge on a stereo system.
However, you can bring the noise floor down by over 3dB my paralleling the two channels together. Phono preamps used to have mono switches that did this (and rumble filters!) but you seldom see these any more nowadays. A big benefit of summing the two channels together is that you cancel any vertical components of stylus movement (the difference between the left and right channels) which will only contain distortion and noise. Some people like more distortion, but I certainly do not...
As far as the rest of your hifi goes, as long as it's properly set up for stereo playback, you do not need to modify it to listen to mono recordings in any way.
I would not waste my money on special 'mono cartridges' which in many cases are simply stereo cartridges with the two channels paralleled internally with a price markup to match. All LP records made post 1955 (not 1964) will use RIAA equalisation and many cut before this will be fine to use with an RIAA preamplifier as they were cut with fairly similar equalisation curves that will generally resolve to a within couple of dB of the RIAA curve. This is satisfactory given the fact that the fidelity contained on such pressings generally may not be too good in the first place and the RIAA curves treble rolloff occurs sooner than the curves that preceded (2.5kHz, 3.18kHz, 4kHz very rarely), so reduces surface noise any any harsh distortion generated by program material in the 2-3kHz range...
If you don't have a mono switch, then you could build one into your flyout cables by having a switch that connects the two cartridge outputs together before they go into the preamp.
Take care.
Interesting question - I want to know this, too. In this case rises up an additional question:
is this additional dependent from the cutterhead ? There are versions in stereo - also for mono recordings - go to
http://www.vintagewindings.com/gen pop/8299543VW8335/NeumannVMS/Neumann-SX-74
and
Some Neumann Cutter head spec....
and of course in mono.
Last edited:
@tiefbassuebertr
Thanks for the links. Interesting quote from the Neumann SX74 cutter head document,
"It is possible to cut high quality MONO-disks with the SX74 at levels unattainable with MONO-cutterheads".
Since the SX74 is a stereo cutter, it is a fair assumption that such disks will replay more accurately with a high quality STEREO cartridge rather than a zero vertical compliance MONO cartridge. This persuades me more towards sticking with my stereo cartridges but still no consensus about the best input configuration. I wish I had access to one of those '70's amplifiers with L, R and L+R mono. The question could be answered in 30 seconds. Sigh.
The increased S/N ratio of L+R is persuasive on technical grounds but as we are well aware, things are not always as they first seem (with vinyl).
Thanks for the links. Interesting quote from the Neumann SX74 cutter head document,
"It is possible to cut high quality MONO-disks with the SX74 at levels unattainable with MONO-cutterheads".
Since the SX74 is a stereo cutter, it is a fair assumption that such disks will replay more accurately with a high quality STEREO cartridge rather than a zero vertical compliance MONO cartridge. This persuades me more towards sticking with my stereo cartridges but still no consensus about the best input configuration. I wish I had access to one of those '70's amplifiers with L, R and L+R mono. The question could be answered in 30 seconds. Sigh.
The increased S/N ratio of L+R is persuasive on technical grounds but as we are well aware, things are not always as they first seem (with vinyl).
For decades, since stereo came about, the MONO button/knob was the answer to playing a mono recording.
It was on virtually every amplifier control panel, from stereo consoles, to high end components.
You simply pushed the button, eliminated any annoying stereophonic artifacts, and enjoyed to music.
Simple!
Yet, threads like this go on for eternity about crap.
Parallel the damn signal and be done with it.
It was on virtually every amplifier control panel, from stereo consoles, to high end components.
You simply pushed the button, eliminated any annoying stereophonic artifacts, and enjoyed to music.
Simple!
Yet, threads like this go on for eternity about crap.
Parallel the damn signal and be done with it.
There was a thread about this fairly recently looking at the 3 main methods of getting to mono and if any of them had a real advantage. The conclusion was that a simple passive mono at line level will get you 80% of the way there and that a lot of discussions on mono cartridges forget that fact that you get noise in more than the vertical plane.
Won't stop me lusting after an old ortofon mono or using the mono MC I had made for me
Won't stop me lusting after an old ortofon mono or using the mono MC I had made for me
So far, that's always been the assumption and thought that offers of mono cartridges is for just make money. But after some listening tests I don't think so anymore.
Intetesting versions zu create mono signal are described here in German:
Mono-Brucken am Stereo Abtaster - Mono - Analogue Audio Association
Last edited:
This maybe works for mono pressings from the transitional period. True mono pressings have completely different grooves. Anybody here can help me with english translations of "Seitenschrift" and "Flankenschrift"?
mono lateral recording & stereo 45deg recording.
dict.cc dictionary :: Seitenschrift :: German-English translation
dict.cc dictionary :: Flankenschrift :: German-English translation
dict.cc dictionary :: Seitenschrift :: German-English translation
dict.cc dictionary :: Flankenschrift :: German-English translation
My translator gives "Seitenschrift" as lateral mono and "Flankenschrift" as 45/45 degree stereo.
The Apt Holman preamp offers several options
You could consider duplicating some or all of these functions in your own DIY equipment designs.
BTW, 1908s audiophiles really loved discovering the huge amount of processing applied to Stevie Nicks' voice on early Fleetwood Mac records. The Left Minus Right feature of the Apt Holman preamp (param2 = 0.50 above) showed just how, um, over-produced those records were.
_
- Output_Right ("O_R") == Output_Left ("O_L") == Input_Left ("I_L")
- O_R == O_L == I_R
- O_R == O_L == (I_L + I_R) / 2
- O_R = (param1 * I_L) + ((1.0-param1) * I_R) potentiometer sets 0 < param1 < 1
- O_R = (param2 * I_L) - ((1.0-param2) * I_R) potentiometer sets 0 < param2 < 1
You could consider duplicating some or all of these functions in your own DIY equipment designs.
BTW, 1908s audiophiles really loved discovering the huge amount of processing applied to Stevie Nicks' voice on early Fleetwood Mac records. The Left Minus Right feature of the Apt Holman preamp (param2 = 0.50 above) showed just how, um, over-produced those records were.
_
Last edited: