| eds65gto |
Has anyone hooked a stereo cartrige up to play mono records?
I know a stereo cart. has a higher compliance than a mono cart.
There was an article a looonnngggg time ago about how to wire the stereo cart. but I cannot find it. This would make the cartrige respond only to the lateral stylus motion and not the vert. motion.
Anyone???:smash: |
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| sek |
Hi,
the RIAA standards for cutting/pressing records are actually ensuring mono compatibility for stereo systems (or so I thought).
You have L+R 'encoded' in the one, L-R in the other direction. Thus, if an L-R cut is missing in the groove, your system's L and R channel both should play the mono signal.
An issue is noise in the vertical plane, but can't you simply mix your L and R signals together to get a true mono signal?
Sebastian. ;) |
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| AndrewT |
Hi,
the horizontal wiggles are the mono signal, just as you suggested.
The vertical wiggles are the out of phase information that the stereo cartridge uses to generate the L & R.
If you sum the 2 outputs from a stereo cartridge into an inverting summing stage you have mono, but it's even easier - just switch the 2 signals together and both channels of the following amps will play a double mono signal. The stereo cartridge does have a vertical compliance to allow it to follow the stereo info. Whereas a mono cartridge has a low vertical compliance that would damage a stereo record.
ps I would put the switch in after the phono preamp. That's the way a mono switch works on all the amps that are switchable. |
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| Frank Berry |
Andrew T is correct.
In the past, you merely connected the L+ to the R+ and the L- to the R- of the phono cartridridge.
It's far better to sum them after the preamp so as to maintain the proper loading on the cartridge and minimize the vertical (L-R) information. |
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| sek |
Cool, :cool:
I was just unsure about the loading effect, that's why I've choosen the tern 'mix' (hinting to a low source impedance). ;)
Actually it's rather unimportant wether you mix them properly (with a summing amplifier input) or just tie them together (using a mono switch) as long as you do it after an appropriate gain stage (or impedance transformer).
Cheers,
Sebastian. |
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