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 Converting Stereo to Mono to suit PU inputs
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 Return to top of page · Post #: 1 · Written at 7:28:43 PM on 12 November 2009.
Rawprawn98's Gravatar
 Location: Newcastle, NSW
 Member since 12 November 2009
 Member #: 578
 Postcount: 4

Hello, I have a reliance skyraider radio, which has a turntable in the top of the cabinet and picks this up via a mono input labelled PU. I have been using this input to play my ipod through the old amp, which sounds great. The only problem i'm having is the ipod has no option to play with a mono output, so I can only hear either the left or the right channel, which is fine for most songs but with some early stereo songs like the beatles and bob dylan, you only hear the song.
Does anybody know a way around this ? is there a stereo to mono converter available? short of converting all my ipod music to mono I haven't been able to find a solution. Any help would be appreciated!!
Cheers, Phil


 
 Return to top of page · Post #: 2 · Written at 12:23:55 AM on 13 November 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Would actually like to know the impedance that the ipod is outputting to.

If its stereo then there is a likely chance that there is a common earth and the two speaker outputs. You could replace the speakers with resitors and then join the two outputs together via a pair of capacitors so that you do not upset the amps...what ever they are?

Secondly (and phasing is important) try a couple of minature output transformers say Jaycar MM2530 or MM 2532 feed the output of the iPod into each secondary, then either parallel or series connect the primaries (in phase). The reverse of a transformer phase splitter.

You may have to add a resistance to load or restrict the output to the voltage to that (specified) which pick up head generates.

A capacitor may also be needed if its a crystal pick up (high impedance) to match to input to the valve amplifier.

This would also DC isolate the two units. We probably need to see the method of input eg Cathode follower.

Hopfully this will get the thinking caps on?

Marc


 
 Return to top of page · Post #: 3 · Written at 10:11:23 PM on 22 November 2009.
Duconbuster's Gravatar
 Location: Riddells Creek, VIC
 Member since 7 August 2009
 Member #: 526
 Postcount: 123

Ipod Headphones have 32ohms impedance.
New Ipods have FM built into the unit as well, wonder how this would sound?
Maybe worth trying an Ipod DOCK as it allows you to then have remote control etc & has output lines (RCA) to allow connection to normal HIFI AMP with 1k .1v input.
Some time ago I coupled a realistic AM car radio FM converter from the 80's on my Healing 401E, fiddly to set up initially but worked OK. Advantage -no mods needed to radio as it simply goes on the antenna line.
Disadvantage- tuning is done through the converter & not the radios dial.

Paul


 
 Return to top of page · Post #: 4 · Written at 10:28:25 PM on 22 November 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

The dock sounds interesting but will probably be stereo. That can be dealt with.

It sounds like iPod could be fed in as a cathode followe,r into the first audio, if it has a cathode resistor?

Marc


 
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