Sometime ago I acquired a Technics SP-15 deck. I took it, at the time as a "stand by" and it has been "standing by" waiting for it's big moment to arrive. A few days ago that moment arrived and I transferred a 78rpm record from it. As it hit the amp it sounded wonderful, both through speakers and headphones. As it went through the Tascam CC-222SL and onto CD it sounded splendid. Play the CD back on the Tascam, Marantz, Pioneer and even the car CD player and everything is beautiful. Play it back through the computer (desk top and lap top) and the sounds terrible; very distorted and tinny. All the more odd is that when I play back from the computer (either the CD or going in directly through and Edirol interface), through an external amp, it sounds fine, yet when I turn up the computer speakers at the same time what comes out of them directly from the computer is very distorted.
Anything else played in the same way through the computers; vinyl from a Thorens, tape from a Teac, any other CD from the Tascam, radio, DATs, Minisidiscs etc are all fine. After having tried just about every permutation of phone leads and sockets that I can think of I am homing in on the SP-15 deck. The computer seem to doesn't like it directly and though other CD players and amps are happy playing the test CDs that hold recordings transferred from the deck, again, the computer is not happy when it comes to tracks taken from the SP-15. (I created a CD with tracks from various sources and all played fine in the computer other than those taken from the SP-15).
I am about to set off and get the deck tested and it might be worth noting that the power lead goes to an AC Converter as this piece of equipment was from the U.S.A but now resides in the U.K.
Any advice on what could be the cause or how to resolve this conundrum would be greatly appreciated.