Well, at least I think that he is...

First; many, many thanks for all of the advice and suggestions given. It is
excellent how members respond when the distress flare goes up and boy, have
I been distressed over the last few days with this. The initial line of
attack, as a result of your suggestions, was the speakers. Having checked
them out, following your guidance, I could not understand why I continued to
draw a blank. In the end my paranoia forced me to stare menacingly at the
computer speaker input sockets. In the end, I had someone fumble about
inside the four month old machine and there, was a loose connection. That
cleared up the play back anomaly. I think that this problem occurred
coincidently while I was trying to get to grips with another problem which I
set aside whilst trying to deal with this.  Having sorted this out I went
back to my original problem. Malcolm's difficulties did ring a distorted
bell and his suggestion did the trick.

Thank you.

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Malcolm Rockwell
Sent: 14 May 2009 17:39
To: [log in to unmask]
Subject: Re: [ARSCLIST] Technics SP-15 to computer nightmare

Odd that this phasing observation should arise now.
I have been transferring some mono 1930s ARC test pressings in stereo 
and noticed that the two signals were seemingly out of phase. I 
initially thought it might be an incorrectly wired cart, but that turned 
out not to be the case. Next I looked at the record groove - normal. 
Then I looked at the signals on the computer again. The run-in to the 
musical content IS out of phase (that's where all the rumble shows up), 
but the musical signal itself is in phase!
Shelving at around 80 Hz and notching at both 60 and 120 Hz should do 
the trick without adversely affecting the program content. I'm going to 
try that.


Tom Fine wrote:
> One possibility is that the 78 transfer captured enough rumble to set
> the computer speakers flapping. That would make them sound distorted 
> because most of the mechanical energy is drained off making the 
> speaker "plut". Headphones and car speakers might have no energy 
> transfer at the rumble frequencies and thus be immune to the problem. 
> My experience is that a rumble filter is always a good idea with 78's, 
> and it's better to use it at the same time you're finding the optimum 
> turnover and rolloff settings because killing off the rumble effects 
> other frequencies, and overall loudness of the musical content. 
> Apparently, some of the rumble elements are out of phase to certain 
> musically-relevant elements, so when those elements are not partially 
> or wholly cancelled, they are louder.
> -- Tom Fine
> ----- Original Message ----- From: "Ted Kendall"
> <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, May 14, 2009 5:48 AM
> Subject: Re: [ARSCLIST] Technics SP-15 to computer nightmare
>> Your computer speakers or amp are evidently at fault here - maybe
>> they can't handle the surface noise from the 78 - I'd not be inclined 
>> to worry about it...
>> Ted Kendall
>> ----- Original Message ----- From: "gary atkinson"
>> <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Thursday, May 14, 2009 10:23 AM
>> Subject: Re: [ARSCLIST] Technics SP-15 to computer nightmare
>> 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.
>> Gary.