Re: phonograph to usp adapter

Arny Krueger wrote:
"Bob Church" <privacy@xxxxxxxxxx> wrote in message

When I tried to record something with it, it seemed to
both lack and add. It lacked high frequency response and
it added noise. I ran the Audio Rightmark program on it,
and that's pretty much the net of my measurements of it
- it adds quite a bit of noise and it rolls off the
highs. But it only does this while recording. Playback
is near CD quality.
I'm not familiar with Audio Rightmark. (I have a Mac.) Did it compare the same record played two ways?

No, it loops a signal through the record and play parts of the iMic, and measures its performance using standard audio technical tests.

The iMic's specs would come in handy. The iMic is suitable for driving headphones directly, so zero db could be 20 db lower than zero db for line level. If you feed the output to the input, that could make the noise look 20 db higher than it would be with a real line input.

I don't have a theory about the high-end roll-off you saw. I don't know how high the frequency response has to go to sound okay to my ears these days. Maybe I should get out my old audio tone generator and see how well the iMic records high frequencies.


You got me curious. I played some songs from a record
that I turned into MP3 last year. The high frequencies
sounded good. I heard only two kinds of noise: an
occasional pop from the surface of the record, and,
between songs, a faint motor vibration.

The iMic adds some hiss, but if the source is very hissy, then it may be masked by the source.

You got me curious again. I listened through headphones. I heard some popping but no hiss.

During the singer's loudest words I heard a raspy sort of distortion. I hadn't noticed it with my loudspeakers. I've always heard such distortion with LPs. Maybe it comes from producers cutting LPs at the loudest possible volume. Maybe it comes from damage to the vinyl. Maybe it's from my stylus's failure to track. After 30 years on the shelf, that LP was badly warped and I was using a tracking force higher than specified.

(Now I realize that the faint hum I've always heard from
that turntable was not electrical but mechanical
vibration. Because the platter is massive, it's hardly
noticeable except when the stylus is not in contact with
the record.)

Strange.

It's pretty faint. I'll have to investigate whether there's any problem with the rubber suspension of the motor.


It also converts USB digital to analog audio. It is
most valuable to me for a use I did not anticipate:
listening to computer audio files. The iMic provides
better detail than my computer's audio circuitry or any
of the CD players I've owned.

IME the line input on many modern PCs vastly
out-performs the line input on the iMic product.

My Mac has no line input, so I can't compare. Besides, I
haven't tried my iMic with a line-level source.

Didn't you record from the tape outs of your receiver?



I've used it with a turntable and with a microphone. I've been meaning to connect it to a tape deck to see if there are old cassettes I want to record.

A couple of years ago I had three receivers hooked to three good pairs of speakers in three rooms. Lightning hit both my chimneys and knocked a hole in the roof. It killed all three receivers although only one was on and one wasn't even plugged in. Since then I've been using an amplifier that hasn't needed a repair in forty years.
.

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