comparing disc to digital

[rhkrhk]

Using a Soundsmith Hyperion cartridge- Krell phono preamp and preamp, and tape out to a Lyra ADC- (all cables Transparent Reference) I record onto a laptop, and listen via Sennheiser headset/amp. A-B comparisons between phono and the signal from within Audacity showed little difference until i started recording Dixieland. The hi-hats are attenuated in the digital version. I don't use the internal laptop sound card for anything.

I use this short signal path to avoid amps and speakers, and to avoid conversion to flac or wav. (I've tried changing everything but the Lyra - and switching inputs and computers -even to a work station- doesn't seem to make a difference. Exporting to flac or wav makes no difference).

Any ideas? Am I expecting too much??
thanks
rhk

[Trebor]

... The hi-hats are attenuated in the digital version ... Any ideas?

Adjust to taste with Audacity's equalizer : boost frequencies above 8kHz.

[kozikowski]

Does your system support 48000 sample frequency in addition to 44100? That's the video standard and it goes a bit higher up. Koz

[Trebor]

... little difference until i started recording Dixieland ...

The different eras and brands of recordings can have different frequency responses ... http://www.gspaudio.co.uk/78rpm-riaa-equalization.htm

http://forum.audacityteam.org/viewtopic ... 99#p203699

[DVDdoug]

Have you considered buying the CD?

A-B comparisons between phono and the signal from within Audacity showed little difference until i started recording Dixieland. The hi-hats are attenuated in the digital version.

What are your levels like? Are you getting any clipping? You shouldn't be getting any audible difference unless you are driving the ADC into clipping or unless your levels are way to low.

Check Windows Control panel to make sure there are no "enhancements" selected. Audacity itself just captures the digital data and sends it to your hard drive, but Windows sometimes messes things up.

Any halfway decent ADC (or DAC) is better than human hearing,* so unless your ADC is defective the digital audio should be "perfect". The line-input on a regular soundcard is often adequate unless you have audible noise. (The mic input on a laptop is worthless for any "serious" recording.)

Are your levels exactly matched when you A/B? If you are listening for differences between two sources, both sources need to be at the same volume.

Note that even with level matching it's easy to fool yourself in a sighted A/B test. "Audiophiles" often hear differences with "better" cables in sighted tests, but when the test is done blind they can't identify which cable is which.

and to avoid conversion to flac or wav.

What format are you using? FLAC and WAV are both lossless.




* It's tricky to do blind ABX test between an analog source and a digital source, but people have done tests where they make 10 (or so) generations of digital-to-analog-to-digital and then perform an ABX test between the original and the 10-generation copy. It doesn't take a super expensive DAC & ADC to pass that test.

[rhkrhk]

Thanks for the input. I'm recording vinyl generally at 24/96,000 - dixieland seems to require 192K to avoid attenuation of hi-hats. May not be scientific, but I've convinced myself the difference is real.

Levels are at 50%or less of maximum, never any clipping. Comparing phono with DAC output does require changing preamp or headphone amp volume - not perfect but i try to match volumes when comparing sounds.

[Trebor]

Thanks for the input. I'm recording vinyl generally at 24/96,000 - dixieland seems to require 192K to avoid attenuation of hi-hats. May not be scientific, but I've convinced myself the difference is real.

You must be part bat. 96KHz sampling is overkill .

... scientific ...

Have you tried a test to find the upper limit of your hearing, e.g. ... http://www.freesound.org/people/Timbre/sounds/162909/ [ need to download that as the Freesound online player adds artefacts ].