View Full Version : radio sound vs cd??

15-01-2007, 12:10 PM
Every time i listen to the radio i enjoy the sound very much, something i have never accomplished with the CD. I always had cheap tuners (a NIKKO previously and a SONY now) whereas my CD's were never in the budget category (a creek previously and a CARY 308T now)

The output of my radio tuner is something less than a Volt, where as my CD has an output of 3.2V (variable). However the radio sounds like it is more dynamic, more live and requires less volume control for the same levels.

How can this be?

15-01-2007, 08:59 PM
Just to make sure i dont give the wrong impression, the comparison only relates to the "gain" of those two sources. Clearly Compact Disc is a superior format from any fm signal and i dont want to stir any conflict in that area. What i state in my previous message is my own impression.
Thanks and sorry for any misunderstanding.

16-01-2007, 09:21 AM
Noted. If I were you, I think that I'd re-run the comparative test with the CD's output turned right down - maybe to only one tenth of the output control's range.

3.2V is an outrageously strong signal - if that is rms then that has a peak voltage of 9V - enough to weakly illuminate a car bulb. The most likely thing (in my experience) is that your amplifier's input circuit is being overloaded. Once overloaded, even though you turn the amp's volume control down, the damage is done: hard, gritty sound. This is because the amp's volume control is usually further into the circuit, not actually at the input sockets.

FM Radio in the UK (and probably everywhere) is compressed, band-limited, has all sorts of distortion problems etc. etc.. Digital Radio, MPEG1 layer 2 (i.e. MPEG2), has another different set of audio problems.

J.A. Boonstra
23-01-2007, 04:34 PM
If you want to lower the output level of your CD-player, please remember that almost all volume/output controls (except the non-mechanical ones) work less wel below the nine o'clock position. It is very well possible that the sound wil deteriorate.
To lower the output of the CD-player, you should try Rothwell inline Attennuators between the CD-player and the amplifier. These inline attennuators will lower the volume approx. 10 dB. Make sure the Rothwells are connected as follows:

CD-player --> interconnect --> Rothwell --> amplifier.

I am well aware, that the signal path should be as pure as possible, but in this case the attennuators will prove to be a "lesser evil" than a volume/output control that is turned back below the nine o'clock position.
An output level of 3.2 V is extremely high (most CD-players deliver approx. 2 V), so a combination of Rothwells and lowering the output using the volume/output control (partially) will do the trick.

J.A. Boonstra

23-01-2007, 09:23 PM
CD-player --> interconnect --> Rothwell --> amplifier.

That's a really excellent solution - many thanks for taking the trouble to tell our members: I absolutely agree with your idea. I think every CD player owner should experiment with reducing the signal level into their amplifier. You can, of course, make an in-line attunuator for just a couple of Dollars with parts bought from an electronics store. Whether you buy or make, the concept is the same: reduce the signal arriving at the amp's input terminal from the CD player to a more realistic level.

25-01-2007, 05:28 PM
Thank you for your replies and suggestions. I will keep them in mind. However for the time being i have found my peace of mind by adjusting the volume of the CD so as the volume pot of my amp to be at about twelve o'clock, more or less.