Hi I met this from John kenny on the net:
"RF Attenuators have been known about & used for many years in both audio & cable/satellite TV reception.
These particular attenuators are in-line adaptors that can be connected at the start or end (or both?) of your SPDIF cable. The idea behind using these attenuators on a digital cable is to reduce the strength of the signal. As a consequence
the signal reflections are also reduced by twice the amount. Reflections are an inevitable occurrence that arise when a high speed signal meets an impedance blip on it's passage from transmitter to receiver. These impedance issues could arise in the SPDIF transport, SPDIF connectors, SPDIF cables, or SPDIF receivers. These reflections are one of the many sources of added jitter in every digital system. Reducing the strength of these reflections should result in a reduction in the jitter generated by the transport to DAC connection. There are many situations where this should result in better sound, for instance, it may be a good way of reducing the sonic penalty usually incurred in using a BNC to RCA adaptor. So this could mean that by using these attenuators an RCA input on your DAC should now be about the same sonically as a BNC input. "
I got an email form Fran Morrin who wrote a fine review of the the modded HiFace MK2 ( I hope he will not mind that I publish a part of his email here):
"Like you, I bought a range of attenuators, 6, 10 and 15dB ones. I knew I wanted them for a few different digital sources, so I got 2 of each I think. Anyhow, the 6dB one was the max I could use with my Squeezebox duet - the DAC I'm using with it wouldn't lock after that. My CDP is a bit different. It puts out a high level SPDIF signal, so it needs to be really knocked back for the DAC to work OK with it. I'm using 2 x 15dB ones with that.
So I guess its a case of trying a few and seeing what works best for you. I can't say whether 6 sounds better than 10 etc, because I'm not really set up to be able to test that easily. However, I hav ea squeezebox 3 and I did try the 6dB and 10db attenuators but couldn't really discern any difference between them. I reckon that some DACs will react differently than others..", I found out -6dB on my Wayne modded SB3 made to my
surprise a discernible improvement in transparency, bigger 3D rendering of instruments and more body to voices in space, and most important more lifelike less an expression of electronic gear
I have a BIG SMILE
