How to remove harshness from my digital gear

Steve at Emperical Audio:

I know I have a great deal of ground loop hum (audible from the speakers at all times). How do i get rid of it?

Geoff - the CD sounds thin due to jitter from the badly formed pits. Rip the CD with dbpoweramp to .wave file and then rewrite onto a CDROM using a good writer and you will experience lower jitter. Reclock the CD transport and you will experience even lower jitter.

IME, its easier and less expensive to go the computer audio route to achieve lower jitter than CD players.

Steve N.
Empirical Audio

Robsker - there are two things you can do to eliminate hum, short of buying different components:

1) try changing the AC power for each component. IF they are all on the same circuit, this should minimize it, but may not stop it. Different phases from the panel will definitely cause hum. Lots of separate power feeds to a single system is usually disastrous.

2) Get a transformer buffer/isolator like the Final Drive or a TVC like the Music First to replace your preamp. This will break some ground loops.

Other things that can cause hum are: direct connection of a cable TV system to your system ground. Buy a Jensen RF isolator and insert in the CATV cable to stop this. Some components just have screwy earth grounding, so hum can be impossible to eliminate on these....

Steve N.
Empirical Audio

FWIW, I never play CDs directly on my system anymore. THey get ripped to music server and played from there using Squeezebox or similar network player with external DAC. This approach takes a lot of the guesswork and uncertainties associated with more error prone real time reading of data on an optical disk and the potential effect of this on jitter, etc. out of the process. Not to say that jitter might not be lowered even further in each case resulting in better clarity, resolution etc., , but I find this puts things in a pretty good place soundwise in terms of no inherent harshness in general. Just my experience.....

Also its worth saying that there will ALWAYS be some CD recordings that are inherently bright due to the way they are produced and mastered. Many newer rock/pop "loudness wars" type recordings come off relatively harsh compared to others. Many others that are mastered and produced better do not. More loudness generally means more of whatever there is in the recording to start with, good or bad. When the waveform peaks get clipped in the process, which is not uncommon in many modern pop/rock recordings, well, there you go, it is what it is and best you can do is damage control.

Robsker, good comments by Steve, of course. I would add that if you already haven't things I think you should do early on (in addition to his item 1) would be:

(a)Verifying that the hum is in fact due to a ground loop, rather than being generated internally within an individual component.

(b)If it is in fact being caused by a ground loop, identifying which two interconnected components (together with their AC power wiring) comprise the loop.

Both of those things can be accomplished by a process of selectively disconnecting components from the system, and TEMPORARILY using cheater plugs (3-prong to 2-prong adapters) on the power plugs of suspected components.

If you eventually determine that the problem is due to a ground loop between two specific interconnected components, inserting a quality transformer/isolator between them, as he indicated, should resolve the problem.

BTW, and this pertains to the OP, ground loop-related noise can be present on digital as well as analog signals (assuming that the digital interconnection is electrical and not optical). In the case of a digital signal it will not manifest itself as hum, but can be a significant contributor to jitter, and therefore to harshness. Differences in the type and length of the digital cable that is involved can make a difference in the severity of that effect, although with little or no predictability.

Regards,
-- Al