TDS "True Dimensional Sound" Black Box

has anyone had any experience in using one of these "black boxes" that supposedly recovers musical nuances lost in the recording process and if so, what, if anything did it do in your system??
I have a few of these.

To be honest, I find they do not offer anything in terms of "recovering musical neuances lost in the recording process". In fact, in some systems, they can do some serious damage to the music.

Basically, they rob Peter to pay Paul. They take away from some frequencies, and put more energy into other frequencies.

This is noticeable in some systems and not in others. I have found that they can have these problems arise in some systems just by changing out a CD player.

So, I sound like I am not a fan of the TDS, don't I? Well, that's not really the case.

Where they work, if you need them, they are nothing short of a gift. In fact, I wonder why more people don't at least give them a try.

What they actually do is double the volume of a system. And, while that isn't so critical for most of us, anyone using a low powered amplifier that has real problems in driving a loudspeaker may just about find their answer. Just think, someone with a 3 watt amplifier who has found only two or three loudspeakers they can use, all of the sudden now can find 20.

As an example, a friend and I were searching for a pair of loudspeakers for his 25 watt AudioValve integrated. It's really a stellar sounding amplifier, but it has one big problem - those 25 watts feel like a lot less than 25. Even at 90% - full volume, the level produced with most "easy to drive" loudspeakers was lower than acceptable(almost a low - medium listening level). In fact, there were basically two loudspeakers we found that the amp would drive, one of which he bought.

Ah, but by chance we stumbled upon the Acoustic Research TDS, and now were making the same sound at only 40% on the volume control. We now had enough power to drive a good deal more loudspeakers.

For a while, in different situations, we could detect no sonic drawbacks. In fact, I gave a couple to a friend who declared it to should mandatory in every system after he performed a couple of intelligent mods. However, since then, I have noticed that there are situations where the TDS takes away from the music, and if you unfortunately fall into one of those circumstances, the TDS definitely ruins the experience.

I suggest you look into the AR TDS, as the cost is far lower. If you can't find any and are interested, please let me know - maybe we can work it out so you can have a listen if things are convenient.

In the end, I suggest you give it a shot if you are in need of the increased volume. Otherwise, it will not make the music better.
I recently purchased one of these for a very low price. I found that it did boost certain aspects of the sound and, with certain CDs seemed to add detail and volume. On others, however, it seemed to add a grittiness to the sound. For example it did a nice job with a recording of Rachmaninov Piano Concerto #2, opening up an otherwise "cloudy" recording. On the other hand, a solo piano performance by Vladimir Horowitz became less smooth and poetic IMHO. As a fan of tube sound, it seemed to take a little of the sweetness out of Vlad's performance. For me, the jury is still out but, I thought I'd send along my impressions.
I have had the AR TDS box for two months and I belive it works well on average recordings, DVD and satellite sourced sound. I never had a volume problem with my system since I match my equpment fairly well. It does take some of the warmth out of certain recordings and if there is serious listening to be done I usually kick it out of the system and remove the additional RCA's. Another pair of RCA's and just the fact the signal is passing through another device will degrade sound to some extent. But for casusal listening, movies and DVD perfomances that are ususally average recordings at best it works quite nicely. If your a purist and you have your great recordings to listen to you will find that it may get into the way. It works especially well when you listen at low volume levels since it restores the detail lost at low volume. I would recommend its usage and as you become more familiar with its sound and your souces you'll know when to use it. You can purchase it for pennies compared to the cost of a good system, it cost no more than a good bottle of wine. It's all for fun anyway you look at it.