JuneBug

Having tried on several CD players in the past, I can tell you that I didn't notice any difference in the sound the players were producing, but I could certainly hear a difference in the players themselves. By this, I mean that adding damping material to players, particularly to the underside of the cd tray itself, *always* produced a mechanically quieter player. Particularly with cd changers and their big cd platters, there was a big difference in how much sound the machine itself produced whenver it was opening/closing the platter, or changing from one dic to another. The machines were always much quieter, and just sounded more mechanically robust. Maybe the best analogy I can make is to closing the door on a well made car, where there is just a nice solid thump when it closes, with no rattles or resonance. I would use the sticky aluminum-foil coated tape that's used for insulating pipes, which has a thin layer of foam in it, and stick chunks of it under the chassis shell, and cut smaller pieces that would fit into the little nooks and crannies under the cd platter. Worked great, was dirt cheap and reversible, and it had the same effect on both cheap cd players and high end transports.

I would suggest that you take a look at a streaming media player, like the Roku Soundbridge or the SlimServer Squeezebox. I use the Roku Soundbridge to stream all my ripped CDs, as well as to play Internet radio stations. It's very easy to set up, and is wireless, so it doesn't have to be in the same room as the PC that contains the music. I have used mine for a little over a year, and really like the way it works. It's streaming a library of over 18,000 tracks, and I have never had a problem with it. I can't discuss the Squeezebox, since I've never used it, but I have looked a the specs for it, and it seems to be pretty much the same as the Soundbridge, but with a higher price tag. There are a other media servers out there, but a lot of them seem to have some sort of limitation, like a too-small screen, won't sort properly, etc. The Soundbridge and the Squeezebox do not have theses limitations.

After going through 12 pages of this thread, I am actually quite stunned at how insular the responses have been. Aside from a couple of plugs for Andrés Segovia and Charlie Christian, practically every response has been limited to vintage electric rock from the late 60's to the late 70's. And almost overwhelmingly American and British guitarists, at that. I am therefore forced to try to expand the field by adding the most gifted guitarist I have ever heard, in any musical form: Paco de Lucía.

One thing I would suggest is to check to make sure that you have correctly set the impedence of the receiver. On my own system, I noticed a while back that voices, sometimes had a "gargly" quality. I confirmed it by listening to an old Louis Armstrong recording. It appears that I had my system set for 8 Ohm impedence. I switched it 6 Ohms, and everything was resolved. It certainly was a very noticeable improvement.

I had been lloking for an Academy (like everybody else) for a long time. I had never heard one before, but the consistent praise it has received on this message board convinced me that I just *had* to have one. I had a KV3 for while, but I always thought of it as just a place holder for the Academy. After much patience, I recently obtained a black one on Ebay for(what seems like) a relatively cheap $350. I have been listening to it for about 2 weeks now. No question, it is a far better match to my Fortes than the KV3, particularly at the top end. However, even though it is really good, it still isn't a perfect match. Guess I will have to wait to have enough space so that I can put a Heresy or another Forte in its place.

Hopefully I can add something to this thread. I have had several versions of the Hughes SRS unit, and have to agree that the first (the AK-100) was truly the best. Hughes only made 2 versions of this thing - the AK 100, and the later AK-500. The AK-500 was a rack mountable unit that did not include the LED display. The rights to the technology were later sold, and a company called Nureality started putting out their version of the unit. Their first version was pretty good, but it did not include the filtering that was available on the AK-100 (which was extremely useful on some material). Nureality then came out with very tiny units that were primarily intended for computer speakers. These worked pretty well, but they had far fewer adjustable parameters. An even later version just had an "effect on" switch, with no adjustability. From what I have been able to find, it looks like this last version was the version that was later licensed to Sony and others. The priniple problem with these later units was the cheaper build quality, and lack of adjustability. I loved the SRS units (yes, I had at least 5 versions of this thing), but they were at their best when used in moderation. A little went a long way in opening up the soundfield, especially on Heritage Klipsch. The original unit was the best because you could tailor the effect to the individual source material without too mutch tinkering. The later units, without any adjustability to the effect, often went the overkill route because of their fixed effects. One of the nicest features on these units was the 3D mono effect. I found that this mode really did wonders with old mono movie soundtracks. It even worked very well when sending the 3D mono processed signal to a Pro Logic or PLII processor. It's the one thing I miss about having gone to the Harman Kardon "digital straightpath" receiver I am currently using. If anyone wants to fool around with this technology, the closest equivalent would be the SRS WowThing. It is an updated version of the old SRS technology, in a very small unit. I haven't heard one myself, but everything I have read about them sounds really good, and for around $30, it can't hurt to fool around with a new toy.

You should not have a problem, since LCDs (both direct view and rear projection) do not generate EM fields. Neither do plasma tv's.

The RFI issue I mentioned appears to be inherent to all PWM amplifiers, not just this one. If I remember correctly, it has to do with the way that filtering is applied to remove the high-frequency artifacts from the D/A conversion in the final stage. I am not surprised that the HK isn't selling well at CC. This particular unit has been available since last year, but I had not heard anything about it. Even though HK won an Engineering and Design award at the 2003 CES for the DPR-1001, it doesn't seem like they put a lot of effort into marketing this unit. If you look around for information on these digital amps, you will continually run across references to the Panasonic units, and occasionally the Sharp 1-bit designs, but practically nothing about the DPRs. As for the quality control problems you mentioned, all I can say is that I knew they had some issues with their stuff in the early '90s, but things seem to have gotten under control lately. I knew about QC issues with their CD players, because I had read a lot of complaints about the 8550 changer. I can honestly say that I haven't had sound quality this good coming out of my system since the days of my my old Denon PMA-590 integrated amp. Even my wife noticed the difference, and she usually thinks that I am insane when I try to talk to her about subtle changes in the system from small tweaks.

After reading your post, there is only one other thing I can think of - did you have the receiver near a CRT TV set? One thing that I did read several times when I was researching these amps is that they may be very susceptible to RF interference. If the unit was near a CRT, it may have been picking up the electromagnetic field generated by the tube. I experienced something like this once with my old (analog) receiver. Due to space constraints in my living room, I was forced to locate the receiver relatively near my old 32" TV. That thing put out a wicked EM field. I could feel the hairs on my forarms stand up a foot and a half away from the CRT tube. It created a really annoying whine that would not go away no matter what I did. I eneded up getting an outboard digital processor to connect my sources with fiber optic cable, and that finally got rid of the whine. As for the discounted price, I think that is more a function of HK quickly coming out with newer, more powerful units, and stores needing the shelf space for these, rather than any inherent problems with the DPR-1001.

I have the DPR-1001 as the only amplification unit in my system. My sources are connected digitally (CD & DVD - optical, Cable - coaxial) so that the only Digital to Analog conversion is at the output stage. I think that might be a reason you got bad results. You are daising chaining a bunch of different components to form a long electrical circuit before you get to the speakers. There must be a significant degradation in sound quality by going through so many boxes. Another possibility is that you may be creating ground-loop problems by going through so many boxes. Also, that completly defeats the purpose of digital amplification.

I have had no issues with hiss. I have the receiver connected to Forte I's, a KV-3, and KSB1.1s, and they are dead quiet, in all modes. I had read one other person mentioning hiss (not on Klipsch speakers), but I think that that may just be an individual unit. I really can't say enough about this unit. It has given me everything I was looking for. I don't think I will be upgrading anything else in my system for a while.

Curious that you posted this today, since I just replied to another thread on digital amps in the 2 channel forum. I had been intrigued by digital amplifiers for several months now, since reading so many great things about them on other forums. I had been most intrgued by the Panasonic units, but had been holding out for the newer models. These were supposed to come out this month, but they seem to have been delayed. I started to look around, and found that there are several companies that are making these (Sharp, JVC, etc). Needless to say, JVC is not well known for quality audio, so I was soewhat aprehensive. Then I cam across the DPR-1001. I had previously had a Harman Kardon receiver from the late 80's (HK 385i), and loved the way it matched up with my Heresy's. I was most intrigued about the low-level resolution that these digital amps are supposed to have, and since they were described as working well with relatively insensitive speakers, i was curious to see how thy would do with highly sensitive speakers like Klipsch. The fact that the digital amps are almost 90% efficient in terms of energy consumption was also of interest. After sniffing around, I found a closeout for them at J&R Audio. They gave me a great price, and I walked away with them. I have to say that after 3 weeks, I am still impressed. Right out of the box, even without calibration, it sounded great. The 2 channel stereo sound is absolutly incredible. The imaging is rock solid, the have zero noise (at all volumes), the bass is super tight. I could go on, but you just have to hear them to believe it. And that is just 2 channel stereo. Multi-channel reproduction is just as good. I was watching Master and Commander the other night, and it was like the cannons were going off in my living room! They are also ultraflexible, since each surround mode is independently configurable. The bass management is great, allowing independent crossover settings for each channel, and options for global settings, or independent settings for each input. My system sounded good with my old receiver (Technics SA-TX30), but it is clearly blown out of the water by the HK. One of the things that bothered me the m,ost about the old receiver was that, like most SS amps, it just did not sound right at the low levels that Klipsch speakers usually run on. I always had to raise the volume to a certain point before the speakers would "bloom" into their best sound. This amp does that at all volumes, which lets me run it comfortably at low levels at night, which is handy when you live in an apartment like I do. I don't think you can go wrong with this amp!

After quite a bit about the (mostly glowing) results other people have gotten with these digital amplifiers, I decided to take the plunge myself. I was originally interested in the Panasonic SA-XR70, but they were supposed to come in August, and I have yet to see them available. After waiting and waiting like a 5 year old waiting for Santa to come, I decided to see if there were any other options. I heard good things about the Sharp 1-bit models, but they were only 2 channel stereo. On a lark, I went down to J&R Audio in NYC, and came across the Harman Kardon DPR-1001. My first amplifer was an old HK385i, which I had hooked up to my Heresy's (which I still have), so I knew the kind of sound quality that I could expect. The DPR-1001 won a design and engineering prize at CES in 2003, and had originally retailed for around $1300. They had only two units left, and were trying to clear them out for the newer, more powerful models. The DPR-1001 is rated at 50 watts, but since my HT system is Klipsch all around, I knew from experience that it would be more than enough. They made me an offer I could not refuse, and I went for it. I am happy to say that these amplifiers are the real deal. The low level resolution is unbelievable. The surround channel separation is fantatic, and straight-up 2 channel stereo reproduction can bring tears to your eyes. The difference between it and my old amplifier (Technics SA-TX30) was like night and day. It sounds equally good at low or high volumes, and it did so right out of the box. I have had it for about 3 weeks, and would not dream of going back. One of the best features it has is it's bass management, which allows independent, simultaneous crossover settings to a subwoofer setting for front, center and rear channels. I have finally achieved seamless integration of all the speakers, and could not be happier!

Just wanted to let people know how this experiment has gone. After a bit more tweaking, I ahve come up with a few more modifications to this beast. First off, I used WinISD to model changes to the port length. The CV manual suggests tuning the port to 35Hz, but this ends up creating a noticable hump in the frequency response at around 40Hz that throws things off. I eneded up increasing the factory port length by increasing length 1 inch. This yields a box that, with this driver, is ported to ~28 Hz. This eliminates the frequency response hump, and extends the lowest usable bass with this compbination box/driver. (I would also mention that the easiest way to fool around with various port lengths is to use a cardboard mailing tube, which is dirt cheap and actually is a bit sturdier than the port tube that came with the stock KSW-12). So what has been the final result? This combination gives me all the bass I ever wanted and more. I have deep, fast bass, and I am reaching 20Hz bass without breaking a sweat. With the stock driver, there was little more than port noise at 20 Hz. Now you can actually *feel* those deep bass notes. Also, a nice side effect I have found is that since the box doesn't produce the peaky bass that it originally had with both the stock driver (and the unmodified port, I have been abe to substantially dial back the volume level of the sub, and still get incredible bass response as well as finally getting the subwoofer to "disappear".

SInce I like the effect that SRS produced so much, I ended up buying several varieties of it's implementation. I currently have these versions: Hughes AK-100 Nureality VHT-200 (Vivid 3D Theater) 3 different versions of the Nureality boxes that were intended for portable/computer speakers. Each of these sounds distinctly different from each other. The best is the original Hughes unit. It has additional features on it (a couple of effect filters)that permit much finer control over the final output. The others got progressively worse, as they all eliminated the filters. The versions of this that I have seen on TVs are really bad, since they don't allow any adjustment of the effect at all. After playing with these, I can say that if you can't find the original unit, the Nureality VHT-200 is the best choice. I can't stress enough that the key to getting really interesting affects from these units, especially on high sensitivity speakers like Klipsch is MODERATION. Initially, I thought, if a little sounds good, a lot will be even better. This is not the case. It is very easy to over do the resulting sound, and depending on the source material, can give end up with a disconcertingly *unfocused* soundstage. I have used the units with other, less sensitive speakers (Advent Baby II) and these have benefited enormously from the effects, and are far more tolerant of overdoing it.