Recommendations for kit amplifier.

[Exstatic]

Hi I am using a David Tilbrook designed AEM 6000 power amp (that I made from a kit many years ago) powering some Acoustat Spectra 11 hybrid electrostatic speakers.

My plan is to use an active crossover (and discard the passive crossovers in the speakers) and bi-amp the speakers.

I have been pretty pleased with the AEM 6000. Over the years I have plugged a number of mid to high quality amps into my system and have never been dissappointed with the AEM 6000. My suspicion is that it is a fairly clean and faithful amp with not too much colouration. Coupled with the Acoustats it provides fantastic stereo imaging and placement of intruments which I really like.

...But because I assume much better kits are available today I will probably relegate the AEM 6000 to driving the woofers.

My main source is a PC duke box playing uncompressed wav files out through an SPIDF port to a Meridian DAC and into a Audio Reasearch LS7 preamp and then to the AEM 6000 and the Spectra 11's

Can any one make some recommendations on what would be a very high quality kit that I could use to drive the Acoustat electrostatic panels.

Keen to purchase as a kit rather than just buy PCBs and make it up as I don't want the hassle of sourcing components and my skill level is moderate.

Many thanks in advance for your suggestions.

[danielwritesbac]

Originally posted by Exstatic
Hi I am using a David Tilbrook designed AEM 6000 power amp (that I made from a kit many years ago) powering some Acoustat Spectra 11 hybrid electrostatic speakers.

My plan is to use an active crossover (and discard the passive crossovers in the speakers) and bi-amp the speakers.

I have been pretty pleased with the AEM 6000. Over the years I have plugged a number of mid to high quality amps into my system and have never been dissappointed with the AEM 6000. My suspicion is that it is a fairly clean and faithful amp with not too much colouration. Coupled with the Acoustats it provides fantastic stereo imaging and placement of intruments which I really like.

...But because I assume much better kits are available today I will probably relegate the AEM 6000 to driving the woofers.

My main source is a PC duke box playing uncompressed wav files out through an SPIDF port to a Meridian DAC and into a Audio Reasearch LS7 preamp and then to the AEM 6000 and the Spectra 11's

Can any one make some recommendations on what would be a very high quality kit that I could use to drive the Acoustat electrostatic panels.

Keen to purchase as a kit rather than just buy PCBs and make it up as I don't want the hassle of sourcing components and my skill level is moderate.

Many thanks in advance for your suggestions.

1). Don't lose your reference.
Please be cautious! This system that you like so much needs to stay intact. You need to keep it intact because it is a good reference for you. Otherwise, you would not be able to tell if your new purchases are better or not. Certainly differences are possible. I'm assuming that you'd rather have improvements than merely differences.

2). Harder is sometimes easier in the long run.
Next, I'd suggest that you decide what differences you'd like to make and then head on over to the Solid State forum. Its not impossible to get truly high end sound out of a chip amp; however, it is easier to do so with a purpose-made transistor amp. That's my opinion on it. In addition to that comment, I also think that the Solid State forum is a more likely spot to find people who are familiar with the speakers that you own and the needs of those speakers.

3). The type of crossover in use may change your mind.
Recently, I made a series-type crossover for my new compact 1/4 size PA speakers. Although these are using 4 ohm aluminum drivers, the speakers use 1/3rd less current than customary 8 ohm speakers. This is designed for a high class keyboard monitor (121db from 48hz), but I'm saving one over to make an old-fashioned-looking tabletop radio that really packs a punch. I think it illustrates that if you have a series type crossover, then your drivers are carefully matched, and there's lesser probability to see any benefit from active crossover as the efficiency and tonality may already be optimized for the given drivers.
The more customary parallel crossovers can also work quite well if their crosspoints are either very low or very high, preferably both. In this case, one could improve the efficiency by changing to active, but improving the tonality is unlikely or is expected to be minor.
See also Harbeth Monitor 40, although this midband driver http://www.parts-express.com/pe/show...number=264-852 is better than what Harbeth used, because the little Tang (in the link) can do series so you don't have to listen to crossover noise, and thereby, you can construct for yourself a set of test speakers with an extraordinarily high resolution so you can test your high fidelity amplifier projects (with less-expensive risk).

Well, there's what I came up with, but its a mighty tall order, considering #1 above, replacement of an already-good reference.

[pacificblue]

Originally posted by danielwritesbac
using 4 ohm aluminum drivers, the speakers use 1/3rd less current than customary 8 ohm speakers.

Georg Simon Ohm must be spinning in his grave.

Originally posted by danielwritesbac
if you have a series type crossover, then your drivers are carefully matched,

If life was that simple...

Originally posted by danielwritesbac
The more customary parallel crossovers can also work quite well if their crosspoints are either very low or very high, preferably both.

I don't even dare to ask for an explanation of this.

Originally posted by danielwritesbac
you don't have to listen to crossover noise

Cross-over noise?

[danielwritesbac]

Originally posted by pacificblue

Georg Simon Ohm must be spinning in his grave.
. . .

A speaker with a series crossover typically doesn't require as much current as a speaker with a parallel crossover.

[danielwritesbac]

Originally posted by pacificblue
. . .
I don't even dare to ask for an explanation of this.


Cross-over noise?

But, its pretty important, isn't it?

The parallel crossover does typically make a distortion, and we hope its an improvement over not using a crossover at all. Okay. Then, and simply put, we should try to locate these crosspoint distortions at the documented points of lesser sensitivity for the human ear.
For reference, see this diy project: http://www.parts-express.com/project...=MagnaCumLaude
It is a prosound type speaker (because its tuned for success during outdoor use), but it uses high-fidelity in order to stay clear at far field.
Adding approximately 2 inches to the cabinet width may adapt it for in-home use, albeit I'd also relocate the tweeter closer to the midband driver.

Please notice that the crossover points "dodge" the ear's most sensitive frequencies, as demonstrated by this chart:

[pacificblue]

Whatever you wanted to say, remains hidden behind your usual jumping from one unfinished thought to another.

The fun of it is, your not very pro-sound reference has a parallel cross-over.

[Exstatic]

Originally posted by danielwritesbac


1). Don't lose your reference.
Please be cautious! This system that you like so much needs to stay intact. You need to keep it intact because it is a good reference for you. Otherwise, you would not be able to tell if your new purchases are better or not. Certainly differences are possible. I'm assuming that you'd rather have improvements than merely differences.

2). Harder is sometimes easier in the long run.
Next, I'd suggest that you decide what differences you'd like to make and then head on over to the Solid State forum. Its not impossible to get truly high end sound out of a chip amp; however, it is easier to do so with a purpose-made transistor amp. That's my opinion on it. In addition to that comment, I also think that the Solid State forum is a more likely spot to find people who are familiar with the speakers that you own and the needs of those speakers.

Re 1 above: Many thanks for your suggestions. I plan to do things in stages. Starting with Bi-amping.

Re 2 above: Thanks I will repost in the soldid state forum. (I am still learning my way around this site.

Once again thanks for your response.

[col]

Exstatic, Have a look at the 41hz.com amp10 to power your tweeters. Do you already have the active crossover? I use all Elliot Sound Project P09b. They work really well.

col.

[danielwritesbac]

Power tweeters? Oh, linear amps are nice for that. Howabout TDA7294 with really small onboard caps? Its known for a sweet sound at the treble, and adapting it to a treble-only amplifier is even nicer.

[Exstatic]

Originally posted by col
Exstatic, Do you already have the active crossover? I use all Elliot Sound Project P09b. They work really well.

col.

I had been considering the Elliot sound project P09. I had heard elsewhere that active crossovers cloud the sound. Have you found any deteriation in sound quality when you use the active crossover?