Preamp Short List

JoshK · « **Reply #60 on:** 16 Dec 2004, 05:56 pm »

It really is all about how you use it with a piece of gear like the DEQX or TACT. If you have interest/time/and brains to figure it out I think you will be rewarded hansomly, but if you want plug and play look elsewhere.

I think people who see these as only room correction tools have missed a huge point about what all they can do.

ted_b · « **Reply #61 on:** 16 Dec 2004, 06:07 pm »

Quote from: 4ears

Before buying the DEQX, you should read the portion of this journal concerning "Equalization . . . can't fix your room acoustics."

http://www.audioperfectionist.com/PDF%20files/journal1rl.pdf

Actually, I consider this a must-read for anyone contemplating audio purchases. I don't always agree with the author, but he provides food for thought.

Personally, the DECX does not interest me. Stereophile likened it to a 4000-band equalizer, and another reviewer mentioned it has a 200-page ...

So...sounds like the DEQX is a unit that one should trial or demo before buying? OK, thanks. By the way...I would think this skepticism and cautiousness should be applied (although not so damn negatively) to all audio purchases.....and I do.
Ted_B

4ears · « **Reply #62 on:** 16 Dec 2004, 06:16 pm »

Ted,

I am glad you at least are not ignoring the journal I linked to. The author eloquently and definitively lays out the case against room EQ.

Apparently this is a hot-button issue.

Well, that's the way it goes. All I can say is that I would not touch the unit with the proverbial ten-foot pole as it runs counter to everything I want in high-fidelity music reproduction.

JoshK · « **Reply #63 on:** 16 Dec 2004, 06:19 pm »

FWIW, I am interested in getting the DEQX and I will absolutely not use it for room correction. I think the real benefits it yields are not part of room correction.

4ears · « **Reply #64 on:** 16 Dec 2004, 06:37 pm »

Josh,

It might be a fine preamp, but its claim to fame lies in room EQ, and that's where a lot of its price comes from. I don't like to pay for features that I don't use.

I grew up before remote controls were invented for TVs, so that might account for why I don't need one for an amp or preamp. My turntable doesn't even have automatic pickup of the arm at the end of a side. I don't think the preamp needs to be reinvented, just refined with modern caps and that kind of thing.

JoshK · « **Reply #65 on:** 16 Dec 2004, 06:41 pm »

Quote from: 4ears

Josh,

It might be a fine preamp, but its claim to fame lies in room EQ, and that's where a lot of its price comes from. I don't like to pay for features that I don't use.

I guess I disagree then. I think its claim to fame is in its FIR implementation, at least in technical circles this is what is touted. I think it is a marketing thing why the room correction is trumpeted. Most of the possible users/buyers won't know enough to use it for what it is really made to do which is why they sell the room correction idea. Room correction is far simpler to implement than FIR crossovers.

woodsyi · « **Reply #66 on:** 16 Dec 2004, 07:41 pm »

I agree with Josh in that it's the digital crossover capability -- variable frequency, slope and most importantly phase and time correction -- that has me intrigued. But as an analogue devotee, I am leary about putting everything in the digital realm to process the signal. From what I remember of Fourier transforms, it still is an approximation and not a replication of the original signal. What signals are we losing in the process of deconstruction and reconstruction? Even if we get a very good approximation (almost identical) of the primary frequecies , how do we know if secondary and tirtiary information such as harmonics and their interactions come through in the process?

doug s. · « **Reply #67 on:** 16 Dec 2004, 07:50 pm »

my take on all this is that it's the x-over that's so nice. even if in the digital domain, if the processing is done at 24 bits/192khz, the errors become to small to decipher w/the human ear. even at the relatively neanderthal redbook cd walues of 16bit/44.1khz, it's still only half-bad, compared to good analog...

and, these errors are so much smaller than passive x-overs, it's really a non-issue, imo. this is why i, also, am interested in this stuff.

re: modern technology, i was old enuff to grow up during the b&w tv era, forget remote control tv. but i am not against progress. which is why i use a tonearm lifting dewice to raise the arm off the record of my fully-manual turntable at the end of a record, & which is why i won't consider purchasing a preamp unless it has remote control.

ymmv,

doug s.

JoshK · « **Reply #68 on:** 16 Dec 2004, 08:07 pm »

Quote from: woodsyi

I agree with Josh in that it's the digital crossover capability -- variable frequency, slope and most importantly phase and time correction -- that has me intrigued. But as an analogue devotee, I am leary about putting everything in the digital realm to process the signal. From what I remember of Fourier transforms, it still is an approximation and not a replication of the original signal. What signals are we losing in the process of deconstruction and reconstruction? Even if we get a very good approxim ...

I am speaking as a numerical analyst (mathematical computation) here, not as someone who knows a lot of the specifics of DSP processing. A few things I would note is Fourier Transformations (i.e. from an infinite perspective) are 100% accurate, not an approximation. However, the FFT is a numerical method of approximation. The bound on error of the approximation is well behaved and easily determined.

Second point is the signal coming in, assuming it is digital (from transport) is already a discretized representation of the original signal and only needs a finite number of terms to represent with 100% accuracy the discretized signal. Now whether or not the FFT on the discrete signal introduces more errors, I am not sure, but I assume it probably does. However this is of little consequence if analysed appropriately. There is a lot known in this realm and the technology is getting there quickly where we can implement it reasonably well, not just on paper.

ted_b · « **Reply #69 on:** 16 Dec 2004, 08:11 pm »

Quote from: 4ears

Ted,

I am glad you at least are not ignoring the journal I linked to. The author eloquently and definitively lays out the case against room EQ.

Apparently this is a hot-button issue. Well, that's the way it goes. All I can say is that I would not touch the unit with the proverbial ten-foot pole as it runs counter to everything I want in high-fidelity music reproduction.

I read it! Hardesty is a well-known writer, some like him, some don't. What I was commenting on is the school of thought that says just because it's new it's bad, even if I haven't heard it (or in some cases, especially if I haven't heard it). The cautiousness should be there, but so should some open-mindedness toward new ideas. BTW, most of the document is 5 years old, a lifetime in the world of technology. Back in 1999 I would never have guessed that I'd be thinking of adding compute power to fix audio issues. Today, well, I'm willing to give it a thought.

Ted_B

woodsyi · « **Reply #70 on:** 16 Dec 2004, 08:27 pm »

Josh,

Do these have an anolog input coupled to an ADC?

JoshK · « **Reply #71 on:** 16 Dec 2004, 08:33 pm »

Yeah I believe they do.

woodsyi · « **Reply #72 on:** 16 Dec 2004, 09:10 pm »

In that case, I really would like to get some feedback from those of you with either DEQX or DACT who have played a record or two through the ADC/digital processing/DAC cycle.

JoshK · « **Reply #73 on:** 16 Dec 2004, 09:20 pm »

I am curious about this myself.

4ears · « **Reply #74 on:** 16 Dec 2004, 10:12 pm »

Quote from: ted_b

BTW, most of the document is 5 years old, a lifetime in the world of technology.
Ted_B

But the thesis of his argument against room EQ is timeless.

doug s. · « **Reply #75 on:** 16 Dec 2004, 10:19 pm »

Quote from: 4ears

Quote from: ted_b
BTW, most of the document is 5 years old, a lifetime in the world of technology.
Ted_B

But the thesis of his argument against room EQ is timeless.

yust as the thesis of those who thought the earth was flat, so long ago, was timeless?

doug s.

Val · « **Reply #76 on:** 16 Dec 2004, 10:45 pm »

or why the Inquisitors didn't need to see the moon's craters through Galileo's telescope because according to Aristotle, as a heavenly body it had to be perfect.

Val

4ears · « **Reply #77 on:** 16 Dec 2004, 11:13 pm »

Perhaps one of the 100 billion possible permutations of the 4000 band EQ will be just the ticket. I'm confident your calibrated microphone will be satisfied, anyway.

You can refuse to read what Hardesty wrote because it doesn't fit your preconceived notions, but that isn't refuting his argument, it's just ignoring it. Galileo: "And yet, it moves."

Val · « **Reply #78 on:** 16 Dec 2004, 11:29 pm »

The microphone? How about my ears? I will give you the same example again, a bit more detailed. You have installed two huge and expensive bass traps and that 100Hz bump still has you on the verge of going crazy. Please tell me why it's so absolutely unacceptable to lower it just a bit with the DEQX (or any other devilish invention) so that you can hear some music instead of the boom, boom?

Val

4ears · « **Reply #79 on:** 17 Dec 2004, 01:28 am »

There's nothing wrong with judicious use of an equalizer to change a recording you're listening to. But it is much better to fix the acoustics of your room if there is always, say, a problem at 100Hz, than to use an equalizer to compensate. EQ masks a problem, while fixing a room's acoustics eliminates the problem.

The main issue is that of using a calibrated microphone. Hardesty explains the technical reasons succinctly why this route is not the way to go. If you don't plan to use the device as a room EQ, we are in agreement.