DEQX

@Handymann,

My experience and opinions just represent one data point, of course, and certainly there are those who would prefer to use a DEQX in conjunction with a traditional line stage.

But FWIW my bias, generally speaking, is to place the burden of proof on adding anything to the signal path that isn’t necessary in terms of functionality. And I’ve been sufficiently happy with the sound of my system that I don’t have any desire to consider adding a separate line stage. Also, finding a place to physically put one in my system, which is in my living room, would be problematical from a practical and aesthetic standpoint.

In addition to numerous other system and listener dependencies that would enter into a preamp/no preamp decision it wouldn’t surprise me if in some cases the tradeoff would hinge on whether the DEQX’s balanced or unbalanced analog inputs and outputs are used. I’ve never tried the balanced analog i/o’s in conjunction with critical sources, as my power amp, headphone amp, and my one critical analog source (a Herron phono stage) have only unbalanced interfaces.

Another thing that may be relevant to that decision, depending on the particular system, is that a DEQX doesn’t provide much in the way of gain. See pages 165 and 166 of the manual. And in fact the default/as delivered positions of the internal jumpers which affect that produce a **negative** gain (-6 db) from the unbalanced inputs to the unbalanced outputs. As you’ll see at the bottom of page 165 of the manual that is done to provide headroom for equalization (and for speaker and room corrections, although that isn’t explicitly stated). Although changing the position of an internal jumper can raise the -6 db to approximately 0 db, while retaining the same amount of headroom (which I’ve done, btw).

Finally, regarding the possible use of your DAC in conjunction with a DEQX and/or your Calypso preamp for listening to CDs:  I’ll mention FWIW that while I found connecting the AES/EBU output of my Bryston BCD-1 CD player to the AES/EBU input of the DEQX to be preferable to using the BCD-1’s internal DAC in conjunction with the DEQX’s A/D converter stage, the difference wasn’t huge, and in fact was smaller than I was expecting.

Best regards,
-- Al

Hi Handymann,

It sounds like you've probably already seen the lengthy "Is DEQX A Game-Changer" thread.

I haven't used the streaming function or the Ethernet interface of my HDP-5, so I can't comment on those features.

The speaker and room "calibration" (i.e., correction) functions do indeed entail a substantial learning curve, and can take a lot of time to fully optimize, if you do it yourself. Which is what I did, with my experiences having been recounted in some detail in the Game-Changer thread. However, as you've probably seen at the DEQX site one or two paid sessions of a few hours each with a "DEQXpert," conducted via the Internet, can apparently get you there much more quickly. Also, the numerous other functions the unit provides, including DAC and A/D converter functionality among others, can of course be utilized without the speaker and/or room corrections.

A laptop or other computer running Windows will have to be connected to the unit to perform the speaker and room calibrations, and to introduce frequency response equalizations that may be desired (which is done "on the fly," with its effects being heard instantly), and to set up different “profiles.” When those things have been accomplished to the user's satisfaction the computer can be disconnected and removed if it isn't needed for streaming.

Depending on the inputs and outputs that are provided in the various models, a DEQX can be inserted into the system either before, after, or in place of the line stage. My HDP-5 can be used in any of those ways, and I use it as my line stage, providing it with analog and digital inputs from several sources.

Finally, keep in mind that performing the speaker calibration process, which can bring any speaker that is not "time coherent" (which means most speakers, including yours) much closer to being so, requires that the speakers be moved to a position that is as far away as possible from reflective surfaces such as walls, so that the measurement microphone (which is placed 2 or 3 feet or so in front of the speaker that is being measured) will pick up room reflections to as small a degree as possible during that process. That figures to be problematical with your 410 pound speakers. Room correction, though, is performed subsequently and separately, with the speakers in their normal position.

So was the time, effort, and expense of my HDP-5 worth it to me in the end? Absolutely. And as I described in the Game-Changer thread, with my speakers (Daedalus Ulysses), and in my living room/listening room, probably the most notable benefit was that recordings having mediocre or poor sonics became significantly more listenable, while the sonics of great recordings were not compromised and in some cases became marginally better.

Best regards,

-- Al