Is DEQX a game changer?

Drewan & Ptss, thanks for your latest comments, which are valued as always.

Pete, a point to keep in mind is that a downside, or at least a potential downside, of the extraordinarily wide bandwidth of your Spectral equipment can be expected to be increased sensitivity to any RFI/high frequency interference that may find its way into the circuitry of those components, compared to components having more typical bandwidths.

Also, as I pointed out earlier the PreMate, which was well reviewed by Kal and has been found to be beneficial in Bruce's (Bifwynne's) very high quality system, uses a switching power supply.

Finally, it would seem understandable that the internal real estate and the additional power required to support inclusion in the HDP-5 of the touchscreen and its associated CPU and other circuitry could very well have necessitated going to a switching power supply.

Best regards,
-- Al

Ptss, what you say is logical and I understand why this concerns you.

I guess I am fortunate that my HDP3 uses the same linear power supply as the HDP4. However the PDC 2.6 I first listened to and the Premate others here refer to both have 'inferior' power supplies, nevertheless all seem happy so I guess it's a question of personal expectations or the different things each listen for.

I recommend anyone who is concerned about this email Alan Langford and ask DEQX directly: [email protected]

He has always replied to me, sometimes after several days and not always with a first response that answers my question but he is helpful.

The HDP-5 is now the top of the line unit for DEQX. Audiophiles are the target audience. You can be sure that the power supply on the HDP-5 is as good or better than anything they've ever used.

Interesting Psag. Implementation must be the key.

An update: I received my new DEQX HDP-5 from dealer AcousticFrontiers.com a few days ago, slightly ahead of the schedule for this production run which DEQX had projected back in March.

Installing the DEQX component in the system was straightforward, although time-consuming in my particular case because I can’t access that or some of the other components in my system from the rear when they are in position, and also because of reconfiguration of many of the interconnections in the system that was necessary (as described in the next paragraph). But once that was done I was immediately able to listen to music via both speakers and headphones, using the DEQX in its as delivered bypass mode configuration.

I then read through the user manual and the software/calibration manual, and installed and browsed through the calibration software on one of my laptops. As he does with all purchasers of such products, Nyal Mellor of Acoustic Frontiers then provided me with a free person-to-person webinar/software walkthrough via the Internet, which took 70 minutes and was highly informative and helpful. One basic point which was made clear was to avoid over-correcting, which can be tempting due to the power and flexibility of the calibration software. Or if one does want to try an aggressive set of corrections, to also create a more conservative set, store them in different profiles (which can be selected between at the push of a button on the remote), and compare the resulting sonics.

I should mention that insertion of the DEQX into my system has involved changing several things at once. I have replaced my Classe CP-60 preamp with it. Due in part to the limited number of analog inputs provided on the HDP-5 (one balanced, one unbalanced), I am connecting the AES/EBU output of my CDP to the corresponding digital input of the HDP-5, rather than connecting the CDP’s analog outputs to the preamp as before. My other critical source is phono (unbalanced), which I am connecting to the HDP-5’s unbalanced analog inputs. I am connecting two relatively non-critical analog sources (tuner and cassette deck) through a DB Systems line-level switchbox to the HDP-5’s balanced analog inputs, using XLR-to-RCA adapters. I am connecting my Squeezebox, which I and my wife just use for relatively non-critical Internet radio listening, to the HDP-5 via an Analysis Plus optical cable, rather than via analog as before. (My research seemed to indicate divided opinion as to whether the Squeezebox’s Toslink output or coaxial digital output is preferable, and given that and our relatively non-critical use of it I figured it would be best to use Toslink and avoid any possibility of ground loop issues or coupling of electrical noise into the HDP-5).

Thus far I have spent several hours with both speakers and headphones assessing its transparency in bypass mode (i.e., with no corrections or calibrations applied), on both LP and CD, with mostly classical recordings (chamber, symphonic, and operatic), but also with some recordings from various other genres. On some recordings I noted little or no difference compared to my previous setup. On some I noted slight to moderate improvements in resolution of fine detail in complex passages, and in some cases also slight expansion of the soundstage. I did not perceive any loss of transparency of any kind on any of the recordings.

I’ll mention also that as might be expected sonics when listening to Internet radio are vastly improved as a result of using the DEQX’s DAC rather than the one in the Squeezebox, despite the severe bit rate compression of the stations my wife and I tend to listen to.

I will post further updates in the coming weeks as I proceed with the calibration/correction processes, but they will be somewhat slow in coming due to other things I will be occupied with in the near future.

Regards,
-- Al