I missed the voting window on features for the new Bottlehead preamp, but when I noted that 8 times as many people voted for a mono switch as for a tone control, I had to comment. I never understood why the industry removed this very useful feature, especially with a high quality bypass. You would be absolutely stunned at how much EQ gets done during the production of a record, not to mention all sorts of other processing. There is EQ at the mixing stage, then more at the mastering stage. Then, sometimes, even more when the masters are converted into various digital formats. Sometimes, there is even EQ at the tracking stage. When the mastering engineer EQs your recording, it is done to his or her taste, in rooms with varying acoustic properties. In short, if you think, under the best of circumstances, that you're hearing what the engineer in the control room heard during tracking, you're kidding yourself.
The best we, as listeners, can hope for is to hear something at least approximating what the mastering engineer heard or at least something that sounds pleasing to us. But how can we hope for that, with a completely different signal chain, and completely different speakers in a completely different room? The answer is that it's almost impossible. In a domestic installation, there will almost always be compromises. The room is almost never perfect. Fortunately, we now have all sorts of inexpensive ways to compensate for that problem. I finally got tired of chasing the "pure" signal path and decided to employ some technology to correct for the deficiencies in my room. That meant measuring the room (I used Sonarworks), then using EQ to build a curve to correct for those problems. Now, a consumer-grade analog EQ would definitely mean some degradation in the sound, and unfortunately, the poor quality EQs that everyone had in the 80s and 90s probably contributed to the widespread notion that all EQs sound bad. But, as I said above, professional grade EQs are used all the time, and do a great job of shaping the sound without undue degradation.
With the advent of digital signal processing (DSP), we can now have EQs that don't compromise sound quality. Ideally, these would be implemented in the DAC itself, immediately before the D/A, and with a software bypass. There are actually quite a few professional interfaces available from Metric Halo, Lynx, Universal Audio, Antelope and others, not to mention relatively inexpensive plug-ins for computer-based music players that support them. In the pro recording world, DSP is finding increasing acceptance, and many engineers are selling off their analog gear as the DSP-based solutions improve.
Unfortunately, there are few consumer DACs that offer DSP EQ. However, RME recently introduced one such product, the ADI-2. It has a 5-band parametric EQ, which is not really enough to do an exhaustive room correction, but it helped me to compensate for some of my room's bigger faults. Even so, it has made a massive difference in our listening enjoyment and I would not want to go back. It feeds a Bottlehead Stereomour Mk1 driving a pair of DeVore Fidelity Orangutan O/96, and sounds lovely.
Obviously, this solution can't work for analog sources, so that leaves an analog EQ, preferably one that is well designed and well implemented that's integrated with the preamp. Live with a good quality EQ for a while and you'll be amazed at how much it will improve your music enjoyment. And for those times when you're feeling in a purist mood, just bypass the EQ. Best of both worlds.
