Interesting comments about gain. I wonder of this is partially a factor here. I do recall with the Purifi, I kept turning up the volume to try and get more ‘life’ out of it. With the 606, I could happily listen at lower levels. Perhaps the more perfect an amplifier is, the better it sounds reproducing music at (roughly) the kinds of levels the music was played at during recording (assuming real world instruments here!). Perhaps I should just stop fretting about the reason(s) and just continue to enjoy my 606 though
Life’s too short.
Understanding the reasons for things is the path to enlightenment. Then you are in control of your preferences rather than being pushed to and fro by what they seem to be on any given day.
The Purifi has lower voltage gain than many traditional amps. So you do have to turn up the preamp more. If the preamp lacks sufficient voltage capability, you may push it into clipping, or you may never reach full amp power. That is not the amp’s fault; it is the amp’s requirement, usually easily fulfilled by preamps that either pass through sources that have sufficient output of their own or that provide some line-stage gain for those that don’t.
My old analog source devices drive line-level output as defined before the digital era: 1 VRMS at peak output. CD players pushed that standard up to 2 VRMS. That is a 6 dB difference—even the earliest digital sources need 6 dB less gain than, say, a tuner of the era, to achieve the same listening level.
My Hypex-powered amp needs 2.4 VRMS to be driven to full power. The active line stage in my preamp, when engaged, provides far more output than that, and thus requires only the bottom portion of the volume control’s range. When its line stage amp is switched out, the volume control has to be much higher to produce the same listening level. When I switch in the line stage, suddenly everything “comes to life”. Sure it does! It’s 10 or 12 dB louder at the same volume setting. Comparing the sound with and without requires real effort not to fool myself as a result of that difference in level. Read, when I leave the line stage bypassed and crank it up to the same loudness, it sounds great, if I don’t run out of the volume-control knob’s range first.
I have tape players that only put out 400 mV at 0 VU on the tape. Without the line stage amplification, I can only drive my power amp to a fraction of its output.
Gain management is important. There’s a reason good preamps of the past provided active line amplification, even if modern DACs that put out 4 VRMS at 0 dB (digital) don’t need it.
Or, maybe your old amp has a bit of the old loudness control effect baked into it. Hitting the loudness button always seemed to “bring to life” the sound at low listening levels.
Rick “knowing what and why is the whole point of ASR” Denney