So I got the Pioneer Elite A-20 amp on the doorstep today. Hooked it up straight away to spin some vinyl and see if it was going to sound better than my old SX-650.
Problem 1, I'm getting a buzz from the ground wire no matter how much I fiddle with it.
First thing I spun was Greta Van Fleet's 'Black Smoke Rising' EP as it happened to be sitting on the turntable. This is a pretty solid sounding vinyl. It was mastered separately for vinyl (which actually shocked me when I got it as I figured it to be a quickie cash grab when they put it out.) With the loudness button off and the tone controls all straight at 12 o'clock, it didn't sound good at all. Tinny, lacking in bottom end punch. Muddy sounding as well, a real lack of separation between the instruments. I engaged the loudness and tweaked the bass and treble a bit and it was much better, but still not even close to the clarity and soundstage I get from the SX-650.
Then I swapped out the vinyl for Crash. This sounded much better out of the gate. Once the full band kicked in on SMTS though, while it still sounded good, I still think the SX-650 gives it much better separation, clarity, and a wider soundstage. Not to mention, despite their allegedly similar power (the SX-650 is 35 WPC at 8 ohms, the A-20 is 30 WPC at 8 ohms) I had to go to around 1-2 o'clock on the volume knob to get the same volume that I get at about 10 o'clock on the SX-650, and when I got up to that level was when I really was noticing the muddier sonics.
I was really expecting this thing to sound a lot better than it did based on everything I've read on it. I switched over to my CD player next, and fired up one of the 6 'Come Tomorrow' CDs that finally arrived in my mailbox today.
This was a lot better. It was really punchy and I got a lot more volume at a lower level (possibly just due to the harsh mastering?) One of my favorite things about my HPM-100's is how tight, controlled, and punchy the bass is and that really shined through on Carter's kick and Stefan's bass. The intro to Can't Stop was hitting me right in the gut in the best possible way. Fonz on VITR was sublime.
The wife headed to bed then, so I couldn't really test drive it much more for tonight, but given how impressed I was by the CD but let down by vinyl, I wondering a few things:
1. Other than the annoying buzz, the the ground wire impacting the sound in any other way? What are some possible remedies to eliminate?
2. Perhaps the phonostage on the A-20 just stinks? I loaned out my TC-750LC phono preamp (from phonopreamps.com) to a friend, and I'm wondering if I should get it back and try that through the aux input on the amp instead of the amp's phonostage to A/B it.
3. Despite the only 5W difference in RMS output rating between the two, perhaps the A-20 simply doesn't have the cojones to drive those beastly HPM-100's at significant volumes? That leaves me puzzled why I had plenty of power and head room to spare when playing a CD though.
4. Maybe it's simply a matter of the SX-650 pairing better with the HPM-100's? They're designed to go together, after all, whereas with the A-20 I'm pairing a 2016 amp with 1976 speakers.
Anyone have any thoughts here? I ordered some banana plugs for the speaker wire, but I don't think that's going to make any kind of significant difference in the sound.