I've been very close to grabbing a WooAudio WA6 headphone amp for my AKGs (701s). My questions is two fold (1) does the following make sense technically and in terms of quality, and (2) might it solve my problem below.
First, instead of grabbing the WA6, which is a head amp only, I was thinking about getting the WA2 which is a headphone amp and preamp. (here). Right now I just have a Marantz PM7001. I'd like to use that for a power amp only (it lets you) for awhile before I can afford a separate power amp (probably 4-6 months or so). Does that make any sense, or am I better off just sticking with the Marantz until I can afford both (i.e., will using the WA2 and the Marantz as a power amp be worse or no better than what I have now). If it doesn't make sense, I could just use the WA2 as a head amp until I get the separate power amp, if I'm sure that's what I want to do.
Second, on to my problem. I have a Rega P2 with an Exact 2 cart (yes, I finally upgraded), a Bellari VP-530 tube phono preamp (basically a VP-129 with a usb out), the Marantz PM7001 and some AKG K701s (also the ProAc Tablette speakers, but they aren't relevant to this question). I have a Classic Records release of James Horner's score for "Glory" (if you haven't heard it, it is beautiful). Through the headphones, when things start to get really heavy (loud timpanis and such) it gets really muddled and distorts. To troubleshoot, I tried turning the volume on the phono preamp up most of the way, and the volume on the Marantz (which is currently driving the headphones) down. It sounded worse - which I expected. Then, I turned the phono pre volume down below where it was before. It sounded much better, but I had to turn the volume on the Marantz up all the way, and I still don't have the volume I want. If I switch to the speakers, they get plenty loud. (that is, I have to turn the volume up higher when I use the headphones).
I'm not well versed in how amplification works, at least not well enough to figure out whether the distortion is coming from the phono preamp or the amp (or somewhere else - I hope not).
Would a headphone amp perhaps solve this problem?