I received my unit today, June 25th. Right out of the box it is a great sounding piece. It is not to be confused with an expensive dedicated headphone amp, but it sounds very good already. It is a bargain for 250 USD. I am using Senn 600s and a Cardas cable. Folks here have found that it sounds very different with different phones. That is understandable. The highs are crisp, hopefully not too much so! I am impressed with the bass. It is full and rich, just as I like it. In comparison I have another system with analog and digital sources (using a PS Audio DAC), running through a ASL OTL headphone amp for my Senn 600s. Not in the same league, of course, but so far, so good. My source now is my Dell laptop running Vista and primarily listening to Pandora and Classical Archive Radio from the internet, plus my stored CDs in iTunes using Apple Lossless.
I am not sure I understand you, LingLing. I have read all the stuff here about Beresford and really don't want to get into that. I am just asking if he likes his unit. I do not work for Beresford and have no affiliation with him. I'm just a guy who lives in rural missouri. If you don't want me to post here, just say so.
Its too bad a guy can't just ask a simple question around here. But, I'll try. I have 15 days to evaluate the 7520. I want to have something that is just for the laptop. My other systems serve my needs. I am looking for a simple one box with USB DAC and headphone amp built-in and less than 250USD. The other digital inputs are nice but not necessary at this time. What are the favorites around here? I could go for just a USB DAC and add an amp, as long as it doesn't cost more than 250 USD. Any thoughts are welcome.
I don't want to confuse ANYONE with facts, so I'll proceed slowly.
here is a picture of the 7510's digital input section. I believe (correct me if I'm wrong) that its essentially the same in the 7520. here is the 7510:
now, does anyone see anything wrong, here?
let me point out a few things. again, bear with me, I hope that introducing actual data and design practices won't get anyone mad at me.
first, I don't see any pulse transformers on the coax inputs. I also see the grounds are all common (if the rear panel is metal, but maybe its plastic?). we can't tell what chips TEC aka B uses since someone has scratched off the labels. would it be the user? or the photog? unlikely. it must be someone else, then.
on the 2 opto blocks, I don't see any inductors (which are often typical of even medium-end systems) on the b+ lines to the TORX blocks. I bet they're cap decoupled, only. ho hum.
looking back at those orange rca's, lets just say I've seen better quality at my local radio shack. connectors don't matter as much in digital but those look pretty below-average to me.
I'm not sure I can comment too much on the trace layout but it also looks suboptimal. look at those right squiggles near the tc-7510 print (above it). pretty ugly and not even useful (there's no timing on those lines, I would guess, so there's no reason for 'extra delay'). maybe they used a cheap pc board layout program. either way, it shows a lack of attention to detail or maybe it was ALL auto-routed (brrr!).
the 2nd board, below, isn't even 2 layer (it has topwires on it). and the op-amp seems like it might be essentially a cmoy. certainly unbuffered.
that's just a corner photo. I don't want to spend more time analysing this POS but its not even commercial grade, imho.
This certainly seems like a shill. Perhaps Mr. Beresford has changed his IP by some method? They really need to do a MAC block on this guy. Too bad this prick makes such an enjoyable DAC, it would be a lot easier to hate him.