Bought an Audio Research Amp


I feel like i should preface this with a basic rundown of my system up til now:

 

Pre: ARC LS25 MKII

Amp: Legacy High Current Amplifier (rebadged CODA Stage 3.2)

Dac: SMSL M400

Transports: Auralic Aries Femto/Sony DVP-S7000

Speakers: LSA-10 Signature

Subwoofer: Recapped Velodyne Servo-1200

 

Anyhow, as the story goes, I recently acquired an old Yamaha RX-770 on the cheap, figured maybe I’d gift it to a friend. When I inserted it into my system to test it, I was shocked by how good it sounded. It sounded really close to my separates. Worse yet, the Yamaha actually made much better bass through my speakers (sub was off). It was louder, faster, and better controlled sounding. This was extremely distressing. 

I thought maybe this was due to the age of my CODA, but the yamaha is actually about ten years older, so that didn’t make sense. The best I could come up with was just a poor match for my preamp. I can’t recall the figures off the top of my head, but i did some math when I bought the amp to ascertain if matching them was appropriate, in terms of both input sensitivity and impedance, and recall that both were  toward the bare minimum.

Having read numerous times that the increase in synergy is substantial between ARC components, I started casually shopping online for an ARC amp. I briefly entertained a VT100 MKIII which seemed a good deal, but the price of retubing it currently is around $1000, and i just don’t think right now is the time for me to jump into tube amplification with the soaring prices of tubes.

A 300.2 caught my eye, but I couldn’t find any information online that convinced me that a Tripath class-d design of ten years ago would better a solid class a/b design, and I can’t really afford to buy an amp just to find out.

Fortunately, I came across a craigslist ad a week ago for a D400 located only an hour away from me, at a price that was a fair bit lower than similar models had sold for recently (as per Hifishark). Awesome. 

I spoke with the gentleman who had listed the amp, and it turned out that he was the proprietor of a stereo service center, and was selling it for a longtime customer who had been using it, along with 2 D200’s and a D300, to power an eloborate horn speaker setup, but who had, due to the onset of Alzheimer’s, become unable to manage the complexity of his own system. This is, I have to say, extremely tragic. The store’s owner told me the amp was in great shape, had been well cared for, and due to being used in a high efficiency setup, had never been run hard.

Needless to say I was extremely excited at the prospect of owning a D400. Wasn’t able to uncover much in the way of reviews, but I was able to find that it shared circuit-design lineage with the extremely well-regarded d240 MKII, as well as reports from other users who’d paired it with an LS25 and reported extremely positive results.

So I made an appointment to bring my preamp down and auidition the amp. When I arrived, the store owner was extremely friendly, more than happy to take the time to talk audio with me,  show me his personal system (Threshold/Altec VoTT), and all the amazing gear he had on hand, even though I showed up shortly before his usual closing time. 

And the Amp? I really wasn’t prepared for how colossally huge it was… it really is a monolith, just beastly.As far as the sound goes, well, let’s just say that by the time I’d been listening to it for 5m, I already knew i was going to buy it!

Once i got it home (nearly destroyed my back getting it out of the trunk), and into my system, it sounded even better! Compared to the CODA, highs were more sharply focused, I gained more of a sense of instruments existing in specific “space”, and the bass/mid bass had tightened up considerably while also increasing considerably in terms of volume and impact. Overall, I’d say the sound is   less on the warm side than the CODA, which I think is better for my speakers  which have a pretty laid back character.

I will, say that the amp runs pretty hot, even at Idle. I don’t know if it’s biased pretty hard into class a, or what. Also, it does does take 2-3 hours of warm up before it sounds at it’s best. I’ve taken to power it up the night before if I’m intending to do a lot of listening the following day.

Really, I couldn’t be more ecstatic; I really feel like I took a big step toward being  “there” with my system. Of course that just leads me to thinking about what I need to start agonizing over upgrading next, ha ha!

Big shout out to Kevin at The Stereo Workshop in Eugene, OR for being such a gracious host and giving me such a fair shake.

rfnoise

Had a ARCD400MkII for 17yrs.In 2008, I believe, I was thinking about having it recapped and ARC told me back then that they could not get the big PS caps any more.I ended up selling it and bought a Ref110 and I was really surprised that everything sounded better now.What really surprised me the most was how much better the bass response was.Maybe the D440MkII really did need to be recapped was my thinking.

I had the same experiences going from nonARC solid state to ARC tubes.  Don't get caught up in the power ratings either.  When I got the Classic 120 mono blocks I also had a Parasound HCA 2200ii.  I fought hard to stay solid state and picked up a 2nd HCA 2200ii.  If I recall correctly, when bridged those put out 750 watts and compared to my ARC 110 watts the Classic 120s were more dynamic and had about the same amount of volume/output.  The only limitation I experienced was the GSi75 integrated.  I believe it is due to weaker power transformers compared to my REF 75SE.  I have Wilson Sophias in a large room and the bass would drop out/distort at very high volumes with the GSi75.  It never happens with the REF75.  To think I used to have 750 wpc and now I have 75 and the sound is vastly superior in all aspects. 

 

A wonderful story and thank you for sharing your journey to your exciting sounding system!  

@dhite71 

I went to the ARC website and found the same list you posted. Thanks for that. I noticed that neither the d200 nor the d300 are on that list, which is curious, as they are the lower powered contemporaries of my d400. Also interesting is that I found a n authorized service center (High End Audio Repair, in Brooklyn) that lists the d400 as one of the amps that they service/upgrade.

I’m not entirely opposed to the idea of a tube amp; as I stated in my OP, I had my eye on a VT100 mkiii that was on USAM. It was only $1800, which seemed a steal. I just couldn’t get my head around spending $1000 to re-tube it. Hopefully tube prices come down sooner than later.

oh btw… jealous of your Wilsons. In my speaker musings, I’ve toyed with the idea of trying a pair of Tiny Tots on stands.

@mmarch 

thats just bizarre! I guess I just assumed that the unobtainium parts would be FETs or something, but capacitors?!

I’m assuming that the caps you’re referring to are the 67000uF 75v ( marked c41, c42, c43, c44 on the schematic). 
I don’t pretend to be any kind of tech, but caps that meet that spec seem to be available.

Here’s one from Cornell Dubilier that’s rated up to 100v

Is there any reason it wouldn’t work in this application?

OP,

I had a reluctance to tube amps for a very long time. The idea of retubing. But a few years ago I went ahead. I immediately realized my mistake. It was false economy to me. My system took on a realism and natural musicality (ARC) I never imagined possible (although I had briefly experienced it here and there). But living with it. I will never go back regardless of retuning cost. Realistically when I was working… retubing would be necessary less than once every 5 years. You only live once. I personally wish I had done it sooner.