Yearly Archives: 2015

Dynavector XX2 Mk. II

XX2-1I was without the 17D3 for a couple of months, as I had returned it for a minor warranty issue.  With no new stock forthcoming, the distributor got in touch and offered me an upgrade to the XX2 Mk. II.  It would be factory rebuilt, and I could either borrow it long-term until the 17D3 came in, or keep it if I liked it; the cart would go into their demo stock for use in trade shows.

Turns out I’ve kept the XX2.  Given that I can now actually see the cantilever, it is juuuust a little bit easier to align. From what I can tell, it uses the same basic cartridge body as the 20X2.  Yet the motor and everything else is improved.

As with the 17D3, the XX2 outtracks that piece of shit Ortofon 2M Black I formerly owned.  I will say that from first impressions, I still think I prefer the sound of the 17D3–it is more neutrally balanced.  Granted, the XX2 has not broken in yet, and I have also not been able to further adjust the cartridge loading in the pre-preamp.  I find it to have a slightly “peaky” sound, almost as though I can hear the resonance of the aluminum body manifesting itself in the music.  Not that it is a glaring problem–it’s subtle. And it very well may go away once it breaks in.

After a few months and a more careful alignment, I will have more impressions on this fine cartridge.


Cables, cables…

IMG_20150416_023644Ever since I dumped those crappy Audioquest snake oil cables back to Amazon, I needed to find interconnects.  I checked many brands, and let’s just say that the prices are crazy on some of them.  And each company has its own spin on cables.  Some are pure silver.  Others, silver-plated copper.  Some are pure copper.  Many are bundled together.  Some are braided, like the Kimber Cables.  And the RCA plugs…brass or copper base metal, silver plating, copper plating, cryogenically treated, etc.


From the marketing hyperbole, you’d think some of them would make you shit magical rainbows.

Having read around somewhat, I came up with the idea of using the Silver Sonic cables from DH Labs.  They base their cables on a copper core with a silver plating.  The premise is that lower frequencies travel deeper into the core of a wire, while higher frequencies reside closer to the skin.  With that in mind, they use the copper core to provide better conduction of the lower frequencies, with the silver assisting the top end.  The wires arrived with an attractive blue jacket and directional arrows.

For RCA ends, I used the Neutrik ProFi plugs.  They come with a unique pressure-fit strain relief system, as well as a unique spring-loaded grounding shield that contacts the RCA jack first when being plugged in, and loses contact first when being removed.

While I don’t believe that the metals in the wire are directional (it is, after all, non-magnetic), the arrows do come in handy.  These cables come with two conductors, plus shield.  I hooked these up in a floating shield configuration.  The red and white conductors are connected respectively to the hot and ground on each end.  The shield, however, is connected only at the source end of the cable.  This prevents a potential ground loop situation caused by the shielding.  The arrows then help you connect the correct end to the source and destination.

Other than some of the lettering flaking off, the cables turned out nicely.

On first listen, they do have a clean overall presentation, perhaps a little bit leaner than I’m used to.  The RCA plugs fit snugly on the jacks.  As for noise, they are dead quiet.

Time will tell as to how they eventually sound once I am used to them.  I made three sets so far.  Next time, I may order up some cable sleeving to neaten things up a bit, perhaps even combining the two cables into one sleeve for ease of routing.

Stay tuned.


Can new cables suck? My brief Audioquest experience…

While moving my equipment around, I decided to upgrade a few interconnects in the system.  Rather than reuse some of my older cables of varying ages and quality, I decided to try some of the more affordable Audioquest interconnects, these being the Evergreens.  I also have one of the G-Snake interconnects, an earlier generation.

AudioQuest Evergreen 1m 3.28 feet RCA to RCA 1m 3'4"Ever since installing them, I have noticed two things–a slight lack in bass drive, and increased noise. These interconnects are thin, and the vague explanation on their site does not lead me to believe that there is any substantial shielding inside these.  Even the crappy Monster brand cables are much quieter, poorly built as some of them are.  (I’ve had the RCA plugs come apart on two separate cable sets. Shameful.)  I also have no-name cables that are quieter, if not as transparent.

Thankfully, Amazon has a gracious return policy, and all of the Evergreens are going back.  The G-Snake I will either keep (as it seems a little more robust), or will resell it (as I bought it used).

I am looking at other options that aren’t in “snake oil” territory (or in other words, hundreds of dollars).  Yet it is hard to find any that aren’t silver plated, as those tend to make the sound brighter.  I do not tolerate bright.  Stay tuned.

Hafler DH-101 gets new capacitors.

After 33-1/3 years (give or take a couple of weeks…seriously!), I finally refreshed the capacitors in the DH-101.  A year or two ago, I swapped out the DH-110 for a handful of reasons.  First, I always thought it was a little “softer” sounding, maybe even mushy.  Second, I bought it used, and the front panel and knobs tend to chip off.  Third, I hated the stepped volume control with a passion–at lower volumes, it was impossible to set to the desired level.  Fourth, the switches and potentiometers were quite noisy, and got noisy faster after a good cleaning.

That drove me to put the DH-101 back into the system.  I’d read comments from some owners preferring the 101’s sound over the 110, the background being “blacker.”  And upon hooking it back up, I noticed it was not only quiet, but sounded a touch more precise.  Faster, maybe?  At any rate, the 101, and the 110 for that matter, were both overdue for a refresh.  Time for some new capacitors in the 101!

Rather than buy them individually, I wound up buying a complete capacitor kit.  I might have preferred caps that were a little more high-end, but the advantage here was that these were electrically paired and matched for a much closer tolerance than what I could have bought on my own.  All of the electrolytics are now Nichicon.

The kit was only for PC4, the main audio board.  It did not include power supply caps.  No problem, as I had other plans.  The process went rather well, I’m happy to say, and it did not take long to replace everything.  A couple of days later, I was finally able to give it a listen.

Was there a huge difference?  No.  But I did notice the sound was cleaner and clearer than before, and the tonal balance was subtly better.  It also seems the highs lost a slight bit of roughness.  It did come out quieter than before, although I was also battling some substandard Audioquest cables at the time.

The power supply caps I ordered from Mouser.  The 101 originally had capacitors before and after the 7818/7918 voltage regulators.  Before the regulators were 1000µF 35 volt capacitors, and after were 100µF 35 volt.

Or, so I thought.  Many years ago, I had a similar problem where the power was intermittent, the preamp would only turn halfway on–the sound was distorted, and the LED was dimly lit.  Back then, I had replaced the caps on one side of the power supply.  That fixed it, for a while.

Only after I took the caps out did I realize I’d replaced the originals with 25 volt capacitors.  Which might explain why they failed again!

Nichicon Muse series capacitor

We’re good now, though.  The new caps are 50 volts vs. 35 (or, oops, 25).  I also read that increasing the value could help the sound, so I bumped them up–the 1000µF are now 3300µF, and the 100µF are 330µF.  What are the advantages?  Better filtering (lower noise), and more importantly, increased storage capacity, as that is one function that capacitors provide.  Luckily I found capacitors with the same lead spacing and diameter, as it’s a tight fit.

So, what happened to the sound?  The noise level is very slightly better, to the point of almost not noticing it (as it is already very quiet).  But the drive…the bass is subtly stronger and clearer now that the voltage does not sag.  Very nice!  The heft of the bass improved with the Nak PA-7 in the system (which has, I think, about 132,000µF total capacitance in its power supply), and this helped it along even more.  It’s subtle again, but the preamp has an even more effortless quality than it did before.  I can turn it up and hear no straining whatsoever.

I bypassed the external processor loop.  Doing so freed up a set of RCA jacks.  I have long wanted to have an attenuated output, so I could regain more of the volume control’s range.  One output is still full power, while on the other, I have two resistors per channel (33k, and 8.2k) in an L-pad configuration, giving me ~12dB-15dB attenuation.  Due to the power output of the preamp, I went with 1-watt resistors.

I will likely not take modifications much further, beyond some mechanical changes.  I may change to a star grounding arrangement to get rid of some stray EMI/RFI.  I might rewire it with premium wiring (even though I did a nice job of routing it when I originally built it up) from DH Labs.

Most notoriously are the horrid RCA jacks on the back.  Made of aluminum, the are quiet dull, and they are also loose to the point of rattling.  I need 22 panel mount gold-plated RCA jacks to make a change here, not so much for sound, but to prevent future problems.  All of my cables are now gold plated, so there will be no metal mismatch.

Despite its age, the little DH-101 still holds its own, and is refreshed for another couple of decades.  I am leaning towards a tubed preamp, but this 101 will not leave my possession.  I might match it back up with the M-500t, or I may find a Hafler DH-220 power amp to pair it with.  That would make for a nice-sounding system.


One amp “killing” another? Nelson Pass vs. Bob Carver vs. Rotel

For years I’d used a Carver M500t. Definitely not an ideal amplifier, but it served its purpose, and was reasonably musical. Late last summer, I’d introduced a Rotel RB-1070 into the system. It was one of those issues where it sounded OK, but…well, more on that shortly.

After several months of searching and researching, I narrowed down my amplifier choices to a select few, and narrowed in on a couple that were available for an affordable sum, but were “sleepers” in terms of popularity or partly due to age, yet had sonics that were the equal of others more costly.

Nakamichi PA-7.

What I came into was a Nakamichi PA-7. I am not a big fan of Nakamichi (after some really bad experiences with an OMS-7 CD player, and the ensuing runaround), but I came across this via a note on the ToneAUDIO web site. The original PA-7 (not its later revisions) is a Nelson Pass “Stasis” design–the design was used by Nakamichi under license from Threshold, the high-end amplifier manufacturer. The design is very stable into all impedances, and uses no overall negative feedback. It also has a lot of energy storage–over 130,000 µF of capacitance in the power supply. Pass himself recommends this PA-7.

Keep in mind that Pass also designed the original Adcom GFA-555, another sleeper of an amp.

The Nak amp, though, is a formidable unit. Heavier enough to be a boat anchor, it has machined aluminum handles and heat sinks. The familiar “STASIS” logo adorns the front. The rear is unassuming as well–a pair of RCA inputs, left and right sets of binding posts, and a receptacle for the power cord. Four tall feet allow you to rest the amp on its back.

Despite my modest speakers (my Martin Logan project is still on hold), I immediately heard a difference.

The M500t, as a refresher, was an amplifier whose “transfer function” was modified to sound like an expensive high-end amplifier. (It was one of two models which won two high end magazines’ “amplifier challenge shootouts”, where Bob Carver successfully modified the amplifiers to sound exactly like a specific model of high-end amplifier.) I will admit that the amp did have sort of a musical, flowing quality to it, but it was plagued by a few minor issues, like noise, and possibly not delivering its full power. Age was working against it–the amp is in need of a new set of capacitors, and a full adjustment.

Vintage Threshold Stasis power amplifier.

The PA-7 comes across as a very dynamic and musical amp. Right out of gate, I heard an openness to the tonal quality, and excellent soundstaging. After it had warmed up (and it does get warm!), playing a few specific tracks stressed the amp’s dynamic abilities, effortlessly processing those spikes in the signal without missing a beat (literally). What really stood out was that flowing, musical quality that was inviting to listen to. The inner details really become evident as well, little nuances and textures I hadn’t heard before. The PA-7 upped the game that the M500t was dealing, besting it in all ways. But, to the Carver’s credit, I would not say the PA-7 embarrassed it: if anything, the Carver’s basic sound signature (*cough* Conrad Johnson *cough*) made a stretch towards the higher end, lacking primarily those last few levels of refinement and detail.

And power delivery…the PA-7 seems very effortless, where the M500t seemed to run out of gas sooner, despite both having similar power ratings. The PA-7 at higher levels does not sound as loud–perhaps because it is not straining. One startling aspect of the PA-7 is that it sounds as though a subwoofer is present. It does not boost the bass, but what I am noticing is how powerful the lowest bass notes are. The power reserves of this amplifier are able to deliver those low notes as intended. The M500t could come close at times, and often did, but at the lack of overusing the term, the PA-7 delivers this bass very effortlessly.

The Rotel? This is one of those rare instances where I will say the PA-7 kills the RB-1070 in just about every aspect. Even before the PA-7, I felt the Rotel to be rather unremarkable and bland, and anemic in power. I know it is rated at 130 w/ch vs. the Carver’s 251w/ch (and the PA-7’s 200w/ch), but still, that level of difference should have played out with just under a 3dB difference in volume. The Rotel just couldn’t keep up, and even at lower volumes it came across as being somewhat flat in dynamics. Not only that, I never felt the Rotel to be all that musical of an amp. Analytic? Maybe, if one is trying to be kind. More like bland and lifeless. I never enjoyed this amplifier. Some others have complained about the Rotel amps being bright. Yet I would not even say it was bright, yet that is one way I might explain its less than inviting midrange. It was…uninteresting. Not engaging at all; some nights, I couldn’t wait to turn the bloody thing off. That effortless bass quality was non-existent in this amp, and bass in general was anemic and, again, flat.

My next step is to replace the preamp. The Hafler DH-101 is no slouch (and is better since I recapped it recently), but I know I can improve on it. Audio Research is one such candidate–I like the SP-16 (primarily due to the remote), but may settle for a few of the others. Reportedly, the matching Nakamichi CA-7A control amplifier has fantastic sonics as well, although it is not a Nelson Pass design.

For now, I can say that the PA-7 certainly lives up to its reputation, and is worthy of a spot in any high-end system. Yet, it will not break the budget. If you are in the market for one, find one with good cosmetics–I have seen a few in less than stellar condition. To step up from this amp at its current price would probably require a tenfold increase in cost.