Short Take: BLISS Shibata Stylus for Ortofon Super OM Cartridges

The Ortofon Super OM 20 cartridge has been discontinued for some time now.  This is a shame, especially for owners of turntables with lightweight tonearms like my long-running Dual CS5000.  The Super OM 20 cartridge provided a warm but still lively sound and seemed to have a synergistic match with the Dual.  Given my last one was in need of replacement due to wear, I began researching a replacement cartridge or stylus.

There are a few makers of high compliance cartridges out there but I have ventured in that area without too much success, at least compared to the good sound I was getting with the OM 20.  With that in mind I decided to buy a replacement stylus.  I could have gone with the OM 30 or 40 replacement, but this aftermarket unit available at TurntableNeedles.com caught my eye.  The Shibata needle profile, in theory, will pull in more detail and have a better high-end response than the ol' nude elliptical of the OM 20.  It's also priced lower than the higher end OM models so I decided to give it a chance.

Given that the cartridge body is the same and the only difference is the stylus, needle, and cantilever what kind of changes did I expect?  Not too much.  The body of the music is the same, as is the fun liveliness nature of Super OM series.  But, compared to the OM 20, there is more fine detail and treble information.  A minor step up to be sure, but one that is the worth the small price difference between a stock OM 20 stylus and its aftermarket Shibata replacement.  Highly recommended.

Project: Building a Pass Aleph J Amplifier

After the success of the ACA amplifiers, I decided to tackle something a little more difficult: the Aleph J, which is yet another Nelson Pass design that he released to the community at DIY Audio. Like the ACA, the Aleph J is single-ended design but instead uses two output devices in parallel, along with a current source. Power output is in the 25W range, which is good enough for my small listening area, even with 86dB efficient speakers. Except for the input capacitor on the negative leg of the input, the entire amplifier is also DC coupled which means the output offset must be nulled out.

Nelson Pass has a manual on the Aleph J here.

DIY Audio Build - with better pictures than mine - is here. Also includes a schematic.

I first stuffed the circuit boards, including the power supply PCB, with the passive parts:

And next was the installation of the Jfets and FETS, along with the placement of the circuit board on the heatsink. I ran into some problems that the DIY Audio community graciously helped me with. Turns out that I have too much of a soft touch with the soldering iron and had a few cold solder joints. It's that fear of burning up those rare 2SJ74 jfets that make me nervous. Also note the Keratherm output transistor insulators which are a lot easier to install than the old "white goop" thermal grease, and also make removing the board easier for troubleshooting. 

  

I'm obviously skipping a lot of the build steps - power transformer installation, power switch, and the wiring. So with the magic of my time machine, here is the end result of most of my labor: some magic glowing blue LEDs. I do have to say that the DIY Audio Store supplied chassis and circuit boards made this project a lot easier - everything, with the exception of the power transformer, just fits without having to drill holes or battle with placement.

Here is a picture of the completed amplifier :

Note on playing the Aleph for the first time in the main system: I'm quite impressed - lots of little detail on records that I hadn't heard before, super fast but delicate sounding - ie, not aggressive. Excellent bass control. Some actual depth and wide imaging. They would make excellent mastering/studio monitoring amps.

The sound is a tad "clean" - lacking some of that bloom that I hear with the best tube amps. So like digital television versus 70mm film. Perhaps not the best analogy but the only one I can think of. It does need some more break-in time so I'll be patient. But - at least in this system - it is the best solids state amplification I've heard. I think a really good SE tube amp would be preferable but at half the cost, the Aleph is certainly in the running.​

01/04/19 Update: The Aleph J is one of the more interesting amplifiers that I've ever experienced.  It has such a lack of apparent "character" that it just blends into the background.  I'm not trying to say it is boring, quite the contrary; you can hear the differences between recordings.  That is to say every record sounds different, as to be expected.  And, for a solid-state amplifier, it has some of the best body and definition I've heard.  I'm really beginning to hear the limitations of my front end now!  The bottom end is also tightly controlled too, giving quite a bit of boogie factor even with the small woofers of the Denton speakers.

Now the Aleph still doesn't sound like a tube amp - but it also doesn't have that upper-midrange glare or treble edginess I hear with lesser solid-state amps.  Highly recommended for its neutral character and dynamic ability.  This amp will be running in my system for a long time while I start to explore different turntable and speaker upgrades.  Stay tuned!

Project: Building the Pass ACA Amplifier

 

The ACA amplifier is a Nelson Pass design created to teach basic concepts about amplifier design. It is low-powered (6-8Ws per channel), run in pure Class A, capacitor coupled on the output, and is even single-ended.

There is a long, and very detailed article from Mr. Pass which, to put it bluntly, far surpasses my more vacuum-tube orientated knowledge. I see a single jfet driving a current sourced Mosfet, capacitor coupled on the input and the output, along with some modest feedback.  Anyone who wants to know the nitty-gritty of this amplifier should take a gander at the link for more information. For those who are a glutton for punishment here is the schematic:

 

My own requirements are modest wattage and an attempt to capture some of the magic that I hear with single-ended tube amps. The ACA amplifier can also be bridged, via an XLR input, to double the power, something I will need with my 86dB efficient Wharfedale speakers that are in a moderately sized listening room.  I won't need gobs of power for reasonable listening levels. Since my Classe Five preamp has XLR outputs, I will be going this route, building two stereo amps to use as bridged monoblocks.

Enough babbling - let's get building the first amplifier:

Here you can see the passive parts and the circuit boards. It's best to populate the small parts first - the resistors, followed by the caps and solid-state devices.

Once the circuit boards were stuffed it was time to start assembling the amplifier chassis for PCB fitment, along with RCAs, XLR, switches, and binding posts.

Here you can see the stuffed circuit boards attached to the heatsink. The Mosfet outputs are mounted too.

And I did some more work on the back panel, which has all of the connections.

Powering up the amp for the first time is always exciting. But I ran into a snafu - the power indicator LEDs would begin to flicker. Measuring the voltage from the power supply brick, I could see it was fluctuating from 24VDC (good) down to 5VDC (bad). A check on the DIY Audio forum indicated this is the lap top power supply going in protection mode if there is short.

To troubleshoot I removed a power supply lead from the boards, one at a time.  Once I found the board with the problem, I disconnected it from the heatsink. And then the problem went away. This was a clue that there was something wrong with this board.  I ended up having a cold solder joint that was easily fixed.  I guess those years of point-top-point wiring has come back to bite me.

Here I am biasing the output mosfets, each side set to 12V:

And then once that was done, I was able to - FINALLY! - give it a listen:

Initial Impressions: lower gain than the old workhorse Adcom 545. Instead of 9-10 o'clock on the dial, I have to turn up the volume to 1 o'clock to get the same sound levels. The ACA is very smooth, a little lacking in bottom end thump but still very articulated. Jazz - like Chet Baker's album Broken Wing - sounds fantastic, while harder rock albums seem to lack some of the macro dynamics. Of course we are only talking 6-8Ws here with 86dB Wharfedale speakers (6-ohm impedance) so not an optimal match. I wouldn't say the ACA sounds like a tube amp - some similarities: with a non-fatiguing top-end - but it also doesn't sound like your stereotypical SS amp either. Obviously some break-in may also be needed.

Luckily the second amp was a lot easier to build, taking almost half the time and with no problems to troubleshoot.

In this picture I still have to install the front power indicator LEDs and the top and bottom part of the chassis, but I did manage to listen to them bridged, using the XLR output from my Classe Five amplifier. Very impressive.  Neil Young - Live the Cellar Door sounds good on just about any stereo I've owned, but this may the best I've heard it, even compared to the days when I had an all tube chain and big UREI 813A speakers. Lots of micro dynamics, very realistic, and engaging. The amps sound way more powerful than the 12-16Ws it is making.

Some further listening - The Bee Gees - Trafalgar - revealed a slight metallic sheen that seemed to fade with further break in. Very clean but not lean. Detail, studio reverb, etc was all there. Frequency response was very even, no warts, and less "lossy" than some of the lesser tube amps I've owned. Single ended Mosfet is interesting, to say the least, not quite tube-y, nor is it "classic" solid-state (whatever that means). Just different, even more so than Class T (Tritpath) designs I've built. The old, and much need of a recap, Adcom 545, when put back in the system, sounded more indistinct, gray, and uninvolving, though it does have superior deep bass reproduction (and better damping and more power).

Gain is still a bit lower than I would like. Deep bass isn't as prominent as other amps, but again, 6-ohm and fairly inefficient Wharfedale speakers with 5" woofers here.


Listening Update: After a few weeks in the system, I'm quite impressed.  Very neutral with a touch of sweetness.  Some of the best depth I've heard out of a solid-state amplifier, along with very good detail retrieval.  Some of the better tube amps I've build or owned are slightly better at separating voices and instruments, but the ACA amps do a very passable job, just not quite as much "breath" to the performers.  Whether the tube amps are revealing realism or a coloration is an interesting question.  Considering the capacitor coupling, low output - even bridged, and the low damping factor the ACAs still managed to control the Wharfedale Denton speakers quite well, with just some minor loss of bass control.  These amplifiers just make me want to build an Aleph J amplifier that much more - stay tuned!

Review: Classe Five preamplifier

 
Introduction:
Given my heavy valve past going with an upscale solid-state preamplifier was a difficult choice.  Though certainly not a heart-wrenching one as I do have more recent experiences with Threshold, Adcom, and even some homebrew gear.  And since I was considering going all separates, different preamps for both phono and line, my choice to buy a full-function Classe 5 may also be a puzzling one.

Classe, however, is one of those companies that have been on my radar ever since I was a twenty-something reading Absolute Sound and Stereophile.  Back then Classe was considered very "tube-like" and warm, completely opposite to the common complaint of much solid-state gear: harsh or strident, especially in the treble region.  Such descriptions, like the warm sound of early Mac SS gear, piqued my interest.  But since I was a poor college student, living on a diet of vintage tube amps, Mac 'n' Cheese, and $2.99 records, anything in the price range of a Classe DR-5 or DR-6 preamplifier was unthinkable. So instead I soldiered on with DIY gear, plenty of Dynaco PAS preamps, and an Eico HF-85.

Well doesn't time fly?  Perusing through the Audiogon ads, I saw a recently listed Classe Five preamplifier.  It had a phono stage, switchable from MM or MC cartridges, and even a remote control.  Their isn't much information out there on the Five but some search engine sleuthing and I found it is essentially an upgraded 1990s version of the original DR-5.  It also features balanced (XLR) or single-ended (RCA) outputs; a single set of balanced inputs too if I ever needed them.  The XLR outputs will come in very handy for my planned bridged ACA amplifiers that are being built sometime very soon.

With the price being right, I put an offer in and it was accepted.  Given the proximity of the seller, I received the preamplifier the next day.  Unpacking the Classe Five and I found myself with a very heavy duty unit that was nearly flawless.  The switches, which have a wonderful tactile feel, worked perfectly, as did the remote control and the various knobs.  The wireless remote has buttons that causes little motors on the volume and balance to physically turn the knobs.  Very neat (I'm still an adolescent at heart!).  This is also great for adjusting the gain to get that perfect playback level from the comfort of my favorite listening chair.

Initial Impressions:
It is always exciting to listen to something new - but the Five wasn't exactly earth shattering.  The sound was dark, a bit muffled, and seemingly missing some bite on the top end.  Bass, however, was controlled and the overall sound was smooth.  With only an hour or so of time, I went to bed, leaving my new preamplifier in standby mode since there is no power off button.

The next day, after work, I heard an improvement in sound.  The smoothness was still there but everything sounded a lot more cohesive.  I fought the urge to do any serious listening, waiting for a quiet Sunday afternoon where I could experience the Classe Five without any familial distractions.



In my doddering middle-age I've become a bit of a Chet Baker fanatic, even exploring his musical output beyond his 1950s heyday.  Nonetheless I still have an appreciation for his signature album, Chet.  It's a brooding masterpiece that has the fingerprints of Bill Evans all over it.  Listening to this album - 1980s Riverside pressing - reveals a lot more detail than I was hearing through the Adcom GFP-555.  The Classe Five does a better job of revealing the light cymbal work, which sounds deeper in the soundstage but with the attack and decay being more apparent as is the metallic nature.  Too many systems turn cymbals into a hard SHHHH noise, instead of the shimmering, complex sound it should be.

Instrument - piano, the brass instruments, and drum - have a more natural body than my old preamplifier.  The overall sound is very smooth but doesn't inhibit the more aggressive tones of the music.  It is a different type of smoothness than I ever heard; not imbued with a golden hue like a vintage tube preamplifier but more as if the sonics were cut from a single, grain-less cloth. 

Willie Nelson has a rich and immediately familiar voice.  On Stardust, the vocals come across as completely natural with just a hint of studio reverb added.  The instruments remain firmly behind the singer, reproducing the very intimate nature of this album.  Tonality is some of the best I heard, exceeding my expectations given the budget nature of the speakers and my turntable and cartridge. Cohesiveness is another word that came to mind, and one that kept popping up as made notes.  No single instrument seemed crowded out while another took the center of attention.



For something more dynamic, I turned to one of the greatest live blues albums ever recorded: Drinkin' TNT 'n' Smokin' Dynamite which has an all star backing band behind Buddy Guy and Junior Wells.  The Classe Five captured the audience background noises allowing me to place them in location and distance from the stage.  The dynamic shifts, given the limitations of the Wharfedale Denton speakers, were impressive; never sounding bloated or blurred.  An example of this is the stuttering starts and stops of the lead guitar, along with the deep bass foundation.  Each instrument had its own space but jelled together as one whole, making for a very toe-tappin' experience.


After that good time, I needed a melancholic change of pace.  Richard and Linda Thompson deliver this in spades with their album Shoot Out the Lights.  Linda's voice is sublime here, all barely hidden pain while the barbed wire guitar of Richard grinds away as if stripping the heart out of his troubled marriage.  His backing vocals sit separate from hers, as if he is giving his ghostly agreement.  This album, needless to say, a heart-wrenching series of songs.  The Classe Five does an excellent job of baring these emotions.





I listened to several other albums of varying quality - like The Fixx, Wardruna, The Police, and even some old 1930s-era Billie Holiday.  Poor recordings sounded like, well, poor recordings.  And mediocre ones weren't given any extra magic either.  The Classe Five appears to be rather neutral, low in coloration, and even-handed.  This one is a keeper.


Takeaways:

The Classe Five has the best treble I have ever heard from a solid-state preamplifier.  At first I thought it was rolled-off; lacking in air and excitement.  However further listen revealed that it is actually a lack of glare and edginess that is often common in lesser solid-state gear.  If a recording is bright, you will hear that.  If it is dull, or poorly recorded, that will be revealed.  There is no heavy coloration going on here.

Along with this natural treble comes the feeling, from top to bottom, that all frequency points are sonically similar; that is to say no part of the sound, be it treble or bass, sticks outs or draws attention to itself.  As I mentioned above, everything is cut from the same sonic cloth.  It's something I never quite heard to this degree with any preamplifier that I've ever owned and took some time to understand this new experience.  A similar situation occurred when I first heard the VPI Aries 1, only then did I hear the warble and background rush of lesser turntables.

Bass control is excellent - tight and dynamic without any bloat or smear.  This is essential for providing the foundation of the song.

Detail is very good; though some listeners may prefer a more hyper detailed presentation.  Perhaps this is the limitation of my front-end or the nature of the Wharfedale speakers.  Some future upgrades will see how well this holds true.

The quality of the Classe Five makes me question, to some degree, my allegiance to valves.  At least with valve gear you can roll in different tubes to find the best match with your system.  But, if you're tired of buying high priced NOS valves or even new stock, then give the Classe Five a try. You may be surprised.


System:
Adcom GFA-545 amplifier
Dual CS5000 turntable with Ortofon OM20 phono cartridge
Pioneer DVD-V7400 DVD player
Kimber 8PR/4PR bi-wire speaker cables
various budget interconnect cables

Review: Ortofon Super OM 20 Phono Cartridge

Introduction: Reviewing phono cartridges is a difficult task.  Why?  Because it's part of a complex system involving the tonearm. platter, vibration, setup, and, based on the quality of the other components downstream, can radically alter one's perception of the whole system.  Also a cartridge that works wonderfully for one system may be dreadful on another.  That's the nature of the analog beast: difficult to tame but, to my ears, worth the trouble.

As for why I decided to replace the Shure M97xE; it's a matter of personal taste.  The M97xE is one smooth cartridge but I had the feeling I was missing something, mostly the very top end sparkle.  And since I'm upgrading my current system - one component at a time - I thought it was time to try something a little different. The OM series was mainly selected because it is supposed to be an ideal match with the lightweight arm on the Dual CS5000 turntable.  The CS5000 originally did ship with an OM cartridge, so why not take the manufacturer's recommendation to heart?

Among the family of Ortofon's OM cartridges I selected the OM 20 - it is affordably priced and, based on my online research, strikes a good balance between detail and listenability.  It's a Moving Magnet cartridge with a healthy 4mV output, which will work perfectly with my soon-to-be-replaced Adcom GFP-555 and my next future preamplifier.

Setup:  Since the Dual CS5000 has a lightweight tonearm, I pulled out the removable 2.5g weight that is inserted on top of the OM20 cartridge.  With the Dual's easy to remove headshell, cartridge swaps are easy; provided you have a pair of good eyes.  I'm definitely due for my first pair of bi-focals so it took a bit of fiddling with the wires, along with some careful tightening of the headship clips.  Once I had the cartridge mounted, I used the protractor that came with the turntable.  The narrow body of the OM 20 cartridge makes alignment easy.  Tracking force was set at 1.2g using my fiddly digital gauge.

Initial Thoughts: After installing the new cartridge I found the sound to be a touch bright and forward.  Lively was the first thought.  Some hotly records vocals were strangely muffled. After adjusting the VTA and double-checking the tracking force, I spun a couple of records that night.  A few days later I felt comfortable enough to start some detailed listening.



Lisa Gerrard of Dead Can Dance has a voice that is both ethereal and powerful.  The Mobile Fidelity pressing of Spiritchaser showcases her vocals wonderfully, as does the Ortofon OM 20.  The notes from that golden throat soar above the primeval music, and roll around, expand, and then come together like I'm under the effects of a psychedelic drug.  This is about as close as one can get to being high without taking an illicit substance.  I've heard this record done a little better on more expensive systems, but not by leaps and bounds.  Nor have I ever heard the Dual CS5000 sound this good.  Sure isn't in VPI Aries 1 territory, and any sins are ones of omission, but I am loving the overall sound coming out of the Wharfedale Denton speakers.  Considering the budget, very impressive.

Bass has depth and impact, while the left-to-right stereo spread go beyond the edges of the speakers.  The real magic is in the midrange - lively, engaging, and with good pace and timing.  The treble is more extended than the old Shure cartridge, but it isn't bright either.  So far so good.  For my next record I picked something a little more down to earth.


I'm not sure if you will find many Outlaw Country fans in audiophile-land, but with Waylon Jenning's Honky Tonk Heroes they're missing out on one humdinger of an album.  This first pressing is pure RCA studios: warm, wonderfully recorded, and just brimming with that old school Nashville production.  Jenning's vocals are rich, and if a system doesn't capture this magic, then you know something is wrong.

Bass: Attack of the deep bass guitar is quick with no overhang.  Warm, dark, and low - like it should be for this era of recording.

Midrange: full-bodied but no excessive warmth.  In comparison the Shure could overdo this portion of the spectrum. The upper midrange of the Ortofon is definitely more lively but still captures the huskiness of Waylon's vocals.

Treble: More extended, lively, but the upper end never becomes aggressive or shrill.  How much of this is the Denton speakers remains to be seen.  In this department the Shure was more rolled-off, and perhaps more pleasing on some hotly recorded albums.  

Other: Channel separation is excellent and every instrument sits in its own space.  I've heard more detail and body with moving-coil cartridges but this moving magnet, at least in this system, is more cohesive.  There is no portion of the frequencies that stick out like a sore thumb.  Depth is also less than the best I've heard.  It's not quite flat-as-a-pancake, but I certainly never got the illusion that the drums were in the next county.


Neil Young's Live at Massey Hall 1971 is an excellent recording that should be part of anyone's collection of good music and good sound.  This is a very system friendly album that sounds great on every stereo I've owned.  This current budget setup was no exception.

The body of the acoustic guitar was about as real as it can get, and so were the vocals.  The effect is similar to sitting mid-row in a small coffee shop.  So a very personal album.  Micro and macro dynamics of the guitar and the piano were fairly realistic, only bettered by the Aries 1 turntable and UREI speakers of yore.  Once again I heard shorter depth and a bit less detail than my older systems, but there was still a cohesiveness that really brought my enjoyment factor to a very high level.


At one time, when I was a much younger man, The Clash was called "The Most Important Rock Band in the World."  If anyone was listening to me, I would have to snub The Clash and go for James.  Their Eno produced Laid is an early example of what makes their albums sound so close to perfection: catchy hooks, memorable lyrics, Tim Booth's powerful vocals, and the ability to bring me near tears with a mix of sadness and elation.

The Ortofon cartridge wrings out the best of the 90s production - deep bass, the sound of the drums, the jangle of the guitars, and the dynamic contrasts.  This is no audiophile hidden gem since it was probably recorded on early digital equipment with plenty of overdubs and even a few effects.  Nonetheless I've never heard this album sound so right.  I had to tap my toes, smile, and remember my youth with wistful melancholy while being uplifted with the wonders of life.

The swelling and rolling of the bass was impressive and was the precision of the midrange.  The treble was never overly aggressive either.  Again there was a slight lack of body and some minor loss of definition compared to more expensive cartridges, but the Ortofon is really no slump in this department.  I'm looking forward to trying out some different phono stages to see if this area can be improved on.  The Adcom, after all, uses op-amps with high negative feedback and currently has some aged components, so perhaps I'm expecting too much out of this budget unit.


Conclusion: With cartridges it is hard to make blanket recommendations, but with the Dual CS5000 and it's lightweight tonearm, the Ortofon OM 20 bests anything else I've tried on this rather modest turntable.  It certainly is more cohesive than the Shure M97xE, an Audio Technica ATN95HE, and even better than the Nagaoka MP-110.  Of course the Ortofon is a bit more expensive than any one of these cartridges, but what is really happening here is a matter of system matching.  And, as a bonus, the Ortofon OM 20 cartridge can take any number of stylus upgrades which will be worth exploring in the future.

As for the sound of the OM 20, it really did exceed my expectations, bumping my rather pedestrian system up another notch in quality.  Considering the odd blend of gear here - vintage American amplification, small British mini-monitors, and a German turntable and cartridge - the sound is cohesive, engaging, and just touching on the fringes of high-end.  I hate to gush since such proclamations are often viewed with distrust, but, at least with this turntable and system, the Ortofon OM 20 is a real winner.  Highly recommended.


System:
Adcom GFP-555 preamplifier
Adcom GFA-545 amplifier
Dual CS5000 turntable with Shure M97xe phono cartridges
Pioneer DVD-V7400 DVD player
Wharfedale Denton 80th Anniversary speakers
Kimber 8PR/4PR bi-wire speaker cables
various budget interconnect cables