Thursday, November 12, 2009

A visit with Magnepan 1.6 speakers


The Magnepan 1.6/QR is a 2-way Quasi-Ribbon Planar speaker. My previous experience with planar speakers had been limited to a pair of Quad ESL-63s and a set of Magnepan SMGs. The Quad ESL-63 has always been one of my holy grail speakers but I was worried about children, pets and my own clumsiness around a high voltage electrostatic panel. The Magnepan seemed like a good compromise as I had a high current amplifier to run them with.

Upon arrival of the speakers, I had my fellow audiophile come over and help me handle the long 80lb box down my basement steps. The 1.6s were soon unboxed, unwrapped and mounted on the stock speaker stands. They certainly are imposing speakers, standing just a bit shorter than me. I shuffled the Maggies about a bit, pulling them some four feet away from the back wall and some three feet from the sides. I threw on a quick CD to make sure everything was working and was happy to hear music coming out of both channels. My friend suggested we try a known LP, so I threw on a copy of Steely Dan's 'Aja' and settled back into the sofa.

My ears were met with a very aggressive bright forward sound but as my ears started getting used to the change in sound I found that the soundstaging and details were simply amazing. Cymbals and voices were lifelike, making my old box speakers sound muddy in comparison. Bass response was different and lighter than the UREIs - which is to be expected since those big speakers have two 15" Eminence drivers. However the Magnepan's bass was extremely fast and articulate.

We then threw on an original copy of the Beatles 'Rubber Soul' and were amazed by the vocal delivery and realism. But there was still a bright spotlight on the upper treble that was annoying. My friend suggested a cartridge loading change. My Dynavector 10x5 was currently loaded at 47k which can cause a rise in the treble. So I took off the top of the Threshold FET-10/PC and via the dipswitch changed the loading to 1K.

The change was certainly for the better as the next record showed - Willie Nelson's 'Stardust' was sublime as was Van Morrison's 'Saint Dominic's Preview'. Further listening on a variety of records revealed a speaker that has a tremendous amount of detail and the ability to throw a large soundstage. Instruments and voices hung in their own space and the music flows as an organic whole. With many standard dynamic speakers you can have (let's say) a gentle ticking of a stick that gets washed out by the crescendo of a guitar. However with the Magnepans the picture never fell apart like that, keeping the different intruments and vocalists distinct from each other. This neat trick allowed me to 'see' into the recording further than before.

Weaknesses? Lower bass doesn't growl like my big UREIs. Bass isn't exactly deficient, but it doesn't plummet the depths like big box speakers do. There is also less 'slam' and dynamics to drums as the excursion of the Magnepan can't match that of a set of big woofers. The Magnepans are also a little cruel with poor recordings, but the music was still enjoyable. Any speaker is a set of trade-offs but in their price range the Magnepans are certainly worth checking out. Highly recommended!

Stay tuned as I'll be playing with stands and perhaps a crossover upgrade in the future.


System:
preamp: Threshold FET-10/HL
phono preamp: Threshold FET-10/PC
amplifier: Threshold S/500
analog: VPI HW19 MkIII - Rega RB300 with Incognito wiring - Dynavector 10x5
speakers: UREI 813A loudspeakers
speaker cable: Canare Quad
Interconnects: Cardas Crosslink and Belden


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Thursday, August 27, 2009

A visit with the KAB EV-1 Record Cleaning Machine


(Picture from KAB)

In the past year my vinyl collection has grown by leaps and bounds so I finally pulled the trigger and bought a $159 KAB EV-1 record cleaning machine. There is nothing worse than finding some vintage treasure that has been marred by dust n' grime of years gone by. I decided to buy one because a friend of mine has a Nitty Gritty Model 1.0 and I was amazed how well it cleaned up a couple of old Frank Sinatra records of mine. Compared to the Nitty Gritty the KAB EV-1 comes in at a cheaper price point by having the user supply their own vacuum power instead of an installed motor. However I will note that the EV-1 is fairly cheap looking with a simple plastic housing, hose connection and manual turning. But what matters in the end is if it gets the job done. So after a quick perusal of the instruction sheet I hooked it up to an upright vacuum cleaner that has a hose attachment and got ready to clean some records.

The first record I tried to clean is a Japanese pressing of 'Haircuit 100 - Pelican West' that is very crackly when being played. Upon visual inspection the vinyl 'looked' clean but there is a constant light pop-pop-pop over the music that is very intrusive. After putting the record on the KAB I applied the cleaning liquid as instructed with the supplied applicator brush. I then turned the record over, switched on the vacuum and made 5-6 slow drying passes over the record. I then repeated the process for the second side. In theory the liquid and collected dust will be removed via the thin slotted opening on the top of the machine. Replaying the record had a dramatic change. The low-level pops were gone and the record definitely stepped up a grade in quality. It could have been my imagination, but the album seemed to have more clarity too.

Obviously the KAB doesn't fix scratches, but I was curious to see how it fared on my beat up copy of 'The Kinks - Lola versus Powerman'. After treatment the record was still noisy in places but was much quieter overall. I would say it jumped from a VG- to a VG+. A cleaning of a recently purchased 'The Hollies - Bus Stop' dramatically improved this 1966 era vinyl. Gone were the constant ticks and pops caused by deeply entrenched dust particles. After cleaning several more records, I always found an improvement of varying levels dependent on actual physical quality of the record, not on the amount of dust. A certain amount of crackles and pops will always exist in this medium, but the record cleaner goes a long way to reducing them.

I'm now of the opinion that anyone who collects records should own a vacuum record cleaner of some kind. Though the KAB EV-1 requires manual operation and is light enough that it needs to be well anchored (it works fine sitting on carpeting), it gets the job done. Highly recommended for the record collector who would rather spend his money on more records than a fancy cleaner.


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Sunday, July 5, 2009

A Visit with the Dynavector 10X5 phono cartridge


I've been less than happy with my main system lately - it has been a tad dry, a bit flat sounding and not really as good as could be expected for the money. I thought of buying some new speakers, blaming my woes on the UREI 813A studio monitors. Perhaps a set of Magnepans? or Martin-Logans? would be the trick to get my stereo to really sing.

As chance would have it, I began discussing my audio problems with one of my good friends. The same guy who got me into this crazy hobby in the first place. He is running an Ortofon 2M Bronze and has been having a really hard time getting it to sound good on his system. I run the inferior 2M Blue and a light bulb went off in my head - perhaps the rest of my stereo was actually outpacing my cartridge. Part of the game of building a good stereo is juggling components and perhaps my Threshold FET-10/PC phono stage was just showing the weakness of my analog front end.

So with the idea of buying a new cart in my head, I began agonizing over which one to get. There are many choices in the ~$500 price range so I researched, read and came to the conclusion of buying a Dynavector DV-10X5. It has a high enough output where I wouldn't have to switch in my head amp and it is known to work well with the Rega RB300 tonearm. At $395 I wasn't expecting much but I was hoping for a bit better performance than my old cartridge.

Installing the 10X5 was an exercise in frustration - the top aluminum plate may not be one hundred percent lined up with the end of the plastic body. The design of the cartridge also makes it hard to see the needle lining up on protractor. Luckily my friend came over and helped me set it up as I'm fairly klutzy with my big hands. We dialed in the tracking force at 2.1gs, fired up the Threshold S/500 amplifier and gave it a listen.

Even without any break-in, the Dynavector 10X5 shows itself to be a great performer. Music has color, vibrancy, dynamics and is now oh so much more fun to listen to. Listening to Supertramp's "Crime of the Century" revealed snarling guitars, deep rich bass and a wonderfully extended but clean treble. Instruments now had air around them and vocals had more definition. We listened to a few more discs - original pressings of Steely Dan, John Lee Hooker and Dire Straits - and reveled in the pure enjoyment of music. The 10X5 punches above it's price point with a quick detailed sound that doesn't get annoying. It is strange how the music sounds so fast but still has a warm natural rhythm and flow. From memory the overall sound reminds me of the original $99 Sumiko Blue Point of yore, but the 10X5 definitely has stronger bass and a more full bodied presence.

And for another point - part of building a great stereo system is understanding how the rest of your components match up together. A different sound may not always be a better sound - I'm sure buying a pair of Magnepans may have changed my system in many ways but still my UREI speakers continue to improve in sound as the rest of my system improves. They really are that revealing and any of their naysayers are probably hearing a deficiency somewhere else in their signal chain. The UREIs were just telling me the truth all along which is in the end is unsurprising considering what they were designed for.

I ended up trading my Ortofon 2M Blue away as I no longer had any need for it. Mind you, the 2M Blue isn't a bad cartridge - it just wasn't a good match for the rest of my system. In another, more budget system, the 2M Blue would be a star.

As for my next purchase, I see a Dynavector DV-20X in my future. But before that I'll concentrate on buying records, upgrading my cables and perhaps getting a better tonearm. Stay tuned!


System:
preamp: Threshold FET-10/HL
phono preamp: Threshold FET-10/PC
amplifier: Threshold S/500
analog: VPI HW19 MkIII - Rega RB300 with Incognito wiring
speakers: UREI 813A loudspeakers
speaker cable: Canare Quad
Interconnects: Cardas Crosslink and Belden 89259


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Saturday, June 20, 2009

A visit with the KEF Q60 loudspeakers


When I first got into audio gear back in 1989, I started reading Stereophile magazine. Since I was only a poor college student, I could only dream of buying the gear they were reviewing. However I still remember reading about these KEF Q60 speakers back in 1991. I remember being intrigued by the Uni-Q driver and the strange looking port. The Uni-Q driver has the tweeter placed right in the middle of the woofer voice coil which makes them a great point source. I wanted a pair but never got 'em due to money and changing speaker interests. Fast forward eighteen years and I see a pair for sale on Ebay for $149. I immediately pull the trigger and get them three days afterwards. You gotta love the modern world.

The KEF Q60 loudspeaker use san 8" Uni-Q driver and is rated for 8 ohms / 90dB efficiency. This speaker is only rated for 100Ws of power and also features a large radius port on the bottom. The size is basically a 'large bookshelf' speaker, though it certainly would take a gigantic bookshelf to place these on, so I would recommend a pair of stands instead.

The Q60s went and replaced my pair of Q30 floorstanders with the 6.5" Uni-Q drivers. The Q30s, though nice, lacked bass and treble extension but were good enough for my second system. They were also fairly undynamic and created little soundstages with little instruments. I could immediately tell that both speakers have an extremely similar house sound - slightly warm and perhaps a touch rolled off on top, but in the end the Q60 is the better all-around speaker.Though the Q60s only uses an 8" driver they were better in the bass and treble department. Images are also larger, though certainly not in the big full range speaker department.

Treble is very smooth, though lacking in ultimate extension and detail. The Q60s bass is good, perhaps going to 50Hz before rolling sharply off. Of course I have them tucked close to the wall so I'm getting a little help there since the lower frequencies are perhaps just a wee overdone. The midrange, though certainly not in electrostat territory, is balanced and works well with vocals. Nothing seems to get terribly confused during complex music or loud passages though I certainly wouldn't call the Q60s a headbanger speaker. After all there is only so much a single 8" woofer can do. Soundstaging is very good for the price range and even listening off-axis is an involving experience.

Overall the KEF Q60s would make good budget or second system speakers - they are coherent, err on the side of omission and give you some sense of what audiophiledom is all about. This is a balanced speaker with no major faults that allows you to hear differences in recordings. Due to their relatively high efficiency and easy 8 ohm load, Q60s would also be suitable for lower powered tube or solid-state amplifiers.


Second System:
Dynaco PAS-3X modified
Dynaco AF-6 tuner
McIntosh MC250 amplifier
Hitachi L55 turntable
Pioneer DVD-V7400 cd player
various budget cables


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Wednesday, June 3, 2009

Bottlehead Seduction updates

I've replaced the .47uF Orange drops with AmpOhm tin foil and oil capacitors available from the Tube Store. I've also replace the .1uF Xicons with Auricaps. After many hours of break-in, I can strongly approve of the AmpOhm units - it has an extremely musical, almost laid back sound that makes you want to spin record after record. It is a good balance to strike with the more lean and forward sound of the 6DJ8 family of tubes.


Regarding tube rolling - I've also tried a pair of Voskhod 80s production 6N23Ps. Though not quite the same quality as the NOS Amperex/Mullard/Telefunken tubes, it has a fast sound that mates well with the AmpOhm oil capacitors.


For a budget tube phono stage, the Bottlehead Seduction is a musical revelation. Though it doesn't compete with my Threshold FET-10/PC in terms of overall detail and bandwidth, the Seduction is certainly no slouch either. Though it lacks the very ultimate in inner detail it is natural, musical and would be a great upgrade over most vintage tube phono units. Now if only it had a White Cathode Follower low impedance output, a regulated tube power supply and... oh, curses I just can't leave anything alone!


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Sunday, May 3, 2009

A visit with the Threshold FET-10/PC phono preamplifier


The Threshold FET-10/PC is a standalone phono preamplifier that was meant to be partnered with the FET-10/HL linestage. With the use of internal dip switches it features adjustable gain for MM or MC cartridges and adjustable capacitance. Designed by the great Nelson Pass in the mid-80s, the 10/PC is a statement piece and the build quality certainly shows that - outboard power supplies, hand selected parts, a frickin' gold plated circuit board, and a RIAA curve that is within .25dB.

I bought my FET-10/PC via Ebay to match my FET-10/HL linestage. Upon receiving the phono stage, I opened up the case and like the linestage was amazed by the build quality. I read the manual and made sure to set the gain to 40dB to match my Ortofon 2M Blue MM cartridge.

How does the FET-10/PC sound? - so far it doesn't sound much like anything at all. It is very neutral, transparent and has excellent control over the sound coming from the Ortofon 2M Blue. Bass is very deep with excellent 'slam' and dynamics. The midrange has a bloom that is very natural and pleasing to the ear. No major faults come to mind - though a good tube unit may have a smidgen more body at the expense of detail. And the details! I heard little things on recordings that were just plain not there on my other phono preamplifiers.

In comparison it makes the Graham Slee Era Gold V sound ever so slightly artificial. The Bottlehead Seduction is just a little less detailed but perhaps a bit more musical.

I'm very impressed with the FET-10/PC and I'm certainly enjoying the complete Threshold amplification chain. Future cartridge purchases can only make the sound even better and this unit will be a good basis for my planned analog upgrades.


Setting up the FET-10/PC:
As for setting up the impedance and capacitance loading - with the top open and the front of the preamplifier facing you, locate the two red 8 position dip switches on the far left side. If a dip switch is set to the left, it is ON. If it switched to the right, it is OFF.

Resistance Loading:
#1 - 22 ohms
#2 - 47 ohms
#3 - 100 ohms
#4 - 1,000 ohms

1-4 OFF = 47k ohms (ie, MM cartridge)

Capacitance Loading:
#5 - 1,000 picofards
#6 - 250 picofarads
#7 - 150 picofarads
#8 - 100 picofarads

5-8 OFF = 50 picofarads


To set the gain, locate the two jumper sliders on the middle left of the board. These are colored blue and each cover two pins of a three gold plated prong.

For highest gain, each jumper slide is positioned towards the center of the preamplifer. In this case the exposed pins are those nearest to the front and back of the preamplifier.

For 20dB less gain, the jumpers are located away from each other and toward the back and front of the preamplifier. The exposed pins will be nearest to the center of the preamplifier.


System:
preamp: Threshold FET-10/HL
amplifier: Threshold S/500
analog: VPI HW19 MkIII - Rega RB300 with Incognito wiring - Ortofon 2M Blue
speakers: UREI 813A loudspeakers
phono preamp(s): Graham Slee Era Gold V phono and Bottlehead Seduction with C4S mods
speaker cable: Canare Quad
Interconnects: Cardas Crosslink and Belden

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Tuesday, April 28, 2009

A visit with the Bottlehead Seduction phono preamplifier

Last week I bought a Bottlehead Seduction via Audiogon. This was a 'factory-wired' unit with the C4S upgrades included. Honestly I'm not sure why I bought this other that for the chance to try some tubes in my (now) all solid-state system. Although I love the Graham Slee phono, I was missing a bit of the body I got rolling an all tube system. Could I capture some of the old magic while keeping the transparency and detail of my new system?

So UPS delivered the Seduction in on Friday while I was talking to my fellow audiophile friend on the phone. He was excited because he has a big stash of 6DJ8 types that he never had much of a chance to use. While he is driving over I went downstairs and plug in the Seduction to my Threshold FET-10HL linestage. I used the stock Electro-Harmonix 6922s that came with the Seduction.

I'm impressed right away - it actually reminded me quite a bit of the Slee but maybe with a little less deep bass control. My friend comes over and we spin a few records. He comments that the sound is great but a little harsh in the lower treble. I agree but we both comment on what a great bargain the Bottlehead (with C4S upgrade) is - if you're handy with a soldering iron you can get some great performance for not too much coin.

My friend then takes a pair of NOS Amperex white letter 7308s out from his stash and we plug them in - BIG difference! The treble is very extended and clean now. The mids open right up and the depth becomes amazing. My pal comments that it reminds him of the sound approaches that of an Audio Research SP-10. A few records later (listening to an original Santana 1st LP pressing!) and I'm happy - a definite notch up in the overall system enjoyment. Detail and transparency is fantastic, while the midrange has opened up with a tube like bloom. Bass is taut and the sound never collapses as the dynamics increase. Now I just have to figure out a way to get a pair of those Amperex tubes!

The Bottlehead Seduction with the C4S upgrade can compete with the one thousand dollar and up crowd - provided you have some good 6DJ8s in place. I will next try to replace the coupling capacitors as the stock unit comes with Xicon and Orange drops - not exactly my two favorite couplers - which still managed to perform to an amazing level. Even though I'm blown away by the current sound, perhaps I can squeeze out just a touch more performance with an upgrade.


System:
preamp: Threshold FET-10/HL
amplifier: Threshold S/500
analog: VPI HW19 MkIII - Rega RB300 with Incognito wiring - Ortofon 2M Blue
speakers: UREI 813A loudspeakers
phono preamp: Graham Slee Era Gold V phono
speaker cable: Canare
Interconnects: Cardas Crosslink and Belden


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Friday, April 10, 2009

A visit with the Ortofon 2M Blue


The Ortofon 2M Blue is a Moving Magnet phono cartridge that prices in at approximately $200. Designed by MĂžllerJensen Design, the 2M Blue sports a high output of 5.5mv and a nude elliptical diamond. There are four cartridge models in the 2M line - starting with the budget Red and ending with the highest priced Black. I had a few weeks of experience with the 2M Red and decided to buy the Blue as an entry level catridge to re-start my journey into analog playback. When first installed the 2M Blue sounded very hard - almost like a bad CD player - so make sure to give it a few hours before coming to any conclusions.

Though the 2M Blue is only one step up from the budget Red, I've found it to be an excellent tracker. Inner groove distortion is extremely minimized to the point where I can't tell when an unfamiliar record is coming to an end. This certainly bests some of the admittedly more budget carts I have heard in the past.

With my Graham Slee Era Gold Mk V phono preamplifier and VPI HW19 Mark III turntable, I get extremely deep and low bass that is tightly defined. More so than I have ever heard with any turntable setup before. The midrange is very transparent and clear, but the top end does seem a bit forward. Mind you it never gets glarey or etched, but the upper mids and treble are certainly a little more pronounced. Measurements by other reviewers confirm a rising frequency response so keep this in mind if you already have a forward top-end on your system.

Detail appears to be very good with some nice information retrieval. On Frank Sinatra's marvelous "At the Sands" original two LP set, I get some nice hall reverberation and audience noise. "Will you stop eating and drinking!" was all I could think during some of the instrumentals as you could hear the clatter of plates and glasses being moved about. This is about the closest you can get to hearing Sinatra live these days so make sure to check this LP set out.

Is the 2M Blue the best of breed? - most definitely not - but it certainly is a step in the right direction compared to the carts I've heard in the lower or same price range. I will be looking forward to the day when I upgrade to the 2M Black, but right now I'm enjoying the best analog setup that I've ever owned.


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Monday, March 30, 2009

A visit with the Graham Slee Era Gold Mk V phono preamplifier


The rather unassuming looking Graham Slee Era Gold Mk V (now that is a mouthful) phono preamplifier is an IC based unit that goes for the rather princely sum of $999. Now that is really a pittance in audiophile money, but when you open the shipping box you expect something larger for something just shy of $1K. In my poverty-filled college days I've driven cars that cost less than this little box! Of course what you are paying for here is a hand-built and thoroughly tested unit. This is a level of quality control that many companies would never do.

The
Era Gold Mk V is meant to be used with MM or high output MC cartridges since it has no switchable gain. Gain is set at a fixed 41.5dB and with no power switch it is also meant to be left powered on at all times. There is only one set of stereo RCA inputs, a grounding lug, a DC input and of course a set of stereo RCA outputs. The power comes from an outboard PSU1 regulator and further regulation also occurs within the phono unit itself.

I bought the
Era Gold Mk V used via Audiogon to partner up with my newly bought VPI HW19 Mark III turntable and Ortofon 2M Blue cartridge. I have to admit I wasn't expecting much from the Slee - having pretty much resigned myself to using tubes in this crucial part of the signal chain. I'm no fan of ICs and thought this unit would just end up being a temporary stop before I bought a more expensive phono stage. To my ears op-amp based circuits normally sound hard and grainy and I've never heard a circuit using them that ended up sounding good.

So how does this little beast sound? In a few words, very neutral. Bass is shockingly deep compared to several of my previous tube preamplifiers. It also does not have any of the round euphonic bass I associate with tube gear - instead bass is taut with excellent definition. The treble is very controlled and non-spitty sounding. However the very last bit of air and sparkle seems to be missing compared to some of the better units I've heard. This is a minor quibble but still worth noting. The most important part - the midrange - seems to be extremely neutral without any major colorations or immediate problems. In comparison tube units have a bit more 'bloom' and 'color' but can also suffer from decreased resolution and transparency. With the Slee, detail is very good without being overdone. At no time does the recording ever sound zippy or forward unless it was mixed that way.

In conclusion the
Graham Slee Era Gold Mk V is a good partner with my Threshold gear. With my UREI loudspeakers I am given a full range, neutral and transparent sound. Even if I purchase another phono unit, the Slee will stay in the stables to provide a reference for future upgrades.


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Monday, March 9, 2009

A visit with the VPI HW-19 Mk III


I first heard the VPI HW-19 turntable way back in my early audiophiles day of 1990. It was a friend's setup using Quad ESL-63 speakers, a heavily modified and fully regulated McIntosh 240 amplifier and a regulated Dynaco PAS. The VPI sported an air bearing Eminent Technology ET2 tonearm and a Sumiko Bluepoint. Up to that point my experiences with turntables was limited to my father's Garrard unit and the various 'mainstream' Japanese turntables that were popular at the time. So needless to say I was surprised how good records could sound. I never heard hall reverberation, vocal and instrument realism like that before. You have to remember that this was the heyday of CDs and everyone was ditching their vinyl collection so it seemed at odds against the stated supposed superiority of digital. Well VPI certainly changed my mind about digital and due to my college budget I ended up buying a used Thorens TD-165 table. I never got the great sound out of the Thorens that I heard on the VPI and at the time I attributed the differences to cartridges, preamps and my cheaper speakers. Back then I made the mistake thinking that the amplifier made the biggest difference in the signal chain.

As the years went by and CD sales grew larger and larger, I ended up slowly decreasing my record collection purchases. With CDs I could copy and rip down songs - plus my interest in new releases and re-issues limited my purchase of records. After my experiences with the Monica NOS and the transformer coupled RAKK DAC I began to think that digital has finally been able to sound good enough to compete with a good turntable setup. And why bother with the fussiness of analog? Record cleaning, cartridge changing and 'table setup has certainly driven away the masses and me along with them.

I recently hooked my UREI 813A loudspeakers back up to do some amplifier testing. I've always liked the overall UREI sound but was disappointed in the higher frequency dryness - attributing any nastiness to the horn loaded compression tweeter. I was thinking of buying some Magnepan loudspeakers and continuing on my digital path until my fellow 'phile friend let me borrow his second vinyl rig. This is his setup that he uses for needledropping and consists of a glass platter Rega P2, Ortofon 2M Red and a simple phono stage that I built for him some 2 years ago. It is basically an ARC SP-3 type 12AX7 based circuit but with a much beefier choke based power supply.

I honestly wasn't expecting much from this setup when we hooked everything up. And I knew there was going to be some bass rolloff problems with the high impedance phono driving the 25k input load of the Threshold FET-10/HL linestage. So we queued up our first record - "Buddy Guy & Junior Wells - Drinkin' TNT 'n' Smokin' Dynamite" - and sat back to listen. Wow! I was taken aback by the smoothness and overall coherent sound of this setup. Sure, there were minor issues - but the musicality beat out my more expensive RAKK DAC on several levels. And oddly enough the irritating drynesss of the treble was gone!

After listening to a few more records I came to the conclusion that all along that the UREI 813As were telling me that many DACs have difficulties reproducing high frequencies. So I was blaming the speakers when instead they were just telling me the truth all along. Soundstaging, detail and body was better too. There was just something 'right' about the sound that made me enjoy music on a more emotional level. Looking back it seems that the RAKK really made me look at music objectively instead of enjoying the beauty and art.

So with that in mind I decided against buying the Magnepans and went for an analog upgrade instead. My vinyl-friend recommended a VPI - he is familiar with them since he runs a MKIV with the TNT platter upgrade and a SME 309 tonearm. So I cruised through Audiogon until I found a MKIII that looked good. This one sports a Rega RB300 and has been modified to have VTA on the fly. I also bought an Ortofon 2M blue and a Graham Slee Era Gold Mk V to round out the signal chain.

The older HW19 turntable are fairly unique for their floating plinth. The plinth supports the heavy platter and arm, but sits on top of four springs. This is meant to isolate the table from the motor. Many more modern designs seemed to have shied away from this approach - using a single heavy plinth to support everything. Though this reduces the construction cost, I would think that unless great care is taken there will still be more motor vibration issues.

How does the VPI sound compared to the Rega P2? Well I'm running a slightly different cartridge - but there seems to be more solidity and more of a foundation to the music. There is more inner detail and the overall sound is cleaner too. In comparison the Rega sounds a little gray and 'dirty' in the background. This is an effect of the less weighty platter and cheaper overall construction. However the Rega is still a good table and worth the trouble for a beginning setup.

I still have some cartride break in and VTA tweaking to do - so I'll report on the Ortofon 2M Blue and Graham Slee on a later posting. But for now I'm pleased with my purchase of the VPI - it has been a big upgrade to my enjoyment of music. I can't wait to start the upgrade process with better cartridges, a VPI SDS power supply, SAMA, tonearm upgrades, etc. This is certainly a fine way to drain my already economically damaged bank account!

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Wednesday, March 4, 2009

Amplifier Update - an 'Universal' Single Ended amplifier

I have sold my Single Ended EL156 monoblock amplifiers to a friend of mine. However he has a number of output tubes that he would prefer to use over the EL156. With that in mind we made some changes to his amplifiers so he could safely run the 6550/KT88/EL34/6L6GC/etc.



The self bias adjustment resistor was changed to a 500 ohm / 5W potentiometer. This allows a large range of bias, allowing the use of several different types of output tubes. I also knocked down the B+ so tubes with a smaller plate dissipation than the EL156 could be used with a bigger margin of safety. Note that I used a 200mA meter to measure the amount of current flowing through the output tube - a 100mA meter would also be suitable for most tube types.



The original 1.5uF power supply capacitor was changed to a .68uF unit. The 82k EF86 dropping resistor should also be changed to 50k.

These minor changes have allowed the amplifier to be used with a wide variety of output tubes. Power output has dropped versus the EL156, but with the right speakers and listening space this amplifier continues to shine. With a pair of original Tungsol 6550s we listened to a few songs on a pair of KEF C-75 speakers and this amplifier sounds very fast with a delicate sweet treble. I'm in love with the sound of this amplifier all over again!

One could also roll EL38s (with plate caps), 6AR6s (with wiring changes), TT21s (with plate caps), and a whole bevy of other output tubes. Have at it.


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Tuesday, February 10, 2009

A visit with the Dynaco AF-6 tuner


I recently picked up a Dynaco AF-6 tuner to use on my second system - it is a nice match to the Dynaco PAS sitting up on top. This particular AF-6 was constructed by some kit builder back in the gloomy days of 1976. I was surprised how warm and natural this old girl sounds. Even with a small antenna it pulls in signals quite well and requires minimal tweaking of the knob to get the best signal. For reliability sake I replaced the back and signal lamps with blue LEDs available on Ebay - it really did a good job of modernizing the overall look. It now has a quiet blue glow that looks lovely when the lights are off.

AM performance is quite remarkable - better than any other tuner I've heard - a good thing to have if you still like listening to sporting events over the radio. I know I like hearing the Detroit Red Wings 'skating right-to-left across your radio dial.'

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Monday, January 26, 2009

Amplifier Shootout: Tubes vs. Solid State


This weekend I pulled my UREI 813A cabinets out of storage and connected the Altec 604 and Eminence drivers back up. It has been five months since I've last heard these beasts so I was a little surprised on how good they sounded. I got familiar with their good points again - the dynamics are simply incredible. There is a clarity and rightness to the overall sound that easily surpasses many speakers that I've heard. But of course no speaker is perfect - there is no big wide soundstage and if you don't sit back far enough the drivers will not integrate all that well. The UREIs are a bit forward and dry too. They also require loud playback levels to sound their best which makes them perfect rock n' roll speakers but not all that suited for baroque. This playback level can also makes them less than popular with anyone not actively listening to them.

With all that in mind, I decided to compare the Threshold S/500 to my DIY Single ended EL156 tube amplifiers. In fairness I invited my fellow audiophile friend over. He has many years of experience with the UREIs - owning among many things a pair of 'no letter' 813s himself. He also has a marvelous set of ears and has always had a top notch tube based system to listen to.

First up were the EL156 amplifiers. This was the first time I've had a chance to hear them on the UREIs so I didn't know quite what to expect. These monoblocks only put out 20Ws or so of class A power and the UREIs aren't that efficient compared to Klipsch, Altec, etc horn speakers. So we were taken aback how loud and dynamic the amplifiers sounded. Bass was surprisingly deep for a single ended amplifier - in this setup I actually preferred it over my more powerful 60W Dynaco Mark IIIs. I know it sounds odd, but the Hammond output transformer on the SE amplifier is a beast and the loop feedback must help too. However there was a slight uncontrolled quality to the deepest of bass notes. Midrange and treble were both very natural sounding - quite like the 'real thing'. Dynamics were also good and only on some big drums recordings - like the Audioquest recorded Terry Evans - did the amplifier seem to run out of steam. At this point the amplifiers sounded a little blurry as the music overwhelmed the short peak power available. But the clipping never sounded harsh or terribly unnatural.

The Threshold S/500 was then fired up and allowed to settle in for a bit. We talked a bit about the pros and cons of electrostat speakers before doing any serious listening. The first cut of a Bob Dylan remaster showed an amplifier that is very neutral. As a side note my friend also remarked that the remaster sounds slightly softer than his original LP. Listening to a few cuts I noted that the top end is extended and the midrange has an inner detail that is some of the best I've ever heard. Bass control is tight as the 250Ws and low impedance really controls the large 15" Eminence woofer. On the Terry Evans cut the snap of the drum stick on the snare or tomtom was shocking and bullet fast - drums would literally hit you in the gut like the real thing. The UREIs certainly excel at reproducing the drum kit. Perhaps there was a little less 'body' than the tube amplifiers, but there was also an overall 'rightness' and coherency from the lowest to the highest frequencies. Power was never an issue either.

What amplifier is the best? Well my friend likened the EL156 amplifiers to a good film print. Very natural and beautiful. The Threshold is more like a high definition digital TV with crisp detail and bright colors. And that pretty much sums up my feelings - the tube amplifiers were natural sounding and a little less 'hi-fi' than the S/500. But they also lacked the total information retrieval that the S/500 amplifier had. As for what sounds best would be determined on what you are looking for in an amplifier. Personally in this system I preferred the S/500 for the dynamic contrasts and detail. But again I could easily live with the more 'romantic' tube amplifier. In the end I was proud of how well my DIY creation held up to the powerful competition.


System:
Threshold FET-10/HL linestage
RAKK DAC with Phillips DVD player
UREI 813A speakers
Cardas 300B interconnects (preamp to amp)
Cardas Crosslink interconnects (DAC to preamp)
speaker cable was Weico silver coated stranded wire

Recordings:
Roxy Music - Avalon hybrid SACD
Terry Evans - Puttin' It Down CD
Bob Dylan - Blood on the Tracks hybrid SACD
Richard Thompson - Shoot out the Lights hybrid SACD
Buddy Guy & Junior Wells - Drinkin' TNT 'n' Smokin' Dynamite CD


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Tuesday, January 20, 2009

How Vinyl Records are Made

A nice little video on how masters are cut and the pressing machinery. Via YouTube of course.



The largest problem facing record production today is plastic quality, mastering quality and the mechanics of an aging technology. Much like steam locomotives, replacement parts to maintain the pressing machinery will have to be found or built by hand. Demand is high for vinyl right now, so maybe we will see some advances or new pressing plant machinery.



Part1:





Part2:




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Friday, January 16, 2009

A visit with the RAKK DAC

(Image from K&K)

The RAKK DAC is a kit (you can also buy a completed version) available from K&K Audio. This unit uses the TI/Burr-Brown PCM1794 DAC coupled with the CS4816 input receiver . I'm currently running the first 'MK 1' iteration that does not have upsampling.

What drew me to this DAC was the novel I/V converter - it does not use an op-amp, tubes, resistor or a mess of transistors - but instead a Lundahl LL1674 1:4 step-up amorphous core transformer. This should provide 'galvanic isolation' from higher frequency digital crud and buffer the PCM1794 from seeing any outside world nasties. This 'transformer' only output is known as the 'Passive Output Stage' and it does suffer from a high output impedance of ~3000 ohms. K&K also offers a lower impedance active output stage using 6N6Ps and Lundahl iron.

A power supply board is also needed - along with RCA jacks, PCB standoffs, wire and of course a bit of solder to hold everything together. I ended up using Vampire RCA jacks and some 21awg solid-core silver wire I bought from Michael Percy.

I stuck the boards and transformers inside of an old Video Generator chassis that already had an IEC plug, fuse and holes for mounting RCA jacks. It sure doesn't look pretty but my DAC budget was already blown by the time I was done buying all the parts from K&K.



How does it sound? It took awhile for the transformers to break in since the treble was initially very edgy and forward sounding. After a few hours, the sound began to settle down. This certainly is some of the best digital I have heard - smooth treble with a fast but surprisingly musical quality. Definition and detail is excellent for Redbook playback, with plenty of appropriate reverb and hall sound coming through. Dynamics are big and lesser DACs sound compressed in comparison. I'm reminded of a good turntable setup - the overall sound certainly doesn't drive me out of the room like some budget CD or DVD players do.

Compared to the Monica 2 DAC, the RAKK is more neutral and has more detail. The Monica is certainly warm and forgiving, but has a thicker sound with a rolled off treble. However the Monica excels at removing the digital nasties from poorer recordings. The RAKK can be more ruthless in comparison.

Compared to the budget Sony SCD-CE595 SACD player, the RAKK has a smoother treble and is more musical sounding overall. That probably has much to do with the 595's op-amp output stage. I'm afraid to say that even SACD discs on the Sony suffer in comparison. The 595 does however slightly outpace the RAKK on information retrieval - but such is the nature of hi-rez digital versus the older redbook technology.

The RAKK has been the only mainstay of my system for the past two years. Someday I'll upgrade or replace it, but for now it continues to satisfy my digital playback needs.


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Thursday, January 8, 2009

Dynaco Mark III Resurrection

In an audio trade I received a pair of vintage Dynaco Mark III monoblocks. The only problem is they were missing just about everything except the output and power transformers. I read a lot and did some talking with a few friends before finally deciding to take the steps to rebuild these old amps from scratch.

Here is how they looked underneath before the operation:
I went with the SDS Power Supply boards available from Triode Electronics. In my case, I didn't use the 50uF in the first section in fear of shortening the life of a NOS 5AR4. Line voltages are higher than the old days so I used a smaller value 20uF/630V Solen in the first section and after the 1.5H choke I paralleled the first two sections together on the SDS board.

For the input boards, I decided on the Poseidon driver boards. I used 5751s instead of the 12AX7 and 12BH7s instead of the 12AU7. The neat part about the long-tail phase splitter is the current sink using a LM334Z - in this case when the tied cathodes sees a large impedance it reduces phase imbalance. There is also a trick method they use to balance unmatched power tubes using the original 10k bias pot and a trimming pot.

To finish the job I had to buy all new sockets, new chokes, new bias pots, bias resistors, RCA jacks and capacitors. I did a flurry of wiring and everything worked on the first try without any troubleshooting required. Excellent products and careful wiring paid off!


Final results on one of the monoblocks:

For final tweaks I went with some MIT RTX and Dynamicap capacitors from Michael Percy. RTX capacitors used to seem very high priced, but these days they are a bargain and well worth the money. Rectifiers are the under the radar Hitachi GZ34s. I've also found some Raytheon 'Windmill getter' 5751s and some NOS RCA blackplate 12BH7s. For output tubes I went with the rugged SED 6550c.

Mark IIIs with the Poseidon and SDS boards, good coupling caps, and the right tubes make for an excellent budget tube amplifier. They have rock steady imaging, deep soundstaging, tight bass for a tube amplifier, and a sparkling treble. With these amplifiers I can really hear 'into' the recording. Many vintage tube amplifiers I have heard simply sound compressed in comparison.


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Tuesday, January 6, 2009

A visit with the Wharfedale W60s

The Wharfedale W60 was made from 1962 to 1966. It is a 2 way system featuring a 12" Alnico woofer and a paper cone tweeter. Mine are the original W60 which has the '5' tweeter. Crossover is simple - utilizing a single 12uF paper capacitor and an L-Pad to control the high frequency output. Construction quality is high - heavily built with even a separate enclosure for the tweeter.

The later W60D uses the 'Super 3' tweeter. Be warned that Wharfedale was an early user of foam surrounds and problems with foam rot have been reported on these later models.

Two years ago I bought my pair of W60s off of Ebay to be used in my second system. I wanted something that was efficient and durable. My wife really liked the almost Ikea-like looks where I appreciated the overall solidity. Well so it goes. The heavy grille cloth certainly kept out some prying toddler fingers or curious cats.

The Wharfedales are not great performers compared to some of the better speakers that I have owned. But they do really excel in the midrange with very natural smooth sounding voices. This works well when listening to radio announcers or vocal heavy music. Lower bass is lumpy and not quite as deep as you would expect with 12" woofer. Definitely more of the polite 'British' sound than say JBL. The tweeter is also very rolled off on top - lacking high end extension. I ended up cranking the L-pad as far as it would go and then eventually just bypassed it when I went in to replace the old coupling capacitor. Inner detail is also lacking and so are many other audiophile tricks like soundstaging and big dynamics.

Can I recommend these? As an audiophile - no. As a music lover - yes. They are warm, forgiving and work wonders with bad recordings. This is not a moot point in these days of hot overly compressed digital recordings. The W60s return a sense of naturalness back to the music. However in the long run my KEF Q30s won out and the W60s have been shuttled on to a friend who was in need of a new pair of speakers.


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Friday, January 2, 2009

A visit with the KEF Q30s

The KEF Q30 is a small 29" tall floorstander that utilizes a single 6.5" Uni-Q (coaxial) driver. Expect to pay approximately $150 for a pair. Built in the early 90s, the Q30 used the second generation Uni-Q driver. Rated for 50Hz-20kHz and 88dB efficiency, the Q30 is best used for a small room. The 6.5" driver can only move so much air and of course there is only a hint of deep bass.

I use a pair of Q30s in my second system utilizing a McIntosh MC-250 amplifier and a refurbished Dynaco PAS preamplifier. The Uni-Q driver is very coherent, providing a nice (albeit small) window into the performance. Pulling them away from the wall decreases the bass response but the imaging as expected from a coaxial driver is fantastic. Treble is very smooth if not a tad rolled off, but with the amp/preamp combination I get a very musical presentation. We listen to hours of music a day through these little floorstanders. Only once in awhile do I wish for a bigger loudspeaker. But hey - that's what my main system is for.

This was my introduction to the KEF 'sound' and it made me curious enough to buy the older and larger KEF C-75. The Q30 is probably best used for small room - condos, dorms, apartments - where you don't want to intrude on your neighbor's ears. They offer a hint of some of the old audiophile tricks - imaging and detail. Pull them away for better imaging or if you need a little more bass they also work well close to the wall. Don't expect big bass or explosive dynamics from these little guys, but do expect a musical and involving presentation. They also would work well as surround speakers that can be tucked into a corner. The wife loves them since they look good and do not intrude into the living room like some of my other speakers.

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