Sunday, November 15, 2020

Project: Restoring a Audio Research SP-8 preamplifier

 A recent purchase was this Audio Research preamplifier that sadly is in need of repair.  All original early 80s, it will need a cap job, a new volume control, and a solid-state regulator supply fix.  More later!

Tuesday, April 21, 2020

Short Review: Lepai LP-2020TI amplifier

I'm in the midst of building a small home studio for recording synth and guitar.  My plan for monitoring was to use a pair of KEF Q350 speakers with a small amplifier.  With my past love of the Charlize and other Class T amplifiers, and a low budget, I decided to give the Lepai LP-2020TI, available from Parts Express, a try.  For $25 it is hard to go wrong.  If I didn't like it, no big hit to the pocket book.

This thing is tiny - like the size of two packs of cards.  It is also extremely light; helped by the 12V outboard power supply.  Build quality is just okay.  I'm not a big fan of the spring clip speaker wire connectors or the tone controls; which can thankfully be bypassed.  The light-up volume control is gimmicky too but no real major complaints given the silly low price.

In my garage system - replacing the venerable Adcom 545 - I was surprised how good CDs from the old Pioneer DVD player sounded.  There was a toe-tappin' excitement to the music with plenty of kick.  The Wharfedale Denton speakers are a good match with this amplifier, making more volume than I expected.  There was a nice speed to the sound too.  Over all I would give the slight nod of the Lepai over the Adcom, but we are talking a garage system so let's not get too carried away!

I originally wasn't thinking of plonking this little amp into my main system, but given the amount of free time I have due to being furloughed, I decided to give it a try.  Initial impressions were rather eye opening.  This is one very nice sounding amplifier.  But a few minutes of listening, even with my Dual CS5000 and Schiit Mani phono, I could hear a loss of detail and blurring compared to the Aleph J.  Bass of the Lepai was also a little rolled off and there was some solid-state grit and forwardness on top.  But to be fair, the Aleph cost in the neighborhood of $900 to build; a far cry from the dinner-for-one price of the Lepai.

Conclusions?  It's a good amp for cottages, garages small apartments, dorms, or where critical listening is not of upmost importance.  I could easily imagine a system with a Rega RP1, Schiit Mani, the Lepai, and your favorite budget mini-monitors.  Such a stereo would best a lot of ones that I've heard (or even owned!). 

Garage System:
Pioneer DV-V7400 DVD/CD Player
Schiit SYS passive linestage
Adcom 545
Wharfedale Denton 80th Anniversary
Belden 9497 speaker cable
generic interconnects

Main System (second turntable)
Dual CS5000
Schiit Mani
Classe Five preamplifier
DIY First Watt Aleph J amplifier
KEF R500 speakers
Cardas Twinlink speaker cables
Cardas Neutral Reference and Iridium interconnects

Thursday, March 5, 2020

A Very Brief Review of the Schiit SYS

I bought this little $49 passive preamplifier to use in a CD-only garage stereo system.

For fun I plugged it between the Schiit Mani phono preamp and the Aleph J amplifier, using the cheaper of my turntables, the Dual CS5000 as source. The SYS sounds really nice. There is that slight lack of drive I've heard before with passive preamps but detail and transparency is extremely good.  None of that (minor) JFET darkness of the Classe either. I should try the Schiit Mani/SYS combination out with my Thorens TD309 but that will have to wait for another day.

For the price, it's a steal and would work wonders in simple system.

Monday, March 2, 2020

Review: KEF R500 loudspeakers

Introduction: Last month I bought a pair of KEF Q350 speakers. I liked some of the attributes over the Wharfedale Denton speakers - mostly the sense of speed and some better detail. My plan was to eventually replace the Q350s with a pair of KEF R3s, speakers that were being sold via Accessories4Less for a very nice price. Things, however, began to move a little faster than I expected.

Fate stepped in: the Walnut R3s were no longer available. With my wife's blessing I instead purchased a pair of reconditioned R500s, the previous generation of the current production R5. It's been a few years since I've owned "full range" speakers so I was curious to see how these would sound in my narrow mid century listening room.

Shipping was fast with a Sunday (!) delivery from Fedex. I managed to unpack and setup the speakers without any help but be warned, the cabinets are heavier than they look. My weekly workout plan paid off! I also liked the spiked feed and the cups to stop damage to the new cork floors.

First Impressions: Where did all that bass and body come from? The two 5.25" woofers move a lot more air than I expected but perhaps I've been living in mini-monitor land for far too long. Sure it's not quite in the old UREI 813A territory with 15" woofers but the KEFs acquit themselves well with most rock music. The blending of the drivers - bass, uni-q midrange and tweeter - is also seamless.  Even though I only have 25Ws of Class A Aleph J on tap I had no urge for more power with the small listening room.

My friend rolled over and we listened to a few favorite records. It was obvious that these speakers still had some breaking in to do since changes were audible even in the middle of an LP side. After a few hours it seemed as if the treble had become more extended and the drivers even faster than before. Forwardness and depth changed with whatever turntable / preamp was being used. ie - the Thorens TD309 / Classe Five gave a "back in the hall sound" while the Dual CS5000 / Schiit Mani was more forward "mixing board" approach but with a little less resolution and bass depth.

Listening: After a week of daily use, it was time for a solid listening session with notebook in hand.   Turntable used was the Thorens TD309 paired with the Classe Five.

The Who - Tommy (Tracks) is an odd little album that I like but only in small bursts.  It is also an album I've heard on several of my systems.  The first side of this German pressed double-LP album has a lot of dynamics and a wide soundstage with a lot of things going on.  The KEFs did a very admirable job here; the firm foundation of Keith Moon's drumming and John Entwistle's bass was some of the best I've heard; only beaten by the massive UREI 813A speakers.  Where the R500s really shined was the attack of Pete Townshend's guitar work, sounding detailed and full of body.  There were a few times where my jaw literally dropped with surprise by the sheer dynamics of the album, not to mention the soundstage height(!) which is something I usually only hear on very expensive speakers.

Dead Can Dance - Into the Labyrinth (4AD) has a lot of acoustic instruments in a wide, sometimes shifting soundstage.  My original 1993 British pressing sounded marvelous.  On the song The Ubiquitous Mr Lovegrove, Brendan Perry's voice had real weight and presence.  The fleshy finger strikes on the heads of the drums was readily apparent..  Dynamics, once again, were excellent as was soundstage depth and width.  Just a stunning album, one that I would use to demo any excellent hi-fi system.

Hiroshi Suzuki - Cat (Coumbia) has recently been re-issued on very clean and quiet Japanese vinyl.  The color of the Suzuki's trombone is vivid with astounding dynamics shifts.  The rest of his bandmates sound as if they are sitting in a living real space.  An example of ths is the song Walk Tall which begins with hand claps that echoed with a natural decay.  The treble is fast and transparent, especially for a metal tweeter driver.  The high end detail doesn't quite match the best I've heard - QUAD ESL-63s or Ionovac plasma tweeters - but still has less aggression than the horn tweeter of an Altec 604.

Creedence Clearwater Revival - Bayou Country (Liberty) is a classic rock 'n' roll album.  This original British pressing somehow bests the American copies I've heard with a cleaner, more see-through midrange.  The attack of the guitar has real body and presence; unlike the past mini monitors I've reviewed.  Once again the dynamics were impressive, especially the harmonica playing which had a real raw and dirty swamp sound.  It sounded as if a whole lot of air was being moved!  The instruments were each locked into their own space, separate but joined in the musical whole. 


Conclusion: As you can tell, I was taken away by the presence the KEF R500s could project.  The body of instruments and vocals were especially enjoyable.  These speakers seemed to sit in a middle ground between the UREI 813As and the Magnepan 1.6QRs, which is to say they could swing dynamically, soundstage quite well both in width and depth, and still provide musical enjoyment.  But they also didn't have the aggressive warts and all sound of the horn speaker, or the dark graininess of the planars.  After living several years with the limitations of small monitor speakers it will be difficult to go back; the ability of the larger KEFs to provide life-like body is something I cannot forget now.

In the future I will be playing with some wiring changes, a different cartridge, and maybe even a more powerful amplifier.  For now, however, the speaker quest is finished.

Review System:
Thorens TD-309 turntable with Ortofon 2M Bronze
 Classe Five preamplifier
First Watt Aleph J clone
Cardas Iridium interconnects
Cardas Twinlink speaker cable

Friday, January 3, 2020

Review: KEF Q350 speakers

Nothing too expensive or too exciting but for the price - brand new - from Accessories 4 Less, I couldn't pass them up. I've been a KEF fan for a long time, owning multiple iterations of the Uni-Q driver over the years. I was curious to see how this similarly priced speaker would sound versus my favorite budget Wharfedale Dentons.

I've been letting the speakers cook with daily usage from a vintage Dual CS5000, Schiit Mani, and Ortofon OM20 combination. At moderate levels the difference between the old *Wharfedale Denton and the KEF Q350 speakers are subtle. The Q350s are a touch cleaner with a brighter tone. Detail - neither are what I would call overachievers here - is also a little better, perhaps the difference between aluminum and woven Kevlar drivers.  The bass out of the 6.5" KEF woofers go down a touch deeper and with a bit more definition than the 5" unit on the Dentons.

With the family out of the way for an hour, I fired up the Thorens TD309 and spun my US copy of Pink Floyd's The Wall. At a higher listening level: within their dynamic limitations, the KEFs do a bit better here too. The busy sound effects come across cleanly and have real depth too. Definition - inner detail and body - are certainly not the best I've heard. These are, after all, no electrostatic speaker or an Altec 604 driver with a time-aligned crossover, but given the price the KEFs are more than acceptable. The old "PRAT" factor is high with lots of toe tapping enjoyment. Bass with the 6.5" driver is good but if you want to go deeper and louder a sub (or a larger Q-series) would be needed.

Further listening with a variety of records revealed a clean midrange with only some minor veiling - again, compared to the best I've heard. ie - there is an ever-so slight blurring of aggressive guitar work and the leading edges of high-hats. The treble is, however, extended with shimmer and shine but still not etched. I was expecting some overdone brightness from the aluminum tweeter but my (aged) ears weren't driven out of the room.

Overall I would give the KEF Q50s a solid thumbs up. They do punch quite above their cost point but these days that's no big surprise given the available computer modeling and testing that would have been a dream for speaker designers in the past.. I'm curious how the R Series would perform. But that's a future hope.

*Regarding the Wharfedale Denton speakers: these are equally good speakers but something I would recommend with a more aggressive digital front-end or amplification chain. In my case the smoothness of the Aleph J and the slight darkness of the Classe Five preamplifier was perhaps too much of a good thing. The Denton appears to have been voiced to have a vintage, smooth sound instead of the "hi-fi" approach of the KEFs.

Classe Five preamplifer
Aleph J amplifier
Thorens TD309 turntable with Ortofon Bronze phono cartridge
Belden 9497 speaker cable
various budget interconnect cables