9-10" tonearms: Denon DA305, Fidelity Research FR24 MkII, FR54, FR64fx and Grace G540L

Tonearms are like violin bows...

When I posted the above picture + caption in my 2020 preview, I was drawing an analogy in which the turntable is a violin, the tonearm is the violin bow, and the phono cartridge is the violinist. Due to unforeseen circumstances that year, I was only able to cover 11-12" transcription length tonearms contained within the Garrard 401 + Alfred Bokrand AB309 essay. Even if I'm committed to transcription length tonearms for ultimate LP reproduction, below are capsule reviews of 9-10" tonearms I also like and use. 

Denon DA305

Spindle > pivot = 230mm

Although not the last word in terms of detail retrieval, the DA305 has the ability to recreate the atmosphere of a fine concert hall. Aside from bringing out the best from the Denon DL103, it also partners well with low compliance magnetic cartridges like the Shure M3D. Musically, very honest!

Fidelity Research FR24 MkII
Spindle > pivot = 230mm

The FR24 displayed excellent synergy with medium to high compliance magnetic cartridges. It was the perfect mate to the Nagaoka MP10 and is equally at home with the high compliance Shure SC39ED. The sound was not as exciting when paired with lower compliance cartridges. A beautiful design with a bejewelled feel!

Fidelity Research FR54
Spindle > pivot = 230mm

Tonally, the FR54 sits in between the DA305 above and the FR64fx below. I love this tonearm because it sounds detailed yet musical - a combination of virtues that's not easy to achieve. It is best paired with low to medium compliance magnetic and moving coil cartridges. Although at the limit of its range, it can handle an Ortofon SPU and does quite a fine job on playback! 

Fidelity Research FR64fx
Spindle > pivot = 230mm

This is the most massive tonearm in this group and the only dynamic balance design. Top flight low compliance moving coils like the SPU are its natural partners - definitely not designed for high compliance cartridges. It allows the proper cartridge to trace every micron of detail from the LP groove. However, there are moments when this virtue gets in the way of musicality, since it can also sound analytical and dry. It's the antithesis of the Denon DA305. Could this be the reason why its FR64S sibling is more sought after? 

Grace G540L
Spindle > pivot = 222mm

In the mid 90s, the G540L proved to my ears that the concept of a removable headshell being detrimental to good sound was a myth. So I unloaded my Rega RB250, RB300 and Sumiko FT-3 and started collecting tonearms that accepted IEC headshells.😊

Happy listening! 🎵

Old Flame - Rogers LS3/5A

As I mentioned in my reply to a reader's query in Snell Type J III, Part 1, I'm the temporary caretaker of a pair of 15 ohm Rogers LS3/5As while my buddy Jose's basement is getting sorted. 

ca. '93

Long time readers know that I was a BBC LS3/5A user. A pair of 15 ohm Rogers replaced my Magnepan SMGas in '86. As a partner in a company that distributed Spendor speakers in the Philippines in the early 90s, I also owned a pair of 11 ohm bi-wireable Spendors. 

ca. '94

In the preceding two pictures, my pair of DIY PP2A3 monoblocks struggled to drive the Spendors in my tiny apartment. Despite that, the BBC near field monitor opened my ears to the virtues of directly heated triodes. Alas, they were superseded by Altec 755s because I needed more efficient speakers to pursue flea-powered single ended directly heated triode (SE DHT) amps.

The Bextrene cone KEF B110  5" woofer + the complex crossover/EQ network = 82 dB/1W/1M, very inefficient! But kudos to BBC engineers, IME, the speaker is still a relatively easy load for low-powered tube amplifiers because of its high(ish) impedance across the audio band. 

Just as I remembered, the LS3/5As are very capable of portraying the midrange magic of an SE300B or even an SE2A3 at near field distances. However, to get some boogie factor out of them, they need the power output of at least a Dyna ST35. But as good as the ST35 amp is, a catch-22 situation ensues because it sounds veiled compared to the aforementioned SE DHT amps.

Snell Type J III + Rogers LS3/5A

I was viewing the past through rose-tinted glasses when I posted (#3) in HiFi Haven - mea culpa! There's a greater similarity in tonal character between the Rogers LS3/5A and Snell Type J III. The Altec sound is another entity altogether!

Given my post SE amp/High Efficiency transducer expectations, the Altec 755As in Dr. Bae/Silbatone cabinets are tonally more lifelike across the audio band, offers better resolution, has more low frequency extension, greater micro and macro dynamics and plays at higher SPLs in a package that's not significantly larger. 

Listening to the LS3/5As was like seeing a former flame. The familiarity is there but the chemistry and fireworks are gone. (◞‸◟)ﾉ

Thorens TD124 Tips

 

Cheap and EZ

Neat P58H/Shield MO19

This experiment was inspired by the spring-mounted motor on my Neat P58H.

Realistic MKVIII

Even if the rubber grommets on the MKVIII are still supple and intact, I replaced them with 302 stainless steel compression (1/2" x 0.600") conical springs, Grainger part no. 1NDB4 and heard a significant reduction in noise.

Left = Neat P58H original
Right = 1NDB4

Heck if it works with the Japanese idlers, it should also work with the TD124. So I ordered smaller conical springs from zorotools on eBay for the TD124 and TD124II.

1NCY2 = 5/16" H x 0.48"

Be careful removing/installing the circlips. They can fly across the room, along with expletives.😁

1NCW4 = 1/2" H x 0.48"  

Some may argue that the "springy" motor mount can introduce pitch instability and also, as originally designed, the belt provided ample isolation from motor vibration. The springs are cheap, so let your ears decide.😉

Magnetic vs. Non-magnetic Platter

 TD124 standard platter = heavy "magnetic" iron

I used to believe there was negligible sonic difference between the heavy iron platter from the MKI vs. the MKII's non-magnetic platter.

Lighter non-magnetic platter
issued with the TD124II 

However, in the intervening years, I've come to realize that the heavy iron platter bestows gravitas to the TD124 design! 

TD124II + heavy iron platter

When I found an older iron platter at a reasonable price, I grabbed it and installed it to my Mark II!

IMHO/IME, as long as one keeps the original aluminum outer subplatter + clutch mechanism intact, the magnetic platter + phono cartridge interface isn't a problem. Ortofon and Thorens were aware of this back in the day and their recommended procedure of setting the VTF as pictured above is still relevant now. I've been using the SPU, DL103 + other phono cartridges on the iron platter for over two decades with no issues.

Let's not go to the light (or no plinth) vs. heavy plinth.😄

Reference

 For maintenance and restoration information, visit The Analog Dept. Thorens TD124 webpage! 👍👏

morrison micro 2A3, reimagined + Kasuga Wireless KA6625ST output transformer

Joe Roberts' piece, "I Never Met a 2A3 Amp That I Didn't Like," from Sound Practices Issue 15, is very persuasive. I built jc morrison’s micro 2A3 amp soon after I received the issue via snail mail fresh from the printers in the mid '90s. After rereading the article in ‘07, I got inspired to make a Radiotron SE2A3 variant.

Kutztown Radio Show - Spring 2021

Most pictures taken with a Sony A7II camera + Chiyoko Super-Rokkor 45mm f2.8 LTM lens

Pavillion 1

Rumor has it that dealer tables were sold out. Just another indication that things are returning to normal.

Pavillion 2

If you're looking for vintage Altec, JBL, RCA, Stephens, Western Electric or '50s to mid '60s classics from Acrosound, Dynaco, Eico, Fisher, Heathkit, Marantz, Scott and etc., they are getting thin on the ground and no bargains are to be found. 

Late 40s to early 50s cutting lathe

This is a fine piece from the monaural era for the serious hifi collector!

Those who are into '70s-'90s components have greater choices.

The main highlight of this season's event was meeting audio enthusiasts from the Philly metro area whom I've only known via Audiokarma and HiFi Haven. I spent most of the time talking shop with them and wasn't able to snap as many pictures as I've done in the past. 

AKG K240 Monitor (left) + K240 "Sextett" (right)
Sony A7II + Schneider-Kreuznach Retina-Xenon 50mm f1.9 DKL

For about a Benjamin, I went home with a pair of AKG K240 Sextett headphones, a TDA1541 chip'd Magnavox CDP, 37s, 76s and 6CG7s, a handful of Jazz CDs + a couple of LPs!

I also found something that's been on my radar for at least 20 years, but it shall remain nameless until...😉

Looking forward to the Fall event!🍻

Hi-Fi for the Deck: Rpi3B >TDA1543x4 DAC > Simple Triode SE6V6 amp > EV Sonocaster

Spring and Fall are the best seasons to enjoy food and drinks on our deck. To complement the beautiful atmosphere, I assembled an e-z to set up and dismantle hifi system!

Music Source

This stack consists of a Raspberry Pi 3B loaded with Volumio music player/streamer tethered to a Signstek USB to SPDiF converter which connects to a Muse TDA1543x4 Non-OverSampling DAC.

Volumio offers a wide choice of radio stations streaming MP3 files up to 320 Kbps. The Radio Paradise channel has even started broadcasting FLAC files. 👍

Amplifier

In the late 80s, I built my first amplifier from scratch using transformers from a cosmetically challenged Dyna SCA35. I used this paraphase circuit from the Dynaco Transformer Catalog with a 6SL7 driving a pair of push-pull 6V6s. Musically, I preferred this amp to my then highly modified Dyna ST70 and pair of MKIVs.

with 6F6Gs courtesy of John Piro

Since I always had reservations about the 1626 triode's musical abilities, I converted the JEL Darling Style amp to use triode connected 6V6s. Wow!👍

!!!WARNING!!! 

The voltages in this circuit are potentially lethal! Build at your own risk!

Input sensitivity = 0.3V, no need for a preamp
This amp also does a good job of driving my collection of orthodynamic headphones via adapter.

 2.825 Vrms into 8Ω = 1W of triode power per channel 
I'm not worried about the slight overshoot/ringing, rumor has it, the Sony/Tamradio OPTs have nickel content 
also, the last time I saw a similar square wave was with a pair of Nature Sound NS70SE OPTs.

Triode connected 6V6s mimic directly heated triodes much better! 🎻🎸

Speakers

This pair of Electro-Voice Sonocasters came from the flea market. I guesstimate the sensitivity to be in the mid 90s dB @ 1W @ 1M. Driven by 1.4 triode watts per channel from the SE6V6 amp, I sure won't be annoying the neighbors. 🤣

The 8" drivers are unmarked but look very much like MC-8s - not quite an Altec 755C or Pioneer PIM8L in terms of refinement or realism, but not too shabby either + a lot more rugged!

Happy Listening!🍻

Marcel Breuer Designed House + Altec 604C + Infinite Baffle

  

This beautiful mid century modern home aka the Snower residence was designed by Bauhaus architect Marcel Breuer and posted by midcenturyhome, whose finely curated photostream I follow on Instagram.

Aside from my interest in mid century modern architecture, the Altec 604C mounted prominently in the living room caught my eye.😄

I've also seen a Fisher 50C preamp (bottom) at FLW's Fallingwater. Unfortunately, interior photography was prohibited there when I last visited. 😞 

The Snower house + hifi installation was already brought to my attention in the comment section of architects, music and hifi  by a blog visitor many years ago. Thank you!

from Dwell.com

More Infinite Baffle Installations

I blogged about this installation before, but this picture offers another perspective of the 2-way horn speaker system installed in Case Study House #9 designed for John Entenza by Charles and Ray Eames and Eero Saarinen.

Scans from How to Build Speaker Enclosures

An office stereo hifi

John Hilliard's home hifi system

Hi-Fi system details

I'm pretty sure all these wall mounted speaker systems were formidable music reproducers! However, ever since soundstaging and imaging took precedence over sound quality, infinite baffle loading fell out of favor. 😔

Lar Retro-resto Shure M65 Phono Preamp

Hamingredient inspired chassis 😉

In the early 2000s, I tried to unload a half dozen or so of my used/test good Telefunken 12AX7s on eBay. The buyer promptly requested for a return claiming that they didn't test well in his TV-7. Was that a sign...? 😉 

So instead of re-listing, I stashed them away. I had forgotten about their existence until they showed up during a 2020 lockdown clean-up spree. 

Shure M65

I met my buddy Lar through Audiomart in the late '80s. He's a trained sound engineer and audio hobbyist who shares my passion for the classic Austin Mini.👍 We hang out and talk shop at ham radio festivals, audio and radio shows. He's firmly committed to tube phono circuits employing active RIAA EQ and posts his projects at Audiokarma and Lenco Heaven.

Shure M65 schematic

The classic Shure M65 "chrome cutie" (as Lar fondly calls them) is one of his favorite platforms for modification. Keen eyes will notice the similarity of this topology to the phono section of the classic Dynaco PAM-1 and PAS-2/3 tube preamps, albeit operated at a lower B+ voltage and with AC heated filaments.

One channel shown

The 0.47uf ceramic disc input coupling caps, C1 and C2 + the 1M shunt resistors, R3 and R4 are discarded. Likewise, the 100k positive feedback resistors (R11 and R12) are eliminated, which I also used to do to my Dyna PAS preamp hacks. IME, this procedure improves transparency. The most significant performance upgrade is Lar's recomputed RIAA EQ capacitor values (see the above schematic) tweaked for flatter response.

I didn't have a Shure M65 but had enough parts to clone one so I could put my rediscovered Tele 12AX7s into good use in the midst of Covid-19 lockdown.

This one chassis configuration sounded fine on first turn on but had an annoying low level hum I couldn't eradicate. 

After trying all possible grounding schemes, I yanked the power transformer out and built an outboard power supply. Problem solved!

My power supply is slightly more sophisticated than the stock M65. The full wave rectified B+ is filtered by a 20H/20mA choke followed by a 47uf/450V cap, which splits to separate left and right channel rails with additional decoupling and filtering. The tube filaments are DC heated. 

1 kHz
stock RIAA EQ

Using the stock RIAA EQ capacitor values, lower frequencies sound bloated with a noticeable treble boost as noted in the Shure M65 literature, which is also visible in the above 1 kHz square wave.

1 kHz
LAR modified RIAA EQ

The 1 kHz square wave is squarer and the phono preamp sounds so much better with Lar's tweaked cap values!

I don't think I was ever able to derive this level of musical satisfaction from any of my past 12AX7 phono efforts using active RIAA EQ. I believe the sonic purity stems from the simplicity of the circuit itself. The Dynaco PAM-1 and PAS-2/3 circuits have an additional cap after the negative feedback RIAA EQ tap + elaborate switching and a balance control in the PAS, all of which can cause veiling. 

In spite of the Shure 5000 ohm output impedance spec, this is still a relatively high output Z device. When connected directly to the 10k ohm input of my Nobsound NS-02g amp, the loss of extension at both frequency extremes was discernible. It sounded best driving a 100k ohm load using low capacitance cables, 3 ft. long, max! 

This phono preamp synergized very well with my favorite magnetic cartridges with conical stylus - Nagaoka MP10, Pickering XV15, Shure M3D and M7D, amongst others. So after a couple of months of enjoying the Lar mod M65, I decided to build it on a nicer (if a bit cramped 😁) cast aluminum box with two pairs of inputs.

Instead of boring you with audiophile adjectives, I'll just say that my RCA passive RIAA EQ octal sounds effortless and airy, while the EAR 834P derived loctal is detailed and dynamic and the Lar retro-resto Shure M65 is sweet and alluring! 

This phono preamp is a most welcome addition to my tools for enjoying LP reproduction. I highly recommend following Lar's phono preamp adventures at Audiokarma! 

Bravo Lar!👏