Saturday, May 2, 2020

JE Labs Man Cave 2020



CV21mm f4

The JE Labs man cave was originally planned as an annual feature. But due to a flood mitigation procedure in the fall of 2019, I blogged about the near-field system instead. 

Fortunately, a new drywall was installed and painted by the tail end of winter. I was at the final stage of arranging my library, cameras, LPs and miscellaneous items when lockdown commenced.  

Typically, I'd be on photo explorations in my spare time during spring. But due to the pandemic, I'm trying to be a responsible citizen practicing social distancing. Since I'm confined indoors, here's a virtual tour of the man cave viewed through my Leitz and Cosina-Voigtlander lenses mounted on a Sony A7II camera.

Leitz Summicron 35mm f2 V1


Main System









Antenna: Winegard HD6010 mounted in the garage attic

CV28mm f1.9

Preamp: JEL Octal + 76 


Speakers: Altec 753C, an homage to the Western Electric WE753C and the definitive evolution of my Altec 2-way project

Cables:  DIY Mogami/Neglex 2534 for phono, Kimber KCAG and DIY PBJ, KS24194/Telco Flex III 14 AWG speaker cable 

CV21mm f4

LPs + audio equipment and miscellaneous

CV21mm f4
 
Cameras + Library

CV21mm f4


Workshop

Leitz Summicron 35mm f2 V1


Workbench

SE10 mono integrated amp (under construction)

Test equipment: Hitachi V650F 60 MHz dual channel scope, Kenwood AG-203 sine/square wave oscillator, Fluke 87 and Triplett 9045 True RMS DVMs, Proster LCR meter, Weller WTCPS soldering station and a General Radio W5MT3A Variac



Summicron 50mm f2 Rigid

Near-field System


Turntables: Thorens TD124 and Mk II, Sony TTS 2500, Shield MO-19 and Rek O Kut B12GH

Tonearms: SME 3012Audio Technica AT1501 Mk II, Denon DA305Fidelity Research FR64fx, FR24 FR54, Grace G565 and G540LStax UA3NLSyntec S220

MM Phono Cartridges: Audio Technica AT110E, Nagaoka MP10, MP11, Pickering 380V15 DAT2V15 Phase IV and XV15Shure M3D, M7D, M44G, SC39B 

Digital Sources: Raspberry Pi 3b+/Volumio + Musical Fidelity V-Link, JVC XL-Z411 CD transport, Magnavox CDB465

DAC: NOS'ed Arcam Delta Black Box or tube buffered NOS TDA1543 

Line TransformerUTC A20

Preamp: JEL Loctal or Realistic 32-1100A mixer + 42-2109 phono 

Amps:  JEL SE300B mono blocksRadiotron SE2A3,  Nobsound NS-02g/JLH 1969 Class A


Speakers: Altec 755A in Dr. Bae/Silbatone Cabs or Altec 755C in 618 Cabs



Headphones


Koss Porta-Pro, Grado SR80 or AKG K72 driven by the Darling amp, JE Labs Style


Mono Hi-Fi 


Turntable: Gates CB77 + Gray 108B + GE RPX or Neat P58H + Calrad SV16 or Velvet Touch + DL102 or GE RPX

Digital Sources: Raspberry Pi 3b/Volumio and JVC XL-Z444 CD Player

DAC: Audio GD R2R-11

Tuner: Sansui T-60 or Sherwood S-3000 II

Amp: JEL mono integrated SE2A3 + Altec 15356 stereo to mono mixer  

Speaker: Altec 756B + Altec 32B + Altec 802 

CV21mm f4


Stay Safe and Happy Listening!







Wednesday, April 15, 2020

Gates CB77 - A Tribute to Art Dudley

It is with great sadness that I learned of Art Dudley's demise. I was very honored when he gave me credit on the Altec 755C/Open Baffle article he wrote for Stereophile many years ago. Even if we never had the chance to meet, we had exchanged a few emails and private messages. Aside from being an audio and music lover, Art was a true gentleman! 

From one idler turntable enthusiast to another, here's to you Art!🍻


My first exposure to this "stick-shift" controlled turntable was back in the late 90s when Ding scored a Gates CB77 at a Hamfest for next to nothing. These broadcast units were still under the radar then and I was confident that I'd be just as lucky. But as time passed, I had to resort to the auction site to add one to my collection.

Drive train sub-chassis built on 1/8" aluminum plate


Aside from the motor mounts which were showing signs of aging, my unit was mechanically sound. 

Replacing the motor mounts

remove motor bracket

drill out rivets

fresh rubber mounts
installed
from
McMaster-Carr

My idler wheel was in excellent condition but it's always good to have a spare. I ordered an idler from Serge at Karmadon. Highly recommended!

L = original idler, R = Karmadon idler 

Since the unit was already stripped down, I decided to repaint the chassis.

1/4" thick cast aluminum chassis

The heart of this machine is the mighty Ashland hysteresis motor also found in the top of the line Rek O Kut machines like the Rondine Deluxe B12H.

CB77 Ashland motor

However, due to the unconventional drive configuration (see the platter below), the Ashland motor is wired to turn at 600 rpm instead of the usual 1200* 1800 rpm.

*Thanks, Nate!

Drive train view with the platter off

Compared to the more sophisticatedly engineered Garrard 301/401 and Thorens TD124/MkI-II, the Gates CB77 is a simpler machine. It utilizes a massive 1/4" cast aluminum main chassis. A rigid 1/8" sub-chassis plate carries the main drive train. The finely machined 1" main bearing slips into an Oilite sleeve. The heavy platter/inner hub is driven by a heavy-duty 3-phase Ashland hysteresis motor running in single phase mode.

Massive platter with the idler driven inner hub and 1" bearing 

After following the required adjustments in the service manual, I mounted a Fidelity Research FR54 tonearm. I used it sans plinth for several months.


Despite the lack of an eddy current brake/speed control, pitch stability is solid. Low frequencies go deep with excellent definition. This motor unit exemplifies the bold and powerful dynamic authority at micro and macro levels of well engineered idler driven turntables.  


I'm not sure if my DIY two-tier medium mass plinth improved its overall performance 🤔 given its already massive stature. Regardless, the option of mounting another tonearm like the Gray Research 108B currently installed, is indispensable for my purpose.😊 Since the design relies solely on rudimentary rubber motor mounts and mass to mitigate noise and vibration, it ultimately lacks the finesse of the Garrard 301/401 and Thorens TD124.



Despite that, the value of this motor unit is on the rise. Its bigger brother, the 16" transcription CB500, has already broken the thousand dollar mark. Perhaps there are enough aficionados who really value the aforementioned dynamic authority over the black background of a high-end belt drive or the digital-like silence of a top-of-the-line direct drive.



Wednesday, April 1, 2020

The Good, the Bad and the Ugly TDA1543 NOS DACs


In spite of its humble origins, I praised the musical abilities of the Philips TDA1543 DAC chip found in late 80s to early 90s budget CD players. Below are two affordable (under $30) Non-OverSampling DAC boards I sampled that use this ubiquitous chip.

Non-Oversampling 16bit/44.1kHz TDA1543 DAC Boards

Don't even consider the DAC board to the left, which can be found all over eBay
 for $16-$20/shipped. Powered by this beefy linear wall wart PS, this is by far the worst-sounding DAC I ever heard! It has no redeeming qualities whatsoever. Enough said. 😣

For another $10 + the same linear PS, the DAC board to the right is a decent music maker. Unfortunately, it went out of stock as soon as it was delivered to my doorstep. Even if the Muse Mini TDA1543x4 (more infosounded dynamically more appealing, this single chip'd DAC board seemed harmonically purer and more authentic. In hindsight, I should have hoarded all the units offered by that lone seller. 😆

!!!WARNING!!! 

The voltages found in this circuit can be lethal! Build at your own risk!!!

Tube Buffer Circuit (one channel)

Since this TDA1543 DAC was configured with a passive I/V converter that already has a decent voltage output, I thought a med-mu 6CG7 tube buffer/cathode follower might mitigate the slight opaqueness in the midrange, improve both dynamics and the (lack of) definition in the frequency extremes - qualities which betray the budget origin of this rather musical DAC chip.

The Ugly 😄

Even if the TDA1543 was [and always will be] a budget DAC chip, the experiment paid off, taking this NOS DAC board to another level. 😊

Listen to lots of music, build a project or better yet, do both!
Stay safe! 🍻