John Linsley-Hood Class A Headphone Amp

Having been a happy user of a John Linsley-Hood (JLH) 1969 Class A amp cloned by Nobsound, I was intrigued by the JLH Class A headphone amp boards featuring discrete circuitry (no ICs or op-amps) advertised on eBay. In the midst of the 2020 lockdown, I ordered this $25 pre-assembled board, which arrived in a padded pouch within 10 days. I also got a surplus 24 VCT @ 2A power transformer for another $15.

!!!WARNING!!! 
The voltages in this project are potentially lethal! Proceed at your own risk!

Typical of Chinese kits, this board didn't come with instructions or any type of documentation. But the board is marked for an experienced DIYer to decipher and set up in no time. Unlike the original JLH 1969 design, which needed DC blocking capacitors at the output due to the single rail supply, this headphone amp module was updated to work with a dual rail (+/-) supply so the output capacitors can be omitted.

 

Unfortunately, I couldn't get stable zero DC offset at the output terminals. Trimming for zero volts after 30-45 minutes of warm up was not a guarantee that in another 30 minutes it'll still be zero - I've measured as much as 0.3V.😞

Since I didn't want to risk frying my headphones and classic speakers, I installed 2500uf @ 16V electrolytic blocking capacitors at each channel’s output. Then, I bypassed the electrolytic caps with hermetically sealed 4uf paper caps just like I did to the Nobsound NS02g.  

Top trace = audio generator
Bottom trace = amp output

In spite of the DC blocking caps at the output, the square waves still show excellent bandwidth, transient response with no trace of ringing. 

Before clipping, I measured 250mW/channel @ 4 ohms, 500mW/channel @ 8 ohms and 950mW/channel @ 16 ohms, 1.2W/channel @ 32 ohms,  395mW/channel @ 150 ohms, 190mW/channel @ 330 ohms and 115mW/channel @ 560ohms. I pretty much exhausted the resistor values from my parts bin to emulate the nominal impedance of typical headphones. 

The 115mW output into a 560 ohm load shouldn't worry headphone enthusiasts since this amp drove my Austrian AKG K240/600 ohm Monitor cleanly beyond SPLs my ears could tolerate. It also had no issues driving less efficient ortho-dynamic headphones like the Fostex T50RP MKII below, courtesy of my friend Nate. Thanks, buddy!

This amp definitely outclassed the Rat Shack mini amps I'm fond of. Its class A design's purity and transparency puts it on another league. Unfortunately, Class A amp designs require a more substantial power supply, which is incompatible with portability. 

The character of this amp is exactly like that of its bigger brother, a fatigue-free solid state amp that almost (but not quite) succeeds in sounding like a good tube amp!

BTW, did I mention that it can also drive my Altec 755As in Silbatone cabinets?

Moving Iron Cartridges: Grado, Nagaoka, Pickering/Stanton and Piezo/Sparta

This is the last installment of my series on magnetic phono cartridges, which commenced with early stereo cartridges followed by moving magnet cartridges. These cartridges were evaluated in the near-field and main system in the man cave. Tonearms used include the Syntec S220, Denon DA305, Fidelity Research FR54 and Grace G565, mounted on the Garrard 401, Realistic MKVIII, Rek O Kut B12GH + L34 and Thorens TD124 or MKII.

Grado

This collection of Grado cartridges dating back to the 80s and 90s is a testament to my being a dyed-in-the-wool Grado fan. They served me well when I spun LPs via a suspended sub-chassis, belt-drive turntable, feeding hacked Dynakit preamps and classic push-pull EL84 and EL34 amps to drive BBC LS3/5As or Quad ESLs.

But as soon as I started dabbling with idler driven turntables + higher mass tonearms, no negative feedback preamps, single-ended triode amps and high efficiency speakers, the voicing of Grado cartridges started sounding contrived and unnatural. I switched to using the Denon DL103 and Ortofon SPU low output moving coil cartridges via mic transformers.

Grado GTE+1 + ZTE+1 stylus

Although the Pickering/Stanton 371 was more fatiguing to my ears, the GTE+1 has a similar tonal curve. The GTE+1's mid-bass sounds boosted, the midrange is slightly recessed, followed by a sudden rise in the upper female vocal range that gives a nasal quality, which is borderline shouty. The rising response goes all the way to the mid-treble range then it sharply rolls off in the extreme high frequencies. 

This kind of voicing presents an exciting sound that has created a fan base as well as harsh critics for Grado. Tonally, the early Grado SR80 headphones I own were voiced in a similar fashion.

Grado Signature 8MZ

The tonal curve I described above is still apparent in the Signature 8MZ but milder. The upper midrange/lower treble peak was refined and the frequency extremes more extended. In the process, however, micro and macro dynamics suffered. Refinement, detail and resolution improved at the expense of musical excitement.

I also noted a lack of air and spaciousness between instruments and vocals as presented by both 8MZ and GTE+1, which resulted in a drier and narrower sound field compared to the Nagaoka, Pickering/Stanton and Sparta S220.

Nagaoka

Nagaoka MP11

In the Fall of 1983, my dearly departed dad, a violinist, conductor and music professor, went on an observational tour of orchestras and music schools in the UK under the auspices of the British Council. Before heading back to Manila, he took a side trip to NYC to visit me and see his old haunts. The Nagaoka MP11 pictured above was his gift + a couple of Popular Hi-Fi and Hi-Fi Answers issues he picked up along Tottenham Court Road.

Nagaoka MP11

Mounted on my stock AR XA turntable in '83, I didn't think too highly of the MP11 and preferred the GTE+1. So it rested for more than three decades. When I revisited it, the tables were turned. Listening to the MP11 exposed the Grados' flaws.

To my ears, the MP11 is the moving iron equivalent of the Denon DL103R. It has a sweet midrange, detailed and extended in the frequency extremes with a middle row concert hall perspective. Even if the presentation is more relaxed than the Pickering/Stanton models below, it still presents musically satisfying dynamic nuances. 

Nagaoka MP110 body + MP10 conical stylus

Encouraged by my rediscovery of the MP11, I kept my eyes peeled for another Nagaoka MP cartridge at close to '80s pricing. Fortunately, I lucked out with a couple of NOS MP10 styli + a cheap MP110 body. 

I couldn't detect any sonic difference swapping the MP11 or MP10 stylus between the MP11 and MP110 bodies. The DCR of the MP11 coils averaged at ~ 550 ohms while the MP110 ~ 600 ohms. Thus, I assumed that the MP11 and MP110 bodies are identical.

Sonically, the MP110 body (or MP11 body) + MP10 stylus = the moving iron equivalent of the Denon DL103.

Pickering/Stanton

Pickering XV15 + D400 conical stylus

The positive attributes I noted about the Pickering 380 + Stanton 371 = Pickering XV15. Compared to the MP10/11, the concert hall perspective is more front row. The midrange is the most three-dimensional in this survey and comparable to the Shure M3/7D. Dynamically, this cartridge is the most exciting in this group. 

The MP11/10 beats the XV15 + original conical stylus in terms of detail resolution. Perhaps with an original elliptical stylus, the detail and resolution in the frequency extremes will most likely equal or even surpass the MP11.

Note that the Stanton 680 is the same exact cartridge and the stylus are interchangeable between the two bodies.

There's a lot of SPU juiciness from this cartridge!

Pickering V-15 Phase IV + IV AM stylus

The Pickering V-15 Phase IV was designed as the entry-level model in the Flux-Valve (moving iron) line up. I measured an average of 780 ohms DCR from its coils vs. 1200 ohms for its higher-end brother, the XV15. 

Its overall performance is formidable and the superiority of the XV15 might only shine through in a direct A/B comparison. The Stanton 600 is the equivalent model.

Sparta 220S

This Sparta 220S cartridge came with one of my Syntec S220 tonearms. The Japanese OEM was identified as a Piezo YM-114 aka Hitachi DS-ST101 by wualta in Audiokarma. It's a very smooth-sounding cartridge with good detail and extension in the frequency extremes. Not as dry as the Grados, but like the 8MZ, it doesn't have the micro/macro dynamic prowess of the Nagaoka MP10/11 and Pickering XV15/Phase IV.

Coda

My Grado cartridge collection survived the '90s purge when I unloaded my two Merrill modified AR turntables, two pairs of Quad ESL57s, a 15 ohm pair of Rogers and a 12 ohm pair of Spendor LS3/5As, a pair of Acrosound TO330 push-pull output transformers, Lafayette KT600, Acrosound 20/20, Dyna ST35, Eico HF87, Leak 20, Pilot SA232, SA260 and many other classic equipment. 

The proceeds financed the acquisition of tubes and directly heated triodes, Tamura and Tango SE output transformers, idler driven turntables, high mass tonearms, high efficiency Altec drivers and other DIY audio materials.

 

Pickering XV15 and V-15 Phase IV + Nagaoka MP11 and MP10

Since these four cartridges emerged as my favorites in this shootout, it might be the right time to let go of my collection of Grado cartridges...

The Wrap 

Moving Iron + Moving Magnet

Nagaoka MP10, MP11, Pickering XV15, Shure M3D
Pickering V-15, Pickering Phase IV, Shure M44

 A couple of moving magnet cartridges deserve pride of place along with my chosen moving irons - the Pickering V-15 + DAT2 for its sweetness, the Shure M44 + EMJ N44G for its dynamic qualities and the Shure M3D for its timelessness! 

Nagaoka MP10, MP11, Pickering XV15 and Shure M3D

Finally, if I could only have four, these are the cartridges I'm keeping!

Kutztown Radio Show Fall 2020

All pictures were taken with a Fuji X-E3 camera + Meike 28mm f2.8 lens

Pavilion 1

This was the first audio related event I've attended since the March 2020 lockdown.

Thorens TD124 MkII

Dyna PAS 3 + ST70, ARXA turntable, Heath W4 amp

H. H. Scott 710 + Gray 216

Garrard record changer, Harman Kardon tube receiver

Weathers Turntable

Time travel to 1948

NOS pair of WE755A + full documentation

If you need to ask how much for the pair, you can't afford it. 😆

Western Electric 597A, probably worth a kidney?

Vacuum Tubes

Pavilion 2

I thought it was a pretty good turn out.

More pictures from past events

Fuji X-E3 vs. Sony A7II + manual focus lenses

taken by an Olympus E-P1 + Voigtlander Nokton 50mm f1.5 LTM 

I've said this before but would like to reiterate that for my intents and purposes, digital photography is mainly about instant gratification. I haven't ventured much into handling RAW files and mostly shoot JPEGs using old lenses via adapters. I'd much rather spend time developing and scanning film rather than manipulating images in front of a monitor. Whether handling film or pixels, I also prefer minimum post processing. 

Olympus E-P1 + Voigtlander Color Skopar 21mm f 4 LTM

Except for a couple of digital point and shoot devices, my digital camera history only encompasses mirrorless interchangeable lens bodies starting with an Olympus E-P1 that I acquired in late 2009. This camera documented my trips to Shanghai and Bangkok.

Fuji X-E1 + Canon 35mm f2 LTM

The Olympus (RIP) E-P1 was succeeded by a Fuji X-E1 in late 2013, which was a much better camera technically and ergonomically. I would've soldiered on with the X-E1 if it didn't die unexpectedly in NYC in the summer of 2019. I still miss this camera since it recorded wonderful memories of our visits to Guam, Hong Kong/Macau and Tokyo!

Sony A7II + Leitz Summicron 35mm 8 elements

I acquired the Sony A7II mainly to experience a full-frame sensor. I'm aware that anything wider than a 35mm focal length lens will have color fringing issues.

 But it's what I could afford for testing my collection of classic glass. For a mirrorless interchangeable lens body, this is bulky and heavy. 

Sony A7II + Chiyoko Super Rokkor 45mm f2.8 LTM

Even if I got used to the controls, ergonomically, it still feels like I'm handling a device rather than a camera.

Sony A7II + Canon 50mm f1.8 LTM

In spite of the lukewarm feedback on the quality of its Out Of Camera (OOC) JPEGs, after a bit of post processing effort, I don't find the A7II images inferior to those from my dearly departed Fuji X-E1. 

I actually welcome the greater depth-of-field and superior dynamic range from the full-frame sensor.

Sony A7II + Industar 61L/Z Macro

Because of the form factor and heft, I've used this camera mostly for taking glamour shots of gear I post on this blog attached to the fine optics of the Industar 61L/Z macro lens. But I should really take this camera out for photo adventures.

Fuji X-E3 + Industar 69

Tish probably noticed my love/hate relationship with the Sony device. Before 2019 ended, she surprised me with a Fuji X-E3. The X-E3 is even slightly smaller and leaner than my beloved X-E1. Except for the touch screen, which manages to occasionally screw up my default settings, its rangefinder-like handling instantly felt familiar.

Fuji X-E3 + Meike 28mm f2.8, Provia film simulation

Fuji X-E3 + Meike 28mm f2.8
Velvia film simulation

The film simulations render beautiful OOC images, Acros and Velvia being my two favorites.

Fuji X-E3 + Industar 69, Acros film simulation

Even if I spend a tad less time post processing files from its cropped APS-C sensor, it still can't surpass the Sony full-frame sensor's depth, detail and dynamic range. 

Fuji X-E3 + 7Artisans 25mm f1.8, Velvia film simulation

However, I can easily slip this camera in my Domke F-5XB along with a Leica or similar RF for a photo expedition. 

Fuji X-E3 + Meike 28mm f2.8 pancake

After all is said and done, I'm still waiting for a full-frame Leica M digital body with a Fuji or Sony price tag. 😆

Rek O Kut Tips Redux

Rek O Kut L34 Rondine Jr. + S160 tonearm

 Although not quite in the same league as the Garrard 301, 401 and Thorens TD124 + MKII, this classic American turntable marque has a steady stream of enthusiasts and followers. 

I've learned a few more tricks to keep vibration and noise at bay since I uploaded Rek O Kut Tips in the early 2000s.

Old and New Rubber Grommets

Even if they all look alike, Lord rubber grommets have different weight capacities. Unfortunately, there are no tell-tale marks. I only learned about this because I asked one of the sellers.

ROK L34 motor

For the larger and heavier motor used in the L34/L37/B12, I recommend the rubber grommets sold by ebay seller 10stan.

Papst Aussenläufer used in the B12GH

The softer grommets sold by tdsbill provided much better vibration isolation from the smaller and lighter Papst Aussenläufer motor.

Under the chassis of a ROK B12GH

 

With proper rubber grommets installed, make sure the motor floats freely and is not jammed by untidy cable routing.

Talented machinists have been offering brand new idler wheels for Rek O Kut turntables in the $50 range. Since the bearings wear out, it might be more cost-effective to just get a brand new idler wheel from a reputable seller rather than getting your old idler wheel refurbished for $35-$40. 

The performance of the idler wheel in the center is as good as a refurbished original wheel with a good bearing.

Karmadon idler wheel for Rek O Kut L34/L37/B12GH

However, this precision idler wheel by Serge of Karmadon was a significant improvement in noise and vibration reduction over the stock and aftermarket units in the preceding picture. A meticulously grounded rubber wheel of proper Durometer rating is bonded to a hub milled from solid brass fitted with a sintered bearing machined to tighter tolerances. The performance gain was at par with using Audio Silente idler wheels on my TD124!  

1/4" ball bearing
steel vs. ceramic

There's a smoothness in the "feel" of turning the platter over a ceramic bearing even if I can't claim that I heard an improvement in sound. Some say the ceramic bearing can wear out the thrust pad, I haven’t noticed any wear on mine after almost 5 years. Use it at your own risk.

Rek O Kut B12GH + Grace G565G

Using the proper rubber grommets, routing the cables neatly, with a Karmadon idler wheel and a ceramic bearing, the only noise I could detect from the ROK B12GH was air-rush from the built-in cooling fins. However, I wasn't as successful in using it in a lightweight plinth like I was with the Garrard 401 and Thorens TD124. 

Rek O Kut L34 Rondine Jr.
+ 
Denon DA305

Unlike its more sophisticatedly engineered contemporaries from Garrard and Thorens, these Rek O Kut idler-driven turntables really need the help of a massive plinth to absorb noise and vibration.

JE Labs ROK L34 + SME 3012 and Excel ES801
DIY Plinth
ca. early 2000s