Eminence Delta Lite 2512 vs. Pioneer PW-302A

Old vs. New

Measuring Output Transformer Primary Z with the FNIRSI LC1020E LCR Meter

For years I had been measuring output transformer primary impedance using an arduous old-school procedure similar to Uncle Doug's and Skunkie Design Electronic's videos. Recently, this video from Mr. Carlson's Lab popped up in my YouTube feed - a significantly simpler process!

Mono Hi-Fi Update: 6AH4GT + Altec 15095A line stage

My plate-choke loaded/triode-connected 6C6 + paralleled 6SN7 K'follower line stage is a fine-sounding circuit. However, in the context of my mono hifi setup, it has too much gain. So I thought of combining the sonic virtues of the 6AH4GT triode and Altec 15095A transformer.

Western Electric 124-style PP 6V6 mono amp

!!!ADDENDUM!!!

Another Western Electric-inspired push-pull amplifier.😊

Western Electric 131A/133A Inspired Amp - Mono

 

While I was relishing a pair of Altec 32C horns in the attic during the late aughts, unbeknownst to me, my stateside audio comrades, Dave V. and Joe Roberts, were praising the same horn's virtues in audio forums. When these veteran audio hobbyists consider the Western Electric 124 one of the finest-sounding amps they've ever heard, I listen. 

See Dave's (@Salectric) WE124 amp project and WECo 133A clone thread started by another 32 horn adherent (@gilmorneau) at Hifi Haven.

Welcome 2026!

A few days before Christmas, I received greetings from two audio buddies, J-Rob and Gary B., with the above caption taken from Part 2 of Shared Dreams article by another friend, Devon T. of OJAS published by MJ Audio Technology in Substack. Perhaps this glitch is one of the reasons why we are being cautioned about AI.😉 

Japanese Idler-Driven Turntable FINALE: NEAT P58 + FAQs

This is the final installment of my Japanese idler turntable adventure but as Sean Connery said, "Never say never again..." 😉

A Tribute to Don Garber of Fi + Robin and Lipman!

Don Garber's Fi 2A3 amp Ad from Sound Practices

My first exposure to Don Garber's Fi 2A3 amp was at a gathering of burgeoning SE-DHT/High Efficiency speaker enthusiasts organized by Mike LaFevre of Magnequest and Peter Breuninger, then president of the Philadelphia Audio Society. This was held in the outskirts of Philly during the latter part of 1994. I attended to assist my friend Steve Melkisethian in exhibiting the Audio Note Kit 1 amplifier since he was the US distributor of Audio Note UK Kits, transformers and parts at that time. Sadly, these guys are no longer with us. 😔

JE Labs Mono HiFi 2024

Over two decades ago, I ventured into single channel music reproduction to trace the roots of high fidelity. From that whole experience, I developed an aesthetic quest for a certain purity and honesty in sound, which runs parallel with my other hobby of black and white film photography! Sadly, I had to leave that particular mono set up in the attic in 2017.

Japanese Idler-Driven Turntable Part 7: Kenwood PC350

Kenwood PC350 - a Japanese TD124 spinning a jazz tune!😉

AliEx amorphous, Hashimoto HL20K6 + Sony TamRadio line output transformers

L>R: 6AH4 + AliEx, 12B4A + Sony/Tamradio and 6AH4 + Hashimoto HL20K6

The last time I saw my buddy J-Rob was pre-COVID, but we keep in touch via email and text messages. During one of those hello/how you doin' moments, the chat progressed to line preamp transformers and how the $100/pr. amorphous jobs from AliExpress perform. 

I used to own a pair of Tango/Hirata NP216N nickel line OPTs, which were featured in my Sound Practices issue 17 homebrewer article. In hindsight, I don't think I gave them a fair chance so this was a good opportunity to revisit the topology.

Two RCA derived octal phono preamps

Keen-eyed readers and visitors to my YouTube channel may have noticed the two octal phono preamps I've been using in my recent uploads. I built them for the following reasons:

1. Although the Loctal EAR 834P had no problems driving the Intact Audio nickel autoformers, the 5k Ohm output Z of the Shure M65 phono preamp sounded very anemic.
2. In the spirit of not leaving stones unturned and my curiosity for other sonic flavors notwithstanding, I looked back to passive RIAA EQ phono circuits I've been wanting to build, which have low enough output impedance to drive an Autoformer Volume Control.

Silbatone Box Adventures

from Western Electric Oscillator July 1947

Whether it's an open baffle as conceived by G.A. Briggs or an enclosed box like the Western Electric utility boxes above, I've always been an advocate for a wide baffle design. The wide frontal area serves as an acoustic reflector that helps propagate sound toward the listener instead of escaping to the sides and back. Somehow the wide baffle, whether open or closed, always makes reproduced music sound more alive to my ears!

A notable exception is the narrow front baffle Silbatone box designed by Dr. Stefano Bae for the Western Electric/Altec 755A. Since I uploaded the cabinet project under the auspices of Joe Roberts, it has garnered a following amongst DIYers who've reported successful results mounting other 8' drivers like the Altec 755C, 755E and the Lafayette SK98/Pioneer PIM8L. 

I finally got a chance to mount and listen to my 755Cs and PIM8Ls + other 8" wide band drivers. Hopefully, this article will encourage readers to DIY this mini-monitor sized box because it really offers a lot of musical pleasure per cubic inch!

To recap, let's start with the...

Finemet FM-ATVR1 + Intact Audio Nickel 28-step Autoformer Volume Control

Japanese Idler-Driven Turntable Part 6: Realistic Mark 8

Just like cars, a new turntable model has to be introduced every year or two to keep consumers' interest and convince them that newer is better.😊

from page 37 of the 1960 Radio Shack Catalog

The Realistic Mark 8 improved upon the similar looking "motor unit-stye" Mark 7 in Part 4 of this series by adding a 16 rpm speed and supplying a half pound heavier cast aluminum platter.

SE171A Amp Remastered

My dad would've turned 97 today. To celebrate his birthday, the video clip above features a recording of his favorite violinist, Nathan Milstein, playing Presto from Bach's Sonata No. 1 in G minor for unaccompanied violin. While he was doing post-graduate studies at The Juilliard School in the mid 50s, he was fortunate to have attended concerts of the great violin virtuosos of that era - Jascha Heifetz, David Oistrakh, Nathan Milstein, etc.

He would later recount that Nathan Milstein's performance of the Glazunov violin concerto was the most unforgettable! Even if he never got a chance to add this violin concerto to his repertoire, he conducted the Manila Chamber Orchestra with me playing the Glazunov violin concerto in 1987. The music of the slide clip above is the middle movement from our performance.

Before I bore everyone reminiscing about my dad and our life as musicians, let's get on with the subject at hand. The amp featured in this upload uses a directly heated triode power tube that was introduced around the time my dad was born.

JE Labs Choke-Capacitance Coupled SE2A3 amp

Canon P + Canon 50mm f1.8 LTM 
Foma 100 in Rodinal

Inspired by my plate choke-loaded 76 line stage preamp adventures, I was curious how a similar driver circuit configuration would sound in an SE2A3 amp. So I pulled out my Radiotron Designer's Handbook, 3rd Edition to gain a better understanding of choke-capacitance coupling (aka plate choke loading) vis-à-vis resistance coupling.

Below are highlights of relevant information I gathered.

Japanese Idler-Driven Turntable Part 5: Lafayette PK300

I bought this Lafayette PK300 idler-driven turntable because it looked like an improved Shield MO-19 (aka NEAT P58H) with the added feature of an eddy current pitch control as found in the Garrard 301/401 and Thorens TD124.

Ortofon STM-72 + Weller WTCPS repair + Hakko FX-888D

One morning, I discovered the right channel of my Ortofon STM-72 was dead. While waiting for the Weller WTCPS soldering station to heat up, I carefully peeled the foilcal to pull apart the 2-piece tubular housing so I can resolder the broken cable connection(s). 

Japanese Idler-Driven Turntable Part 4: Realistic Mark-7

Here's a tale of two idler-driven turntables of Japanese origin sold by Radio Shack in the late 50s. They share the same model badge and engineering features but they aren't exactly twins.🤔