Wednesday, May 22, 2024

Shielded Finemet FM-MCT1 MC Step Up Transformers


It's been almost a year since my favorable review of this Finemet MC step up transformer. Overall, it has given me great musical pleasure! However, when tasked to amplify MC phono cartridges with lower output than a typical Denon DL103, in particular the Ortofon SPU and Fidelity Research FR1 MkII, hum could be intrusive in softer passages of classical music, especially when not carefully sited away from motors and power supply transformers.

As I had suspected in my initial review, the FM-MCT1 wasn't as well shielded as the Hashimoto HM7, Tamura TKS83, Altec 4722 and other vintage MC SUTs in my collection.😔 Now, I had no recourse but to compromise my aesthetic preference for an open chassis in favor of an enclosure to provide additional shielding.

Since the TKS83, 4722, 15095, etc. are all potted in magnetic steel cases, I ordered the heaviest gauge steel box I could find on Amazon.

After patching and sanding an unsightly hole, I gave it a coat of silver hammerite paint and let it cure for 48 hours.

Some internet sources claim that copper has the best shielding properties. 

So I lined the interior with copper tape for additional shielding.

Wired and ready to make music

When placed near my idling breadboarded nosTDA1541tube DAC, the shielded FM-MCT1 still hummed unlike my other MC SUTs.😞 But once I turned off the DAC, it became absolutely quiet. This was not the case before I installed it in a shielded case.😊 

I just wish this exceptional sounding Finemet MC SUT wasn't fussy.

Hum used to be a big issue when situated between a spinning Garrard 401 and 301. But now it’s just as quiet as all my other MC SUTs. Even if these Finemet SUTs are still not as well shielded as my other units, enclosing it in a shielded steel box has significantly improved its susceptibility to magnetic induction. 😊👍🏻🍻

Sit back and immerse yourself in Nathan Milstein's Bach!

Wednesday, May 8, 2024

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...

Monday, April 22, 2024

SETUP 2024

Single Ended Triode Users of the Philippines 2024

At the dawn of the 21st century, I uploaded hifi systems owned by audio buddies who had been inspired by the Sound Practices ethos. These were the guys who originally coined SETUP. After a couple of decades, the number of Filipinos who indulge in this hobby has increased exponentially.

Here's what I saw and heard during my recent visit.😊

Harana Audio Workshop

Altec 311-60 horns + 288 drivers with Fostex super tweets on top of a pair of Harana V-Vent bass bins with partial horn loading

Friday, March 22, 2024

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.

Friday, March 8, 2024

OJAS 529B Horn

During my visit to the OJAS listening room late last year, Devon asked me to evaluate a pair of horns OJAS developed in collaboration with Lycan R&R. The OJAS 529B is a 500 Hz horn rescaled from the large format Altec 329A for use with 1" format Altec/GPA compression drivers.

  This horn was designed with a throat inspired by the Western Electric 32 horn to avoid the harshness and distortion I (as well as others 😉) associate with the Altec 811 and 511 horns
For more details about this horn's evolution and construction, please click here.