Friday, July 21, 2023

Finemet FM-MCT1 MC Step Up Transformers


Looking back to my late 90s home brewer article for Sound Practices issue 17, I noticed that a good number of components in my hifi system then are still serving two and a half decades later. The Tamura TKS83 moving coil step up transformer is one of them.


After building a hifi system for my cousin during lockdown, the Hashimoto HM7s made me realize that while the Tamura TKS83s can equal the HM7s in terms of bandwidth, the TKS83s can sound mechanical. It also became apparent that there are areas in which the classic Altec 4722s and 15095As can be improved upon.


When I finally heard a pair of Peerless 4629s, I was very impressed by their uncanny ability to reproduce very lifelike 3-dimensional vocals. However, I was quite disappointed when I played anything greater than a string or jazz quartet because the sound started getting mushy and dynamically compressed. 

Overall, my ears still prefer the smaller and more affordable brother, the Altec 4722!


During the most recent Kutztown radio meet, John Piro handed me this finely crafted wooden box to audition. As mentioned in my Kutztown coverage, a good friend from Manila, Tony, aka Mr. November HiFi Show, scheduled his visit so we can hunt for tubes, parts + LPs. 

Upon our return from the expedition, a sumptuous dinner prepared by Tish + a bottle of Ripasso awaited us. We capped the evening by hooking this wooden box to my hifi. Our jaws dropped each time we played an LP!

Housed inside the box is a pair of Finemet FM-MCT1s

In the ensuing days, I did further evaluation and indeed, these Finemet MC transformers are doing something extra special. My only reservation was, in spite of the potted construction, the FM-MCT1s are more susceptible to hum induction compared to the Altecs and Tamuras. Even if John lined the wooden box heavily with copper shielding, I still had to keep them away from power transformers, AC motors, etc.

Inspired by the sonic niceties I heard, I was undeterred so I contacted Mr. Kimura of General Transformer Sales Co. Ltd. After a few emails aided by Google translate, I finalized my order. 

Gtrans.co.jp is headquartered in the same location as the former Noguchi store we visited in 2015, which is in the basement of Tokyo Radio Department Store in Akihabara.

Kimura-san specified a 3-4 week window for delivery. So I downloaded the spec sheet, studied the schematic and ordered a cast aluminum project box from Amazon.

Within 18 days, the transformers were at my doorstep.👏

Finemet FM-MCT1

These are very well made and quite hefty! They're heavier than the TKS83s which, if memory serves me right, are about the same weight as the HM7s.

 

I chose a different layout for the 145mm x 121mm x 40 mm MC step up transformer chassis for neater routing of RCA cables.

Under the hood

 

The input and output RCA jacks are on the backside mounted on top of the chassis. Only the ground lug was mounted on the side.

I installed the 3-position gain/impedance load selector in front of the chassis.

No matter which cartridge I used - Denon DL103, -R, -C1, Fidelity Research FR1 MkII, Ortofon SPU #1s, -G, -GM, Supex SD900, etc. - male and female vocals + instruments are portrayed with 3-D presence and realism in a deep and wide sound space. The musicians are in my man cave!

Boosted by the Finemets, even the most analytical and dry-sounding MC cartridges in my stash, like the Goldbug Clement II and Sony XL44 came to life with more warmth. If that's a coloration, it's certainly most welcome!

  

These Finemet MC transformers seem like they were configured to resolve every note in the complex musical score and massive instrumentation of late romantic symphonies along with the wide range dynamics from pianississimo to quadruple fortes inscribed therein by the composer. They also excel in reproducing the ambience, airiness and spaciousness of the concert hall's acoustics embedded in well recorded LPs.

I finally found a pair of MC transformers which combine the organic midrange and harmonious richness of classic vintage iron + the wide bandwidth, detail retrieval, and dynamic range of modern magnetics!

Ever since I became an audio DIYer, I pride myself in not being impulsive about upgrading components in my hifi. This is a rare exception!😉

CODA

As luck would have it, last week we had a family get together because a cousin based in Tokyo was visiting and brought some goodies!

Stereo Sound
Tube Kingdom Volume 104

If I got it right, in this survey of commercially available MC step up transformers, the Finemet FM-MCT1 was the only DIY unit.


Despite the wacky nature of the Google translate app, the gist comes across as quite positive!


Enjoy browsing the magazine to Bobbi Humphrey's tune spinning on a Garrard 401 + AB309 tonearm with a Supex SD900 boosted by the Finemet FM-MCT1s!✌


Click here for the shielded version update!






4 comments:

  1. Thank you for sharing, this is awesome (as always)! Can you post the diagram of how you wired everything with the two switches and inputs?

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    1. Anyone with moderate DIY experience should be able to figure out the wiring with the "under the hood" picture I added + the spec sheet.

      JE

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  2. Do you mind shedding some light on your grounding scheme??

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    1. It's much more complicated and subject to greater confusion if I describe it in words, which is why I uploaded the high resolution photo, please copy and paste this direct link - https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiWgd7IN_IhJl3kXvOg730DuVe2Ozb9-W-vz2WlDlwfQAu-HJQvHa7SzYv1jGFCWJV8SESMB-UYJ6Us1b7kB9oRvUF3ktMSZtxbPpjvia0t9hvivqS1kx9c7RjYIBzuc067crU0t2lmQF5hOedOnYtxID8B9x0EBL8gwifl3LCP2ms0l0vOB7lJq-T88d0/s900/IMG_3177.jpg

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