NOTE to non-Japanese readers: This article — a deep dive into the history of Mercury’s injection-molded styrene LP records — is written only in Japanese, except the conclusion and summary part (also written in English). Or you may read the entire page with the help of the “Translate to English” feature on many modern web browsers, although I’m not sure if my entire Japanese sentences are translated into English correctly and properly.
5回目となる今回は、1964年の Burt Bacharach = Hal David 両氏へのインタビュー記事に登場する射出成形スチレンシングル盤への不満という面白いエピソードのほか、英国の射出成形ヴァイナル盤研究開発を捉えた興味深い動画の紹介、同じく射出成形ヴァイナル盤製造を1970年代に行っていた日本コロムビアの学術論文、最後に21世紀になって登場した「エコフレンドリーな」射出成形PET盤について、それぞれみていきます。
「射出成形盤はいつ頃から製造されたか」、「米国における圧縮成形 vs 射出成形のバトルはどのようなものだったか」、「圧縮成形のスチレン盤は存在したか」、そして「Mercury の例の廉価盤はなにか」などをみていくわけですが、2回目となる今回は、RCA Victor が1957年と1976年に社内技術紀要に掲載した2つの解説論文をたよりに、レコード製造技術の概要を改めてみていきます。
RCA Victor は、米国レコード業界を牽引する立場でもあり、長年に渡りレコード製造技術の自社開発を積極的に行っていましたし、またそれらの成果を学術論文や社内技術紀要などに比較的積極的に公開していたため、このような資料が残っていることには感謝しかありません。
HumminGuru Ultrasonic Record Cleaner, which I obtained via Kickstarter in Oct. 2021, is a great product at relatively affordable price, and I have been cleaning records almost every day.
Cleaning “Lean In / Gretchen Parlato & Lionel Loueke” (Edition Records EDNLP1216, 2023) with HumminGuru
Initially, I cleaned records with only distilled water — as instructed in the operating manual. But recently I’ve settled on using “90% distilled water + 10% isopropyl alcohol + a few drops of surfactant such as Photoflo or Driwel” (although not a officnally recommended way), and I’m generally satisfied with the result.
Here Comes HumminGuru NOVA (HG05)
2024年8月1日、Happy Well 社から新製品 HumminGuru NOVA の先行予約を案内するメールが届きました。
On August 1, 2024, I received an email from Happy Well International Enterprise Limited, announcing the new product HumminGuru NOVA.
コスパの高さから、オリジナルの HumminGuru に不満は全くないのですが、どのように進化したのか、$378 → $699 という価格上昇分に見合うだけの性能向上を果たしているのか、興味があったので、後継機種の HumminGuru NOVA の購入を即断、8月10日に届きました。
Although I have no complaints at all about the original HumminGuru due to its excellent value for money, I was curious to see how it had evolved and whether the performance improvements were worth the price increase from $378 to $699. I decided to purchase the successor model, HumminGuru NOVA — then the parcel arrived on August 10.
The packaging style of the HumminGuru NOVA (HG05) is almost the same as that of the previous model (HG01).
Top View of HumminGuru NOVA (HG05) package opened
Top View of HumminGuru (HG01) package opened
Unit Size Comparison
本体のサイズ は、旧機種 (HG01) が 34.2cm x 15.2cm x 27.4cm、新機種 (HG05) が 34cm x 15cm x 26.1cm、と微妙に異なりますが、基本的な作りはほぼ同一といえます。
Although the size of the unit is slightly different, the basic structure is almost the same. The dimension of the original (HG01) is 34.2cm x 15.2cm x 27.4cm, while that of the NOVA (HG05) being 34cm x 15cm x 26.1cm.
Comparison of HumminGuru NOVA (left) and HumminGuru (right) The water tank mistakenly placed each other… (cleaner tank on the right is the one that came with NOVA, while the dulled one due to the deterioration over time, is for HG01) 私のミスで、ウォータータンクを入れ違いに置いてしまいました… （右の透明度の高い方が NOVA のもので、経年劣化でくすんだ方が HG01 のもの）
Water Tank Comparison
ウォータータンク 自体は、同一寸法で同一仕様のようでした。
The water tanks themselves appear to have the same dimensions and specifications.
Comparison of the Water Tank of HumminGuru (left, deteoriorated over time) and HumminGuru NOVA (right, brand new)
There are differences between the AC adapters (wall wart) of the old and new models, but the output of both is 12V 5A and the connector shape is the same.
AC/DC Adapter (Wall Wart) for HumminGuru (left) and HumminGuru NOVA (right)
Main Control Panel Comparison
新旧機種での違いはいくつかありますが、まず目につくのが、操作ボタン 部分です。
There are several differences between the old (HG01) and new (HG05) models, the most noticeable of which are the control buttons (or “Main Control Panel”).
In the new model (HG05), the washing time can be selected from 2 minutes / 5 minutes / 10 minutes. Similarly, the automatic mode (washing and drying) can be selected from these three options.
Additionally, when the washing mode is used instead of the automatic (washing → drying) mode, the cleaning water is no longer drained. So it is now possible to perform only ultrasonic cleaning of multiple records in succession without drying them. However, the owner’s manual states “When the washing mode has been running continuously for more than 30 minutes, power off the machine and let it rest for 15 minutes before starting the next washing cycle.”.
Support for 7-inch / 10-inch records
12インチ以外のサイズ（7インチ、10インチ）への対応方法も変更されています。
The method of handling record sizes other than 12-inch (i.e. 7-inch and 10-inch) has also been changed.
The original HG01 is designed for 12-inch vinyl records, so the 7-inch / 10-inch vinyl adapters have to be used (which was avaiable for free for the original Kickstarter backers as the stretch goal).
10-inch Record Adaptor for HumminGuru (HG01) Shulie A Bop c/w Polka Dots and Moonbeams / Sarah Vaughan EmArcy 16005 (1954)
The new model (HG05), on the other hand, can clean 7-inch / 10-inch records directly, without having to attach them to the adapters as was the case with the old model (HG01). However, it is still necessary to attach the support parts.
HumminGuru NOVA’s “arrow” indicator of the wheel position for 7 / 10 / 12-inch records 左の穴に付属のツールを差し込み回すと、右の矢印の位置を動かせ、それによりレコードを保持する両端のホイル位置を7/10/12インチ用に変更できる
Rotation wheel adjusted for 7-inch record 7インチレコード洗浄用のポジションにしたところ
Both the HG01’s record adapter method and the HG05’s mechanical method require some effort, but the new method seems to be meant to avoid unintentional damage to the record itself, such as dropping it when attaching to / detaching from the record adapter.
In addition, an additional “Water Funnel” (for pouring cleaning water into the basin) is included, perhaps to prevent accidental wetting of the mechanical area to accomodate multiple record sizes.
Water Funnel (upside down) じょうごを上下さかさまにみたところ
Water Funnel (correctly installed) じょうごを正しく設置したところ
Water recommendation
オリジナルの HumminGuru (HG01) が登場した2021年当時は、マニュアルに記載されているように「必ず精製水を使うこと」というのが公式見解でした。その後、日本の水道水レベルの軟水であれば問題ないことが確認されたのか、HumminGuru NOVA (HG05) のマニュアルでは「水道水が硬水のエリアの場合は、水道水の使用は避けるべき」という表記に変更されています。
When the original HumminGuru (HG01) was introduced in 2021, the official stance was that “distilled water should always be used” as stated in the owner’s manual. Later, perhaps because it was confirmed that the soft water at the level of tap water in Japan is not a problem, the manual for HumminGuru NOVA (HG05) changed the statement to “if the user resides in a hard water area, it is advisable to avoid using tap water”.
I have long been using water that has been passed through a water purifier in the kitchen tap, then further purified with a tabletop distilled water maker “Pure Maker”, and then blended with isopropyl alcohol and DryWel.
そういえば、HumminGuru NOVA (HG05) には、HumminGuru 純正の洗浄剤 “The Small Bottle” が付属しています。こちらには、アルコール成分が一切配合されていない、とのことです。
…I nearly forgot to mention that the HumminGuru NOVA (HG05) comes with a genuine cleaning agent “The Small Bottle”, which does not contain any alcohol.
The noise level during ultrasonic cleaning and drying, which had been quiet enough since the old model (HG01), is almost as quiet (noisy) in the new model (HG05).
It is unclear to what extent the 40kHz ultrasonic cleaning power has been enhanced in the new model (HG05), but as mentioned above, the addition of a 10-minute “Heavy Washing Mode” makes it possible to clean more deeply.
Also, the increased output of the drying fan has reduced the drying time from 5 (or 10 minutes, selectable with a switch on the side of the main unit) to 3 (or 6) minutes, which seems to be a big advantage. In addition, the noise level during the drying process (as far as my subjective impression goes) seems to be the same as that of the previous model.
One of the most welcome improvments of the new model (HG05) is that the cleaner lid can now be used as a record jacket display stand, as well as a drying rack holding up to five records 🙂
By flipping the cleaner lid upside down, it becomes a drying rack (holding up to five records) as well as “now playing display”.
裏返すことでジャケットスタンド & レコード乾燥用スタンド（最大5枚）にもなる、本体ダストカバー
HumminGuru のロゴである鳥のデザインも可愛らしく、娘にも好評でした。
The bird design of the HumminGuru logo is also cute, and was well received by my daughter.
When the cleanr lid functioning as a “dust cover” as its original purpose, “HumminGuru Birds” are stored upside down, which is also humorous 🙂 ダストカバー本来の機能を果たす際には、鳥たちが上下逆さまに格納されているわけで、これはこれでファニーですね（笑）
If you already own the original HumminGuru (HG01), you may be wondering if you need to spend extra money to replace it. Certainly, there are various additional features an performance improvments, but the HumminGuru (HG01) itself was originally designed with simple functions and a reasonable price, and that is why it is so satisfying and “must buy”.
However, if your first purchase candidate is the HumminGuru NOVA (HG05), you wil be comparing it to higher-priced equipment such as Kirmuss Audio KA-RC-1, Degritter Mk II, and KLAUDIO KD-CLN-LP200T. I can highly recommend HumminGuru NOVA, as its great value-for-money will become more and more apparent.
I am not sure if HumminGuru NOVA’s 40kHz ultrasnoic cleaning is really the best or if it is powerful enough to remove all dusts and impurities, but the price (of USD 699 + shipping cost from Hong Kong + import duties) is very reasonable and attractive for such a full range of features.
I also highly recommend HumminGuru’s support quality: when I got the original HumminGuru (HG01) through Kickstarter, I reported a minor technical problem and received a detailed response via email the next day. They are also very friendly and responsive to all kinds of questions.
Good-bye HumminGuru (HG01) — make the new owner super-happy!
The original HumminGuru (HG01), which has been with me since October 2021, successfully found its next owner on a certain social-networking service, and was taken back at half of the price I paid in 2021.
The last time my HumminGuru (HG01) worked at home for operation check test, before being sent to the next owner 次のオーナに送る前に、最終動作確認として我が家で最後のお勤めをする HumminGuru (HG01)
I sincerely hope that the original HumminGuru (HG01) will continue to work in its new place and clean many more records. I also hope that it is not instantly resold… 🙂
Before digging deeper about EQ curves, I started to study from the very beginning: why the EQ curve was born, why it was/is needed for phonograph recording (and playback). Also, I tried to re-study the very basic – how the recording sounds are converted to a modulated spiral groove. So I’m afraid it will take very long before I reach the story of the EQ curve itself…
Following is just the beginning of the long series of the study I have been doing for a while, regarding the controversial topic “Phono EQ Curves” – people having various opinions on it, although many of them are subjective and not scientifical. I started the study and research of the history of disc recording as a whole, from the very early electrical disc recording technology in the 1920s.
Since 2006, I’ve been using Esoteric Sound (Rek-o-kut) Re-Equalizer (actually I replaced it with the most recent version Re-Equalizer III in 2021) for 78rpms and pre-RIAA LPs. It’s a niche phono EQ compensator.
Esoteric Sound Re-Equalizer III (above), bought in 2021 Esoteric Sound Re-Equalizer (bottom), bought in 2006
