I passed these test results on to my friend, but his reply was, “I totally get how good a power bank is, yet having to recharge it regularly – even if it’s only occasionally – is still a pain”.
そこで、次善策として、USB-C 5 V DC を取り出せるリニア電源ユニットを探してみることにしました。これならば、バッテリ駆動に近い結果が得られ、かつ充電の面倒臭さから解放されますので。
So as a fallback plan, I started looking for a linear power supply that can deliver 5V DC over USB-C. It should get us close to battery-powered performance without the hassle of regular recharging.
The other day I had a chance to visit a friend who’s a hardcore music lover. His daily spins are mostly LPs – original jazz, soul and R&B pressings mainly from the ’40s to ’50s – plus 45 rpm singles and even 78 rpms of the same genres. CDs rarely make it onto his system, and PC-based audio or streaming? Zero interest.
He’s especially fond of artists like Billie Holiday, Johnny Hodges, Willie Smith, Aretha Franklin, Helen Merrill, Dinah Washington, and Solomon Burke, and he treated me to a parade of prized and treasured LPs and 78 rpm records of original pressings.
This series have documented my process of learning the history of EQ curves and disc recording. In the previous Pt.24, I examined the patterns in which frequency response characteristics and phase characteristics can be changed in the recording chain and reproducing environment, and I learned again that the sound creation (especially in popular music) is often done through the use of variable equalizers and the like. I also introduced the comparison of various CD reissues to confirm the differences in sound between single masters of the time, LP masters of the time, remastered from multi-track masters, etc., before passing through the disc recording equalizer.
This Pt.25, which will be the final part, is a summary of the vast amount of information that I have learned and researched over the past two years. I will then summarize what is currently known — and some tentative summary and conclusion based on my current understanding of many thories — about the EQ curves of disc recordings. Also, in order to make it as easy to read as possible, I have inserted casual dialogues between two virtual characters 🙂
source: The Measure of Your Phonograph’s Equalization (Dubbings D-101, 1953) from my own collection
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… 🙂
In my home audio environment, until I installed a used TEAC VRDS-25X in 2004, I listened to CDs with a portable CD player (which was also used with my car audio system), or with a LD/CD player I got for free 🙂
This was because analog was my main source for listening at the time, but that does not mean that I was an “analog supremacist”, and I still prefer digital playback as much as analog playback.
2012年初頭、（のちに Musical Surroundings MYDAC II として製品化された）DAC のプロトタイプ基板 を開発者の Michael Yee さんにいただいたことをきっかけにして、CD を直接再生することはなくなり、CD をリッピングしたのち PC から DAC 経由で再生するようになりました。ここから我が家での本格的なディジタル再生が始まりました。
In early 2012, Mr. Michael Yee, the developer of the audio components, kindly gave me a prototype DAC board (which later commercialized as Musical Surroundings MYDAC II). After that, I stopped playing CDs directly, and my primary digital audio playback method became “playing digital files (that were ripped from CDs) from PCs via DACs”. This was the beginning of full-fledged digital playback in my home.
Even since before 2012, I have always used such software as Exact Audio Copy and XLD (X Lossless Decoder) to rip the CDs as digital files in ALAC (Apple Lossless) format on my SSD or NAS. Recentely I always play these audio files using the combination of Audirvāna Origin and Music app (was: iTunes) via the DAC.
I still use Audirvāna Origin in “Music Integrate Mode (legacy)” mode (i.e. Audirvana for backend, iTunes/Music for frontend), simply because there is no way to bring statistical data (such as imported date, play count, last played date etc.) to other apps.
上記余談はさておき、CD 上の音源を PC 上にもってくることで、ディジタルデータとしての客観的な数値やパラメータを目にすることが容易になります。
Returning to the main subject — by bringing the sound source on the CD to the PC, it becomes much easier to see the objective values and parameters as digital data.
今回のお題、「CD におけるモノーラル音源」も、そんな中で気づいたものでした。
The subject here, “monaural sound sources on CDs” was also something I noticed in this context.
2012年7月下旬、あるモノーラル音源のCDをリッピングしている時、トラックによってファイルサイズがかなり違うことが気になったのです。残念ながら、この時の CD がどれだったのか、いまだに思い出せずにいるのですが。
It was in late July 2012, while I was ripping a certain monaural CD (which I still can’t remember it was, though), I noticed that the file size varied considerably from track to track.
Throughout this article, I am NOT going to discuss “is the true 2-track mono CD (with binary identical channels) better audio-wise than the CD which is not?”, but am just interested in what made this difference.
In the previous Part 23, I learned an interesting article on RIAA deviation of 1970’s consumer amplifiers, as well as LCR recording/reproducing equalziers that had been the legacy especially in the United States.
This time on Pt.24, I am going to revisit and learn the signal chain from the audio source to the groove cut into lacquer discs, as well as the history and evolution of these.
This time on Pt.23, I am going to learn the interesting article on RIAA deviations of 1970s’ consumer amplifiers, as well as LCR recording equalizers that had been the legacy especially in the United States.
On the previous Part 21, I learned the history and diversity of “Frequency Test Records”, which had been available since 1930s — i.e. before the microgroove record era.
This time on Pt.22, I am going to learn and study the history of consumer amplifiers — especially the transition of the built-in phono equalizers — in the late-1950s to mid-1960s.
source: Scribd. Bell 3030 アンプの PHONO プリアンプ部回路図抜粋 左チャンネルは Eur / RIAA / LP それぞれに専用フォノEQ回路があるのに、右チャンネルは3ポジションともに同一 (RIAA) 回路となっている From Bell 3030 Amplifier’s schematic: right channel shares the RIAA de-emphasis circuit among the Eur / RIAA / LP position.
