It's taken me much longer to try the next level of Yazaki-san's Ultimate Ruby Mica capacitor mod for the SPEC RSA-M3 EX Real Sound Amplifier than I had anticipated, due to the arrival of the Covid-19 pandemic, and its impacts on my life and health.

You can read my original SPEC RSA-M3 EX Real Sound Amplifier review in Positive Feedback HERE, if you so desire. Astonishingly, that has been five years ago now - how time flies!

Ultimate Ruby Mica Capacitors. Photo courtesy of Yazaki-san.

However, when I got up this morning, while drinking a cup of coffee, I thought, "Today is the day I listen to the next level of Yazaki-san's "Ultimate Ruby Mica Capacitor" mod for the SPEC RSA-M3 EX Real Sound Amplifier - woo hoo! 

SPEC RSA-M3 EX Real Sound Amplifier.

First let me remind you what the SPEC RSA-M3 EX Real Sound Amplifier is all about.

The SPEC RSA-M3 EX Real Sound Amplifier is a new-generation class-D amplifier, that uses amplification modules developed by Yazaki-san's friend, Honda-san, for International Rectifier that are intended specifically for high-performance audio.

Honda-san's amplification modules possessed a directly-heated single-ended-triode (DH-SET) type of musical & sonic balance, which Yazaki-san and friends voiced in the development of the SPEC RSA-M3 EX Real Sound Amplifier to sound like Yazaki-san's custom DA30 DH-SET amplifiers that he uses to listen to music with on his Altec & Onken horn loudspeaker system.

DA30 SET monaural amplifier.

Yazaki-san's Altec-Onken loudspeakers.

Yazaki-san told me that from the development of the class-D amplifier modules, to the selection of every single component that makes up the SPEC RSA-M3 EX Real Sound Amplifier, that he and the entire SPEC team paid serious attention to voicing the amplifier to sound as musically satisfying as the transparent, beautiful tone color, rich, and dynamic nature of his DA30 DH-SET reference amplifier.

So what you have in the SPEC RSA-M3 EX Real Sound Amplifier is an integrated amplifier that was voiced to sound like Yazaki-san's DA30 DH-SET reference amplifier, but it is much more powerful than most DH-SETs at 60 watts (into 8 Ohms), meaning that it has enough power to drive a wide range of loudspeakers, like my Harbeth Super HL5 and Tannoy Westminster Royal SE loudspeakers that were used for the review.

The result is the SPEC RSA-M3 EX Real Sound Amplifier is a high-performance integrated amplifier that will impress even the most die-hard DH-SET enthusiasts with its musical & sonic prowess, and its not limited to use on highly sensitive loudspeakers like Altec's. 

Ultimate Ruby Mica Capacitors. Photo courtesy of Yazaki-san.

In Yazaki-san's article, My Adventure With My Old Marantz Model 7 Part 8 HERE, you know Yazaki-san was so impressed with the Ultimate Ruby Mica capacitors performance in his Marantz Model 7 preamplifier, that he had Mr. Manabu Matsuzaki, president of specialty company Matsuzaki-denki, produced a small custom batch of capacitors for him and his friends to use in their audio projects, and Yazaki-san has made some of them available to Jeff's Place readers should they want to join in the fun.

Yazaki-san's vintage Marantz 7k preamplifier.

From my review of the SPEC RSA-M3 EX Real Sound Amplifier, you might remember Yazaki-san describing the importance of the audio board (below) in the SPEC RSA-M3 EX, which is located at the final stage of the amplifier just before speaker terminals, and consists of a low-pass filter and a snubber circuit (an energy-absorbing circuit used to suppress the voltage spikes when a switch opens).

Yazaki-san told me, "This filter and the circuit are very important for the sound quality. In other words, M3EX's tonal quality depends largely on the parts used in these circuits."

"You can see two hermetic oil-filled capacitors on the audio board made for us by Arizona Capacitors, Inc. Yes, these capacitors are custom-made for us and each capacitor has a different tonal character. One has a beautiful mid-to-high end, and the other has a rich mid-to-low range like a vintage capacitor."

"And another special quality part are the two little black cubic boxes you can see on the audio board, which are custom Mica capacitors that are custom made for us in Japan, and they are one of the best sounding capacitors of all ages for a signal capacitor. These days Mica capacitors are so rare to have, but they are wonderful sounding, highly transparent like a blue sky. The clarity of the Mica capacitors combined with the rich sound of the oil-filled capacitors gives the really incredible deep tonal character to the SPEC RSA-M3 EX."

It turns out that the original mica capacitors in the SPEC RSA-M3 EX Real Sound Amplifier, described above, were improved upon in the development of the Ultimate Ruby Mica capacitors.  

Yazaki-san sent a pair of the Ultimate Ruby Mica capacitor's for to me to try as a mod for the SPEC RSA-M3 EX Real Sound Amplifier, and because the the mica capacitors described above connect to the binding posts inside the amplifier, it was probably the easiest mod I've ever done, as all I needed to do was install the Ultimate Ruby Mica capacitor's into the binding posts.

SPEC RSA-M3 EX integrated amplifier with the Ultimate Ruby Mica capacitors installed on binding posts.

This is a modification specific to the SPEC RSA-M3 EX Real Sound Amplifier, and has a specific function, as Yazaki-san explains:

"This simplest modification is only fitted to Class-D amplifier solution using PWM (Pulse Width Modulation). This capacitor is working well just as a part of Low-Pass filter, already installed in this RSA-M3EX. This LPF is the essential circuitry for taking out the analog current for driving the speakers from the PWM carrier about 400 KHz. And the mica capacitor’s outstanding characteristic of high frequency over 100 KHz can easily run into this demodulation noise to the ground. It’s really strange, but I seem to have a correlation between “Musicality” and this high frequency noise. How to remove unnecessary noise could surely lead to true high fidelity playback. Well, it would be another example that by removing the switching noise caused by the power supply diodes, the sound quality can be improved. Of course, in the case of such power supply, the mica capacitor can work very well."

In my first report of my initial listening impressions, I found that the SPEC RSA-M3 EX integrated amplifier equipped with the Ultimate Ruby Mica capacitors sounded very compelling musically.

The sound was nicely rich and luxurious tonally, very musical, and with lots of nuance coming through. There was not even the slightest hint of grit, grain, forwardness, unnatural sibilance, harshness or the like coming through.

All in all, the Ultimate Ruby Mica capacitors took the already great sounding SPEC RSA-M3 EX integrated amplifier to the next level, enhancing its a gorgeous musical & sonic presentation of the music.

Ron, Leo, Chad, Santos, and myself all having a good time at Jeff's Place.

In December 2019 I followed up my first impressions of the Ultimate Ruby Mica capacitors mod of the SPEC RSA-M3 EX integrated amplifier with a group listening session with friends Ron, Leo, Chad, Santos, and Jeff & Ashley (HERE).

Jeff & Ashley dancing to the music!

As I reported in that post, the difference in performance of the SPEC RSA-M3 EX integrated amplifier was really easy to hear (i.e. big in magnitude), and there was a definite improvement in both musicality and audiophile-style sonics due to the addition of the Ultimate Ruby Mica capacitors.

Transparency and resolution improved rather dramatically, imaging became more solid, and tonally everything sounded more natural and real. The Ultimate Ruby Mica capacitors were an all around improvement in pretty much every aspect of the musicality and sonics SPEC RSA-M3 EX Real Sound Amplifier.

Unanimously, all present considered the addition of the Ultimate Ruby Mica capacitors a definite improvement, and if you have a SPEC RSA-M3 EX Real Sound Amplifier the Ultimate Ruby Mica capacitors mod makes for an easy way to gain a considerable performance enhancement.

In fact, during our group listening session we were all rather amazed at how large of a positive difference such a simple modification made to the performance of the SPEC RSA-M3 EX Real Sound Amplifier.

Yazaki-san has also told me that the amount of improvement increases as you add more Ultimate Ruby Mica capacitors across the binding posts. Yazaki-san has found three pairs of Ultimate Ruby Mica capacitors to provide the maximum amount of performance improvement. 

Ultimate Ruby Mica capacitors in a doubled pair.

Yazaki-san sent me a doubled pair of the Ultimate Ruby Mica capacitors (above) in February 2020 so I could hear the improvement he was hearing with three sets of Ultimate Ruby Mica capacitors for myself (see the post HERE for more information).

Due to the arrival of the Covid-19 pandemic, catching the virus myself, and its impacts on my life and health, I haven't been able to follow back up and report on the performance of a triplet of Ultimate Ruby Mica capacitors added to the SPEC RSA-M3 EX Real Sound Amplifier.

As you know if you've been following along, I've been experiencing an audio love affair with the combination of the Audio Note (UK) CD 2.1x/II Level Two Red Book CD player (review to come) combined with the Audio Note (UK) Oto Phono SE Signature integrated amplifier (reviewed HERE) powering my Duelund-ized "Stokowski" Altec loudspeakers from the Duelund-Altec Project (HERE). 

For my tastes, The Duelund-ized "Stokowski" Altec loudspeakers are the highest performing loudspeakers I've ever heard anywhere, and they seem to get the best out of every source and amplification device I've tried with them.

Whether playing vinyl or digital, this system is the most musical and most "real" sounding system I've ever had in my own home.

The Acoustic Revive RCA Absolute FM Interconnects.

For this post, I used the Audio Note (UK) CD 2.1x/II Level Two Red Book CD player as the source, connected to the SPEC RSA-M3 EX Real Sound Amplifier with Acoustic Revive RCA Absolute FM interconnects.

Acoustic Revive Absolute Power Cable

I connected SPEC RSA-M3 EX Real Sound Amplifier to the AC mains with an Acoustic Revive Absolute Power Cable, and to the "Stokowski" Altec loudspeakers with Duelund DCA16GA tinned-copper speaker cables.

I placed the SPEC RSA-M3 EX Real Sound Amplifier atop the same Acoustic Revive Air Floating Board RAF-48H that I've been using with the Audio Note (UK) Oto Phono SE Signature integrated amplifier.

First I listened to the SPEC RSA-M3 EX Real Sound Amplifier with one pair of the Ultimate Ruby Mica capacitors to reacquaint myself with its musical & sonic performance.

I'll tell you what, the Audio Note (UK) CD 2.1x/II Level Two Red Book CD player sounded gorgeous musically & sonically with the SPEC RSA-M3 EX Real Sound Amplifier, and really impressed me. 

SPEC RSA-M3 EX Real Sound Amplifier with triplets of the Ultimate Ruby Mica capacitors.

After listening to a few my favorite jazz CDs, I then added the triplet Ultimate Ruby Mica capacitors to the SPEC RSA-M3 EX Real Sound Amplifier's binding posts, and hooked everything back up for some more listening.

I listened to the Enja 2-CD set of Chet Baker's "The Last Great Concert" album that I had listened to earlier with one pair of Ultimate Ruby Mica capacitors. This album was recorded by Enja in 1988 at a Funkhaus concert in Hannover, Germany, two weeks before Chet's death.

Chet is in top form, and Enja captured the performance in gorgeous warm and natural sound. If you are a Chet Baker fan you've got to get a copy of this album if you don't have it already!

The triplet of Ultimate Ruby Mica capacitors enhanced the SPEC RSA-M3 EX Real Sound Amplifier's imaging, with images having more presence and a greater feeling of "body" to them, there was more resolution of recorded nuance, more transparency into the depths of the soundstage, and there was an increase in the sense of the recorded acoustic, or space, of the recording venue, as well as around each instrument, which made images seem more "holographic" on the soundstage. 

From a musicality perspective, the triplet of Ultimate Ruby Mica capacitors made the SPEC sound tonally richer and fuller across the frequency spectrum, more articulate for small dynamic variations, which served to enhance the portrayal of melodies.

Pretty much across the spectrum of musicality traits, timbral realism, the resolution of tone color, melody, rhythm, tempo, dynamics, and the ability to play naturally at live-like levels appropriate to a piece of music, all improved. 

I also noticed that applause from the audience sounded noticeably more resolved and "real" with the triplets of Ultimate Ruby Mica capacitors.  

The next album up for listening was Joe Pass' album For Django. This album features Joe Pass on guitar, John Pisano on guitar, Jim Hughart on bass, and Colin Bailey on drums. 

The For Django album by Joe Pass is considered a classic, and it is a theme/ tribute album of songs written by - or for - the great gypsy jazz guitarist, Django Reinhard.

As with Chet Baker's "The Last Great Concert" album, the triplets of Ultimate Ruby Mica capacitors enhanced both musicality and sonics.

In addition to what I noted earlier about sonics and musicality, with the For Django album by Joe Pass, I also noticed a greater sense of liquidity and flow with the music with the triplets of Ultimate Ruby Mica capacitors, and a general overall sense of greater "ease' to the music being played.  

While timbral realism, the resolution of tone color, melody, rhythm, tempo, dynamics, and the ability to play naturally at live-like levels appropriate to a piece of music, were all improved, there was also a strong sense of the presence of the instruments in the listening room, giving the music a "reach out and touch it" sense of realism.

I would be remiss if I didn't mention Frank Potenza's fabulous album For Joe, which is a tribute / theme album of Joe Pass's album For Django. 

For Joe features the same musicians that played on For Django (very cool!), with John Pisano on guitar, Jim Hughart on bass, Colin Bailey on drums, and Frank Potenza taking the late Joe Pass' place on guitar.

There are some of the same songs on For Joe as on For Django like Rosetta, For Django, Fleur D'Ennui, as well as a number of songs not on For Django. 

The SPEC RSA-M3 EX Real Sound Amplifier with the triplets of Ultimate Ruby Mica capacitors makes Frank Potenza's For Joe sound every bit as glorious as Joe Pass' For Django.

If you love jazz, I recommend you get all three of these albums if you don't have them already, as they all possess wonderful music and are recorded very well.

Two sets of triplets of Ultimate Ruby Mica capacitors.

Well, Triplets of the Ultimate Ruby Mica capacitors are a "no-brainer", and improve the performance of the SPEC RSA-M3 EX Real Sound Amplifier across the board both musically and sonically.

They are also rather inexpensive, which should make them even more enticing, and it is about the easiest "modification" you'll ever do, as all you have to do is slip the capacitors leads into the binding posts along with the speaker cables.

I'd like to thank Yazaki-san for sending the Ultimate Ruby Mica capacitors to me, it really is an ear-opener to hear such a simple modification make such a nice difference in performance.

For more information contact Yazaki-san HERE.

As always, thanks for stopping by, and may the tone be with you!