May 302015

For those of you who have been following along, Mr. Shirokazu Yazaki (below, second from left) of SPEC Corporation fame (The Real Sound Amplifier, et al) encouraged me to try a ‘Capacitor Adventure’ with one of my vintage McIntosh amplifiers (MC30 monaural amplifiers, MC225 stereo amplifier, and MC240 stereo amplifier).

64 Mr.-Sirokazu-Yazaki and the SPEC Team

My MC30 monaural amplifiers and MC225 stereo amplifier were beautifully restored both electrically & cosmetically by Yves Beauvais, who is actually a famous & talented record producer by day, as well as a vintage vacuum audio enthusiast by night (Ok, I’m kidding a bit here, Yves is actually both a famous & talented record producer and vintage vacuum audio enthusiast both night and day!) Both the MC30s & MC225 were purchased from Yves at retail pricing through his Vintage Vacuum Audio business.

Yves’ McIntosh amplifiers are fantastic, but they are built to a cost point to make them accessible to enthusiasts. But what if you didn’t have to observe costs with retail considerations in mind?

Well that’s what we’re doing here at Jeff’s Place, we’re taking Yves’ fantastic MC30s as a starting point and going where no man has gone before, so the Capacitor Adventure has now become The Great MC30 Adventure!

33 MC225

MC225 stereo amplifier in foreground, MC30 monaural amplifiers in the background.

After talking over which of my vintage Mac’s would the best choice for our Capacitor Adventure with my friend and vacuum tube equipment expert, Ron-san, he recommended the MC30 monaural amplifiers for their simpler circuit, vacuum tube rectification, and relatively spacious interior that would make laying out and doing modifications fairly straight forward.

Ron at work

Ron-san at work in his electronics studio.

Now here’s the situation that I find so intriguing: Yazaki-san has had a very successful professional career designing audio equipment, was the head of the Research & Development division of Pioneer Corporation, and started SPEC Corporation to pursue designing his own state-of-art audio products (like the SPEC Real Sound Amplifier shown below).

61 SPEC-RSA-M3-EX-front

In parallel with all of this, Yazaki-san also is a life-long audio passionista for vintage vacuum audio equipment, and has an enormous amount of experience with building, restoring, and modifying vacuum tube electronics to get the highest level of performance from them, which he calls ‘the real sound’.


Yazaki-san’s home system.


Closeup of Yazaki-san’s DA-30 SETs and heavily modified Marantz 7 preamplifier.

15 DA30 mono closeup

Close-up of DA-30 monaural amplifier.

Mr. Yazaki-san has an enormous aural database of experience from his lifetime of audio designing with the different capacitors, resistors, vacuum tubes, wire, etc., that makes up an audio amplification device, and because of that aural knowledge he can look at a schematic for a particular vacuum tube audio amplification device and make recommendations on how to improve it to achieve ‘the real sound’ as he calls it, which is his perception of the sound of real instruments playing music in real space. It’s also a perception that is very much my own, so in that we are definitely kindred spirits!

Cap Adventure schematic - 1

Yazaki-san looked at the schematics for the MC30 monaural amplifiers and made some recommendations using some of his favorite components, and thus the Capacitor Adventure was born.

Cap Adventure schematic - 2

I’ll update this a bit later with all the components involved and ‘the why’ of what we did in detail. I think it’s a really fascinating discussion and I want to tell you all about, and it has been very illuminating for me.

Ron desoldering an MC30

Ron-san laid out all the modifications in the chassis and installed all the components, and he did a beautiful job. It was a big job with all the desoldering, layout, soldering in of the new parts, testing to make sure all parameters were in the right range, and ultimately that everything was sounding & working right. The first MC30 took about 16 hours of time to upgrade, the second went a bit faster, but it still was a huge effort. The Capacitor Adventure would not have been possible without Ron-san’s generous amount of help – thank-you Ron-san! Those are the completed Capacitor Adventure MC30s in the photo below, and they sound magnificent!

Yazaki-san capacitor adventure MC30s

The ‘Capacitor Adventure’ MC30 monaural amplifiers are a combination of Yazaki-san’s ideas & components, and Ron-san’s expert layout and modification skills. Thank-you both!

Mr. Yazaki-san has suggested that we now up the ante on the MC30s’ performance even further, and do a Resistor Adventure, so that is now in the works.

Also, Ron-san has suggested that we install IEC connectors into the MC30s’ chassis so we can use high-performance power cords like those of Mark Coles at Sablon Audio, which are simply the very best power cords I have ever encountered. At Mark’s suggestion I ordered a pair of Oyaide Power Inlet R IECs from Chris Venhaus at VH Audio.

To top it all off, Yazaki-san has suggested we do a little vacuum tube rolling to pick out the ultimate tube set for the MC30s – I’m breathless!

When we’re done with these MC30s they may very well be the ultimate MC30s on Planet Earth!

So there will be much more to come on the Great MC30 Adventure! Stay tuned!

Thanks for stopping by, and please stop back by to join in on the fun!

Oh, I almost forgot to mention it: I have something else really exciting to tell you about very soon too – an exotic (and affordable) SPU tonearm that’ll give you a Woody! More soon on this SPU Woody Fresh Catch!

 Posted by at 9:50 am

  12 Responses to “The McIntosh MC30 ‘Capacitor Adventure’ just became …”

  1. Can’t help but wonder what capacitors & resistors Yazaki-san would recommend for an MC-225, and how they would differ from an Yves Beauvais re-build. Is there a protocol for informing Yves of these modifications?

    • Hi Mark,

      Ron-san and I talked about modding the MC225, but we decided that Yves did such a nice job with it that we’re going to leave it alone.

      It sounds great, and Yves did say it was the best sounding MC225 he’s built.



  2. Thanks for the clarifications about the MC-225 and the Belden IC. I thought the stern reaction from Blue Jeans Cable was quite comical. These unconventional and/or vintage solutions seem to work, although no one seems to have much of an understanding why they work. Last time I paid attention to fine audio, there was hardly any focus on cables of any sort. For instance, the ARC SP6c had only a captive power cable, like your Macs.

    • Hi Mark,

      Best-Tronics Pro Audio (mentioned in the first Belden 8402 post) will build anything you want, you just have to tell them how you want it done. They’ve been great to deal with. The only downside is that my post created so much interest in Belden 8402 that they sold out of cable and are waiting for more. Terrific guys to deal with.

      The Western Electric wire and the Belden 8402 microphone cable appear to be well engineered products. They’re made in ‘pro-style’ with multi-stranded tinned copper conductors with rugged casings. It is against the current trend of thinking of thinking to do that, most ‘high-end’ cable companies are going for ultra-pure copper or silver conductors and casing designs that give maximum resolution. Some of these cable designs sound good, others not so much.

      The WE and Belden 8402 seem to have gone for ruggedness & good musical attributes rather than just trying to exaggerate sonic artifacts of the recording process that are not part of the actual music. The old-timers like WE and Belden seemed to understand that it was about preserving the musical content of recordings.

      While very good custom cables like Mark Coles’ Sablon Audio cables can sound extremely good, it is nice to see there are lower priced alternatives like the WE and Belden 8402 that come very close to that level of performance for much less cost.

      Anyways, enjoy those cables!



  3. For me, putting in an IEC inlet on a classic McIntosh amp would be a tough decision. Have you considered hard wiring a really good power cable instead of adding the IEC inlet? Of course, having the inlet allows you to roll power cables, but it also permanently alters the look of an iconic amplifier. I have an Audio Research line stage preamp with a hard-wired stock power cable, and I have decided to leave it as-is. With an original Dynakit Stereo 35 amp I restored, I replaced the stock zip cord power cable with a better, heavier Belden cable.

    • Hey Rich,

      In my vintage McIntosh article I wrote: “I group my fellow vintage McIntosh audio enthusiasts into two schools, the first being the collector who wants everything to be as original & pristine as possible, with only new old stock parts (or their closest sensible replacement) used to minimally electrically refresh them; and the second being the enthusiast listener, who just wants to enjoy listening to music with restored vintage McIntosh gear because of its considerable musical prowess, and who doesn’t mind if its been cosmetically restored and modified a tiny bit with artful combinations of caps & such to get the most out of them musically.”

      My pristine original Mac MX110Z and MC240 fall into the collector category, and I won’t be doing any major changes there.

      My MC30 monaural amps and MC225 stereo amp are both electrically & cosmetically restored rather than being original & pristine examples, so they have only a little appeal to collectors, so they’re more in the enthusiast listener category.

      Hard wiring in a good power cord like the Sablon Audio ones would still require a modification of the chassis (they’re big, and you’d have to put in a bigger chassis opening), and I wouldn’t be able to swap cords easily, so that’s out.

      Adding an IEC doesn’t really change things much appearance-wise as long as there’s room for it (I think there is, but haven’t measured things up yet). The other option would be to snip the power cord off, wire the IEC into the snipped cord external to the chassis, and then heat shrink it so it looks nice. That way you don’t have to do chassis mods. But it’s not nearly as a clean looking way to do it, and probably doesn’t sound quite as good.

      Two Oyaide Power Inlet Rs arrived today in the post from VH Audio, so we’ll see what happens. I suspect they will result in a very nice performance improvement if past experience is any indication.



  4. Jeff—
    Thanks again for another clarification. I didn’t know that Best-Tronics also terminates. I can wait for them to re-stock the Belden as I’m still eagerly (not anxiously!) waiting for Louis’s speakers & the Decware amp.

    Musical content vs. sonic artifacts just about sums it up. Someone asked me once about whether I was looking for realism or accuracy. My reply: neither. Just an esthetically satisfying representation of a musical event.

    With all the equipment news I miss you mentioning what you’re listening to. I’m rediscovering jazz violinist Johnny Frigo, especially a terrific Chesky recording with the Pizzarellis, padre e figlio, and Ray Brown.

    • Hi Mark,

      I agree, a pleasing representation of the musical event is probably the most important factor for most listeners (and me), and the Belden 8402 & WE16GA do a great job of that.

      Thanks for the music listening comment. It’s been so hectic here I haven’t had as much time to write as I’d like. I’ve been getting lots of great jazz (and other stuff too), and hopefully I’ll be able to catch up a little on telling you about the good ones. 🙂



  5. Jeff,

    I am in a process have an expert restoring a pair of MC30 for me (my 2nd pair). I really like your Yazaki Cap Kit in this pair. Since I am not an expert reading schematic nor having enough knowledge to translate it myself. Can you please publish a dumb-down version of the part list for this kit? Also which position have you replaced the Arizona cap with Duelund caps in the later stage, in what value? Thank you very much for the BIG help.


    • Hi Griffin,

      Here’s a link to my article about this project with a parts list and schematics that your tech can use to do the work.

      Have fun!



      • Jeff,

        Thanks for the link. I am ordering the caps kit myself. Yazaki San was very kind, and willing to sell the SPEC mica caps direct.

        On you part list for MC30. I suspect there is a typo where at R30 position says Ohmite, Brown devil B12J5KE-ND 5K/12W, well, this part number does not exist, should it be B12J5K0E-ND? There is a “0” between K and E, which is a Brown devil wirewound 5% resister.


        • Hi Griffin,

          That’s the part list from Yazaki-san, and it’s just been too long now since I ordered them, so I don’t remember for sure if their was a typo or not, or if that particular one’s been discontinued, or …

          Hopefully Yazaki-san will see this message and be able to tell us.



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