It's always exciting to hear from our friend Yazaki-san, and this time Yazaki-san really outdid himself!

You all know how much I love my humble vintage Altec loudspeaker collection of the A5 Voice of the Theatre, Corona 832A, and the "Stokowski" Altec's.

Well, our friend Yazaki-san sent me a special issue of Stereo Sound from 2006 that focuses on vintage Altec loudspeakers and amplifiers that arrived in the mail today, with over 300 pages of Altec goodness - woo hoo!

This issue of Stereo Sound includes sections on the origins and history of the Altec company, an overview of the history of many of Altec's products, including compression drivers, low-frequency drivers, crossovers, enclosures, and amplification, just to name a few of the interesting topics - along with listening impressions of certain vintage Altec products. So cool!

The Altec issue of Stereo Sound is printed in Japanese, so I'm using my Google translation app to get an idea of what was discussed, and Yazaki-san has offered to translate difficult sections for me if I get stumped on the translation.

There is an index section that describes all the Altec products with a partial listing of their specifications. In the photo above you can see the index for the 801 field-coil and 802 AlNiCo 5 fixed-magnet compression drivers, for example (among other things). 

The 801B field-coil was that Granddaddy from which the 802 series of compression drivers would evolve (above).

This is so exciting!

Yazaki-san, you totally made my day! Thank you so much for sending this Stereo Sound treasure trove of Altec information! It shall provide me hours of pleasure investigating the different sections and translating the text - what fun!

Before I leave the Altec topic, let me also mention the very rewarding conversation I had with one of the USA's top Altec experts, Todd W. White.

Todd regaled me with fascinating bits of Altec history related to its origins, the people involved, the role of military funding to the advancements in audio technology it allowed, the evolution of the Dr. John F. Blackburn designed Altec 801 field-coil compression driver, which would evolve into the Altec 802 driver and its iterations. Todd told me his favorite version of the 802 was the 802G, which had the big magnet, tangerine phase plug, and an output up to 20KHz.  

Todd described to me how Dr. John F. Blackburn designed drivers and horns for Altec, and John Hilliard designed crossovers (and was the first to recognize the importance of the time alignment of drivers and adjust for it). 

During the war AlNiCo 5 was perfected for military applications, and John Hilliard adapted it to loudspeaker drivers. Shortly after the war the Dr. John F. Blackburn designed Altec 801 field-coil compression driver was modified by John Hilliard with a fixed AlNiCo 5 magnet, which became the Altec 802 driver. 

The Voice of the Theatre line was designed by John Hilliard, and was manufactured by Jim Lansing. 

There's lots more I could say here about my fascinating discussion with Altec expert Todd W. White, but I'll stop there for now.

A big "Thank you!" to Todd W. White for taking up some of his valuable time to discuss all things Altec with me!

I encouraged Mr. White to write a book about Altec for posterity, before the information becomes lost.

Also, Yazaki-san sent two paired sets of Ultimate Ruby Mica capacitors to try in the SPEC RSA-M3 EX Real Sound Amplifier, so I'll be looking forward to reporting on them in the near future.

You might remember that I wrote about the Ultimate Ruby Mica capacitors in Today's Fresh Catch: Yazaki-san's Ultimate Ruby Mica Capacitor Mod for the SPEC RSA-M3 EX Real Sound Amplifier! Part 1. (HERE) and Yazaki-san's Ultimate Ruby Mica Capacitor Mod for the SPEC RSA-M3 EX Real Sound Amplifier! Part 2. (HERE).

As I mentioned in my Part 2 post: 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 with 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."

The Ultimate Ruby Mica capacitors made for a nice performance improvement in my SPEC RSA-M3 EX Real Sound Amplifier, and it's such an easy modification it is irresistible. 

Reports from the field have been very positive, as you can read in the comments on the posts. In particular, Yazaki-san and other experimenters have found that using two pairs of the Ultimate Ruby Mica capacitors further improved performance on the one pair that I auditioned.

So Yazaki-san sent along a doubled pair of the Ultimate Ruby Mica capacitors from me to try in my SPEC RSA-M3 EX Real Sound Amplifier so I could hear for myself the performance improvement they offered.

As you can imagine, I'm really looking forward to giving that a try.

Ok, that's all for now, with much more to come on these topics!

A big "Thank you!" to Yazaki-san for sending the Stereo Sound issue about Altec and the doubled pairs of the Ultimate Ruby Mica capacitors to try in the SPEC RSA-M3 EX Real Sound Amplifier.

Also, many thanks to Altec expert Todd W. White for taking time out of his busy schedule to talk with me about all things Altec.

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