Hashimoto H-203S from Kasuga Wireless

In September 2018, I lamented the demise of Noguchi Transformers. Fast forward to November, my brother-in-law visited Tokyo, and was kind enough to pick up a couple of transformers at Kasuga Wireless.

How to get to Kasuga Wireless

Kasuga Wireless

Address: 1F, New Akihabara Center, 1-16-10, Kotobuki, Chiyoda-ku, Tokyo 101-0021

Hashimoto H-203S

The H203S was installed as a 3.5k primary Z output transformer in the je2a3 mono integrated amp. 

Testing

Top trace = audio generator

Bottom trace = amplifier output

100Hz

1kHz

10kHz

5.324Vrms to an 8 ohm load = 3.5W 

In the past, I've used Hashimoto transformers for a pair of SE2A3 and a pair of SE10 mono-blocks I built for friends. I know these transformers are well designed, are of high quality construction and sound excellent. Thus, before Hashimoto ceases production, I had to add it to my collection. 

My mono SE2A3 integrated is ready for prime time!

Now I have to find a nice circuit for a pair of Kasuga KA6625ST OPTs. 😉

Altec 753C

After many years of raving about the Altec 32 horn, the only stone left unturned was using it as it was originally designed, that is, with the compression driver oriented to radiate upwards.

Last year, I received a message from John Piro, whose beautifully crafted preamp project was previously featured in this blog. He sent me pictures of his interpretation of the legendary WE753C using an Altec 414-16B woofer + Altec 32A + Faital Pro driver. 

Altec 414A + 32C + 802D + 20275 

I was very impressed and requested if he could build a pair for me. We finally met at the Kutztown Radio Show last September. He and his wife had dinner here at home when he delivered my beautiful cabinets!

A Western Electric 753C used as a monitor at WABF in the early 50s

As an homage to the legendary Western Electric 753C, which was a major inspiration for this project, I henceforth christen this speaker system as the Altec 753C.

Altec 2-way XO redux

I've settled on running the 414A woofers in full range mode (ala J-Rob) and replaced all the crossover resistors with non-inductive 12W Mills. This took away the last vestiges of grain in the upper frequencies.

RTA Graphs

Altec 2-way

Altec 614 + 414A + 32C + 802 with GPA34258

The above RTA was taken from this blog entry

VS

Altec 753

Altec 753 + 414A + 32C + 802D with 20275

I could've lived happily with my Altec 614 or repurposed 861 (aka Madrid) cabs + the inverted 32 horn situated on top. However, with proper horn orientation, the sound was taken to another level of refinement. Now the blend between the 414A and horn is practically seamless and I bask in the airiness of the top end, which I attribute to significantly improved high frequency dispersion, precisely as envisioned by Western Electric engineers.

In spite of the stellar midrange performance of the Open Baffle mounted Altec 755As, I started the Altec 2-way project in the late 90s to address the following issues:

1. More efficiency
2. Extend the frequency extremes
3. Less congestion in dynamic peaks with complex musical passages

After 20-some odd years, those goals have been realized. The Altec 753C is pretty much end game!

Thanks to my buddy Joe Roberts, who explained the intricacies of proper 32 horn orientation. The idea was carefully stored in my mind. I just had to wait for the right opportunity to implement it. And of course, a big thanks to my friend John Piro (aka RCA NUT), craftsman extraordinaire!

Let's hear some music. 😊