AliEx amorphous, Hashimoto HL20K6 + Sony TamRadio line output transformers

L>R: 6AH4 + AliEx, 12B4A + Sony/Tamradio and 6AH4 + Hashimoto HL20K6

The last time I saw my buddy J-Rob was pre-COVID, but we keep in touch via email and text messages. During one of those hello/how you doin' moments, the chat progressed to line preamp transformers and how the $100/pr. amorphous jobs from AliExpress perform. 

I used to own a pair of Tango/Hirata NP216N nickel line OPTs, which were featured in my Sound Practices issue 17 homebrewer article. In hindsight, I don't think I gave them a fair chance so this was a good opportunity to revisit the topology.

SETUP 2024

Single Ended Triode Users of the Philippines 2024

At the dawn of the 21st century, I uploaded hifi systems owned by audio buddies who had been inspired by the Sound Practices ethos. These were the guys who originally coined SETUP. After a couple of decades, the number of Filipinos who indulge in this hobby has increased exponentially.

Here's what I saw and heard during my recent visit.😊

Harana Audio Workshop

Altec 311-60 horns + 288 drivers with Fostex super tweets on top of a pair of Harana V-Vent bass bins with partial horn loading

JE Labs Choke-Capacitance Coupled SE2A3 amp

Canon P + Canon 50mm f1.8 LTM 
Foma 100 in Rodinal

Inspired by my plate choke-loaded 76 line stage preamp adventures, I was curious how a similar driver circuit configuration would sound in an SE2A3 amp. So I pulled out my Radiotron Designer's Handbook, 3rd Edition to gain a better understanding of choke-capacitance coupling (aka plate choke loading) vis-à-vis resistance coupling.

Below are highlights of relevant information I gathered.

MC step up transformer redux + Hashimoto HM-7

When I ordered this pair of MC step up transformers from Mr. Isao Asakura of tube-amps.net (highly recommended👏) for my cousin's system, he suggested the use of high-quality 24-gauge stranded copper wire. I also took note of his MC step up page, in which he discussed his chassis mounting experiments.

Taking the cue from my buddy Nate aka Redboy at HifiHaven.com, who’s a prolific audio DIYer and MC step up builder, I ordered a cast aluminum project box + 24-gauge stranded tinned copper wire from Amazon.

Hashimoto HM-7 - specs

Upon inserting the freshly mounted and wired HM-7 into my hifi set up, my Tamura TKS83 and Altec 4722 sounded comparatively hard and mechanical...🤔

I had to retrace my steps.

Tamura TKS83

Those who are familiar with my Homebrewer article in Sound Practices #17 will remember that the TKS83 was mounted on an aluminum plate + wooden base while the Altec 4722 + others were on plastic project boxes. These were also wired using 99.999% 19-gauge solid-core silver wire + Teflon sleeving, Kimber TCSS or a combination of both. 

In hindsight, whether commercial or DIY, all the Japanese MC step up transformers I've seen in the metal or in MJ Radio Experiment and Stereo Sound Tube Kingdom magazines, were always housed in all metal enclosures or chassis.

Altec/Peerless 15095A + 4722

Before doing further listening comparisons, I remounted all my MC step up transformers on cast aluminum chassis and used 24-gauge tinned stranded copper for wiring. Since we're dealing with very delicate signals at tenths of a millivolt, very fine strands of high purity copper wire + maximum shielding make a lot of sense!

Hashimoto HM-7

After the playing field had been leveled, the Hashimoto HM-7 no longer outclassed my beloved MC step up devices. However, I'm pleased to say that the HM-7 sound falls somewhere in between the detailed and dynamic TKS83 and the organically rich and spacious airiness of the classic 4722!

Alas, these cast aluminum boxes weren't available when I started experimenting with microphone transformers as MC step up devices in the late 90s. Otherwise, I would've used them since I love the industrial vibe of unfinished aluminum!

A Cousin's Listening Room

 

This is a hifi system I built for a cousin who loves music!

The speakers, which I dubbed Altec 753C, is the culmination of my Altec 2-way horn system project.

Western Electric 753 inspired cabinets meticulously handcrafted by John Piro of Hommage Audio

Garrard 301 turntable + Ortofon RMG309i tonearm + Ortofon SPU Synergy for stereo LPs and Alfred Bokrand AB309 + SPU Mono for mono LPs 

Turntable plinth by Hommage Audio

The JE Labs preamp line stage is a plate choke loaded 76 while the SE300B mono block amps feature a Komuro-inspired circuit using type 37 input tubes + Intact Audio nickel plate choke loaded 6V6s or 6F6Gs (connected in triode) and Hashimoto H-30-3.5S output transformers. 

Preamp and amp woodwork by Hommage Audio.

Hifi cabinet by George Nakashima Woodworkers.

Projects like this keep me busy during the pandemic.😊

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. 😉

Listening Room - Minimalist no more?

Among the audio systems of my friends, this is the only set up that has no LP playback ability. Neither does the owner have interest in DVD-A, SACD or a music server/streaming device - only16 bit linear PCM sampled at 44kHz red book mastered CDs, period!

Since our last visit, a Northstar CD transport replaced a CEC TL51X, while another belt-driven CEC TL5 CD transport is being contemplated. The NOS (Non-Over-Sampling) Zanden Signature DAC equipped with a double crown Philips TDA1541A-S2 chip remains. Now you know why I hunt for unloved TDA1541 CD players from the 80s.😎

The most significant change in this system, however, is that
the Phy-HP Co-Ax speakers have been replaced by a pair of field coil powered Western Electric descendants - G.I.P. Monitor 1s.

According to the owner, the JE Labs line level preamp +
SE10 mono-blocks with Hashimoto H20-14U OPTs,  give life to GIP Labs! He is such a good friend. 😉

Here's a video clip I took of the setup when I visited in 2024. 

Hashimoto HC-203U SE output transformer

In the past I have used a pair of H20-14U for the JEL SE10dx monos project and I'm also very familiar with the not quite so Simple 45 fitted with H20-7Us built by Setup 2 for the November Hi-Fi Show head honcho. Today I will report on the entry level SE OPT offering from Hashimoto.

 

Colors in Kanji

Technical and listening tests were conducted using the JEL SE2A3DX circuit.

Scope jockeying the HC-203U

(Primary DCR=150 ohms)

100hz

1khz

10khz

vs.

Tango U808 (Hirata not ISO*)

(Primary DCR = 200 ohms)

100hz

1khz

10khz

*Tango ISO (successor to Tango/Hirata) closed operations in September 2013.

Aside from a 3.71mm difference in lamination thickness and use of flying leads instead of terminals (U808) these two transformers seem to be technical and physical twins. But sonically they're not even distant cousins. The HC-203U is a bold performer and gives a front row presentation. Given its rather small stature, it has bass slam and definition that I associate with transformers twice its size. Vocals are presented in a lifelike manner and there is enough extension in the highs to give a sense of spaciousness and airiness. The Hashimoto HC-203U is what I always wanted the Tango U808 to be.

Listening Room - Minimalist

A music lover's system based on a CD transport + DAC as source, JEL 76/6SN7GTB line stage preamp with remote volume control, JEL SE10 mono block amps driving PHY-HP 2-way 12" co-axial speakers housed in Hans Kortenbach enclosures.

JEL SE10 amp

A Harana Audio/JE Labs collaboration

After the November 2009 Hi-Fi Show, a friend commissioned a pair of mono block SE10 amps. Given my busy concert schedule I needed the expertise and assistance of our friend Joey of Harana (Serenade in Filipino) Audio for the chassis and woodwork.

Me and Joey drafting the layout and marking pilot holes

Hashimoto H20-14U output transformers, C10-10W chokes

+  proudly Filipino wound power transformers on M6 laminations by Edrel Sison

Wiring, scope and ear testing at the attic 

E-P1 + Summicron 50/2-IV

JEL SE10 monoblocks' new home driving (1600mW per side!) PHY-HP drivers in Hans Kortenbach enclosures

E-P1 + Summicron 35/2-I

Thanks for waiting and happy listening!