JE Labs

Tuesday, September 26, 2017

Shure Mic Transformers

Ben C was hunting for Altec 32s, Emilar EH800s
and EH500s at Jammin' Jersey

Tipped off by my buddy, Ben C (dude in the middle), I scoured eBay for Shure Mic transformers that can be repurposed for MC step-up duty. These transformers typically sell for under $50/pair shipped within the USA.

They don't have model numbers so I'll identify them based on their step-up ratio.

Primary DCR = 35 ohms and 3500 ohms in the secondary.

I measured a step up ratio of about 1:17, which suits the Denon DL103 and DL103R well. It can be a pinch hitter for the Ortofon SPU in my system, but ideally more gain is needed.

This unit has slightly less gain at about 1:12, primary DCR = 20 ohms and secondary = 2000 ohms. What it gives up in gain is made up for by slightly wider bandwidth. If I were to split hairs, I'd pick this over the 1:17 model above if I were using a DL103 exclusively.

The tonal balance of both Shure transformers is actually quite similar to the Altec 4722 with just a touch less transparency and authority throughout the audio band. At their present asking price, I can highly recommend these transformers to those who want to sample the delights of listening through a classic Denon DL103 low output moving coil cartridge.

Happy listening!

Thursday, August 10, 2017

Lens Filter Ring Vise

I recently fixed two lenses from my collection which had dented filter rings using this $36 tool from Micro-Tools.

The tool didn't come with instructions but using it is pretty straightforward. As a precaution, I covered the front element with cardboard. First, I positioned the moving jaw of the tool on the dent and aligned the threads from the jaws of the tool to mate with the threads of the filter ring. Then I gently spread out the jaws of the tool to press out the dent. I cannot over emphasize going slowly but surely!

Dent was between 10 and 11 o'clock
impossible to fit a hood or filter

After the procedure, a 46mm
screw-in lens hood fits with
minimal fuss

Dent was between 3 and 4 o'clock

Not perfect but better than it was

The tool has paid for itself ;)

Friday, July 28, 2017

Noguchi Finemet: FM-3WS-H + FM-6WS output transformers

This was the last extensive testing and listening session I did in the attic before we moved back to the states. I misplaced some data and just recovered them recently. So as promised in a previous blog entry, here's the write-up on the two entry-level SE Finemet OPTs from Noguchi.

WARNING

These are bonsai-sized output transformers. If HUGE iron + HIGH inductance and thumping bass frequencies is your idea of high-fidelity you should STOP 🛑 here!😉

However, if the finesse and realism a WE/Altec 755A can provide within its 70-13 kHz bandwidth is your idea of a GREAT time, please proceed!😊

Noguchi FM-3WS-H

Noguchi FM-3WS-H + Tamura F7004

David vs. Goliath - indeed, the FM-3WS-H is tiny. I had to mount it on a perf board so that it wouldn't fall from the square mounting hole left by the Tamura F7004 ;)

JPY 13,910 or US $124

Noguchi FM-3WS-H
100Hz (top left), 1kHz (top right)
and 10kHz (bottom right)

Technical and listening tests were done with the output transformer mounted in the SE10/VT25 amp, which resides in the attic mono system.

Noguchi FM-6WS

Noguchi FM-6WS + Tango U808

The FM-6WS is not that much bigger either.

JPY 16,000 or US $142

Noguchi FM-6WS
100Hz (top left), 1kHz (top right)
and 10kHz (bottom right)

Technical and listening tests were done with the output transformer mounted in the Radiotron SE2A3 stereo amp in place of a pair of Tango U808 OPTs.

Color Chart in Kanji
for wiring
transformer leads

Subjective evaluation of both OPTs

I have to admit that given the Lilliputian dimensions of these OPTs, I was predisposed to expect poor bass performance in spite of the claims from their respective spec sheets. The 100Hz square waves verified the manufacturers' claims and the quality of bass I hear more than compensates for the lack of ultimate extension which, in my experience, can only be had from OPTs the size of a Tango XE60/NY15s or Tamura F2000/F7000 series. In fact, when I invited my seasoned DIY Audio buddies for a listening session, none of them noticed significant bass deficiency.

Back in the 90s, there were two types of exotic transformer core material vying for the best - Permalloy and Amorphous. I learned then that the virtue of exotic core material shone through the mid-range, rather than at the frequency extremes. I never quite made the leap to Amorphous because I was already satisfied with the life-like mid-range abilities of Permalloy. I heard the Amorphous Tamura F5002 in a familiar circuit and system context, and thought that in spite of its edge in resolving detail, it sounded clinical compared to Permalloy. Finemet is supposed to have evolved from Amorphous. However, the mid-range performance from these two entry-level Noguchi Finemet OPTs have the warmth and lucidity of Permalloy without the antiseptic quality of Amorphous.

With such fine midrange performance I didn't expect any high frequency aberrations and the two 10kHz square wave oscillograms above confirm the smooth falling response beyond 20kHz (no ringing or phase shift), as shown in their respective spec sheets.

If I didn't already have Tamura and Tango Permalloy OPTs the bigger Finemet offerings from Noguchi are very tempting!

!!UPDATE!!

The entire line of Noguchi is now represented by General Transformer in the same location at Tokyo Radio Department Store in Akihabra and they accept international orders.

Wednesday, July 19, 2017

Harrisburg Hamfest

After playing the first concert for the July 4th Summer Series with Harrisburg Symphony, I received a text message from a friend that there was a Hamfest in town on July 1st.

The venue was only 10 minutes away from our hotel.

Pick of the day!

Friday, June 30, 2017

Spring 2017 Camera, Hamfests and Radio Shows

Kutztown Radio Meet

May 12-13, 2017

Kutztown, PA

I used to frequent this radio show until I left in '08. It used to be a relatively small event but has evolved to the biggest radio show in the east coast.

Contax II + Helios 103
Foma 100 in Rodinal

A pair of MC60s + a Dyna PAS 3 preamp

RCA preamp/mixer + 2 x Rek O Kut B12s

My friend Larry's booth featuring handcrafted and modified tube preamps and amps

Contax II + Helios 103
Foma 100 in Rodinal

Mike used to sell vintage audio but has shifted to classic/vintage film cameras. An avid music lover, he still listens to a hifi system using carefully chosen classic equipment.

Got an EV MC12, loktal triodes, 6C6 pentodes, a 10Y and a Ciro-Flex C TLR

Classic cars in the field

more Kutztown pics

Photorama USA

June 3, 2017

Centreville Moose Lodge

Fairfax, VA

Fuji X-E1 + Voigtlander Heliar 15mm f4.5

Twenty some years ago I frequented Photorama shows in the Washington, DC/Baltimore area.

Fuji X-E1 + Voigtlander Heliar 15mm f4.5

This was a good place to source classic cameras, lenses and accessories during pre-eBay days. Since I've been in the market for a Sonnar 50mm f2 or f1.5 for my Contax II, I thought I'd try my luck at this event...

Fuji X-E1 + Voigtlander Heliar 15mm f4.5

Even if the show was only a fraction of what it was 20 years ago, I did find a nice Opton Sonnar 50/2 with a dead Contax III (good for parts) rear lens cap for less than the going rate on eBay.

Icing on the cake: Tewe Zoom finder, Paterson Tank, a book and freebie expired TX400s

Radioactivity 2017

June 15-17, 2017

College Park, MD

From the early 90s until '08 I attended this event regularly. Many of the tubes, transformers and chokes I am still using in my hifi system came from this radio show.