JE Labs

Wednesday, June 24, 2015

6F8G

I recently discovered a few of these cool-looking ST glass equivalent of a 6SN7 in my tube stash. This tube plugs into an octal socket but has different pin outs (vis a vis 6SN7) and requires a 1/4" grid cap for the second triode section. So I rewired the line stage section of my JEL mono preamp to use it.

JE Labs Mono Preamp
6SL7 + 6F8G

Not sure if it sounds better,
but it certainly looks a lot better ;)

Monday, June 15, 2015

Thursday, May 14, 2015

Asano, MJ and Stereo Sound Tube Kingdom

The Bookshelf

In the past, I've posted pictures of books and magazines which shaped my audio DIY journey like Sound Practices, Radiotron 3rd edition and RCA tube manuals. The following publications were also significant influences, despite my not being able to understand Japanese. The schematics and high quality pictures speak for themselves.

Asano -- Volume 1 and 2

Isamu Asano (1914-1981) was a banker who built amplifiers as a hobby. His projects were compiled in these two volumes.

A 3 stage RC coupled 27>27>45 SE amp.

A single-ended Western Electric 205D triode driven by two stages of type 56 triode.

Mr. Asano also contributed articles to MJ.

MJ - Audio Technology

MJ articles cover vacuum tubes all the way to the latest in digital technology.

Some issues may feature a listening room or two...

or even a recording session

technical graphs

Stereo Sound Tube Kingdom

A quarterly vacuum tube(centric) publication + special issues devoted to classic equipment and components.

Issue No. 3, 1996

This was the source of inspiration for my Open Baffle project.

The Altec 618 2 cubic foot sealed cabinet for the 755A

A Japanese DIYer's take on a Western Electric SE104 amp

Western Electric 753C speaker system: Jensen 15" woofer and WE32A horn + WE713A compression driver

A couple of featured listening rooms

Speaker system: Jensen EP807 bass reflex cabinets loaded by WE TA4194A woofers, KS6373 horns with WE555 drivers with tungar PS for the field coils
Amp: WE91B
Preamp: WE129
Turntable: EMT 927st

Speaker system: 2x755A in flat baffles with auxilliary Jensen cone tweeters driven by Altec 127 amps fed by 2 x Altec 1567A preamps. Sources: Thorens TD521s turntable and Accuphase DP70 CD player

Field coil speaker system powered by Tungar PS: Altec VOT 825 bass bins loaded by Magnavox 15" woofers, WE555 + WE3 horns and Kanno 597 (WE clone) horn super tweeters
Ampifier: Western Electric 118A (PPP 6L6)
Preamp: Western Electric RA1214
Turntable: Rek O Kut 16" turntable with Ortofon RMG309 + Gray 108 tonearms

This level of quality does not come cheap and depending on the exchange rate, an issue can cost anywhere between US$30-$50. But it's invigorating to sense the innate passion of Japanese culture by thumbing through the pages.