Wednesday, March 15, 2017

Radio Shack


In February of 2015, Radio Shack filed for Chapter 11.


So I was delighted to see this Radio Shack store announcing a comeback in midtown Manhattan during a visit in the summer of 2016.

When I was a student in NYC in the 80s, a neighborhood Radio Shack store was just around the block if I needed a resistor or capacitor for a project on a Sunday afternoon. By 2008, I was in the suburbs and Radio Shack was in a strip mall just a mile and a half away. Now I have to drive 35 miles to the next town ;(


In the early 90s, many SE amp DIYers started their foray into efficient speakers inspired by this book by David B. Weems. The speaker projects used various raw drivers from the Radio Shack catalog.

40-1354A



Radio Shack no longer had 2A3 triode tubes on their shelves when Sound Practices started publishing in 1992,  but one could still buy this 5 1/4" full range driver listing for less than $10, IIRC. This speaker was efficient enough to be driven by an SE2A3 amp to satisfying levels.


I used this driver in a compact bass reflex box...

from David B. Weems book

...as well as in a Tapered Quarter Wave Tube (TQWT)


Not quite in the same league of sophistication and refinement as the Altec 2-way, but lots of fun since they can boogie on a couple of triode watts ;)

Time Warp



During a recent "let's see where the wheel takes us" expedition, my wife and I spotted this in Pennsylvania. 

40-1310


As I browsed around the store, a pair of 40-1310 super tweeters bearing their original sticker price immediately caught my eye. I told my wife about them and she insisted that I get this pair of NOS Chinese-made plastic version for $60 + tax, so I can time travel.


These drivers developed quite a following in the 90s because the original all-aluminum units embossed Realistic were allegedly OEM'd in Japan by Fostex. The graphs above and below should corroborate this speculation. Later versions with a plastic pod and horn were subcontracted in South Korea and then China.

Fostex FT17H

I didn't join that 90s bandwagon. Instead, I bought a pair of the equivalent Fostex FT17Hs sans pod from Madisound for $70. I used them as super tweeters for Altec 755Cs and 755Es until they were superseded by a pair of superior Altec 3000Hs.

 Brand new Fostex FT17Hs are now made in China and can be had for a little less than $100/pair. I still believe they are excellent value for the money. Perhaps the early Japanese all-aluminum 40-1310s can command a slight premium, but beware of unscrupulous eBay flippers asking ridiculous amounts for the plastic version.

Subtlety



Before inserting the 40-1310 into the Altec 2-way, I bypassed the built-in electrolytic cap/choke crossover components. For the past 20 years, I've been using smooth and natural sounding paper in oil caps in the signal path of my preamp, amp and crossover, nothing else.

Altec 2-way + 40-1310

Altec 2-way sans 40-1310

In this application, the 40-1310's positive terminal is protected by a 1uf PIO cap and then connected to the high-pass section of the crossover. The effect of the super tweeter is subtle...just a touch more air.


As I was about to sit back to reminisce the 90s with the 40-1310, an internet friend informed me that Radio Shack just filed for another bankruptcy claim ;(

This prompted me to visit my favorite branch...




...fingers crossed. ;(

Wednesday, March 1, 2017

Altec small format diaphragms: Aluminum vs. Symbiotik



I've been playing around with Altec drivers for almost 20 years and have only listened to aluminum diaphragms until now.

Tuesday, February 21, 2017

Vostok Bezel Mods

From NATO'ed to Bezel mods



Vostok Amphibia 110640 + Bandukh Bezel


Murphy 1050 bezel + Seiko 'Pepsi' insert
=


Vostok "mod" Amphibia 420432

Wednesday, February 1, 2017

Budget SE OPTs - Edcor and Noguchi



All output transformers were tested in the je2a3 amp using the same procedure as I did in the Hammond 125ESE many moons ago. Listening sessions were done through the same amp driving a single Altec 2-way speaker system

Thursday, December 29, 2016

Dr. Jose P. Rizal


Rizal portrait
by
Juan Luna

In commemoration of our national hero's martyrdom on December 30, 1896, let's reflect upon a few words of wisdom he left behind. They are very relevant today as they were over a hundred years ago.


On Education:

"My countrymen, I have given proofs that I am one most anxious for liberties for our country, and I am still desirous of them. But I place as a prior condition the education of the people, that by means of instruction and industry our country may have an individuality of its own and make itself worthy of these liberties."




What Rizal stood for:

"I do not write for this generation. I am writing for other ages. If this could read me, they would burn my books, the work of my whole life. On the other hand, the generation which interprets these writings will be an educated generation; they will understand me and say: 'Not all were asleep in the night time of our grandparents.'"




Dr. Rizal's Noli Me Tangere and El Filibusterismo have been required reading for high school students since the 1950s and the essence of these novels is still very pertinent in our present day society. But why have we allowed the oppressors to develop from within?





Sunday, December 11, 2016

November 2016 Hifi Show Report

Sierra Audio


Back in the late 90s, I frequented a west coast based website, Sierra-Brooks, that featured beautiful hand crafted wooden horns. Half of that partnership was Victor Sierra, a Filipino from Cebu City. In the interim, Victor had been busy managing their family business. The local audio community warmly welcomed their premiere participation in this event!


Their demo featured 3-way horn loaded speakers.



Driven by a stereo SE45 designed and crafted by one of his collaborators (below, left) using locally wound transformers by Edrel Sison


Congratulations Victor (right). Good job!

Friends in Audio 



This group of audio enthusiasts featured a 2-way horn system + super tweeter using my favorite Altec 414 woofer and a handmade wooden horn driven by an Altec 806A + EV T-35 super tweeter. At the front end was a Garrard 301 with a locally crafted linear tracking tonearm. A custom tube preamp and amp completed the system. 



Harana/Setup/Tono



Garrard 401 with a Dynavector DV507 tonearm fitted with either a Denon DL103 or Ortofon SPU-GME and a laptop/DAC combo digital source fed through a pair of Western Electric WE111C repeat coils


JE Labs stereo preamp dressed in Harana Audio hand crafted wooden case, loktal 7F7 tubes for the phono stage + 6F8Gs for line level


Harana Audio dual mono SE300B amps - Jensen input transformer > WE417A > Tango NC20 > WE300B > Tango NY15-3.5S output transformer


Harana Audio 2-way horn speakers - 15" Beyma woofers in V-Vent II enclosures, JBL 375 compression drivers behind carved horns + JBL super tweeters

For more pictures and information, please visit the November Hifi Show FB page.

Sunday, November 20, 2016

NATO'ed Vostoks

Vostok Amphibia 420432 



Lug width = 18mm



Vostok Amphibia 110640



Lug width = 22mm


Monday, October 24, 2016

November 2016 Hi-Fi Show

The one and only Hi-Fi event in the Philippines, a must-see for enthusiasts in Manila!


Sneak peek of what you'll see and hear in room 447 (Harana/Setup/Tono)



Sunday, October 23, 2016

Stuff I regret flippin'...

...in the early days because I was an idiot ;( 


In the summer of '86, I acquired my first Thorens TD124 equipped with the above tonearm at an estate auction for $1!!! I kept and used the turntable but the plastic cover of the counterweight was cracked so I replaced it with a Sumiko MMT. I eventually sold this tonearm for $10. I didn't know what an Ortofon SMG212 was then.


I purchased a box lot of tubes and parts for $5 at a hamfest which contained one of these. Later that day, I accepted a $15 offer for the transformer. I've been looking for another one since...


Found one at a flea market for two bucks and flipped it at a hamfest for $20. I didn't know it was an Altec 3000B, the phenolic horn looked too cheesy. 

Sunday, September 18, 2016

je2a3 amp


Twenty three years ago, I built my first 2A3 amp in the basement of the very same house I'm staying in right now. This was a pair of PP2A3 amps with a Mullard-Style driver circuit pumping 8W per channel of pure Class A to drive 82dB/1W/1M (in)efficient BBC LS3/5As, with external preamplification.


As I enter another phase in life, I am back in the same house, mellower with age but hopefully wiser, building a single channel, single-ended 2A3 amp with 3.5W output to drive a 99dB/1M/1W efficient Altec 2-way horn system, with a phono and line stage on board.


This project started with a chassis and choke (amongst other things) handed over by Joe Roberts at the Capital Audio Fest last July. Additional parts were either donated by my hamfest/radio show buddy, Chong Ong or ordered online, like the Hammond 272X power transformer, which came from Steve at Angela Instruments. Back in the 90s, I could have built this amp (except for the output transformer) using parts sourced from hamfests and radio shows. But times have changed, sadly for this project, the only parts I got from a hamfest were the tube sockets ;(


I had been exchanging emails with J-Rob regarding the WE/Altec 32, Emilar horns/drivers, ROK idler TTs, viscous damped tonearms, vintage cartridges like GE RPX, Shure M3D, etc. Among the tubes he suggested I try in lieu of my favorite octal 6SL/SN7s and 5-pin 27/37 and 56/76s, which are getting quite expensive, are the Loktal equivalents + the "Mickey Mouse" plate and grid-capped 2C22/7193 med-mu triode.

WARNING: the 2C22 is not for the faint-hearted, there is over 200VDC in the plate cap if accidentally disconnected while the amp is operating!!!



As depicted in the above block diagram, this is classic (nothing new = boring) JE Labs ;) I used 2 x 7B6 loktals in the RCA derived RIAA phono stage sans variable EQ. A stereo > mono mixer via a WE111C repeat coil to process digital sources was integrated into the chassis, then a single medium-mu triode 2C22/7193 acts as a line stage preamp cap coupled to a Radiotron SE2A3 amp.

!!!WARNING!!! 

The voltages found in this circuit can be lethal, build at your own risk!!!


The chassis was painted in Silver Hammerite, but wiring had to wait due to actual music making and more important projects ;)


Fancy-schmanzy boutique parts were not used in this amp - just plain old carbon resistors, paper in oil caps and electrolytics in the tube rectified/choke filtered power supply.


The amp section is currently fitted with a Noguchi PMF-15WS OPT I got in Akihabara. It sounds really good! You just have to take my word for it since I don't have a scope and audio generator to prove it ;)


At a later date I might swap in the PMF-10Ws, but ultimately I'd like to permanently install an American made OPT, maybe an Edcor or ask/beg Mike L. at Magnequest to wind a single TFA204 OPT just to keep the amp an ALL American classic ;)

Time Out



ala  Turk