Category Archives: Uncategorized

Calling All (older) Correspondents

Having lately been involved in the archiving of old articles and various correspondence, some frustration has been noted. My contact info is not up-to-date! But this is understandable, as the associated time periods predate email and today’s Internet.

So, I’d love to hear from anyone with whom I shared letters way back when, especially from the 1980s and later.  Please pass on this note if you know anyone in this category (email contact here).

I was especially reminded of this, when I read Michael Wilcox’s note of February 9th, about a passive eq RIAA preamp, which had origins within my 1980 AES paper.

Many thanks in advance!

Walt Jung



Making Web Comments

After fighting various forms of SPAM comments for way too long, we’ve decided to try a new system for comments from users. It is effective now, and will enable a comment sent via email, on any aspect of this website.

Simply use MakeWebComment at as your target email, after changing the ” at ” appropriately (no spaces, subbing an uppercase 2). That’s it. Write on!


Sources 101

This was a great article and I actually built a test circuit based on Figure 16a in part 2 of the article.  However, I wanted to use the source for a mosfet in a headphone amp circuit.  The circuit is designed to operate the mosfet at 150 mA.  I used a more robust transistor in place of the pn2222a.  It worked just fine and I was able to dial in 150 mA of current.  However, I don’t have the test equipment to measure performance.   I’m curious if anyone has tried to get more current out of this circuit and what type of performance resulted.

Edward T. Dell Jr. — Remembering an Audiophile’s Editor/Publisher

Edward T. Dell Jr. (2009 photo courtesy Chad Dell)

Audio editor and publisher Edward T. Dell Jr. passed on last week, not long after celebrating his 90th birthday with his family and friends, including many from his local parish, All Saints’ Church, in Peterborough, NH. His funeral will take place at 11AM on Saturday, March 9, at All Saints Church.

Ed was born February 12, 1923, and died February 25, 2013. He was very well known among audiophiles, having published thousands of their articles in his various audio-related publications — The Audio Amateur (TAA), AudioXpress, Audio Electronics, Speaker Builder, and Glass Audio. These audio publications began back in 1970 with TAA, in Swarthmore, PA. Later on Ed moved his Audio Amateur, Inc. operations to Peterborough, NH. He was recognized by the Greater Peterborough Chamber of Commerce in 2010 as one of their “Legends of Business: Publishing Pioneers”.

Over the past 40 years, I was fortunate to write many articles for Ed’s various magazines, beginning in TAA issue 2/1973. That was the start of a long and fruitful relationship. Ed Dell was a pleasure to work with on those articles. Today, this is a satisfying thing to me, knowing that many of them are here as web versions, hopefully useful for some time yet.

It is difficult to write a concise summary of a person’s work spanning more than four decades, and capture the essence in a couple of sentences. Shortly after learning of Ed’s passing, I exchanged some emails with fellow author Jan Didden, on the influence of Ed’s work.  I said this to Jan:  “Ed Dell certainly did leave large footprints along the path towards better audio, especially our DIY audio, where he was really the one who did the most. He was simply a great enabler for folks like you and me.”

Well, I think that’s a true statement centered on Ed’s greatest contribution; he enabled and encouraged many people to tell stories of their audio designs, especially with home built equipment. Yes, he was also a great editor, and one learned lots of useful insights on audio technical writing working with him.  But the combination of a skillful editor sharing your own objective of making better audio working on your articles was, to me at least, a most invaluable thing. I’m sure that many other authors feel the same way. Ed’s love of audio was the same as mine, and this was perceived mutually!

In 2011 Ed Dell sold his publishing assets to the Elektor group, which today publishes audioXpress. They recently published an online memorial, Edward T. Dell, Jr.: In Memoriam.

Jan Didden interviewed Ed Dell for the pages of audioXpress in October of 2011, and has kindly made this available on the web. Jan has also started an “Ed Dell memorial” thread on DIYAudio, which can be found here. Understandably, one can find many comments there underscoring the value of Ed Dell’s audio efforts. Waltsblog readers can also leave comments here as well, should they wish (just register first). I especially want to encourage any of Ed’s many authors over the years to do so.

Our audiophile editor/publisher friend Ed Dell deserves honor for all the good work he did for so many years. He’ll be missed here, as well I’m sure in many other places populated by audio nuts. He has left truly a great tangible legacy within all those audiophile magazines, for forty-plus years. So, I’d advise you to hang onto them!

Condolences to Ed’s family on their loss. And, thanks to son Chad Dell, who helped with several details of this memorial.

Thank you so much for everything, Ed.

Walt Jung

Jim Williams and Bob Pease Remembered

It is a sad time for analog designers and indeed, all of us familiar with the writings of Jim Williams and Bob Pease. Both men passed on within the last week or so, Jim after a stroke, and Bob in a car accident, just after attending a service for Jim.

I prepared a remembrance of Jim and Bob for Paul Rako, EDN’s analog editor, which appears within his Anablog. Paul has done a great job of assembling tributes to these two men, and everyone will find these memories a very good read. Very sad as well, but still, lots of good things to remember about both.

Some further tributes to these two prolific analog engineering contributors have been posted by Rich Pell and Patrick Mannion.

Kent Lunberg has prepared a bibliography of the works of Jim Williams.  He has also embarked on a (re)reading of Williams app notes, and blogs about this.

Linear Technology has prepared a special web page dedicated to Jim Williams Remembered.

National Semiconductor has prepared a special web page dedicated to Remembering Bob Pease.

Walt Jung

Memories of Bob Milne

The post below was originally prepared as a stand-alonepiece, but has grown in context with numerous comments  from Bob Milne’s fellow editors and other friends. Be sure to scroll down and read all of these comments!Bob Milne (courtesy ED)

Bob Milne was an Electronic Design editor for more than 20  years. He was one blessed with not only great technical skills, but also a wonderful persona. He was born Mar 22, 1940 and passed away Feb 14, 2011.

When I received news a few months ago of Bob’s passing, I wrote up a piece similar to what is below, and passed it on to ED columnist Bob Pease and the Electronic Design editors. Now with the more recent passing of Bob Pease (see the related posting here), it seems all the more important that Bob Milne (who in fact edited Pease’s columns) be honored. Bob Pease also had some very good things to say about Bob Milne, on Milne’s ED retirement.

With regard to Bob Milne, I’d go so far to say that he was an engineer’s editor. He was always wary of publishing rules, but also well tuned into the technical side, especially the analog art. And, he knew what would fly and what wouldn’t. Always fun to work with.

My personal association with Bob began around 1990, when I visited the Electronic Design New Jersey offices while with Linear Technology. With mutual interests in analog, audio, and computers, Bob and I simply hit it off from the start. It was to be a happy working rapport that lasted until Bob retired fully from Electronic Design, around 2005.

During those years, we worked together many times. He taught me a lot about magazine technical publishing, especially during 1997-1998, when I was doing the “Walt’s Tools and Tips” column, while with Analog Devices. Bob was primarily responsible for my opportunity to do such a column, and for this I will always be grateful. He was very good at honing a wordy manuscript down to size, while minimally impacting technical content. We had great fun doing that series, and I valued that relationship and our continued friendship after his retirement.

Our friend Bob deserves honor for the good work he did for so long and so well. He’ll be missed here; as well I’m sure in other analog-savvy places.

Walt Jung