Jack Sondermeyer 1939 -2015

[JohnRoberts]

Death is a natural part of life so I won't proclaim some great tragedy in Jack's passing this weekend. He had a suitably long and fruitful life. I do want to note the passing of a "great" audio engineer who's work touched millions of people, whether they know it or not. Most do not. 

I worked with him as a co-worker  for 15 years and learned a ton from him. He was a brilliant engineer with many accomplishments. Perhaps his most iconic product design was the CS800. Modest by todays standards but back when it was developed 800W was a lot of power and $1/W was a bargain price. Of course times have changed since those days but back in the '90's I did a marketing promotion where I counted the number of CS800 amps sold and came up with more than 500,000 amps sold. So my claim that millions have been touched by his designs is surely conservative. Millions have actually lifted his designs.  ;D ;D

Jack has more than 30 patents, so he was more than a one trick pony, and I am proud to be a co-inventor on one of those patents (the angled heat-sink patent). It was the result of a brainstorming session in Jack's office over a new amp packaging approach. At the time I was already working in marketing, but Jack was meeting with his head packaging guy and I walked into his office to chew the fat,. We made a little magic that day.  8)  I like to joke "you can take the boy out of engineering, but you can't take the engineer out of the boy".  8)

But back to Jack... He was a solid tube guy.. the brains behind AMR's  well regarded tube preamp (VMP)  and limiter (VCL). He was an early transistor expert hired away from RCA by Hartley to get his Peavey amps to stop blowing up, and Jack succeeded famously. 

RIP Jack, you are gone but not forgotten. 

JR

 

[emrr]

Thanks John, rest in peace Jack. 

 

[ruairioflaherty]

A nice tribute to a friend and mentor John. 

CS800 were truly everywhere, I used many back in my live sound days in Ireland.  It's interesting to me how we fetishize certain pieces of gear that sold in the hundreds whereas a true smash hit like the CS800 goes unnoticed in most people's eyes.

His knowledge lives on in your sharing here.

 

[Spiritworks]

Sorry for the loss of your friend, John. You gave him a nice eulogy here.

 

[PRR]

Thanks for sharing.

> $1/W was a bargain price

$1/Watt was often touched in transistor amps. The Phase Linear 400 was 2*201 Watts sold for $399. While solid in home use, we killed a lot of these in big venues. Crown DC-300 was solid in any abuse, but was twice the $/W. The bigest McIntosh transistor amp was solid, but also solid money. People forget how unreliable transistor amps used to be in heavy overdrive into loudspeakers and bad cable shorts. We still touch or exceed $1/W today (inflation is funny) but most large power amps today are unkillable.

> Millions have actually lifted his designs

I missed that pleasure. (I was still running tubes, then moved to fixed work.) However I am well aware that after one bad year, the Peavey amps never failed. Always in-stock at the pawn shop with 30-day money-back assurance.

> Jack has more than 30 patents

Patents by Inventor Jack C. Sondermeyer
http://patents.justia.com/inventor/jack-c-sondermeyer

The first, 6515859, slanty sink, has a guy named John.

That list is obviously incomplete; elsewhere I found US3417339 "Push-pull transistor amplifiers with transformer coupled driver" 1968, assigned to RCA, which at a glance looks like Delco's 1958 design for a 100W amp.... ah, he has bootstrapped the driver. Claim: reduces voltage breakdown on driver transistor.

Somebody needs to be writing these people up.
https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Professional_sound_production/Article_requests
Jack Sondermeyer has no WikiPedia page, but neither do HH Scott, Richard S. Burwen, Bob Cavin, Don and Carolyn Davis, Marantz and McIntosh, on and on.....

 

[emrr]

Somebody needs to be writing these people up.
https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Professional_sound_production/Article_requests
Jack Sondermeyer has no WikiPedia page, but neither do HH Scott, Richard S. Burwen, Bob Cavin, Don and Carolyn Davis, Marantz and McIntosh, on and on.....

Yes!  Before it gets away!

 

[JohnRoberts]

Thanks for sharing.

> $1/W was a bargain price

$1/Watt was often touched in transistor amps. The Phase Linear 400 was 2*201 Watts sold for $399. While solid in home use, we killed a lot of these in big venues. Crown DC-300 was solid in any abuse, but was twice the $/W. The bigest McIntosh transistor amp was solid, but also solid money. People forget how unreliable transistor amps used to be in heavy overdrive into loudspeakers and bad cable shorts. We still touch or exceed $1/W today (inflation is funny) but most large power amps today are unkillable.

The Phase Linear amps were popular for the power/price but would blow up if you looked at them side ways.  When I designed my DIY amp back in the early '70s I recall looking at the transistor protection circuit from the Phase Linear and and thinking to myself that wouldn't protect anything. I tweaked the values accordingly for my amp that never blew up.  The DC300 had a good reputation for robustness with the bad habit of passing DC that could be damaging to speakers (Crown didn't sell speakers so not their problem).  The dollar per watt was a hard rule for engineering the successive generations of CS800. It was interesting to see how the designs evolved to get smaller, lighter, and better, while holding the iconic price point despite general inflation and increasing labor costs. A lot of subtle but very good engineering involved.   

> Millions have actually lifted his designs

An unintentional word play... I meant literally lifted products he designed, while his also iconic DDT clip limiting was also widely copied despite being patented. While that patent has long since expired.  (Unfortunately in my experience patents do not always prevent copies).

I missed that pleasure. (I was still running tubes, then moved to fixed work.) However I am well aware that after one bad year, the Peavey amps never failed. Always in-stock at the pawn shop with 30-day money-back assurance.

The CS amps and Peavey PA gear in general were very popular in rental programs because they were indeed hard to kill, and designed to deliver good results to inexperienced operators. Unfortunately the association with inexperienced operators defined the brand identity, but there was money to be made servicing that segment.

> Jack has more than 30 patents

Patents by Inventor Jack C. Sondermeyer
http://patents.justia.com/inventor/jack-c-sondermeyer

The first, 6515859, slanty sink, has a guy named John.

8)

That list is obviously incomplete; elsewhere I found US3417339 "Push-pull transistor amplifiers with transformer coupled driver" 1968, assigned to RCA, which at a glance looks like Delco's 1958 design for a 100W amp.... ah, he has bootstrapped the driver. Claim: reduces voltage breakdown on driver transistor.

Jack was a smart transistor guy... I think he wrote part or all of the RCA design manual while working there. That's how Hartley found him...

Somebody needs to be writing these people up.
https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Professional_sound_production/Article_requests
Jack Sondermeyer has no WikiPedia page, but neither do HH Scott, Richard S. Burwen, Bob Cavin, Don and Carolyn Davis, Marantz and McIntosh, on and on.....

Yup.. I recall my disappointment near the end of Rudy Bozak's life when I tried to get an audio magazine editor to interview him. After he sold his business we remained friends but he was not in good health, and despite one editor expressing interest he died before I could make it happen.

Jack's legacy is the many products he designed, and the young engineers he mentored who carry on his brand of audio design. Jack shows up in the index of the Peavey Revolution (an informal history) 11 times, so there is some written record.

I was already a senior engineer by the time I joined Peavey to lead the recording products division so never worked directly for Jack while we co-operated on several products. My input on the AMR tube products done by Jack's group was limited to features and broad strokes advice (I am not a tube guy). On the preamp I suggested that the simple tone controls be limited in amount of boost/cut so they could not be adjusted to make bad sound. I also suggested that the gain control go up to 11. For the Tube limiter Jack's first inclination was to use tube transconductance as the gain element. Instead I steered the design toward opto-LDR for gain reduction function but left the circuit details to Jack to figure out. Both of those designs were actually done by junior engineers in Jack's group under Jack's direction. 
-----
Jack and I used to lead a class together during the dealer seminars where we would explain new technology and product applications. I used to joke when introducing Jack that he had forgotten more about power amp design than I will ever know,  ;D ;D ;D but I was only half kidding. He was a wonderful resource and I wasn't shy about picking his brain whenever I had questions about power amp design.

JR

PS: There are others better qualified to document Jack's personal history, he is just a friend and work associate who is warmly remembered.

 

[lassoharp]

Sorry to hear of his passing.  Thanks for sharing.

 

[Rochey]

Lovely Eulogy John,

I can only hope that some day, in the far out (very far out) future, someone writes something as kind for me.

$1/W is pretty darn impressive.

/R

 

[JohnRoberts]

$1/W "was" impressive back decades ago when a CS800 was a powerful amp... modern technology has since eclipsed all that.

JR

 

[PRR]

Just found this.

Designing Silicon-Transistor Hi-Fi Amplifiers
by R. D. Gold and J. C. Sondermeyer
RCA Electronic Components & Devices

Electronics World, 1966, Sept Oct and Nov

All three parts extracted and stuck together:

Sondermeyer-EW-1966.pdf
5.3MB PDF file
https://pdf.yt/d/51PM6w1n7kJHzRJC

Note: no differential-pair inputs, no practical complementary outputs, no current-source loading (bootstrap not the same), protection slim to none, driver transformer not obsolete.

The world became very different the next year: Crown DC-300.