Great timing.
nakdoc
the Cave Research Foundation's 50th annual meeting. What great timing
to have a group celebrating the Plasmatronic speaker. I will certainly
let them know about the group, but I would also like to ask him any
questions you all might have.
John Mayberry
I would love to read about the inspiration, the history, the trials and
tribulations, the owners (eclectic I suspect), and so much else. I suppose
the very first question I'd ask about is the rock!
Most importantly, I've love for him to join. I started a Lecson Audio
group two months ago, and it's likely to be similar in format.
http://groups.google.com/group/lecson-audio
Thanks,
John Mayberry
www.emmaco.com
626 799 9993
nak...@bellsouth.net
Enclosed is a picture of Alan for posting on your site. It is circa 1966.
Location is above Crystal Cave in Mammoth Cave National Park. The brass
object that looks out of place is the standard carbide light we use in our
cave trips. Alan is inventing a low frequency ground penetrating radio for
use in caves. At this point he is viewing tapes of shock noises transmitted
by conduction through rock, recorded on the Nagra you see in the background.
You will also note a Dyna MkIII in the stack of equipment. This acoustic
radio failed, but he later succeeded with a 1kHz pulsed radio that could
penetrate 150 feet of rock.
I was 13 at this time and was fascinated with all the science he
brought to bear. What is wonderful is that he explained the principles of
his experiments to me, and they made sense!
Tom Brucker csm
Hi Tech Service
2934 Nolensville Rd.
Nashville, TN 37211
615-331-9241
hit...@bellsouth.net
John Mayberry
You need to upload it to the Files Section. Click on Upload once you're in
there...
Looking forward,
John
P.S. I used some modified Dyna Mk IIIs to drive Quads for years...
nakdoc
This picture is copyrighted by the Cave Research Foundation, and used
with permission on this site only.
John Mayberry
-----Original Message-----
From: hill-plas...@googlegroups.com
[mailto:hill-plas...@googlegroups.com] On Behalf Of nakdoc
Sent: Tuesday, October 09, 2007 2:28 PM
To: Hill Plasmatronics
John Mayberry
nak...@bellsouth.net
Alan was not in the best of shape. His doctors had discovered last week
that he had been having heart attacks without realizing it. He is excited
about the Group. He says there is another group that claims he is now dead,
a victim of ozone poisioning!
If he doesn't join I'll converse through e mail with him. I believe he
will join, however. Let me know when you have the site looking the way you'd
like it to, and I'll send him the link.
tom
Tom Brucker csm
Hi Tech Service
2934 Nolensville Rd.
Nashville, TN 37211
615-331-9241
hit...@bellsouth.net
-----Original Message-----
From: hill-plas...@googlegroups.com
[mailto:hill-plas...@googlegroups.com]On Behalf Of John Mayberry
Sent: Friday, October 05, 2007 5:06 PM
To: hill-plas...@googlegroups.com
Subject: RE: Great timing.
John Mayberry
I'd love to have him participate (as in I would really love it!) but
honestly hope the immediate focus on him getting better.
Thanks very much!
John Mayberry
Didn't get the attachment!
Anxious to see the picture,
John
John Mayberry
last year working on two other Google Groups- one for the old English Gale
audio equipment, the other for the old Lecson group. Both have 30-40
members and are fairly active.
We've been able to capture the history of the company, all of the products,
the manuals, and most importantly involve some of the original principals of
each company. Each group tends to develop its specialists, one for
repairs, one for what's currently being sold, one with a historical bent,
etc. Typically there are 1,000 to 2,000 messages per year, most of which
have meaningful content. Friendships have developed, and spare parts have
been shared all over the world.
When we started, no one knew what happened to Ira Gale. A few months ago I
tracked down Ira's younger brother Bruce, working as a psychiatrist about 20
miles from where we live. I called him, and he was stunned that someone
cared about Ira's legacy. He has since joined the group.
Bruce ended up joining and filling in the blanks. Sadly Ira had passed away
during the 1990's, generally feeling unappreciated by the audio community.
Bruce showed his father our website, who was fascinated to see the family
legacy continue in such a vein. Their father died last week at age 94,
still listening to music daily.
The Lecson website in some sense is even more interesting. The legendary
Stan Curtis joined around a year ago, who was chief engineer all those years
ago. Stan ended up as Managing Director for Quad, Mission, Wharfedale, and
a number of other companies along the way and has filled in all the concept,
prototype, and history of the company- including pictures. I'd love to see
something similar for Plasmatronics.
On a personal note, back in the 1970's I was a technician working for Neil
Sinclair's Absolute Audio down in Santa Ana, California, a Plasmatronic
dealer. One of my first tasks was to get a set running for a Catholic
priest down in Laguna Nigel. I think I met the basic qualification- being
able to lift a helium tank by myself and telephone the factory for help!
I was so impressed with the speakers I ended up buying a used pair from a
guy in Sacramento (being a poor college kid at the time) which I still have
today. During the '80's I send the plasma units back to the factory, which
Tony fixed up.
We ended up having three kids and thought it best to leave in the "off"
position. They're grown up now, and my goal is to get the speakers running
again this summer.
-----Original Message-----
From: hill-plas...@googlegroups.com
[mailto:hill-plas...@googlegroups.com] On Behalf Of nakdoc
Sent: Friday, October 05, 2007 3:47 PM
To: Hill Plasmatronics
Subject: Great timing.
michaela...@aol.com
I do not have a set of Hill Plasmatronics yet.....but I do have some neat stuff:
Infinity IRS Series III - Triamped with Krell's
also Apogee Diva's bi-Amped with DAX
and Yamaha NS-1000M's
Goldmund Reference Turntable (T4F Arm) - Koetsu Urishi Cartridge
Jeff Rowland Consumate Balanced Phono Preamp
Sequerra and Day Sequerra Tuners (with Panalizers)
Krell KBX Crossovers
Wadia 861 CD Player
Marantz 615, 620 & 630 CD recorders
California Audio Labs CL-15 Balanced CD Players
Wadia, Sony and Yamaha Analog to Digital Converters
etc.
Come visit, listen and go spelunking.
Michael Marks
(931) 561-1668
John Mayberry
The green monster is in the building…
John Mayberry
This weekend I finally got around to using a pink noise source, FFT, and
electronic crossover to adjust the Hills. I went triamped, switched the
midbass polarity so they're all the same, and really am enjoying the
results.
Truly enjoyed your story.
Thanks,
John
-----Original Message-----
From: hill-plas...@googlegroups.com
[mailto:hill-plas...@googlegroups.com] On Behalf Of
You received this message because you are subscribed to the Google Groups
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analogdesigner
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John Mayberry
A Yamaha SP2060. Basically it does exactly what you want once you figure out how to connect it to a PC which was mind numbingly aggravating. Fortunately the Yamaha national distributor is now far away. It takes 3 minutes each time you rewrite the configuration, which gets a little old but still it works well. Samples at 96k and I figured my 54 year old ears aren’t really performing that well above 48 kHz anyway.
Picked up a used one for around $400.
Also had to completely bypass the internal passive crossover.
Bought an Emotiva 5 channel 200 Watt amp… got rid of the old electronics and got XLR connections from the crossover to the LF drivers to boot. Still RCA levels into the Plasma crossover.
Started out with LR 24 dB/octave in triamped mode. The midbass driver needed some serious padding.
If you’re interested, I’ll write down the configuration.
I bought a pair of tanks twenty years ago. Just exchanged one empty for one full at a welding supply house a few weeks back which cost $110 here in Southern California. Didn’t seem to care if the hydro was out of date.
I am looking for a tech that can work on the crossover. Need to replace the frayed (sp?) power cord, get one group of the display working again, and retube it… I just don’t seem to have the time to do some of this stuff anymore…
Thanks,
John
From: hill-plas...@googlegroups.com [mailto:hill-plas...@googlegroups.com] On Behalf Of analogdesigner
Sent: Monday, February 18, 2013 5:14 PM
To: hill-plas...@googlegroups.com
Subject: Re: Great timing.
Hi John,
For more options, visit this group at
http://groups.google.com/group/hill-plasmatronics?hl=en
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Jay Philippbar
John,
Yes, finding time has been a serious problem for me as I seem to have no free time anymore. Thanks for the update.
Jay
MIchael Marks
( in stock ) for use with the Hill Plasmatronics and other high end
speakers.
Yamaha D2040 - Digital Stereo 2, 3 & 4 way
Peavey PC4XL. PC4XLa, CEX4XL and CEX4La - Digital - Stereo 2 Way or
Mono 2, 3 & 4 Way
Bryston 10B-LR - Analog LR - Stereo 2 way or Mono 3 Way - No IC's
Krell KBX - Analog - Stereo 2 Way - No IC's
My own brand that I make myself ( 24 dB/Octave ) - Linquest Riley all
Discrete Transistors - No IC's. - Stereo 2 Way
Glad to help anyone out that might be interested.
Michael Marks
(931) 561-1668 Voice and Text
John Mayberry
Do you have a discrete LR4 three-way?
I'm thinking it might be a nice replacement for the SP2060 once dialed in...
Michael S. Rovner
I just wanted to chime in and make some suggestions.
I have been building and designing high end speakers for over 30 years. And have built many systems with electronic crossovers.
The route of using a crossover and individual amps for each driver can result in the highest performance possible.
But only when you understand what each driver needs to correct it's irregular frequency response and you use 6db per octave slope crossovers.
First you will want to measure each driver and then use eq to make it as flat as possible. Use parametric eq's to deal with resonances and peaks from the speakers and room issues.
Higher slope filters are fine for PA use where you need the highest power outputs, but it does not belong in any high end effort. Higher slope filters ring with transients, so although it may measure flat with sine wave sweeps, while playing music it creates unnatural frequency and phase issues.
24db/octive filters are only phase summed at the crossover region and have a 360 degree phase warp overall. You will sacrifice imaging and natural harmonic overtones due to severe phase shifts.
Once you have each driver eq'd - turn one driver on, add the next driver and then using time delay or phase adjustments (don't forget to try inverting phase to see which is really correct) , get the two drivers to be in phase by listening for the best blending use pink noise to do this.
Once you have the full system going, use parametric eq's to dial in spots that still need tweaking.
Hope this helps -
Michael Rovner
MSR Systems, Inc.
John Mayberry
Unfortunately when I lost my TEF Machine I lost my ability to do Nyquist
plots.
That was a wonderful way maximize system performance.
Anything "not right" deviates from the perfect circle.
An add might be "low" Q equalization generally works better to your
comments.
Sent: Tuesday, February 19, 2013 9:44 AM
To: hill-plas...@googlegroups.com
tom brucker
Tom Brucker
Hi Tech Service
2934 Nolensville
Pk.
Nashville, TN 37211
615-331-9241
hit...@BIRCH.net
Michael
I am another Michael and I would like to chime in.
I kinda disagree with some of what is said below.
I myself have been building and designing speakers for over 45 years.
I find that most speakers are actually quite LINEAR in their useful range.
I find minimal anomalies from uniform liner output over their INTENDED USEFUL RANGE.
Especially with good speakers.
(Of course there are always exceptions).
I myself prefer 24 dB/Octave Linguest - Riley crossovers ( yes constant phase - with one cycle of phase delay between the drivers ).
I find with audio signal, which is for the most part quite repetitive, the one cycle constant phase delay results in an " IN PHASE" system, with superb imaging.
I have never had an imaging problem, left to right or front to back.
With a 6 dB/Octave set up there is always a 90 degree phase variation between some of the drivers that you can never get rid of.
Also there is great overlap of the output between drivers when there are many frequencies that you have 2 adjacent drivers with different characteristics contributing to the speakers overall output signal. This I have found muddies the water much more than the steep slope of a Linquest - Riley set up.
So what I am saying is the world is nothing but compromises.
You make your decision as to which compromise you prefer, then you design the system around this compromise, to perform as perfectly as possible, so it works the best.
I guess some of us are 6 dB/Octave guys, and others are 24 dB/Octave L-R guys.
( Some of us might even want to use 18 dB/Octave on the woofer and 6 dB/Octave on the MR/HF side - a very common commercial compromise - which also works well ).
( Still others might be 12 dB/Octave people as well.)
I have always designed my own 24 dB/Octave LR crossovers, although there are some good ANALOG Commercial ones out there.
I like the Krell KBX and the BRYSTON 10B-LR ( and mine ).
I have extra Krell KBX and Bryston 10B-LR crossovers if any one is interested, or I can make you one of mine.
So I hear you, but I do not necessarily agree with you.
I love the results of using 24 dB/Octave LR Crossovers for my home stereo systems and would match the performance of mine with any of you out there.
Anyone who wants to is welcome to come visit an see / hear what I have achieved.
Michael Marks
Bowling Green, KY
(931) 561-1668