Subject: Re: What did Fourier say?
Date: Tue, 1 Sep 1998 15:38:02 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/01 at 15:38:01, RALPH@SMTP {ralph@atma-sphere.com} wrote:
>On 1998/09/01 at 15:06:38, HARPER@SMTP {harper@q3-consulting.com} wrote:
>
>I rather think that milk bottle production lines hadn't been invented
>when Fourier invented his transform. In any case what it says is
>very simply that any repeating waveform can be represented as the
>sum of harmonically-related sine waves, of the form:
>
> sigma ai sin(omega it + pi)
>
>For example (and pertinently) a square wave is the sum of gradually
>decreasing odd harmonics (I forget the actual coefficients). Given
>a set of samples, it is straightforward to do the transform. Spice
>and my software scope both do it if you ask them.
>
Can you reassemble them afterwards? Most of the systems I've seen can't.
>[snip]
>Now, if orthodoxy is to be believed, the human ear can't detect those
>harmonics either, and so the fact that they are suppressed is irrelevant.
>There are people who claim otherwise. They may be right, too. Who
>knows. I guess you could test it by computer-generating two waveforms,
>one a true 10kHz square wave, and the other stopping at the 2nd
>harmonic, and see if people can tell the difference (given a high
>rate sound card, obviously).
>
>What IS clear is that 44kHz sampling introduces substantial phase
>distortion at the higher audio frequencies, and that this may well
>have an effect on things like imaging.
>
>
I found that changes in the EQ rolled in @50KHz have a substantial sonic
effect. Thus I had to spec the RIAA out to 100KHz (even though the RIAA
don't themselves). The test for digital systems that seems to tell the story
is to record and play back from an analog sweep generator, a sine sweep from
20KHz to 20 Hz. Never been able to get rid of the birdies (do the sweep slow
so they are easy to hear). In any event, after nearly twenty years, digital
so far has not delivered on the promise. So analog remains the reference.
-Ralph
- You'll be hearing more from us! -
Subject: Re: What did Fourier say?
Date: Tue, 1 Sep 1998 16:31:37 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/01 at 16:31:36, BLAYER@SMTP {blayer@uswest.net} wrote:
Hi John,
Thanks for pointing out to me that I was in fact trying to comment on
Nyquist, not Fourier.
What's a brain?
Bill
Subject: Re: Digital again
Date: Tue, 1 Sep 1998 19:58:05 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/01 at 19:58:04, BBB@SMTP {bbb@castle.net} wrote:
Atma-Sphere@ManicReader.com wrote:
> On 1998/08/31 at 19:28:39, TRE@SMTP {tre@ncplus.com} wrote:
>
> Atma-Sphere@ManicReader.com wrote:
> >
> > On 1998/08/31 at 16:31:07, BBB@SMTP {bbb@castle.net} wrote:
> >
> > Hi Bob,
> > I have to disagree what you have been said. It has been mathematically
> > proven that the minimum sampling frequency required in order to
> > "perfectly" re-construct the original time domain signal is twice that
> > of the target signal. I just do not see why people still have doubt
> > about that, just like someone still doubt 1+1=2.
> >
> You are assuming that the 20kc is always a sine wave.
> In the second edition of the audiocyclopedia when talking about the
> freq.
Am I assuming 20kc?? sine wave? happy guessing!
> responce needed to reproduce 20-20kc Tremaine says because of sum and
> difference tones a responce up to 200kc is needed.
>
> The problem here is that two assumptions went wrong ( similar to some
> > soc. ideas ::)):
> > 1. the ear only can hear upto to 20KHz. this is wrong, wrong wrong!!
>
> You are Right Right Right. In fact the deaf can "hear" 30-35kc through
> the bones in there heads.
Maybe old / deaf people do that. I listen to music by ears which still function normally.
> > 2. All the DA/AD conversion has negl. residue sum error. It is not true
> > for any commercial product. ( When I was working for NASA, I had chance
> > to experience some customized cost no objective convertor/filters, they
> > are so true to the original signal...) Plus, the time sequence reference
> > is not perfect for most commercial digital gears which distorts the
> > sampling space at first place.
> >
> > 200KHz sampling frequency sure helps, but how about my ear can feel
> > 150Khz? And higher sampling freq. requires more accurate time reference,
> > Uhm - commercially, may not so!
> >
> > I have to say Best LP today is better than the best 16bits/44Hz CD. But
> > LP is not perfect neither. I know the sound of violin from any LPs are
> > not true for my own experience, I can bet on a spectrum analysis on
> > this. We have to strive for the better for our own sake, let's promote
> > better affortable digital sources and ditigal playback system! Do not be
> > so negative! Looking forward instead of backward! I know, I know, I
> > sound like JFK now.
> >
> > I want an "All Mozart" ticket right now. "You pay for what you get"
> >
> > Ben Yang
> >
> > Atma-Sphere@ManicReader.com wrote:
> >
> > > On 1998/08/31 at 07:51:20, JOKKER@SMTP {jokker@motorsims.com} wrote:
> > >
> > > I had a most pleasant conversation with the leader (Ralph) last week regarding digital audio. We had to have spoken for a good 30+ minutes on this subject. A couple of things Ralph said struck home.
> > >
> > > Frequency- Ralph made the point digital is much more promising when it meets the "instrument" spec which is 10X the highest audible frequency. I may be slightly misquoting here. A friend of mine who's an EE backed this up and said something to the effect you can't accurately sample a square wave unless you have 10X the samples of the frequency. He somewhat lost me at this point but the jest of both conversations are 44khz is entirely inadequate unless all the sound energy is in the lower octav
> > >
> > > By extension then, 200khz would be the appropriate standard for full frequency audio produced digitally. This implies that two of the newer proposed suggestions, namely SACD (200khz) and DVD-Audio (192khz) have a chance to be a real improvement. Note that this is not 96/24 DVD-video bases audio. I've been playing around with 96/24 and its a real improvement over CD. I went back and listened to the pieces that sounded great and in all cases contained a surplus of energy in the lower and midrang
> > >
> > > Other issues were storage. CD's, DVD's and other digital disk storage media do not have long shelf lives. I have come across this with Laserdisc audio with disks delaminating. The glues that bind do not bind forever. Vinyl can last a long time as we all know. Probably not forever but longer than CD.
> > >
> > > I do know that digital can be exact as long as we don't use loosy compression techniques. The new Meridan compression technology has real promise here. I am still concerned with the accuracy of the D/A conversion process but maybe time can solve this issue as did phono cartridge makers for vinyl. Clocking errors can be the final frontier, but buffering and reclocking can largely resolve the jitter problem.
> > >
> > > It was a enjoyable conversation and I'm not retiring vinyl for now.
> > >
> > > Bob
> > >
> > > ----------------[ Uuencoded File Attachment: NONAME01.HTML ]----------------
> > >
> > > I had a most pleasant conversation with the leader (Ralph) last week
> > > regarding digital audio. We had to have spoken for a good 30+ minutes
> > > on this subject. A couple of things Ralph said struck home. Frequency-
> > > Ralph made the point digital is much more promising when it meets the
> > > "instrument" spec which is 10X the highest audible frequency. I may be
> > > slightly misquoting here. A friend of mine who's an EE backed this up
> > > and said something to the effect you can't accurately sample a square
> > > wave unless you have 10X the samples of the frequency. He somewhat
> > > lost me at this point but the jest of both conversations are 44khz is
> > > entirely inadequate unless all the sound energy is in the lower
> > > octaves. Ralph also totally discredited the methodology that the 44khz
> > > standard was set under. By extension then, 200khz would be the
> > > appropriate standard for full frequency audio produced digitally. This
> > > implies that two of the newer proposed suggestions, namely SACD
> > > (200khz) and DVD-Audio (192khz) have a chance to be a real
> > > improvement. Note that this is not 96/24 DVD-video bases audio. I've
> > > been playing around with 96/24 and its a real improvement over CD. I
> > > went back and listened to the pieces that sounded great and in all
> > > cases contained a surplus of energy in the lower and midrange areas. I
> > > would guess only the harmonics reached way up there. Other issues were
> > > storage. CD's, DVD's and other digital disk storage media do not have
> > > long shelf lives. I have come across this with Laserdisc audio with
> > > disks delaminating. The glues that bind do not bind forever. Vinyl can
> > > last a long time as we all know. Probably not forever but longer than
> > > CD. I do know that digital can be exact as long as we don't use loosy
> > > compression techniques. The new Meridan compression technology has
> > > real promise here. I am still concerned with the accuracy of the D/A
> > > conversion process but maybe time can solve this issue as did phono
> > > cartridge makers for vinyl. Clocking errors can be the final frontier,
> > > but buffering and reclocking can largely resolve the jitter
> > > problem. It was a enjoyable conversation and I'm not retiring vinyl
> > > for now. Bob
Subject: How about some more controversy?
Date: Tue, 1 Sep 1998 20:36:33 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/01 at 20:36:31, WB6RHQ@SMTP {wb6rhq@loop.com} wrote:
Hello ASOG members,
All of this controversy about analog vs. digital, sampling rates, Mr.
Fourier, vinyl, and even polycarbonate has been a lot of fun. I hope it
continues. We've all learned a great deal. This is the reason the ASOG
exists.
Speaking of controversy, I'd like to add even more. What I'm about to
discuss is not a factory recommended modification. This is strictly an
"enter at your own risk" idea. How many of you have heard about the
6336? The 6336 is a JAN (Joint Army/Navy) military tube. It was built
to the strictest standards and is extremely rugged. Its construction
makes the 6C33 look a bit anemic. It is a dual triode sporting a
zirconium coated graphite plate. Its plate is supported by ceramic
insulators and its mica insulators look like they're four times at thick
as those in a 6AS7. Plate dissipation is 30 watts, compared to the 13
watts of the 6AS7. The envelope is "hard glass" and considerably
thicker than the 6AS7. It has a mu of 2.7 and listed a medium mu tube.
Be sure your 150 ohm grid stop resistors are installed. Installing
anything past six 6336s in an MA-1 will cause serious oscillation
without the grid stoppers! The 6336 is a battleship in the world of
series regulator tubes. So what, you say? Why am going into such
detail? The 6336 has an octal base with the same pin out as the 6AS7.
Looking at the 6336 curves, its clear that each triode is essentially
equivalent to two 6AS7 triodes. The 6336 filament requires twice as
much current as the 6AS7. Some of you probably already know where I'm
going with this discussion, I'll bet.
Tangent: The 6336 has a bit larger cousin called the 7241. Its much
like the 6336, except that it has three triodes in the same envelope,
requires three time the filament current and needs what's known as a
"jumbo 7 pin socket". There's no way you can plug it into a 6AS7
socket. All three of its plate are tied to a common pin.
So, back to the controversy. My MA-1 (clone) has two rows of 6AS7s.
Each row has seven octal sockets. If I unplug the 6AS7s, I can replace
them with four 6336s per row. That means I need to install a 6336 in
every other socket. This is equivalent to 16 6AS7s. The filament and
output supplies have enough reserve to handle what equates to two extra
6AS7s. If I was using 6AS7s, I would set the bias for 60 ma average
plate current. With the 6336, I set the average plate current to 120
ma. If you have an M-60, you could probably install four 6336s for
equivalent power, or perhaps six 6336s for a bit more power. The
filament transformer should do fine with the extra load, but you may
want to beef up the output supply filtering by installing more
capacitance in parallel. This is especially true if you want to install
six tubes.
Now why would anybody do something like this? Have I lost my mind
again? You decide. Here's my thoughts. I think the 6336 looks really
cool compared to the 6AS7. OK, I mean aesthetically pleasing. The huge
ribbon filaments are much brighter and exhibit a fine glow. I'm the
first to admit one of the biggest reasons I'm into tubes is for the
glow. The 6336 glow is much better. There are probably better
reasons. More power is one. I know I don't have to explain this one.
Examining the curves carefully, its easy to see the 6336 is more linear
than the 6AS7. I think the 6336 has better bass and a more detailed
midrange. Reliability should far exceed the 6AS7.
The 6336 isn't for everyone. Until recently, they were very hard to
find under $50 each. For reasons I can't explain, they've just started
showing up at ham radio swapmeets. A month ago, I bought five for $5
each. Last Saturday, I bought 31 for $2 each. Fair Radio sales has
them available for $30 (NOS) each. I'm way too cheap for that kind of
price. Having talked to a friend of mine, who works at Vandenburg AFB,
we can probably expect to see a lot more very soon. Most people don't
know what they are, so prices are bound to be very good. I had no
desire to tell the guy at the swapmeet what he had. If you frequent
swapmeets or surplus houses, look for something that is obviously
military. The envelope looks much like a 6550 or a KT-88, from a
distance. I have seen the 6336 under the Cetron, Raytheon and TungSol
brands.
I hope this gives some of you something to think about. I'm sure having
a lot of fun with the 6336!
Best regards,
mark gilmore
Subject: Re: How about some more controversy?
Date: Tue, 1 Sep 1998 22:08:39 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/01 at 22:08:36, BLAYER@SMTP {blayer@uswest.net} wrote:
Hi All,
>Speaking of controversy, I'd like to add even more. What I'm about to
>discuss is not a factory recommended modification. This is strictly an
>"enter at your own risk" idea. How many of you have heard about the
>6336?
I'd watch the 6336 on stock ASMS amps. Xfmr ratings aside, filament wiring
may not be up to the current draw of the 6336 heaters. No big deal to beef
this up though.
The xfmrs in the MA-1 and M-60 are capable of 38 amps continuous, with
nominal temp rise.
Have you encountered any issues regarding section matching in the 6336?
This was one major complaint I have heard may times over the course of
several years. When imbalanced, they tend to run away and eventually
arc-over...
My fear is of losing these pricey tubes, not running them. Still, the
robust sound is not to be ignored.
Bill Layer
St.Paul, Minnesota USA
"Quantity has a quality all of it's own"
Subject: Re: How about some more controversy?
Date: Wed, 2 Sep 1998 0:22:44 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/02 at 00:22:42, HARPER@SMTP {harper@q3-consulting.com} wrote:
Bill (and ASOG),
>
>The xfmrs in the MA-1 and M-60 are capable of 38 amps continuous, with
>nominal temp rise.
>
Speaking of xfmrs, do you know the rating of the driver stage units
in the M60? I am getting keen to do the driver stage B+/plate
current upgrade, for which I will have to replace them with
something that can do 500-0-500V.
Thanks,
John
Subject: RE: How about some more controversy?
Date: Wed, 2 Sep 1998 7:07:12 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/02 at 07:07:11, MARK.GIL@SMTP {mark.gilmore@smtek.com} wrote:
Good reverend Dr. Bill,
>I'd watch the 6336 on stock ASMS amps. Xfmr ratings aside, filament wiring
>may not be up to the current draw of the 6336 heaters. No big deal to beef
>this up though.
I've not seen any measurable additional voltage drop due to wiring.
>The xfmrs in the MA-1 and M-60 are capable of 38 amps continuous, with
>nominal temp rise.
Agreed, this is 2 amps over their continuous rating. Using half the 6336s
will result in what should be the same filament current. It's only when you
try to push things, like I'm always doing, when this issue might rear its
ugly head. There are actually two different versions of the 6336. One is
simply labeled 6336 and the other is the 6336-A. The A version is supposed
to want 4.75 amps of filament current, instead of 5 amps. The A version is
otherwise identical, except for about a 20% higher Gm. In our application,
this is of no consequence. I was curious about this .25 amp difference, so
I measured several samples of both on the bench, with my big clip leads
doing the honors. All of my samples wanted 4.75 amps, whether they were the
A version or not. So, this means that eight 6336s really want 38 amps. Are
we good, or what?
>Have you encountered any issues regarding section matching in the 6336?
>This was one major complaint I have heard may times over the course of
>several years. When imbalanced, they tend to run away and eventually
>arc-over...
The 6336 does not come with the warning, "Not intended for fixed bias
service". I always hated that piece of fine print in the tube manuals.
That makes me feel a lot better already. I have not had any fireworks from
a 6336 arc-over so far. I'm glad to report that the 6336s are much better
in terms of matching as well. I have 6AS7s that have sections so different
that one section will pull half the current, given the same grid bias
voltage. The worst 6336 I've seen is still within 10%. Good point here,
Bill. If arc-over does occur, the 6336 will momentarily put twice the
current through your woofers that a 6AS7. This may, or may not be a
problem. Only you know your woofers and their fusing and capabilities. The
6336 does have the same kind of internal fuse elements, on its cathode,
just like the 6AS7. All of my 6336s were good, except for one that had a
heater/cathode short. I put it on the bench to see how the internal fuse
would blow. As I hoped, it blew just like a 6AS7. When in doubt, add a
fuse for each triode. By the way, I had to do 500 ma of plate current, for
about 10 minutes, before the internal fuse went. The power supply, on my
bench, is only good for a half amp. This tube is rugged. Try that one with
a 6AS7
>My fear is of losing these pricey tubes, not running them. Still, the
>robust sound is not to be ignored.
This is why the surplus market holds so much promise. I've been lucky to
find 6336s for substantially less than the price of premium 6AS7s. Go for
the sound. Did I mention the much improved glow factor?
Best regards,
mark gilmore
Subject: RE: How about some more controversy?
Date: Wed, 2 Sep 1998 7:30:57 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/02 at 07:30:56, B.LAYER@SMTP {b.layer@vikingelectronics.com} wrote:
Hi Marcus Otlieus,
>>I'd watch the 6336 on stock ASMS amps. Xfmr ratings aside, filament wiring
>>may not be up to the current draw of the 6336 heaters. No big deal to beef
>>this up though.
>
>I've not seen any measurable additional voltage drop due to wiring.
Ok, but I'll bet you used something heavier than the 20-22AWG
stranded/tinned wire tht is in the stock amps. My recall is that 22AWG is
rated at 2.7A for a 10C rise... Does anyone have a chart for this?
Bill Layer
Sales Technician
----------------------------------
Viking Electronics, Inc.
Hudson, WI. U.S.A
715.386.8861 (ext. 210)
----------------------------------
"Telecommunications Solutions for the 21st Century"
Subject: Re: How about some more controversy?
Date: Wed, 2 Sep 1998 7:37:55 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/02 at 07:37:54, B.LAYER@SMTP {b.layer@vikingelectronics.com} wrote:
Hi John,
>Speaking of xfmrs, do you know the rating of the driver stage units
>in the M60? I am getting keen to do the driver stage B+/plate
>current upgrade, for which I will have to replace them with
>something that can do 500-0-500V.
I don't recall, but I doubt the whole shebang draws more than 35mA. I would
just do a current measurement on the existing setup. This HV winding is one
very conservatively operated part.
The driver filaments draw just under 3A, including the (2) Mk.II panel
lamps, w 150mA bulbs.
Bill Layer
"Quantity has a Quality all of it's own." -JL
Subject: RE: How about some more controversy?
Date: Wed, 2 Sep 1998 7:49:43 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/02 at 07:49:42, MARK.GIL@SMTP {mark.gilmore@smtek.com} wrote:
>Ok, but I'll bet you used something heavier than the 20-22AWG
>stranded/tinned wire tht is in the stock amps. My recall is that 22AWG is
>rated at 2.7A for a 10C rise... Does anyone have a chart for this?
Dear Billius Maximus,
You're sure right. You know me and my paranoia (anality) too well. I used
#12. I had to be sure. I remember discussing this with Al Sekela when he
was wiring the filament circuits in his MA-1s. Both of us went the way of
brutal overkill.
I can't put my hands on the chart in a hurry. I'll bet it in one of my
reference books at home. I'll bet somebody can get this information well
before I get the chance.
Best regards,
mark
Subject: IEEE SPECTRUM article about tube audio
Date: Wed, 2 Sep 1998 11:42:27 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/02 at 11:42:22, B.LAYER@SMTP {b.layer@vikingelectronics.com} wrote:
>>From ebarbour@svetlana.com Wed Sep 02 12:53:01 1998
>From: Eric Barbour
>Reply-To: "ebarbour@svetlana.com"
>To: "'tubehifi@worldnet.att.net'" ,
> "'b.layer@vikingelectronics.com'"
>Cc: "'TubeGarden@aol.com'" ,
> "\"'\\"Russ Sadd\\" '\" <\"Russ Sadd\""
,
> "'jatwood@one-electron.com'"
>Subject: IEEE SPECTRUM article about tube audio
>Date: Wed, 2 Sep 1998 10:53:23 -0700
>Organization: Svetlana Electron Devices
>X-Mailer: Microsoft Internet E-mail/MAPI - 8.0.0.4211
>
>Would you please let people know that the SPECTRUM
>article about tube audio is now visible on the public area
>of IEEE SPECTRUM's web site? Post it on rec.audio.tubes,
>alt.guitar.amps and sci.electronics.design also.
>
>http://www.spectrum.ieee.org/select/0898/tube.html
>
>The full basic text of the article is there.
>Unfortunately, people will have to buy the printed copy to
>see the distortion tests of tubes vs. transistors--it's not
>listed on the website.
>
>The printed magazine is $24 from
>IEEE Operations Center
>445 Hoes Lane
>PO Box 1331
>Piscataway NJ 08855
>(800) 678-IEEE
>
>Eric Barbour
>Svetlana Electron Devices
>Portola Valley CA USA
>
>
Bill Layer
Sales Technician
----------------------------------
Viking Electronics, Inc.
Hudson, WI. U.S.A
715.386.8861 (ext. 210)
----------------------------------
"Telecommunications Solutions for the 21st Century"
Subject: Re: IEEE SPECTRUM article about tube audio
Date: Wed, 2 Sep 1998 19:22:16 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/02 at 19:22:16, REBANK@SMTP {Rebank@aol.com} wrote:
So, what do those "distortion tests of tubes vs. transistors" show? Has
anyone seen the test data?
Thanks
Ed Bank
In a message dated 98-09-02 14:52:50 EDT, Eric Barbour writes:
<< >Unfortunately, people will have to buy the printed copy to
>see the distortion tests of tubes vs. transistors--it's not
>listed on the website.
>>
Subject: Preamp
Date: Wed, 9 Sep 1998 13:49:50 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/09 at 13:49:47, JOKKER@SMTP {jokker@motorsims.com} wrote:
We'll after grinding on it for a while I'm gonna use the Casablanca for what it was designed for (Video). So I'm going to add a preamp to the setup and run the front channels of the theater out of the aux. on the preamp.
My question is what's the difference between the MP-1 and MP-3. Other than cost other than cost of course!!
Bob
----------------[ Uuencoded File Attachment: NONAME01.HTML ]----------------
We'll after grinding on it for a while I'm gonna use the Casablanca for what
it was designed for (Video). So I'm going to add a preamp to the setup and
run the front channels of the theater out of the aux. on the preamp.
My question is what's the difference between the MP-1 and MP-3. Other than
cost other than cost of course!!
Bob
Subject: Re: Preamp
Date: Sun, 13 Sep 1998 8:08:59 -0700
From: Atma-Sphere@ManicReader.com
Organization: SMTEK
To: Atma-Sphere@ManicReader.com
On 1998/09/13 at 08:08:58, WB6RHQ@SMTP {wb6rhq@loop.com} wrote:
> We'll after grinding on it for a while I'm gonna use the Casablanca
> for what it was designed for (Video). So I'm going to add a preamp to
> the setup and run the front channels of the theater out of the aux. on
> the preamp.
>
> My question is what's the difference between the MP-1 and MP-3. Other
> than cost other than cost of course!!
>
> Bob
Dear Bob,
I'll have to refer you to Ralph or Bill for discussion in great detail.
I think I'm qualified to answer this question based on big differences.
The MP-1 has two chassis, the MP-3 has only one. The MP-3 is also
available as a line stage only, the MP-1 is not. Perhaps this will
inspire others with great knowledge and wisdom to supply more
information.
Best regards,
mark gilmore