keithr wrote:
"Patrick Turner" wrote in message
...
keithr wrote:
"Patrick Turner" wrote in message
...
snip,
I mentioned......
He'll be the second student to have a go to automate my logic flow.
The first one 3 years ago only got as far as calculating turns
and core size for a for a given power and load value.
Time ran out for him.
That is the sort of thing that I do for a living, you get a requirement from
the originator of the project. It may be a comprehensive specification or
just a few words, you check that it makes sense, going back to the
originator if needs be to come to an agreement on something that is suitable
to automate and meets their needs. You then break the task down into steps
each being an independant task which preferably can be easily verified
during the design and coding process, then you code it. You run as many test
as you can to verify and debug the program, then give it back to the
originator to try and destroy.
I looked at your stuff in regard to the push pull case, there doesn't seem
to be any rocket science there, but I am surprised that you don't mention
bifilar winding which we always used to consider the "Proper" way of winding
PP transformer primaries as it assures perfect matching betweem the sides.
Harder to wind I have to admit.
I think you are very wrong about primaries on PP OPT.
First of all, bifiliar windings of any type are a nightamre of
difficulty
for the average diyer or boutique maker.
Second, I have NEVER found any reason to
wind bifilar or trifilar windings anywhere.
Thirdly, if bililar or trifilar windings are ever used, ideally the dc
potentials should be
equal on all windings concerned. But the ac potentials also MUST be
equal
to avoid a high amount of unwanted shunt capacitance between two lots of
say 500 plus turns each
of say 0.4mm dia wire. McIntosh do bililar PP primaries, and the ac
potentials are equal
between one tube's cathode winding and the other's anode winding ans
vice versa.
But the windings have 470Vdc between them, and to prevent shorts and
arcs the wire is grade 3 insulation,
ie, has much thicker enamel coating than grade 2 standard high temp
winding wire.
The bifilar windings give extremely low leakage inductance between the
two
windings but very high shunt C, and thus a low Fo for the set of
windings.
Follow all my ways of winding OPT and you will hace a recipe which is
equal to all the best
makers on the planet.
Fourthly,
The bifilar P windings might give equal winding resistance to each PP
side.
But the normal way its done is to use TWO bobbins, one for each 1/2
primary.
Williamson specified this in 1947, and the complete recipe is in RDH4.
But its a terribly difficult thing to wind just for the sake of
having equal Rw per PP side.
In a typical PP amp with a 5k : 5ohm OPT, winding Rw of the whole P
should be no more than
2.5% of the P load, ie, 125 ohms.
So you could end up with say 55 ohms on one side, and 70 ohms on the
other.
The difference of 25 ohms makes an extremely tiny effect on THD/IMD.
You could place a 100 ohm R in series between one anode and its OPT
connection and
see virtually no easily measurable difference in technical performance.
The amp will sound exactly the same.
I believe my OPT methods are the best easy and effective way to get
Motzart through glassware
without upsetting his hairstyle.
I didn't need some dumb & expensive writer **** to write my website and
draw up all the schematics.
If you cannot and or will not write up your own
true story about your productions then something is very wrong.
In my experience, few designers do a good job of it.
In my view someone who cannot describe their design in a schematic
and a few paragraphs and maybe a few formula has not trained himself
well enough as a communicator.
That may be true (at least in some cases) on something as simple as an audio
amp, but it certainly hs not been true of any number of complex projects
that I have been involved in. Hell, it isn't even true of a service manual
for a TV set.
The designer needs to be able to convey what he wants to those who
hate to think, and just turn up at work to do the least they can to
avoid the sack
and still take home the money.
include the simple methods of matching the transistors.
Far better to design curcuits that do not require component matching
to
within 1%
People wanting to own an ME 850 amp should get a far better deal
than they get now for their $6,000.
Yes like $4000 change.
Peter Stein doesn't care that his product appeals to only a tiny itzt
bitzy
weeny percentage of ppl.
He must think he can "hang out" for the big price.
However, I could also be accused of charging too much per watt.
But the work I do for $6,000 is vastly more than whatever Peter Stein
does.
Any SS amp is child's play to make compared to a serious tube amp.
Why?
Well, for example, consider the last pair of monoblocs with 2 x 845 in
parallel for
60 watts into 4 ohms.
There are two complex PTs, and two complex OPTs, same size, 51mm tongue,
x 72mm stack GOSS.
Thousands of well placed turns with correct insulation and the PT has 48
connections,
OPT has 24 connections. Many taps and windings.
It takes a week to make just one tranny.
That is only because you choose to make your own tranformers. There are a
number of reputable manufacturers who have a range of products that would
meet most requirements, and, if you cost your time, no more expensive
either. It is beyond me why anybody would even want to design/manufacture
their own power transformer, when there is such an array available on the
market. Personally, I'd want to use a torriod anyway and they would be a
******* to wind without the proper machinary
Makers of diyer amps can select a range of PTs for
all the different voltages I place on just ONE PT.
There are no available CHEAP sources of iron-wound components wound to
my standards
anywhere.
I MUST wind all my own everything.
If I bought from say Sowter, or Lundahl or Plitron et all,
the cost would be horrendous, and that's a wage i don't earn.
There is all the custome metal work for 4 chassis, two for two PSUs,
two larger for two amp chassis.
Chasssis work is as complex as you care to make it. If I were making a tube
amp, I think that I'd make a wooden frame for the sides with a polished or
anodised duralumin top plate carrying the circuitry. Looks nice and is dead
easy to make. A SS amp would require nearly as much metal bashing as a tube
model.
The timber has to be 40mm thick and hardwood and made very well to avoid
becoming a mass
of splinters in a minor fall.
Anodized Al is fine, but you have to be extremely careful.
Anything goes for diyer, but for something I sell,
the standard is non combustible materials and all steel.
Its stronger, and cheaper than the timber/Al method, and it takes up
less room.
There are a total of 6 chokes for each channel,
and on each amp chassis there is a hand crafted heatsink to cool
resistors producing over 50 watts of heat without
becoming hot, so I have 36 square cm of aluminium area per watt.
I can see no reason at all for making chokes. They are very rarely critical
components, off the shelf products will do an excellent job 99% of the
time.SS amps require more extensive heatsinking that any tube amp that I
have ever come across
Then if you don't like chokes, don't use them.
While you are at it, dispense with the tubes entirely, and bundle a few
transistors into a box with a generic PT and a few caps, and if you had
an uncle, his name
might be Bob.
But I like chokes AND large amounts of capacitiance.
Each 845 amp has 14 x 470uF x 400 V rated electros in the B+ and B-
supplies.
Plus two x 4H chokes, plus some series 100 ohm R to avoid resonances
and get splendid filtering with only a few mV ripple in each rail.
This is extremely important in an SE amp where there is no CMRR
in the output or driver stage.
And there is only 8dB of global NFB.
Rout with this FB = 0.33 ohms.
Without global NFB its about 0.9 ohms.
Everything is hand wired onto hand made terminal strips.
With an SS amp you either have exactly the same amount of wiring, or more
usually you are up for the design and manufacture of a PCB or PCBs and then
stuffing the components onto that.
All much easier and faster, but the wiring up of an SE amp
isn't the large part of the work.
Several weeks of design work are required for every set of amps I make.
Then there is a the tweaking and OPT gap adjustment, and potting of all
OPT and PT with sand and resin.
The 4 chokes used for the two pairs of choke input dc supplies for 3.5A
to the
845 heaters are also potted in sand/resin mix to ensure their silence.
Then comes the metalwork for the covers over the transformers on the amp
chassis.
Then grilles and gurds to stop tube breakage.
These items are tough, but carefully made, so that if the amp falls off
a table it won't
bend in half. Total weight is 85 Kgs split into 4 chassis.
If a 20odd Kg chassis fell of the table, I'd be worried about the floor.
I'd be very worried if it falls onto a clients foot, or a sleeping cat,
or very concerned if it it falls onto the tail of a dozy Dobberman.
BOWSY WOWSY I bite your leg off maybe.
Such amps could fall through a timber floor onto occupants having a
meal at the dining table below.
Not my REAL concern though. Its all their fault that sort of thing.
bring up a major advantage of SS gear, you could build the equivalent at a
quarter or less weight.
Special rugged umbilical cables have been made using mobile crane
cables.
There is the active protection board in each amp chassis to guard
against tube failure or excessive
cathode current.
Same protection requirement for SS amps
There is the paintwork of the chassis covers and grilles, drilled out
guard plates
around tubes, and bottom plates and drilling out for ventilations.
Just the same for a SS amp.
I do it all without any help, except this time I had a metalworker
bend up my steel chassis and weld it all and make it nice like a Quad-II
chassis standard.
There isn't anyone I could train who'd settle for becoming an amp worker
like me.
The wages are way too low. So young men who might like to
become some sort of tradesman will choose to be an electrician or
plumber,
because its easy and very well paid, despite working in bathrooms and
toilets,
or in rat infested roof areas of houses.
Or become a programmer, the pay is good, the work is light (physically
anyway) but you do have to be mentally alert, be willing to think outside
the box, and relearn large chunks of your trade every few years.
Maybe that partially answers your question of 'why'.
As I have noted above, I don't think that it is any more complex than
designing and making a SS amp.
Man, how many 60 watt SET amps have you ever made?
Its not until you have made a pair of 300W SS amps and a pair of 60W SET
thinges that
you really learn that at least 3 times the time is needed for the tube
amps,
and even if you just buy a motely collection of trannies
and chokes made by Hammond, the costs will be twice that of the SS amp.
Cost and time per watt for SET amps is enormous.
But if you wanted 3,000 watts in PP Ab2 then a tube amp
begins to catch up with the SS amp, unless its a switching amp, or PWM.
You do choose to do many things the hard way,
and I am unconvinced that that makes the result significantly better,
certainly not in proportion to the effort involved
People here like the difference, and will pay for it.
Then it depends who you compare me to. Some chinese makers are selling
5050 Watt stereo tube4 amps on-line
and direct from the maker without western round eye arsole middlemen
for
$700.
But they are junk, and badly made.
I have owned several Japanese SS amps costing 10-20% of an ME and have
never
had the least trouble with any of them, the only reason that they have
been
replaced is to get something a little better.
Japanese amps, yes, often very good.
The Japs discovered that to woo the west they needed to
invent better quality than anything made in the west.
I worked for the Japanese for 16 years and visited Japan maybe a dozen times
in that period, my assessment was that they aren't good at thinking up new
ideas, but give them a start and they will take it to it's logical
conclusion. The Japanese home market demands absolute quality, nobody but
the poorest would even contemplate buying seconds or rejects, outlet stores
were unknown there last time I visited 10 years ago. Electronics of the same
model as is current here can often be found there at knockdown prices
because they are no longer the latest model and nobody (other than
foreigners) want them. Everbody interested in any form of electronics should
visit Akihabara at least once in their life. It is jaw dropping both for the
range of stuff available and the prices
Indeed...
People here buy second hand jap cars with low miles.....
In the 50s, after WW2, the Jap crap was allowed into Oz, and
many hated it because of Japan's attempt to ruin so many lives
during the war years. Many liked it though because it was cheaper,
had better features, but still was junk anyway.
The japs only learned to solder in the late 60s, before that a standard 8
transistor radio would have a complete roll of multicore in it and about 50
dry joints
The junk got better and better as the decades rolled on and cars and
cameras
and some electronics from Japan was pretty **** hot.
By the 80s their quality was the best in the world.
Not all though, and much stuff for export to Oz was
much below domestic quality destined for the locval Jap consumers.
But the Chinese have yet to graduate to real quality.
Mybe in another 20 years they will realise that their **** stinks just
like I know mine does.
I'll be gone of course, and won't have to worry what the **** they do.
The Real Mccoy is much more expensive.
I don't care if you make steam engines forsale. Good luck if you do.
But if you didn't have the service information about your engines, i'd
be right onto you.
If you can't service your own steam engine without help, you shouldn't be
owning one. I don't think that Watt had a web site.
But you'd need to know all about the engine parts and how they were made
and to
service it. For example if your steam engine was a 1950 made type 38
express locomotive
used on mainline express passenger routes in NSW, a manual would be
essential.
In such nice old toys, a boiler change isn't so easy to perform.
Especially without a huge pre-existing railway yard workshop
with dozens of blokes to help out.
The local Railway Historical Society has a large articulated Garrat
loco, 16 driving wheels,
4 lots of cylinders.
They have other simpler locos. They have manuals.
Books are kept on work done to each engine.
Yep, I have seen it run, even ridden behind it. I have never seen a manual
for a steam loco, I was under the impression that the knowledge to fix them
was just passed down from generation to generation.
Dig deep, and there will be a large set of drawings and a specification.
It seemed that way when
my father worked on the railways. When I have my house sorted out, I may
join the Dorrego steam museum and help restore some of the huge number of
old pieces of machinary that they own. It was great as a kid having a father
on the railway, I got to ride on the footplate of steam locos and all sorts
of cool things
I inform, and teach, and Wilson spews BS about **** all to make
himself look good. I don't care how bad I look;
I will always have time for the truth about technical issues about which
Trevor seems to have
almost no idea at all.
As I said before, that is your hobby. I have no idea what TW does with his
spare time other than to post here. As a fixer of audio gear, I don't think
that he has any obligation to explain stuff, only to be accurate when he
does choose to make statements. I just wish that either you two would come
to some agreement or else to ignore each other, the same crap repeated ad
nauseum is quite boring.
Anyone coming to the news group posing as some commercial operator and
knowall must not act like a fool.
I will give them a very torrid painful time if they behave like fools.
Its ironic that Trevor Wilson told the group I cannot tolerate fools for
longer than 1 second.
I don't toloerate his lies, bull****, and plain woeful articulation
of any technical aspect of engineering.
He cannot even explain the ME amp design in any way whatsoever which
makes
any sense to anyone.
Its all blather, artless posturing for sales and fame, but among
the few who do understand technicals, he is a clumsy minded klutz.
Trevor used to have a website, http://www.rageaudio.com.au
Its under construction. The man cannot even maintain a website any more.
Does he even want/need one?
I don't have a clue. He did have a site, and
there was no demonstration within its conetnt that he knew very much at
all.
There is the ME website at http://www.me-au.com/index.html
Not the most informative site and it contradicts itself on the availability
of the ME850HC, but it is about what I'd expect from a semi dead company.
The un-dead walk amoung us....
There is not the slightest bit of technical info.
But there is a mention there of the stack of parts Stein has for
future productions. So it does seem he purchased gear left over from
when his factory
and equipment was sold off years ago as a result of a divorce.
Perhaps his wife found him rather difficult and stubborn, obsessive, and
uncomunicative.
I doubt we will ever see a workshop manual, ever.
If you ain't seen it by now, I can't see any likelyhood of seeing it in the
future.
But they deseve the negative publicity.
I'd take a similar club to Bruce Candy of Halcro if he ever dared show
his face on the groups and try
to tell us all there was no need for a workshop manual.
That's why most CEOs and VIPs in the world of audio manufacturing avoid
the news groups like the plague.
They will deservedly get told they are arsoles because of their gross
shortcomings, over pricing,
false claims, and utter BS, and will be asked what time next week will
it be when the problems have been fixed.
They don't like the blow torch.
Patrick Turner.
Keith