In article ,
Harold and Susan Vordos wrote:
s
"DoN. Nichols" wrote in message
...
In article ,
Harold and Susan Vordos wrote:
[ ... ]
Beware of one problem -- assuming that you have a commercial
"demand" priced power, instead of domestic. (It is often the case that
[ ... ]
Yep! They (PUD, Public Utility District) installed a demand meter. I'm
so far from being able to run the induction furnace at this point I'm not
too concerned, but it's a reality for the future.
Good! You know about the problem. That is the main thing.
[ ... ]
meter. I was told that the cost increase would come at 50 KW, so unless I
draw a full load, I could avoid any overcharge. I'll be careful to keep
the compressor from running when I fire up the induction furnace, and
Will the induction furnace go to full power each time, or can
you use it at reduced power?
[ ... ]
Is there a difference in the distance from the listening room to
the shop? (You may have spelled this out earlier in the thread, but I
[ ... ]
another. The shop is a different critter. From the electronics to the
shop will be in the neighborhood of 120'. Not measured, but I have a fair
idea I'm very close. Long distance is the point, not just the next room.
That makes things more difficult.
[ ... ]
Note that your Macintosh amplifier has provisions for accepting
600 ohm inputs (the three-pin connectors on the back panel, according
to the web site).
Unfortunately, my amp is not the one you're discussing. I run an old
Mc2300, built in the mid 70's. All connections from the preamp, in and out,
and the in connections on the amp are limited to RCA jacks. Mc used them
for years with no changes. The modern gear is a product of new ownership as
far as I know.
O.K. Not that it would matter, unless you got a second
Macintosh for the shop anyway. Note that you can add input transformers
to the more common RCA jacks for input and get the balanced input. And
it is a lot easier to get a big enough transformer for the power levels
involved in line level inputs (just a few db over 1 mW) than for the
speaker power levels.
Ted's circuit may well do all that you need in the shop, and
there should be better control of the speakers with a local amp than
[ ... ]
Chuckle! Ted's a great guy, but he didn't offer me one of his amps, which
comes as no surprise.
He may offer you the information to build your own, if he thinks
that you will actually *use* it.
Go ahead and run the high current wires -- but also run the
shielded twisted pair to allow a comparison test when you get a good
amplifier for the shop. They won't take up much space in the conduit.
I have 1½" conduit in place for the run, so it shouldn't be too crowded,
regardless. I'm thinking of installing a pull piece just in case I decide
to add something in the future, at which time I could pull a second pull
piece. I realize how difficult it can be to pull wire once some occupies
the space. Possible, but often very difficult, especially on turns.
Agreed. Best to pull everything at once, if possible.
I would suggest that you also run something like a 25-pair phone
cable which you could use for phones (of course), 10BaseT to connect
your shop computer to the home computer (and the outside net), *and* a
possible remote control for a CD-changer or some of the other devices.
(Obviously, the Reel-to-Reel would need to be manually rethreaded, so
that isn't much help there.)
And -- if possible, make your high current pairs twisted as well
(that is, both wires for a given channel are twisted together), which
will reduce some of the problems which they may introduce.
I like that idea and will do just that. Considering I'll be running two
pairs, would you recommend I twist each pair, then twist the two pairs of
pairs?
Nope! Just twist each pair (in the same direction -- either
both CD or both CCW -- but the same) Then run each twisted pair parallel
to the other. Twisting each pair separately minimizes crosstalk.
Twisting it all together might make things worse. And you'll need some
extra length for those twisted pairs compared to straight. How much
depends on how tight a twist. It would not hurt for one pair to be a
tighter twist than the other.
Any benefit in doing so?
No -- other than making it into a fatter bundle which will be
even more difficult to pull around corners. :-)
In either case they'll be in the same
conduit, but with the twist, perhaps there's something to gain. From all
indications, I'll have to pull through only two 90's, so the overall large
bundle should pull fairly easily---especially considering I'll be using THHN
stranded wire.
Good.
I'm going to go with my original idea, if for no other reason, it served me
well in the past, although the run was considerably shorter. Power isn't
an issue, I have more than plenty, and loss at the high end isn't a concern,
not when listening in the shop, anyway.
What I would be more concerned about with that length is
possible loss of control of speaker overtravel, thanks to the added
resistance.
Like most of us, my high end
isn't what it used to be. I haven't heard the sound of a flyback
transformer in a TV for a long time.
I was not able to hear that even when I was in high school.
Something which I and done before had damaged my high end.
[ ... ]
I had that, minus the equalizer (had it, but not on site) with my old
setup,
which I will emulate here. In fact, I have three sets of controls, the
autoformers I spoke of. They were purchased long ago, from a company in
Utah, where I used to reside, that specializes in sound distribution. I
was totally pleased with the performance they provided, and should be
again.
Do they change volume in steps (that is a tapped
autotransformer), or continuously variable (like a Variac designed for
audio power levels)?
Steps. The stainless steel face plate is calibrated 0 through 10 over about
320°.
O.K. Switched taps. That is reasonable enough for the
application -- other than changing the load impedance seen by the output
from the amplifier.
[ ... ]
Again, I'm not nearly as concerned with that as I would be having to listen
to a radio, where I'm subjected to music I despise. Even the jazz station
we frequent, KPLU, which is found online, plays a fair amount of music I
don't prefer. They're big on vocalists, which, for the most part, I don't
like. Of late they're playing way too much Norah Jones. She's likely a
lovely lady, but I can't stand her voice, nor her choice of songs. Mostly
related to country music. I'd rather kiss a pig on the mouth than listen to
that stuff. Ella Fitzgerald, Sarah Vaughn, Joe Williams, Mel Tormè, Nat
King Cole, Sinatra--------No problem.
O.K. I have my preferences for vocalists too -- in a different
field -- traditional music (what used to be called "folk music" before
the recording companies ran away with the term and changed what people
think it is.
Perhaps the ability to listen in the shop without inflicting
your choices on your wife back in the main house? (I don't know how
good the acoustic isolation in your listening rom may be.)
[ ... ]
I'm a lucky guy, DoN. My wife listens to and enjoys the same music, and we
agree almost perfectly on our likes and dislikes. Neither of us like
country western, and both of us prefer the baroque when listening to
classical. She almost always is listening when I am. Both of us are real
MJQ fans, along with many others. Brubeck happens to be a favorite for both
of us. Life is good!! When I'd be in the shop, she'd likely be listening
to the other speakers in the house, as has been our habit as long as we've
been married.
That helps. My wife won't listen to classical, though I used
to. But we are pretty much in agreement for the rest. (And we met
through the local Folklore Society. :-)
Is your amp going to be fed from recordings, or from a tuner?
The latter would be likely to require
You seem to have dropped the ball here,
Remember -- I've read only part of the thread leading up to this
point.
but to answer, I'd use the system in
all ways. Tuner (we have a McIntosh MR-78 FM tuner, and don't listen to AM)
plus various playback systems, including reel to reel (Crown CX 824),
cassettes (Nakamichi 1000 II) and an inexpensive Nakamichi CD player. We
still have the turntable and our large collection of vinyl recordings, but
they don't lend themselves to shop listening because of the distance to the
listening room from the shop.
And you certainly would not wish to subject good vinyl
recordings to the mangling from a changer.
Too inconvenient. We plan to add a good
quality CD player, most likely a McIntosh, when we inhabit the house. Not a
worry meantime.
O.K.
I'm quite happy with may Hafler amp (which was a kit), and you
might be as well. I presume that they are still made.
Could be I would be happy with it, but I'm not sure I'd be up to the task of
assembling one. The only amplifier I ever built was when I was just a
kid, hanging out at the local radio repair store. Built it from scratch
with the help of a guy that worked there, but it would hardly qualify as an
amplifier in the scheme of things. I was crazy about electronics, but
realized early on I didn't have what it took.
The Halfer kit was not that much of a kit. The wiring required
was the power supply wiring, mounting of the transformer, and connecting
input and speaker connectors to the amplifier modules which were
pre-built on heat sink modules. So it was not even as difficult as a
Heathkit (which probably had the best of assembly instructions -- the
only way to get into trouble with those was to think that you didn't
need to read some of the instructions, and forge ahead without them. :-)
They seem to have dropped the kits, anyway, and are now selling
only pre-built ones. (Hafler was the designer of the Dynaco amplifier
kits, before he started his own company.)
Here is the URL for their web site:
http://www.hafler.com/
Then go to the studio/broadcast selection, and select the P1500, which
is probably the closest to what I have (with additional features, such
as balanced input, and LED monitors.)
I was always somewhat
confused by things, very unlike machining. I made up my mind in high
school that I'd pursue machining and give up my quest to learn electronics.
When solid state devices hit the market, I was all the more confused. I
think I made a sound decision considering my aptitude for such things.
I was playing with electroncs long before I got a chance at
machine tools. The shop class in high school only taught woodworking,
which was not a good fit for me. It was not until I was working at an
Army R&D lab that I got a chance to learn machining from a couple of
resident machinists -- and I have been glad that I did. (Of course,
before that, I was trying to do things like building a tape deck for
10-1/2" reels from scratch -- mostly with hand tools and an electric
drill motor -- and files and coping saws. :-)
Again -- good luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. |
http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---