--

stereo if different!

2006-03-14T14:58:00.000-08:00

Please note: my prior notes have been for mono.
Indeed, the Radios Shack aattenuators ar only mono too.

Should you want stereo PC output go go to stereo mixer input,
you need two attenutators, one for the Left, one for the Right,
all sides sharing the same ground.

At this point my mind is boggling as to why a manufacturer ISN'T
MAKING THIS!!!

In the meantime, check out the Rolls musician's stuff:
http://www.samedaymusic.com/prodsearch?cat2=3581
There's something in there somehow, especially the "active direct" box on p.2
They make great stuff at good prices.

Still, a simple selection of pre-made attenuators would be nice!

The pro stuff is bulky and pricey.

Suggestions for PC-to-mixing-board

2006-03-14T13:14:00.000-08:00

A Jeff Duke has written about noise issues when trying
to connect the PC headphone output to the input of
a mixing board. I'm assuming that the mixing board
input is at "line-level" (the rca-phono-plug level that
stereo components use).

It seems the neither of the Radio Shack attenuators is ideal for the
job, although the lesser attenuation has a slight chance.

A decent attenuator allows you to easily adjust your volume to
stay well above the buzzy noises of the PC audio board, but below
distortion levels.

It will take some tweaking, but here is a way to fiddle for the right level.
In a line that has been cut (or in a nice box with phono jacks) we put:

1) a 50-ohm resistor from the center conductor to ground, on the headphone-out side
(makes the PC happy)

2) a 10K-ohm resistor from center to gnd, mixing-board side.

3) the grounds of the two sides connect through

4) and then, from the headphone-center to the mixing-board center,
you try a 1k-ohm, 3k-ohm, 10k-ohm, or 33k-ohm resistor.
(see what gives a good saturated signal with 1/4 to 3/4 volume
adjustment on the PC)

Most PC noise is a matter of keeping the output up. The low-volume
dirt is terrible on a PC.

However, sometimes ground hum can be there between the PC and
the mixing board. A little telephone isolation transformer,
on the headphone side (I think??) input-to-PC / output-to-attenuator,
would probably snuff the ground hum safely.

A lot of the "scratchy" sound you hear when headphone-level is connected
to line-level will go away with a proper attentuator, as above. That's what
the to-ground resistors help with: keeping each side happy with its
intended load.

home-made dubbing attenuator

2006-02-28T06:00:00.000-08:00

Looking to get a better sound for
tape-player-earphone-jack ----> PC-microphone-jack,
I made this:

(a 1/8 mono plug to 1/8 mono, cut/stripped in the middle)

--> facing the recorder earphone plug, a 100 ohm resistor to ground
--> then, a 33K-ohm resistor in series (with the center conductor)
--> and a 4K-ohm resistor to ground facing the computer PC

This attenuates things for mid-hi volume out from the tape player,
and keeps the voltage a bit high in the resistors to keep noise down.

You can easily adjust the attenuation by changing the center resistor (series)
anywhere from 3K-ohm to 100K-ohm. 33K-ohm is good, although 22K-ohm would
probably ease back on the tape player voume a bit. It was not at the distorted
level yet. I adjusted the volume during a sample run until the level line
in the XP sound recorder showed occaisional 'blobs' to 1/2 if the total height.

I made a great alternative to a chassis, for the attenuator:
1/2" extruded foam insul. layers (sandwich resis / wires),
with tight fiberglass tape bands, and then electrician's tape
(to keep the fiberglass tape from pulling up)

So that completes my 2nd "shoebox studio" setup for recording speaches.

Sound clarity and noise performance was a bit better than the Radio-Shack 60dB dubbing cord,
but there will always be an advantage to tweeking your own attenuator. This approach
would also work fine for the output of a digital recorder, but you need a very
high-grade recording mode to avoid rattle/buzz when recording to MP3 on the PC.
Cassette tape recorders have no such issue.

recording note

2006-02-14T10:01:00.000-08:00

The Radio Shack 42-2461 60db attenuating cable can be used to play a
portable cassette earphone jack into your PC microphone jack.

But the 42-2152 (a 90 db attenuation) does NOT work, without CPU noise (mid-volume)
or tape player clipping (full-volume).

This is a shame, because there are dozens of recommendations for the 42-2152 out there..beware!

Using adaptors with no attenuation makes for either a dirty recording, or overload,
or even a blown input.

There should be a redesign for today's players and today's PC-mic levels.
If I have the spare time I'll tinker to set up a proper attenuator.
A first-try would be:
---facing the recorder/MP3-player/etc.., a 33-ohm res. to ground
---then, in series, a 2K-ohm resistor, (or try 20K: adjust this middle one)
---then, to ground, facing the PC, a 2K-ohm resistor.
(notice: the ground/shield) line is never broken)

insulation tidbits

2006-02-09T17:45:00.000-08:00

Some rare information about insulation:

---crumpled/decrumpled newspaper layers make excellent insulation

---9tbsp Borax and 4tbsp Boric Acid per 64oz water make a flame retardant for paper

---corduroy pants and oak bark insulate by making a semi-still air film: outside!

---oak bark is low-IR-emissivity, helping retain even more day sun heat

---loose oak leaves have high insulation value: under 1 foot of oak leaves one
10F morning, the dirt was 54F! Fresh snow adds more insulation.

---damp cold can penetrate woven wind shells with its water vapor: a rain-proof
wind-breaker helps in this circumstance.

---(sound) past 2 layers of glass, windows don't block much more sound: the secret to
super sound-blocking in specialty windows is one layer twice the thickness
of the other, and spacing of 3-5 inches between layers. Each of those does a lot.
For low frequencies, sealing is key.

---as outside temperatures become very cold, fiberglass actually loses some of
its R-value. This is due to convection becoming strong enough to move
through the fiberglass

---A 15mph wind will remove almost half if the insulating resistance of a single
glass layer, because the two "air films" on either side of the glass are
most of the R-value, and one air film is whisked away. This also means that
on a windy day, double glazing is even more than twice the insulation of single.
(4 air films, one lost versus 2 air films, one lost)

That's only a fraction of the info I accumulated, but it's the more interesting
stuff.

newer mini notebook system

2006-01-23T12:54:00.000-08:00

My apologies to the folks at www.journalisimo.com
for not doing a nice photo-n-description article
on my plastic/quarter-sheet/spring-clip system.

The clip(s) were bugging me, and a pouch I made to
service that system is now actually proving to
work better as the notebook!

I have ~.020" plastic (like used in blister-packing of
pegboard goods) rectangles, taped 3 sides with
electrician's tape, a little bigger than the
quarter-sheets of paper within. This is a great
note system, and has a nice show-through of the notes.
Most important, cutting a little semi-circle in the
top of the pouch makes things "deploy" for writing
much quicker than with the spring-clips. I use
97-bright 20# 8-1/2 by 11, folded/knife-cut.
It comes out fantastic with the P-500 or G-2 pen.
Ball-points may skip, due to all the extra kaolin
on the 97-bright paper. But the pens above, or the
uniball signo, work great. Remember, the paper is
important too!

Current pocket notebook system

2006-01-05T06:03:00.000-08:00

I have settled on a way of taking notes and jotting prose
that can fit in my pocket.

--I use a Pilot P-500 pen (quite fine and dark)

--There is a small stack of quarter-sheets of paper
(4.25 x 5.5 inches), easily made by fold/cut or paper cutter

--Back and front covers are made by cutting flat 1/16" poly.
(I used a kid's roll-up sled for mat'l: you can also
score+crack some clear arcylic window matl. for a stiffer base)

--A little 3/4" wide spring-clip (or 2) holds it together

--When you tuck the top cover behind the back, you have a
firm clipboard-type writing surface. And yet it fits in the
pocket. I rounded the corners to minimize pocket wear.

---------------issues and fixes--------------

---I always have trouble with my writing alignment, and
that costs space in a small notebook. So I simply
slip a dark-black-lined template sheet behind the one
I'm writing on, and I can see lines without having them
show later!

---Paging through is obviously an issue compared with
bound notebooks. But if you fan the pages like
money-counters, you can easily flick through.
How do you fan pages?
1) Take the page stack out, tap it to align edges
2) Grab one end firmly
3) Bend the pages in a ~2" radius
(you should see page-staggering at the loose end now)
4) Grab the opposite end
5) Let go of the first end you gripped,
and un-bend the stack
6) If you repeat steps 2, 3, 4, and 5 quickly a few times,
the flicking will be easy! The pages will be staggered well.

(advantages over a notebook is the ability to rearrange and
organize, of course, and the lack of wear+tear at the bound end)

---The 4.25" width is a bit full for pants and too much for shirts.
I am pondering a 3" cut-width. You lose a lot that way though..

You can see all sorts of similar personal organizer/books
at www.journalisimo.com :

Thomas Jefferson had a pivoting ivory notebook, so the pencil
could be erased when notes were transferred.

An IT guy has shortened hole-punched 3x5 cards on a carabiner.
Covers are "sail-cloth" (fiberglass?)

A Canadian MP actually has a stack of 3x5" cards with a clip.
A lot like my system, but without the backers, and the cards are
thicker than paper. So his system is simpler, but with
less max. capacity. Great for holding up single sheets outdoors.

People all around seem to be using nice pens and notebooks
or stacks and putting down their organizer widgets.
Paper is still less annoying and more flexible for some things!

----------------------------

pens

2006-01-03T11:37:00.000-08:00

Many normal ball-point pens have ink the fades...bad news.
Beware!!

My favorite gel-pens that have ink that is resistant
to light and fading:

---Pilot P-500 and P-700: fine, crisp, black, and lasting!!

---Pilot G-2: ballpoint retractable version...great!
almost, not quite as precise as P-500/700

---sanford uni-ball Onyx back/fine:
a great deal in gel-pens: crisp, dries quick, archival pigment..
wears a bit toward the end, but a great price!

---uni-ball 207 signo micro: ooooh! smooooth! Almost as fine as P-500,
(widens a little over time),, and very smooth. The regular (non-micro)
signo 207 is super-smooth!