Gordon Rankin's AV8 tube
amplifier project.
DIY Digital Cable which also makes an excellent video cable too!
Click here to learn more.
Save Money By Making Your Own Cables!
Click here to learn more.
Make Your Very Own Vinyl Record Cleaner... cheaply!
Frank Gales shares with us his homemade cleaner. So if you're handy with
building things and wanna save yourself a few bucks, please see this article about his
cool cleaner.
Click here to see the D.I.Y
Record Cleaner article.
Making Your Very Own Crossover Network
Haven't ya ever wondered how to make a crossover. Well, if you don't have
the proper program then this www page link below may be just what you're lookin' for.
Can't get much easier then this my friends. Enjoy!
Click here to go
to the crossover calculation www page.
Make Your Own Pure Silver Interconnects
So ya want one of them there $300+ pure silver interconnects but your bank
account sez no way huh? Fear not my friends 'cause here's how ya find silver, prepare it,
and make your very own pure silver interconnects. Pure silver can be purchased very
cheaply from your local jeweler. The downfall with purchasing your silver this way is
twofold. First off, the silver has no insulation and therefore must be either
polished/sanded clean to remove oxidation. Secondly, you must seal/insulate the silver
after cleaning it. Buying silver from your local jeweler should cost you about $15 for a
meter length in a rod form (18-22 gauge wire is fine here). Two lengths are necessary for
a simple twisted pair approach or you'll need three lengths for the braided type
interconnect approach like Kimber Kable stuff or for making a XLR ended balanced cable.
Here's what cha need:
1) two or three even lengths of silver wire
2) very fine sandpaper (1000 grade or so)
3) polyurethane
4) a pair of XLR or RCA jacks
5) a soldering gun
6) solder (preferably Audio Note or Wonder)
The first step is to lightly sand one silver rod. This is to clean off any
oxidation that may have built-up on the outside of the wire itself. Immediately after
cleaning one rod is to wipe it clean with a cloth, then immediately paint a thin even coat
of polyurethane in a well ventilated room to seal/insulate the silver. Repeat the above
steps until all the strands have a single coat of polyurethane. Once all the strands of
wire are thoroughly dry from their first coat of polyurethane add five more thin coats of
polyurethane to each strand for a total of six coats.
Kimber Kable Method
Now comes the fun stuff. You can use three strands and braid them like
Kimber does for their RCA interconnects. Kimber uses two strands for the shield/ground and
one for the center, positive lead. By marking the positive lead on both ends before you
start braiding the rods will insure you don't mess things up. Once all the braiding is
done, solder the positive lead on one end to the center pin of an RCA connector. Solder
the other two rods to the outer part of the RCA connector. Repeat these steps for the the
other end of the cable using another RCA connector. Congratulations, you have just made
your very own braided pure silver RCA cable!
Twisted Pair Method
Another method is to simply use two silver strands and lightly twist them
at a rate of about three twists per foot. Make sure you mark the positive lead before you
begin twisting so as not to mess things up. Solder one of the positive leads to the center
pin of the RCA jack. Solder the other lead to the outer part of the RCA jack. Now simply
repeat this process for the other end of the cable and you're done.
XLR Balanced Cable Method
If you're making a cable for balanced application using XLR jacks simply
follow the plan like the Kimber Kable method braiding thingie, but make sure you mark all
three leads before you begin braiding. Then simply make sure you solder the same end of
each wire to the same pin of each XLR jack.
Hopefully this little ditty will bring you the reality that making your
own goodies can be fun, enhance your music reproduction system, and save you righteous
bucks too! As for me personally, i'm again getting into building my very own stuff and
modifying gear as fast as it rolls in here. Keep those irons hot and the solder flowing!
Wanted: Good Pot
No, no, no. Not that green leafy substance but a potentiometer. It never
ceases to amaze me how (a) good pot enhances my music/movie/sound reproduction system. On
really expensive gear they seem to use a very good potentiometer, yet on the
lesser stuff they may leave much to be desired. May i humbly suggest you read on and learn
more about what makes a pot tick? Better still, do as i have done for years and avoid
using (a) pot!
You see my friends, unless you use only digital sources and have a way of
digitally controlling the analogue output of your DAC/preamplifier, your analogue signal
MUST pass through some type of potentiometer. Yes, there are quite a few types, sizes,
values and quality available. We must first see what the rating is of the stock unit and
how it's mounted. Some manufacturers use a circuit board mounted pot whereas others are
kind enough to use a stand alone type of part. If it's of the circuit board variety our
choices may be a bit more limited unless you are willing to become more
inventive/creative.
An ideal pot would be one which acts as a variable very high quality
resistor. Yes, the resent photometer idea seems nice, yet to incorporate on in your
preamplifier may be harder than a normal tweakaholic (is there such a thing?) can do. Well, our current
technology doesn't allow us the privilege of a variable single resistor so what are we to
do? Well, there are quite a few places that sell high quality pots as well as what i feel
is better. That is, a stepped attenuator.
Let's take a look inside a potentiometer and "see" what makes it
tick. Basically a normal high-quality pot consists of a circuit board with a precision
signal trace. A metal piece basically scrapes across the signal trace to give us the
desired volume level. Simple huh? Unfortunately all's not well in Oz my friends. These
types of potentiometers may suffer, among other problems, three downfalls. These downfalls
may be the suffering of precision channel tracking, inducing signal noise, and (especially
with those nasty traditional carbon track controls) it's value may change over time/usage.
So what's a woman to do?
She can go shopping! Shopping for a stepped attenuator that it. A
precision attenuator is much closer to that proverbial "variable resistor" than
the potentiometer is. Let's look under the hood of an attenuator and see what makes it
tick. Well, basically we have quite a few resistors soldered on circuit boards. Sometimes
there is only one resistor per channel in the signal path. Other times there may be two
resistors. This device basically uses various values of resistors in sequence to obtain a
certain resistance value. In turn, this action produces various volume levels. It's the
k.i.s.s. method in action.
Another side benefit is that YOU may choose the manufacturer and quality
of the resistors. Some of you lucky few can afford silver foil resistors with silver
lead-out wires whereas others may be able to afford only the copper foil type. Better yet
for us dudes low on fundage, buy the silver foil resistor type in the most used volume
setting(s) and skimp out on the lesser used levels! Life IS goooood. As always, if you
have any questions please feel free to e-mail them to me BEFORE you do ANYTHING.
The Parts Connection
2790 Brighton Road
Oaksville, Ontario
Canada L6H 5T4
voice (905) 829-5858
fax (905) 829-5388
Click
here to go to The Parts Connection's www site.
Click here to learn how to make your very
own stepped attenuator.
Tubed Electronic Crossover
Well cool dudettes/dudes, we've been blessed by none other than
Jean-Michel Le Cleac'h of Paris, France. This cool dude was kind enough to allow us to
post ALL the schematics he has recently posted pertaining to tubes electronic crossovers.
So if you got your printer ready, please click on the link below and have fun!
Click here to see various schematics of tubed electronic crossovers.
KILLER Speaker Stands On The Cheap!
Kirk Olson sent this to me recently and i felt it's a great idea.
HECK, i've even done it! Thanks Kirk for the article!
RE: Ultra-Cheap stands for Ultra-Cheap Speakers
Anybody ever suggest the old
cinderblocks-as-speakerstands trick around here yet?
The blocks are heavy, acoustically inert, paintable,
and here's the best part: they're REALLY CHEAP!
Most hardware stores have 'em for a buck a
piece (or less.)
Stack two vertically per side and you've got a stable
31" high 7.5"X7.5" platform. Be sure to use lots of
Fun-Tac/Blu-Tac between the blocks and under
the speakers (only if you can get it for $2 or less
a pack, of course!)
This approach works well for out-of-sight
applications (surrounds above and behind a
couch for instance) and anywhere the interior
design police aren't on duty. It's also acceptable
for your system in your "utility" room (where $250
Audiophile-grade fillable steel stands might seem a little out of place.)
Have Ya Ever Been Too High???
The below ditty was okey doekeyed to be printed here by the writer.
Personally, i admit that the less parts in the way of the signal the better. BUT there ARE
times when some music is GREAT yet the sound engineer should have been shot (or at least
received the death sentence). The circuit below looks sane and safe enough. If ya got any
questions please feel free to e-mail them to him. And here we go:
Here's an ASCII circuit (yechh) of a 'filter' that is
intended to take the harshness off some sources of sound,
mostly CD's, and LP's that have an upward response tilt.
If you are using a Microsoft thing to look at this,
make sure the font is set to 'fixedsys', otherwise it gets
mangled.
I made this circuit since my speakers have an overall
flat response, compared to a 'desired' response that tilts
downward. Whether they should tilt down is a good question,
but it seems that the industry assumes that to be a 'normal'
response. Also since I sit quite close to the speakers
(about 2 meters away), the response gets a bit aggressive.
Anyhow, I use this little circuit a lot, it seems that
many recordings are too 'hot' for my tastes. It is no way
as extreme as tone, or bass and treble controls. Simulations
of the circuit using PSPICE show a fairly benign response,
with little 'nasty' stuff as the audiophile would see it.
This circuit should be fed from an impedance not more than
1 or 2 kilohms. This is normal for semiconductor amps and
preamps, but is rather low for tubes. Anyhow, you're not
likely to encounter tubes in a CD output circuit, except for
a few wacky brands. The below diagram is for one channel.
You will need to build two for stereo.
sw1a . o--------------------------------------------o . sw1b
/ \
o-' '-o
in 1k 1k 1k 1k 1k out
o-.-/\/\/-.-/\/\/-.-/\/\/-.-/\/\/-.-/\/\/-.--o
| | | | | | |
| \ \ \ \ \ |
| 20k / 20k / 20k / 20k / 20k / |
| \ \ \ \ \ |
| / / / / / |
| | | | | | |
| .001 | .002 | .0047 | .01 | .022 | |
| --- --- --- --- --- |
| --- --- --- --- --- |
| | | | | | |
| gnd gnd gnd gnd gnd |
| |
| |
'------------/\/\/\/\/\/ 50k pot |
T |
'-----------------------'
Capacitors: are in mfd's, 10% or better. use film types.
If you must use ceramics, try to avoid the the hi-k types
(the ones that pack a lot of capacitance in a small pkg. They
have very bad drift with temperature)
Resistors 5% or better (you could use 22k instead of 20k)
Switches: low level (gold contact type)
sw1a,b DPDT (switch is shown in bypass position)
Pot: 50 kilohm dual (stereo) log taper. Use the wiper and
common, leave the 'input' of the pot open.
The switch (sw1a,b) bypasses the circuit when you don't
want to use it.
The circuit is basically 5 shelving filters, close
enough so that they won't show the 'step' in the
frequency response. It offers a response that tilts
downward from the lowest frequencies, up to the highest.
It doesn't cause a lot of phase shift, or anomalies to
pulse or square wave inputs.
The 'tilt' is controlled by the pot, being minimum (flat)
at 0 ohms, and maximum tilt at the highest value. A log
taper will give an audible effect that's roughly proportional
to the setting. If you use a linear pot, most of the change
happens at one end of the dial. The circuit will affect the
overall volume at the max. tilt end of the pot.
Use decent audio jacks - they don't have to be high end,
but should be something that isn't going to tarnish and give
intermittent or semi-conducting connections. Most Radio Shack
stuff should be fine. The case should be made out of metal,
you need to shield the circuitry from 60 Hz, RF, transients,
stray audio etc.
Since it doesn't use any power, you shouldn't be able to
blow yourself up, or get zapped. Don't expect miracles from
this circuit - it will just tame the aggressive response that
some half deaf sound engineers like to put on a CD (or even
some LP's!).
-Paul
Please click here to mail Paul
your questions/comments.
May i humbly suggest you see our Tweak Page because it
has a few great projects as well.
High-Performance Audio Reviews
