DZ Stepping Volume Attenuator is
now Available Published Wednesday, August 27 @
00:40:07 CST by ericchu
There
are many kinds of volume control Variable
Resistor (VR) available in the market, such as the Metallic Film,
Carbon, etc. If it is use on the volume
control for the Stereo system (2-channels and up), it
will requires at least with dual control or more (deck). Because
of the manufacturing process and it's mechanical
tolerance that it may have during the making, for
example, in one of
my case I use one of the local made 10KA Carbon VR for
the test, while one deck is at 5K level, the other deck is
at 4.2K. With this minor resistance changes, it may cause an
imbalance in the stereo's volume output.
This imbalance may also cause a soundstage shift and
blurring the sonic image.
A high quality VR needs to have a tighter tolerance
range. As in the common example of an ALPS
RK27112A (Blue Square shape), its tolerance is +/- 3db
and the ALPS
RK40312A has the tolerance of +/-2dB. I used
to have one TKD
(Tokyo Ko-On Denpa) 2P2511 that has a even smaller tolerance. I use the multimeter to measure it and
it only has about 1% tolerance. That's why the high
quality VR nomally demands a higher premium and also the
quality of the resistor material also affects the sonic
quality.
Stepping Attenuation -- A hard to reach item How
about the Stepping Attenuation, if we are to look for a
precision control? In the past, I have purchased a
GoldPoint Serial Type 24 imported by DZ and it costs
me a chunk of $3,000+ NTD (Taiwan dollar, about $90 USD).
This one uses the ELMA channel selector body and German's 1%
Metallic film resistors. At that time, as I was just
buying it for my hobby, I didn't know that their is a
difference in different types of the stepping
attenuation like the Serial type, Shunt type and the
Ladder type. After I purchased it, I later found
out that the Ladder type will cost even more that $6,000
NTD (About $180 USD)! It is too expansive for
me....
The high cost does has its reason! What a
Stepping Attenuation can bring is a more precise
control with a lower tolerance in resistance. At
the same time, it can also utilize the advantage of a
high quality resistor's material that produces less
distortion to the sound itself.
The common types of a Stepping Attenuator are:
Serial
Type It uses the resistor in series. The
advantage of this is that it only requires one deck
(layer) of each channel selection and the input
impedance can be kept in constant. The
disadvantage of this is that the signal (sound) path
pass through
a "series" of resistors and may cause a higher
noise level!
Shunt Type The signal path only
pass through two resistors. It also requires one deck
(layer) for each channel selection. The drawback
of this application is that its input impedance is a
variant. Its input impedance will be higher when
the resistor value increase!
Ladder
Type The signal path only pass through two
resistors. In theory, it has the lowest noise and
the input impedance is stable. However, it
requires 2 decks (layers) for each channel and therefore,
the quantity of resistors used is double when compare to
the Serial type. And the other drawback is its
higher cost.
DZ picks the superior Ladder Type Design After
our brief introduction of the different designs of the
Stepping Attenuator, you should be able to find out that
the Ladder type is the best in all the characteristics
and it's disadvantage is the higher price! Now, DZ has
prepare the affordable Ladder type Stepping Attenuator
kit for everyone. The kit includes a sealed 24-positions, 4 decks attenuator. All the contacts
are silver plated and incorporated the so-called
"Make before Break" to reduce the switching noise. The
resistor we pick are the military grade, Dale RN60D, 1%
precision resistor. This really is a great
combination for the serious hobbyist! Most
importantly, the cost is kept affordable! How can an item like this not making one
felt excited!
Please allow me to do a simple
demonstration of how to make this new DZ Ladder type
attenuator, that has 92 resistors and almost 200
soldering points, step-by step.
1. Count your parts. I printed out all the
resistor values into two A4 (Letter in US) sheets
(details I will describe it at the bottom of this
article). I put each resistor in each paper
grid. This will make the later soldering much
easier! The correct number of resistors is
92. If you miss any, please contact DZ right away
and they will send you the missing piece. If you
have more than it should, that's your bonus! There is also the
Attenuator body, one sand-blasted Aluminum knob that
came with the
kit.
2. Make a wire in circle to solder the resistors. I
use a bare copper wire (using pure silver wire is even
better). I use the 1.6mm solid copper wire that I
already have at hand and make a 57mm diameter
circle. The simple tool to make it into the desired
circle is the plastic Coke bottle, which is
about the same diameter size. (Translator Note:
The two ends should overlap for about 10 mm) At one end, bend a
15mm wire for connection to the body. You will
need four of these rings.
3. Make sure the direction of each position (or step):
As shown in the figure above, face the
shaft toward you and count the pin clockwise. The
position starts from 1 to 24. Make sure this
sequence when you start soldering the resistor. Do
not make the mistake; otherwise, you will encounter
trouble later....
4. Do it from the bottom up. You need to do each
deck by sequence from the bottom up. The gap
between each deck is very small, it will be hard if you
do the other way....
5. Beware the Rin、Rg deck
connection: This attenuator has 4 decks for a Stereo
(Dual-) channel usage. That means each channel will have 2
decks to connect to and each channel will have both Rin
deck and Rg deck. Therefore, if we counted from
the bottom up are: 「 Rg」->「Rin」->「Rg」->「Rin」.
Of course we can also use it as 「Rin」->「Rg」->「Rin」->「Rg」,
as long as each channel has both Rg and Rin deck.
Using this alternative deck is more of a enjoyable in
cosmetic and easier for soldering.
The connection starts with the Rg deck from the
bottom. The connection is connect the bended wire
to the connector No. 1. Then solder the Rg
resistors from No. 2 to the end, using the resistors
already lying on the sheet.
For the Rin deck, it is doing the opposite. You
populate the 1~23 positions with resistor and the final
24 position, you solder it with the bended wire.
6 Solder a 3-point connection first. As in figure
shown above, first you solder the 3-point, No. 1, 12 and
24. This will help not only to fix the circular
wire in place, but also will assist you in resistor
soldering.
7. After several hours of hard work, like building a
house one story at a time, I have completed the job, as
shown above. It is an amazing structure, isn't
it! After finish this, I bet you will feel some sort
of an achievement!
How to use your Stepping
Attenuator? Connect the IN to input signal, GND
to ground and OUT to output signal, as shown in the
figure. Each channel's Rg and Rin should be
connected together in order to function properly.
(Blue letter in photo below: the OUT connector is almost
hidden...)
You can also set your resistor value to
your desire The kit DZ provided is set to 10K
value. If you would like to play around with other
resistor value or for your other channel's volume
control, then how should one decide his/her resistor
value? In here, we have provided a simple
programming tool to help you do that. You can set
your desired condition and then calculate the resistors
you need. It is simple and fast. This is
different than the Excel spreadsheet you normally will
find in the Internet. This program provides you
with an user-friendly interface and has a unique
function to match the available resistor value in the
market. This will reduce the time for you to find
the correct and proper resistor. You are welcome
to use it on-line. If you find any error by using
it, please give us your comment and feedback.
Thanks.
Automatically
select the market available resistor value
Result：
Designed
by Eric Chu in 2003 Version 1.2 Any
error advice welcomeE-mail
me，Thanks！
End of translation)
Making a Stepping
Attenuator for Volume VR is not that difficult, but will
need some hard work, time and a challenge to your
soldering skill! I look forward that you can also
enjoy having a Stepping Attenuator of you own!
DZ
Stepping Attenuator Volume Control VR Kit Program If
you are a Hi-End audio fan, then you definitely are
familiar with the superb performance of a Stepping
Attenuator. Even though its outstanding
performance, its price is also very expansive;
especially when you equip it with the imported military
grade resistor on it and the price will shoots up and
let people hesitate to buy one!
To fulfill the dream of DIYer, DZ has specially
prepare this Stepping Attenuator kit. This kit
adopts the widely accepted Ladder Type structure.
It's signal attenuation only pass through two military
grade resistor, in any volume level. It has the
benefits of short signal path, low noise and it is quite
perfect!
The kit includes a sealed 24-positions,
4-decks control. All the contacts are silver
plated and incorporated the so-called "Make before
Break" to
reduce the switching noise. The resistor we pick
is the military grade, Dale RN60D, 1% precision
resistor. Most importantly is the price is
kept affordable! How can you not
felt excited about it!
Note: This kit has impedance of 10K. You can
also use it to replace 100K、50K or 10K volume control VR.
Supplement to the Article（Eric Chu) 由 LIMIN-WU 於 Thursday, August 28 @
12:02:40 CST http://www.diyzone.net/
This Stepping Attenuator's resistor value is based on
GoldPoint's recommended value. The reason we use
it is because it has been examined through our listening
evaluation and found it is smooth. After I look at
the chart I realized that pin No. 24 is not connected
and available positions only up to 23. For this
reason, during our process of making one, when turning
to the maximum, the attenuation is -3 db and it is
almost to the full volume (many speaker's has a
Frequency Response of +/- 3 db). I think in
reality, we seldom use it up to the maximum volume (some
system may have distortion before that point!).
The normal usage is open the volume to about 12 o'clock
position and below. In this, we do have a smooth
volume control and does not affect the sonic
quality. However, if you really like to gain this
3 db back (which is not really that necessary), this is
how you can do it:
1. Jump the pin 23 and 24 together in each deck. 2.
Take the No. 23 resistor in the Rg Deck, which has the
value of 6.8K.
Using this two steps, you can
easily gain the full output volume. This is only
for your reference.
Editor Notes: The above is only for your
reference. We still recommend user install it
according to the original design. You do not have
to do the above two steps, because the one merely use
that kind of volume setting. As a matter of
fact, if you have a need to use such high volume, either
your are using a low pre-amp or your gain is too small!
Some reader asked who not make the Attenuator to a
full 24 positions? This is because if we make a
full 24-positions, the body will have a "Full-revolutional"
design. When you turn to the 24th position, the
next one will be the 1st position again and on and
on. This is not a natural instinct to our human
nature in using it.
一 As mentioned by Eric
Chu, DZ's Stepping Attenuator is based on widely used Gold
Point resistor value in the design. We feel this
is most reliable and stable design.
Translator's Note: The photos below are other examples of how you can
make your Stepping Attenuator. For your reference.
