Finding a rotary switch for a stepped attenuator
 

Hi

Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??

I've looked at previous posts reccommending Blore Edwards but I can't
seem to find them on the web....maybe they're not trading anymore??
Farnell and RS gave me no joy.

I've got a home made amp and I'm currently using a conductive plastic
pot but I'd like to hear the difference in going to a stepped
attenuator.

Thanks in advance

Steve

Finding a rotary switch for a stepped attenuator
 

One simple step forward is a linear cermet 1meg pot with a law faking
resistor to bring it down to 100k or 10k or whatever you want - that
should improve over conductive plastic.

I use 12 way cheap Lorlin switches as shunt attenuators in balanced
mode - simple and effective. I can live with 12 steps (now don't take
that the wrong way....)

I do believe stepped attenuators beat the rest - including Alps blue
and Black Beauties (I've used both). I have some Elma ones with gold
contacts. These are currently available.from various sources.
http://www.hificollective.co.uk/comp...tiometers.html is
one.

There was a firm called Sussex Surplus which used to do big silver
contact switches - I think they changed their name - anyone know?

Finding a rotary switch for a stepped attenuator
 

In article .com,
Andy Evans wrote:
I do believe stepped attenuators beat the rest - including Alps blue
and Black Beauties (I've used both).

I'm old enough to well remember stud faders used in broadcasting - built
regardless of cost (balanced faders would probably cost over 1000 quid if
available today). And the regular need for cleaning them. Conductive
plastic was a welcome invention...

--
*If at first you don't succeed, redefine success.

Dave Plowman London SW
To e-mail, change noise into sound.

Finding a rotary switch for a stepped attenuator
 

wrote:

Hi

Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??

I've looked at previous posts reccommending Blore Edwards but I can't
seem to find them on the web....maybe they're not trading anymore??
Farnell and RS gave me no joy.

I've got a home made amp and I'm currently using a conductive plastic
pot but I'd like to hear the difference in going to a stepped
attenuator.

The classic switch for this in days of old would have been a Painton part.

You might try an Elma switch or maybe Grayhill.

Graham

Finding a rotary switch for a stepped attenuator
 

On 2006-06-05, wrote:
Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??

What about a ready-made attenuator, like a DACT CT2?

http://www.dact.com/html/attenuators.html

Not cheap but it saves much work and the UK distributor is:

http://www.audiocominternational.com/

(There's some fault on the webite but a search for CT2 works.)

--
John Phillips

Finding a rotary switch for a stepped attenuator
 

wrote in message
ups.com...
Hi

Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??


I've got a home made amp and I'm currently using a conductive plastic
pot but I'd like to hear the difference in going to a stepped
attenuator.


The DACT stepped attenuator is good value for money.
They also make multiway switches if you really want to
try a homebrew..

Also Grayhill UK will supply switches to any format.
If you want a really high-grade stepped attenuator try TKD.
Not much change from UKP350 bought retail.

I am currently working on a valve power amp, with a
pair of TKD stepped attenuators (40 way) on the inputs.
A pal of mine here has fitted stepped motors to them
with a remote which works beautifully.

The main advantage of a stepped attenuator is the tracking
accuracy. You will certainly hear a difference. There are
people who will tell you a resistor is a resistor is a resistor.
They also think a saxophone is a saxophone is a saxophone.
Listen, compare, and make up your own mind.

Good luck
Iain

Finding a rotary switch for a stepped attenuator
 

In article , Dave Plowman (News)
writes
In article .com,
Andy Evans wrote:
I do believe stepped attenuators beat the rest - including Alps blue
and Black Beauties (I've used both).

I'm old enough to well remember stud faders used in broadcasting - built
regardless of cost (balanced faders would probably cost over 1000 quid if
available today). And the regular need for cleaning them. Conductive
plastic was a welcome invention...


Blimey!, I've still got some of them around somewhere, made by Painton IIRC
signal box levers I thing we used to call 'em..

And I had a load of P&G faders and gave them away too!....
--
Tony Sayer

Finding a rotary switch for a stepped attenuator
 

In article , tony sayer

wrote:
In article , Iain Churches
writes


The main advantage of a stepped attenuator is the tracking accuracy.
You will certainly hear a difference.

Or at least, you *might* hear a difference if - for example - the balance
tracking of the two items being compared differ enough to be noticable.
:-)

There are people who will tell you a resistor is a resistor is a
resistor.

ahem There are also people who will tell you that they have run
comparisons, and - when the compared units were of reasonable quality and
the tracking and levels were OK - no-one who tried could tell one type from
another simply on the basis of the sounds. Spock's Law: A difference which
makes no difference is no difference. :-)

FWIW In the tests I've run in the past, I ended up preferring a decent
stepped attenuator like the 40mm Alps simply becuase of the close tracking
and the well-defined set of steps. But neither I or anyone else could tell
these from other pots in terms of any kind of 'sound' if the pots were of
appropriate value, had no manufacturing flaws or deterioration, and were
used appropriately.

They also think a saxophone is a saxophone is a saxophone.
Listen, compare, and make up your own mind.

Indeed. And don't accept everything you are told. Ask for evidence, and
consider how reliable or plausible is may be. This should help you to
distinguish between a resistor and a saxophone... it may also be useful
in deciding when a line of argument makes sense for one, but is irrelevant
to the other. ;-

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Finding a rotary switch for a stepped attenuator
 

Thakns for the info....

I've found a source of 24 way elma switches www.4most.co.uk

Cheers

Steve




wrote:
Hi

Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??

I've looked at previous posts reccommending Blore Edwards but I can't
seem to find them on the web....maybe they're not trading anymore??
Farnell and RS gave me no joy.

I've got a home made amp and I'm currently using a conductive plastic
pot but I'd like to hear the difference in going to a stepped
attenuator.

Thanks in advance

Steve

Finding a rotary switch for a stepped attenuator
 

In article ,
tony sayer wrote:
I'm old enough to well remember stud faders used in broadcasting -
built regardless of cost (balanced faders would probably cost over 1000
quid if available today). And the regular need for cleaning them.
Conductive plastic was a welcome invention...


Blimey!, I've still got some of them around somewhere, made by Painton
IIRC signal box levers I thing we used to call 'em..

Quadrant types weren't balanced though - it was only the older vast round
ones from Type A desks.

--
*Support bacteria - they're the only culture some people have *

Dave Plowman London SW
To e-mail, change noise into sound.

Finding a rotary switch for a stepped attenuator
 

In article ,
Iain Churches wrote:
The main advantage of a stepped attenuator is the tracking
accuracy. You will certainly hear a difference.

You're getting image problems with a normal decent stereo pot? Perhaps you
need to go to M&S as was used in the days of stud attenuators on pro desks
to prevent image waggle...

There are people who will tell you a resistor is a resistor is a
resistor. They also think a saxophone is a saxophone is a saxophone.
Listen, compare, and make up your own mind.

Hmm.

--
*(over a sketch of the titanic) "The boat sank - get over it

Dave Plowman London SW
To e-mail, change noise into sound.

Finding a rotary switch for a stepped attenuator
 

"Dave Plowman (News)" wrote in message
...
In article ,
tony sayer wrote:
I'm old enough to well remember stud faders used in broadcasting -
built regardless of cost (balanced faders would probably cost over 1000
quid if available today). And the regular need for cleaning them.
Conductive plastic was a welcome invention...


Blimey!, I've still got some of them around somewhere, made by Painton
IIRC signal box levers I thing we used to call 'em..

Quadrant types weren't balanced though - it was only the older vast round
ones from Type A desks.

I remember those cylindrical ones. In fact I think I may have a couple of
them at home in the UK. When I was a teenager, we sometimes used to
hang around a small local studio.. The owner had a six channel mixer,
either Grampian or Vortexion, with carbon pots. When they got noisy,
he used to take the back of the pot case, and rub the carbon track with
a soft led pencil. It was a low tech wonder-cure.

Iain

Finding a rotary switch for a stepped attenuator
 

"Dave Plowman (News)" wrote in message
...
In article ,
Iain Churches wrote:
The main advantage of a stepped attenuator is the tracking
accuracy. You will certainly hear a difference.

You're getting image problems with a normal decent stereo pot? Perhaps you
need to go to M&S as was used in the days of stud attenuators on pro desks
to prevent image waggle...

Did some tests in M+S just a while ago. It has been a very long time since
I tried it last. I still have a matrix.

I have no problems with pots. We use 60 pos stepped attenuators:-)

Iain

Finding a rotary switch for a stepped attenuator
 

In article ,
Iain Churches wrote:
You're getting image problems with a normal decent stereo pot? Perhaps
you need to go to M&S as was used in the days of stud attenuators on
pro desks to prevent image waggle...

Did some tests in M+S just a while ago. It has been a very long time
since I tried it last. I still have a matrix.

With M&S any pot mismatch results in a width variation which is far less
noticeable than image wiggle.

I have no problems with pots. We use 60 pos stepped attenuators:-)

You don't mind the severe image wiggle when you operate it?

--
*Learn from your parents' mistakes - use birth control

Dave Plowman London SW
To e-mail, change noise into sound.

Finding a rotary switch for a stepped attenuator
 

"tony sayer" wrote in message
...
In article , Dave Plowman (News)
writes
In article .com,
Andy Evans wrote:
I do believe stepped attenuators beat the rest - including Alps blue
and Black Beauties (I've used both).

I'm old enough to well remember stud faders used in broadcasting - built
regardless of cost (balanced faders would probably cost over 1000 quid if
available today). And the regular need for cleaning them. Conductive
plastic was a welcome invention...


Blimey!, I've still got some of them around somewhere, made by Painton
IIRC
signal box levers I thing we used to call 'em..

And I had a load of P&G faders and gave them away too!....

Maybe Dave was referring to the BBC *rotary* stud faders.
Mechanical works of art they were, with a knob the size of a saucer.
The fader assembly fitted into a cylindrical case a bit like a shell-case,
and latched with a comforting "click"

Iain

Finding a rotary switch for a stepped attenuator
 

In article , Iain Churches
wrote:

"Jim Lesurf" wrote in message
...
In article , tony sayer
wrote:
In article , Iain
Churches writes


The main advantage of a stepped attenuator is the tracking accuracy.
You will certainly hear a difference.

Or at least, you *might* hear a difference if - for example - the
balance tracking of the two items being compared differ enough to be
noticable.

Try a long fade with a rotary pot compared with a stepped attenuator,
say an API, TKD or Studer 60 step. Not difficult to differentiate
between them.

In what terms? Do you mean their stereo tracking accuracies differ? ...or
what? Difficult to comment on the above as it is a rather vague and
sweeping a statement.

If you are referring to differences in channel level tracking then I did
indeed note that in my posting, so I am not sure what point you are wanting
to make here.

However I had thought your original comments about 'resistors' were in the
context of a discussions of the use of the (alleged) 'sounds' of different
attenuators in a domestic audio system.

I can see that a large number of accurate, fine-resolution steps would be
very useful for working in a recording studio, or in similar circumstances
where input level ranges may be high. However this tells us nothing about
any 'sound' differences between different types of pot/resistor/attenuator.
Nor does it mean such a 60 step attenuator would be needed in a domestic
audio system. Hence your mentioning it may confuse or mislead some readers
who are unaware of the different requirements between pro recording and
domestic replay.

To go back to the early part of the thread, it may be that if someone
*does* require many fine/accurate steps with well-matched tracking, then
a digital attenuator may make far more sense in a domestic audio system,
and may produce a 'sound' that is indistinguishable for expensive analog
attenuators. That said, I suspect most users would be just as happy with
either a continuous analog pot of good tracking, etc. I doubt most people
would care if their replay level on one day was, say, half a dB different
to on another day. :-)

It is also fairly certain that the better faders will also perform more
accurately for a much longer time.

Comment as above. Also, please put this in the context of using volume
controls of faders in domestic audio equipment.

The reality here is that - in domestic systems - people may not mind much
if over the years the pot/attenuator drifts slightly. They may simply not
notice, or be bothered. May have no effect on the 'sound' so far as the
user is concerned.

FWIW I find it convenient to be able to set a 'known gain' and repeat this,
but this has nothing to do with the sound as such.


By the way, Alps, which you mentioned are not rated very highly, and
seldom seen on prof equipment.

Comments as above. :-) My experience is that they work very well in
domestic audio equipment. I certainly remain quite happy with the ones
in the kit I built 20+ years ago. And when I've checked the performance,
I've not noticed any significant changes. Doesn't seem to have harmed
my enjoyment at all. ;-

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Finding a rotary switch for a stepped attenuator
 

"Iain Churches" wrote in message


The main advantage of a stepped attenuator is the tracking
accuracy.

Agreed, but at a cost - the steps may not be to your liking.

You will certainly hear a difference.

If you compare a stepped attenuator to a non-stepping attenuator, it is
unlikely that absent test equipment, you'll ever get the two to match
attenuations close enough to have a valid listening test.

There
are people who will tell you a resistor is a resistor is
a resistor.

Bogus straw man argument.

They also think a saxophone is a saxophone is
a saxophone.

Bogus red herring argument.

Listen, compare, and make up your own mind.

Just be sure that you are comparing apples to apples.

Finding a rotary switch for a stepped attenuator
 

"Arny Krueger" wrote in message
...
"Iain Churches" wrote in message


The main advantage of a stepped attenuator is the tracking
accuracy.

Agreed, but at a cost - the steps may not be to your liking.

You will certainly hear a difference.

If you compare a stepped attenuator to a non-stepping attenuator, it is
unlikely that absent test equipment, you'll ever get the two to match
attenuations close enough to have a valid listening test.


Hi Arny.

I am not talking about the cheap and cheerful Yamaha 02R
attenuators which you use. Try a TKD or Studer 60 position,
and forget your toy shop console for a moment:-)

Stepped attenuators are available level matched to 0.25dB and
even when motorised, and offset, can maintain this setting
accuracy throughout their working life.

Iain

Finding a rotary switch for a stepped attenuator
 

"Iain Churches" wrote in message


I am not talking about the cheap and cheerful Yamaha 02R
attenuators which you use. Try a TKD or Studer 60
position, and forget your toy shop console for a moment:-)

Just like you Iain to not know that the Yamaha 02R96 panel controls don't
attenuate audio at all. They are programmable human user interface
transducers that control DSP-based functions.

Stepped attenuators are available level matched to 0.25dB
and even when motorised, and offset, can maintain this
setting accuracy throughout their working life.

Seems pretty crude compared to 02R96 main channel and aux channel
attenuators which have 0.1 dB steps, 0.0 dB channel tracking, and 0.0 dB
resettability.

Finding a rotary switch for a stepped attenuator
 

"Arny Krueger"


If you compare a stepped attenuator to a non-stepping attenuator, it is
unlikely that absent test equipment, you'll ever get the two to match
attenuations close enough to have a valid listening test.


** What a Classic " Bogus straw man argument " !!!

PLUS also a " Bogus red herring argument" !!!

Arny has excelled himself - LOL !


For a scientifically valid listening test, levels MUST be matched using
audio test equipment - Arny has publicly stated this fact countless
times.

By definition, a continuously variable attenuator can be set to exactly
match any setting on a stepped one.

Arny is out to lunch here.




........ Phil

Finding a rotary switch for a stepped attenuator
 

wrote in message
ups.com...
Hi

Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??

I've looked at previous posts reccommending Blore Edwards but I can't
seem to find them on the web....maybe they're not trading anymore??
Farnell and RS gave me no joy.

I've got a home made amp and I'm currently using a conductive plastic
pot but I'd like to hear the difference in going to a stepped
attenuator.

**You'll certainly hear a difference, alright. 20 steps is utterly
inadequate to resolve the differences in level required for a decent system.
Try 100+ steps and you'll be getting somewhere. To do that, I'd suggest a
relay/resistor matrix is the way to go. The most recent example I've worked
on was in a Conrad Johnson preamp. It was pretty impressive. At least as
good as an Alps 'Blue Velvet' pot. Without the latter's (slightly) superior
ability for fine volume adjustments.

20 steps, you have to be joking!


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

Finding a rotary switch for a stepped attenuator
 

In article , Trevor Wilson
wrote:

wrote in message
ups.com...
Hi

Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??


**You'll certainly hear a difference, alright. 20 steps is utterly
inadequate to resolve the differences in level required for a decent
system. Try 100+ steps and you'll be getting somewhere.

20 steps, you have to be joking!

Oddly enough, I find that 21 steps suits me fine in use. Been using 21-step
attenuators for years, and find both the range of adjustment and the sizes
of the steps are no problem in practice.

Looks like there is a dramatic and unexpected distinction between 20 steps
and 21. :-)

Above said, I'll add two caveats.

1) The above is for domestic replay equipment. If I wanted to adjust levels
in the context of professional 'live' recordings then I'd agree that 20
steps would be insufficient. It would lack the required range and
resolution. But the point here is I find that the recording/broadcast
engineers have already set decent levels to the point where a 21 step seems
to me to cope fine.

2) I do tend to modify the input sensitivity and/or output levels of
sources to avoid the situation where I'm having to switch between a 2V
nominal source and a 150mV nominal one and having to wind the volume
setting up or down around 20dB just to correct for this. This is largely
because I tend to use a mix of 'old fashioned' and 'more modern' sources,
though.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Finding a rotary switch for a stepped attenuator
 

In article ,
Jim Lesurf wrote:
2) I do tend to modify the input sensitivity and/or output levels of
sources to avoid the situation where I'm having to switch between a 2V
nominal source and a 150mV nominal one and having to wind the volume
setting up or down around 20dB just to correct for this. This is largely
because I tend to use a mix of 'old fashioned' and 'more modern' sources,
though.

Heh heh - I've got amps on the outputs of the DVD recorder, Freeview tuner
- both fed into the TV - and an amp on the output of the new TV to bring
that up to pukka DIN standard phonos of the old Philips this has replaced.
Otherwise it would have meant altering everything else feeding the main
amp, which like you I spent some time getting as near right as possible...

--
*Why is it that rain drops but snow falls?

Dave Plowman London SW
To e-mail, change noise into sound.

Finding a rotary switch for a stepped attenuator
 

In article , Dave Plowman (News)
wrote:
In article , Jim Lesurf
wrote:
2) I do tend to modify the input sensitivity and/or output levels of
sources to avoid the situation where I'm having to switch between a 2V
nominal source and a 150mV nominal one and having to wind the volume
setting up or down around 20dB just to correct for this. This is
largely because I tend to use a mix of 'old fashioned' and 'more
modern' sources, though.

Heh heh - I've got amps on the outputs of the DVD recorder, Freeview
tuner - both fed into the TV - and an amp on the output of the new TV to
bring that up to pukka DIN standard phonos of the old Philips this has
replaced.

In our 'living room' system I use a switch to select between the SPDIF
outputs from the DTTV tuner, the DVD recorder/player, and the CD player.
Fed to a DAC, and then to a Quad 34. This works fine - although I have
altered the sensitivity of the 34 input connected to the DAC. It nominally
means they all are presented to the preamp as coming from a source with the
same output ref/0dB level.

Most of the time the volume setting I use with this system is in the range
from step '5' to '10'. In practice, '5' for TV/DVD/popular music and '10'
for Classical music on CD, etc.

Exceptions being '4' for some exceptionally loud DVDs which seem to be
level compressed to 0dBFS all the time, and around 12-13' for some CDs
recorded from R3 DAB with no level adjustment made during recording.[1]

I also use an FM4 into another input, again with the preamp sensitivity
altered so that I find the range from '5' to '10' is fine for listening to
BBC stations.

The control on the Quad 34 (as is usual for such attenuators) doesn't have
uniform steps. However from my experience a 20- or 21-step with steps of
about 2dB would actually be fine in normal use. The only snag being that
you might want a preamp sensitivity that you can set appropriately for
different inputs (i.e. different signal sources).

FWIW one of the reasons I like the Quad 34 is that the circuit diagrams and
the board layout (with component numbers printed on the PCBs) makes
modifying the input sensitivities, etc, dead easy.

I suspect that if I were designing a preamp for general sale these days,
I'd include a simple way for the user to set the input sensitivites of
individual inputs over a 20dB range, and then provide a 20- or 21-step
attenuator as the volume control. IIUC some amps do this in various ways,
and it seems a sensible approach to me as it overcomes having to use the
volume control to deal with having different sources with inherently
different reference/0dB levels.

Slainte,

Jim

[1] i.e. recorded by feeding SPDIF from a DAB tuner to a CDRecorder with
the digital gain left at 0dB - i.e. the recorder accepting the levels as
presented. The results for R3 concerts seem to show that the level almost
never peaks above about -6dB. i.e. two or three steps on the Quad
attenuator in the range I use.

The 'loudest' DVDs I've come across aren't a blockbuster film. They are the
'Saint' colour TV collection. These seem to have been compressed to death.
Perhaps they assume anyone old enough to want these because they recall
liking the orginal broadcasts must be deaf... ;-

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html