23 step attenuator potentiometer/vishay resistors -

mp9 · 22979

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Offline mp9

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on: October 23, 2009, 03:07:01 PM
- i'd like to know what people here think of it and if it's worth buying?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300351726617&ssPageName=STRK:MEWAX:IT#ht_2042wt_808



Offline Grainger49

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Reply #1 on: October 24, 2009, 01:50:36 AM
You do know that this is a balanced volume control.  That is not for use with an RCA jack (unbalanced) input/output device??  If your system is unbalanced they have other devices that will work.

I have bought a few items from this seller.  They have not been cheap but are not built cheaply. 



Offline mp9

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Reply #2 on: October 24, 2009, 03:36:00 PM
i have the XLR option but the more i think about it i'd rather not buy new interconnects any opinions on the following one?

http://cgi.ebay.com/Valab-23-Step-Attenuator-Potentiometer-100K-Stereo-Log_W0QQitemZ300355947359QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ee9c0b5f#ht_2259wt_808



Offline dmannnnn

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Reply #3 on: October 24, 2009, 06:55:33 PM
Personally I prefer the ladder style.  I tried the dact series attenuator and I found the cheap ladder to sound better especially at low volume levels.  I don't know if this is because the series attenutator runs through all those resistors at lower settings or if I'm just hearing things.

http://cgi.ebay.com/Assembled-Dale-23-Step-Attenuator-Volume-Control-100k_W0QQitemZ270311271326QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3eefceab9e

The seller also has these as a kit.

Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12


Offline mp9

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Reply #4 on: October 24, 2009, 07:14:14 PM
Great that's the kind of response i was hoping for and thank you i may try one.



Offline cvandyke

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Reply #5 on: October 25, 2009, 04:37:14 AM
I'm using these and wish I had spent a bit more and gotten ones built with regular resistors rather than the surface mount (such as this http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110448818328&_rdc=1). The surface mount resistors are held in place only by solder and so when soldering wires on, the resistors can easily become disconnected. While I did get it to work, I found the experience very frustrating. I use only lead free solder with a higher melting point than lead/tin solders so this probably made it much worse.

--Chris

Chris Van Dyke


Offline Grainger49

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Reply #6 on: October 25, 2009, 07:34:24 AM
I just want to be sure.  Is the ladder attenuator is the same as VoltSecod's S5 (single series single shunt stepped attenuator)?

Here is his page.  I'm asking is the "Standard Stepped," Shunt Mode Easiest Stepped" or "Single Series Single Shunt Stepped" attenuator what is being called a ladder?

http://www.siteswithstyle.com/VoltSecond/12_posistion_shunt/12_Position_Pure_Shunt.html

Above is VoltSecond's attenuator page.
« Last Edit: October 26, 2009, 09:13:23 AM by Grainger49 »



Offline dmannnnn

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Reply #7 on: October 25, 2009, 02:20:16 PM
'Shunt mode easiest' looks like it is a normal series attenuator wired in shunt mode with a fixed input resisitor YYY.  This could be done with a normal dact or sweetest whispers attenuator. 

The ladder attenuator would be closest to the 'Single Series Single Shunt Stepped (S5)' attenuator.  But in the ladder attenuator the input resistor YYY is also switched.  There are 2 resistors for each step.  This way the YYY and SSS resistors always add up to the total impedance eg. 100K.  The S5 can be built with a single pole switch, but the ladder requires 2 poles for each channel.

Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12


Offline Grainger49

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Reply #8 on: October 25, 2009, 02:27:21 PM
Thanks, I get it.  And now I remember the S5 has a minimum and maximum impedance.  I'd think not a good thing for the Seduction.
« Last Edit: November 07, 2009, 12:41:49 PM by Grainger49 »



Offline dmannnnn

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Reply #9 on: October 25, 2009, 02:32:23 PM
Here is a link to a great calculator for customizing your own ladder attenuator.  No need to settle for a standard 10 or 100k attenuator with standard 1 or 2 db steps.  Choose your own impedance and your own attenuation steps.  The calc will tell you which resistors to order.  I tried using VS's calculator but got a little too confused (it happens alot). 

[http://homepages.tcp.co.uk/~nroberts/atten.html

Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12


Offline dmannnnn

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Reply #10 on: October 25, 2009, 02:58:50 PM
Wow, here is one I haven't seen before.  New style of 21 step switch with SMD resistors.   Very compact and only $15 shipped for stereo!  If anyone tries these, let us know how they work.

http://cgi.ebay.com/DACT-Type-21-Stepped-Attenuator-Potentiometer-50K-300B_W0QQitemZ120473999989QQcategoryZ3280QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26ps%3D63

Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12


Offline ironbut

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Reply #11 on: October 25, 2009, 05:59:53 PM
Wow, those are cheap.
How's the quality/feel of those ladder types you linked to dmannnn?

steve koto


Offline dmannnnn

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Reply #12 on: October 25, 2009, 10:13:53 PM
I've had them about a year now and haven't had any problems whatsoever.  No switching noise and I'm pretty hard on volume controls.  I bought 2 of the 2 pole blank switches for mono controls.  Building them was a bit tedious to say the least. 

The bodies are all plastic and they feel well built. The terminals are fairly malleable and can bend during shipping, but can be bent back easily.  I haven't had one break.  There is a good solid feel when switching, not springy like the standard sweetest whispers switches.  You can actually take them apart and add or remove layers(poles) like a cake.

I am very taken with those Polish attenuators.  I think they are called Khozmo's?  They just look so cool, but I'm sold on ladder style attenuators over series attenuators.  Unless the series attenuator is wired as a shunt, but then switching noise becomes a problem even with the better switches.  If the switch breaks contact at all, there is no attenuation to the amp.  This will cause some serious popping.  The DACT attenuator (Elma switch) I had wired in shunt started making noise almost overnight.  I think dust was getting into it.  The dust out here in the desert is so fine, and when the wind blows 50 mph it will find its way into everything, no matter how tightly your house is sealed up. 

I haven't tried the blue switches as shunt controls yet.

Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12


Offline Paul Joppa

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Reply #13 on: October 26, 2009, 07:49:59 AM
... Unless the series attenuator is wired as a shunt, but then switching noise becomes a problem even with the better switches.  If the switch breaks contact at all, there is no attenuation to the amp.  This will cause some serious popping. ...
That does not happen if you wire the shunt attenuator as we do in the Foreplay III.

Historical note - this is derived from what was called a "ladder attenuator" back in the thirties; since then the meaning of that term has changed. I've never seen this variant elsewhere, though I can't imagine I'm actually the first to do it this way.

Paul Joppa


Offline Grainger49

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