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Old 2nd July 2008, 06:53 PM   #121
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Gee Steve... that's a destroyer ship which is about to shoot one lytic missile.

Thankfully is only unity gain
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Old 2nd July 2008, 07:59 PM   #122
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Quote:
Originally posted by apassgear
Gee Steve... that's a destroyer ship which is about to shoot one lytic missile.
Hehehe. Yeah, I rather rushed the assembly of that unit so I could get it to the photographers.

Thankfully it didn't launch, but only blew its load of electrolyte all over the circuit board.

se
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Old 2nd July 2008, 08:57 PM   #123
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Quote:

and the LSK170 is available and cheap enough.


It would be nice to organize a group buy for the Linearsystem . Such LSK389 and LSK170 .
They are really cheap after all .

Sorry if eventually that is already made before and I didnt noticed it .


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Old 3rd July 2008, 12:26 AM   #124
jackup is offline jackup  Viet Nam
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For me the R1 information is not clear. I see R1: 1 3W. Please tell me what does "1" mean, may be a typo?
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Old 3rd July 2008, 12:46 AM   #125
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Quote:
Originally posted by jackup
For me the R1 information is not clear. I see R1: 1 3W. Please tell me what does "1" mean, may be a typo?
The "1" means 1 ohm. The "3W" means it's a 3 watt resistor.

se
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Old 3rd July 2008, 07:15 PM   #126
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Default Stepped attenuator

I found a "reasonable" price on a 24 position rotary switch, and since it seems like dual gang linear taper potentiometers are hard to find, I decided to try my hand at making a stepped attenuator (I just can't stand the idea of dual mono pots to be adjusted separately).

My question: will a shunt-type attenuator be a bad idea for this circuit? What I'm worried about is that the pot supplies the input resistance. Is 2K input resistance at the loudest volume enough?

- diomedian
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Old 3rd July 2008, 08:17 PM   #127
udailey is offline udailey  United States
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Here is an even easier way to do something similar and yet completely different. This, I think, is my afternoon project sometime in July after F5 and B1 are built.



Dual Audio Taper Potentiometer with Pushbutton Control
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2778
* Two digitally controlled, 65-position potentiometers
* Ultra low-power consumption
* Software and hardware controlled mute
* Digital or mechanical pushbutton wiper control
* Potentiometers can be linked for stereo control
* Logarithmic resistive characteristics (1dB per step)
* Zero-crossing detection to eliminate noise
* Serial port communication
* Can be daisy-chained for single-processor, multidevice designs
* Operating temperature range: -40°C to +85°C
* Operating voltage range: 3V or 5V
* Resistance available: 45kΩ
$2.56 @ 1k
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Old 3rd July 2008, 08:28 PM   #128
Tolu is offline Tolu  Germany
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Quote:
Originally posted by udailey
Here is an even easier way to do something similar and yet completely different. This, I think, is my afternoon project sometime in July after F5 and B1 are built.



Dual Audio Taper Potentiometer with Pushbutton Control
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2778
* Two digitally controlled, 65-position potentiometers
* Ultra low-power consumption
* Software and hardware controlled mute
* Digital or mechanical pushbutton wiper control
* Potentiometers can be linked for stereo control
* Logarithmic resistive characteristics (1dB per step)
* Zero-crossing detection to eliminate noise
* Serial port communication
* Can be daisy-chained for single-processor, multidevice designs
* Operating temperature range: -40°C to +85°C
* Operating voltage range: 3V or 5V
* Resistance available: 45kΩ
$2.56 @ 1k
That is what Nelson Pass used in the integrated amp (INT-150).
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Old 3rd July 2008, 08:58 PM   #129
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Default Log Taper Pot

I don't know why it didn't occur to me before, but can a log taper pot be used instead of the linear taper noted in the article?

The nice digital pot shown above is log taper...

- diomedian
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Old 3rd July 2008, 08:58 PM   #130
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One of the keys to good performance with that chip is an
extremely high impedance load.
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