R2R Shunt Volume with 3 selectable sources - diyAudio
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Old 14th September 2015, 06:08 AM   #1
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Default R2R Shunt Volume with 3 selectable sources

This design:


HQ-R/2R VOLUME Technical Specifications:
– low tolerance 0.1% R-2R network with melf resistors
( resistors in parallel produce a pure resistor).
– attenuation in 64 steps - each step 1dB
– Input resistance ranges from 20k to
47K for a Rload of 47K.
– Output resistance ranges from
22K to 47K.
3 selectable inputs with option to edit input name
– one direct input
– display back-light programmable On/Off - if Off timeout 10s
20X 4 display characters for wide view
– tube menu for delaying plate voltage
- 3-modules design: Powers Supply (PS), Control and Display Unit (CDU), Relay Module (RM) in SE or Balanced modification.
-Volume attenuation by rotating optical encoder or from IR remote control.
- Input selection by rotating optical encoder or from IR remote control
- Display auto dimming with adjustable brightness level
- ONE open collector outputs for power On/Off and tube plate delay
- Main AC power on/off control
– AC power consumption, Max. 6W.

Special : The avoidance of clicks is the major improvement with respect to my original attenuator design of several years back.

in most of the design volume -32db relay at transition to -31dB, the relay volume 64 steps are emitting huge sound in the speakers, causing discomfort, not safe for the system.

I definitely settle this phenomenon, therefore, very smooth transition Volume and sound great.

This link for Video of Volume: https://www.youtube.com/watch?v=s9QEZduZavs

this complete module assembled including the aluminium remote at 250$ + shipping.


please see some other designs:

The δ1 relay-based R-2R stereo attenuator

Audio Volume Relay Attenuator with IR Control

VC-03 Volume Control
Attached Images
File Type: jpg Relay 1.jpg (144.3 KB, 101 views)
File Type: jpg relay2.jpg (83.4 KB, 102 views)
File Type: jpg relay 3.jpg (151.1 KB, 100 views)
File Type: jpg relay4.jpg (142.2 KB, 98 views)
File Type: jpg relay5.jpg (119.0 KB, 98 views)
File Type: jpg relay6.jpg (123.6 KB, 43 views)
File Type: jpg Remote-control-silver-aluminum volume.jpg (62.9 KB, 38 views)
File Type: png Shema relay R2R 64 hq.PNG (87.1 KB, 53 views)
Group buy DAC-END R (ES9018) full assembled board
update 06/14/2013 :http://www.audiodesignguide.com/DAC32/index2.html

Last edited by quanghao; 14th September 2015 at 06:41 AM.
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Old 27th November 2015, 03:58 AM   #2
Junie is offline Junie  Philippines
diyAudio Member
Join Date: Sep 2010
Location: UAE
This seems to be a good option for my GM preamp clone, what is the size of the LCD display? I have a Chassis but I want to know if the display will fit on the front panel.
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