compact stackable relay attenuator - something new - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st October 2012, 04:53 PM   #1
diyAudio Member
 
Join Date: Apr 2010
Location: Hungary
Default compact stackable relay attenuator - something new

There are many options when a DIY-er want volume control. Some of them are regular and some are very high-end. High-end options usually prevent the audio signal from going trough a potentiometer and uses fixed steps with more precise matching between channels.
What I show you is not entirely new, it is a relay based stepped attenuator.
Stepped attenuators can be very-very precise and can replace old potentiometers. In a regular stepped attenuator there are like 24-26 steps. This is why the relay based stepped attenuator is made, which can do easily 4x the steps, or more.

My idea was to design such an attenuator for my DIY projects but something hit my mind. Many of us likes the ODAC the USB DAC designed by NwAvGuy. When I first got my hand on it I was amazed how small it is. And it got me to think if I can do a layout for my attenuator in such a small form factor.

For this I had to use a 2 board stack design. But not only 2 boards are possible. The way I show You next is possible to have:
Single ended setup (most stereo setup)
Balanced setup (like some headphone amplifiers)
Multi-channel setup (home cinema)

To complete the specs.:
It supports 128 logarithmic steps, it has 2 channel input with source selector, remote control receiver and an external delayed relay drive (possible headphone pop protection).
Size: 58mm x 50mm x (stack high)

Click the image to open in full size.

I have a working prototype on my desk, it sounds excellent. I will make a few more.

Click the image to open in full size.


Next to do:
-buying long leg stackable female headers
-fine tuning layout
-taking more photos
  Reply With Quote
Old 22nd October 2012, 03:58 PM   #2
diyAudio Member
 
Join Date: Apr 2010
Location: Hungary
How do You guys like it?
Are there any live multi channel DIY projects I can check on?
  Reply With Quote
Old 22nd October 2012, 07:01 PM   #3
diyAudio Member
 
Join Date: Apr 2010
Location: Hungary
I have to correct myself as there was some misunderstanding on a different forum. The attenuator was made in sight of a company for an ODAC. Thus it was first planned only single ended, as the ODAC.
My plan was to build a small box, and a desktop amplifier with USB DAC, this way, the attenuator could be mounted below an ODAC to occupy the least space in the box.
Only in the design process it turned out it could be expanded to balanced or even multichannel (for an appropriate source).

Last edited by Earfanatic; 22nd October 2012 at 07:03 PM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yet another relay attenuator jwb Solid State 34 21st July 2010 07:17 AM
YET another relay attenuator question robmil Solid State 0 14th April 2008 05:44 AM
Relay Attenuator for tube amp Vidi Tubes / Valves 9 11th December 2006 04:09 PM
relay based attenuator squadra Solid State 21 1st December 2004 10:10 PM
Ladder relay attenuator or so? Eccu Solid State 0 6th October 2003 11:00 AM


New To Site? Need Help?

All times are GMT. The time now is 07:57 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2