Attenuator opinions? - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, 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 29th December 2003, 03:21 AM   #1
diyAudio Member
 
tsmith1315's Avatar
 
Join Date: Jul 2003
Location: Doerun, GA
Default Attenuator opinions?

Hi all.

I'm looking to add an attenuator into an automotive preamp I'm designing.

After mixing or switching the inputs from cass/CD, the first stage will be a follower with gain of 10 or so. I'm using an Analog Devices AD 797 for this, and to capitalize on the low noise aspect of this op-amp I'd like to use a stepped attenuator to provide constant input and output impedances. Frequency compensation is a viable option with this arrangement as well.

Looks to me like I'm going to need a 2-gang switch per channel to achieve the desired constant Z. Therefore, a 4-gang switch will be needed for two channels. This limits switch choices to about 6 positions. In light of this, I'm thinking of using a second switch (rotary or toggle) with 10dB steps or so like the old Pioneer SPEC-1 did.

Am I making things too complicated?

I have some *very* nice components to mate this with, so extra effort in design and construction will be worthwhile.


TIA,

Tim Smith
  Reply With Quote
Old 29th December 2003, 11:37 AM   #2
diyAudio Member
 
Join Date: Jan 2001
Location: Scandinavia
Do a search in the Trading Post area for the Apox discussion which should be completely enlightening.

Petter
  Reply With Quote
Old 30th December 2003, 05:12 AM   #3
diyAudio Member
 
hifimaker's Avatar
 
Join Date: Oct 2003
Location: San Jose
If you are looking for a simple rotary attuenator, this guy cannot be beat. I already bought one and the qyality is awesome! He will build any value you like.

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3063320842

-David
  Reply With Quote
Old 30th December 2003, 03:12 PM   #4
diyAudio Member
 
tsmith1315's Avatar
 
Join Date: Jul 2003
Location: Doerun, GA
Petter suggested:

Quote:
Do a search in the Trading Post area for the Apox discussion which should be completely enlightening.
Whoa... 1100+ replies. Interesting reading, this may take some time.


and David plugged:

Quote:
If you are looking for a simple rotary attuenator, this guy cannot be beat.
Not quite what I'm looking for, but a very cool design and at a great price. I wonder how many of them switches he has.

I can't spend a bundle of money on this, but time and effort aren't a problem. It's beginning to look like I'll be scavenging for used parts and working around the parts I find.

Thanks for the help!

Tim
  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
attenuator Matt MacBeth Solid State 1 18th November 2006 01:56 PM
P-1.7 attenuator pinco Pass Labs 1 17th October 2006 08:48 PM
FS:TKD Attenuator sma Swap Meet 1 28th April 2004 12:48 AM
tkd attenuator sma Parts 0 28th December 2003 04:11 AM
attenuator for A75 Vlad Pass Labs 0 8th September 2002 09:17 PM


New To Site? Need Help?

All times are GMT. The time now is 05:51 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