Potentiometer with bass boost pin for Simple SE? - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 26th October 2008, 01:39 PM   #1
dubdub is offline dubdub  United Kingdom
diyAudio Member
 
Join Date: Jan 2008
Default Potentiometer with bass boost pin for Simple SE?

Hi

I have purchased 50K Potentiometer for my Tubelab Simple SE with 4-legged connections (IN) (OUT) (GROUND) plus the fourth leg which can be used for 'bass boost'. Has anyone come across these before? I was wondering if it would be possible to hook up the 4th pin to a switch where I could flick for a bass boost on/off. Being an Ebay jobbie it probably wont sound too good but wanted to experiment anyway.

can be found here:

http://cgi.ebay.co.uk/2x-50K-Stereo-...742.m153.l1262


Any Advice would be appreciated!

Thanks
  Reply With Quote
Old 26th October 2008, 02:25 PM   #2
diyAudio Member
 
Ty_Bower's Avatar
 
Join Date: Mar 2007
Location: Newark, DE
Quote:
One function of the fourth terminal on the volume pots was a tap for the loudness switch. The tap was tied to ground through a capacitor and resistor. The loudness switch would short across the capacitor. I would guess that the circuit also gave the pot a response similar to an audio taper pot. Probably a cheap way to do two things at once.
  Reply With Quote
Old 26th October 2008, 04:51 PM   #3
dubdub is offline dubdub  United Kingdom
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally posted by Ty_Bower

Thanks Ty! do you have any idea of how to connect the cap and resistor to a flick switch and what value? any help/advice is appricated
  Reply With Quote
Old 26th October 2008, 07:02 PM   #4
diyAudio Member
 
Ty_Bower's Avatar
 
Join Date: Mar 2007
Location: Newark, DE
There's an idea here:
http://www.diyaudio.com/forums/showt...099#post392099

You could probably dig up a bunch more by searching "loudness tap circuit" or "loudness tap schematic".
  Reply With Quote
Old 27th October 2008, 03:57 AM   #5
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Usually there will be a series resistor and cap. Normally to defeat the loudness you short the capacitor - this prevents significant changes in signal levels above the corner frequency of the series rc network. (RC network with free end of resistor to tap, free end of cap to ground.)

The resistor in the series RC network will usually be some fraction of the resistance from the loudness tap to ground.. Near equal value provides about 6dB of boost, and something like half about 10dB. (Caveat math probably way off, but you get the point.) Cap value can be selected based on the desired corner frequency.. Something on the order of 50 - 80Hz probably would not be unusual depending on the application. You can experiment to find the best combination(s) for your speakers, listening preferences, music, etc.. You can also make the corner frequency switchable by having several switch selected capacitors - this could be a rotary switch that also provides the loudness defeat function. (Since this is a first order network something like an octave apart would be a starting point.) You can reasonably iterate until you find the appropriate values..
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  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
bass boost odysseybmx414 Chip Amps 3 26th August 2005 09:05 AM
Bass Boost Q UNDERSTANDIN Subwoofers 5 26th July 2005 08:49 PM
Bass Boost UNDERSTANDIN Subwoofers 3 22nd July 2005 04:37 AM
bass boost lawbadman Solid State 4 29th August 2003 02:20 PM
simple bass boost circuit deepanger Solid State 11 28th December 2002 01:37 PM


New To Site? Need Help?

All times are GMT. The time now is 04:33 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