Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

adding volume control to my chip amp
adding volume control to my chip amp
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
Thread Tools Search this Thread
Old 23rd September 2010, 02:55 PM   #1
darkczar is offline darkczar  United States
diyAudio Member
Join Date: Mar 2010
Location: New york city
Default adding volume control to my chip amp

Hi - I just finished a TDA 2050 stereo amplifier - my first project. Now I'd like to add a volume control. I think I need a "passive attenuator". I need less volume from the CD player, basically. Can someone point me to a simple schematic or something? I assume I just need to solder a potentiometer into the input path, but I guess I need to somehow mechanically gear them so that both channels are adjusted with one knob? I'm in the UK, so 'll probably be ordering parts from Farnell.co.uk.

I would love to add bass/treble control, but I'm going to save that for later, unless it's very simple, cheap and quick.

I did some searching on here before I posted this, but I couldn't find what I need. If the answer is somewhere obvious, can you please hook me up?

  Reply With Quote
Old 23rd September 2010, 03:23 PM   #2
firechief is offline firechief  United States
diyAudio Member
firechief's Avatar
Join Date: Sep 2008
Location: Near Seattle Wa
Search on this forum, or google "dual gang pot". Once your understand the function go to your parts distributer and see what's out there. Do you know the input impeadance of the TDA 2050 amp? as this will be important information in selecting a pot value. Also the output impeadance of teh CD player. (perhaps low like <1K).
  Reply With Quote
Old 23rd September 2010, 06:31 PM   #3
Mankysteve is offline Mankysteve  United Kingdom
diyAudio Member
Join Date: Aug 2010
Here what ive learnt so far from recent question I've posted. For one choose a decent pot if you going the Pot route. Nobel have been recomened to me as well as Alps
potentiometers - Hifi Collective see here for UK supplier.

You'd use a pots that has is stereo compatibility from the get go. no need for connectors and such.

Also look at using a shunt resistor.

Also take a look at stepped attenuators
  Reply With Quote
Old 23rd September 2010, 09:47 PM   #4
wakibaki is offline wakibaki  United Kingdom
Join Date: Jan 2008
Here's the basic idea. You need a dual-gang logarithmic potentiometer. Dual-gang means 2 pots linked on a common spindle

Click the image to open in full size.

The 100k pot shown is from a valve amplifier, 10k is probably more appropriate for a CD player and chip amp. You might conceivably need to go as low as 1k, but I doubt it. The value should ideally be higher than the CD player output impedance and lower than the chipamp input impedance. You connect the input signal to one side of the pot, signal ground to the other, and take the signal from the wiper (centre connector) to the amp. If the volume control is not clockwise for UP then swap the input signal and ground connections.


Last edited by wakibaki; 23rd September 2010 at 09:49 PM.
  Reply With Quote
Old 23rd September 2010, 10:36 PM   #5
dmx2020 is offline dmx2020  New Zealand
diyAudio Member
Join Date: May 2005
Location: auckland
Here's some (bass mid treb vol). (found on google)

Adam's Amplifiers: Tone Stacks

Tone Control circuit diagrams using IC TL082 | ELECTRONIC CIRCUIT

Portable Mixer - RED - Page53
Attached Images
File Type: gif ToneControl.gif (3.7 KB, 670 views)
File Type: gif active-Tone-controll-that-Boosts.gif (5.5 KB, 673 views)
  Reply With Quote
Old 24th September 2010, 08:36 AM   #6
darkczar is offline darkczar  United States
diyAudio Member
Join Date: Mar 2010
Location: New york city
Thanks all! This is great stuff. I'm going to research my impedances and order a dual gang pot.

I'll probably be switching between the CD player and my ipod, so I guess I'll just pick a potentiometer that seems like it will work for both.
  Reply With Quote
Old 24th September 2010, 09:06 PM   #7
AndrewGM is offline AndrewGM  United Kingdom
diyAudio Member
Join Date: Jun 2008

Not sure about tone controls in th context of your question but what I did was
type ' Stepped Attenuator ' in E bay and choose a value to suit.
You can spend a lot or spend very little and still get good results.
There are plenty of values to choose from once you decide or find out the best impedance match for your kit - as already mentioned.

  Reply With Quote
Old 24th September 2010, 10:04 PM   #8
tryonziess is offline tryonziess  United States
diyAudio Member
Join Date: Apr 2007
The 23 step resistor type attenuators on ebay work pretty darn good for less than 20.00 each. You will notice at times that the switch does not fully engage the slot and may need to be touched. Once set they are almost invisible in the circuit. You could search long and hard and spend serious money but these chinese units are really good.
Please ask for a wiring schematic from the seller. It sometimes speeds things up. There is also a seller for the full monty, source selector step attenuator and all which comes with a nice aluminum housing and all. You may have to search for it. A complete passive in one housing. It is important to order the input impedance your amp design requires or your volume settings may be too low or too high.

Good luck on this project you are now addicted to diy Tad
  Reply With Quote
Old 25th September 2010, 12:00 AM   #9
darkczar is offline darkczar  United States
diyAudio Member
Join Date: Mar 2010
Location: New york city
HI - I couldn't resist walking over to Maplin this morning and buying a 10K dual gang pot for 2 pounds and 53 pence. It's made in the UK. It seems to work fine. I had to solder a few different times before I got it set up correctly, but it works OK. I plugged my TV's audio output into the amplifier, and it's wicked loud, but I was able to turn the volume almost all the way down, and it was OK.

I'm definitely going to add some bass and treble next. The TV puts out very bass heavy sound through my amp and speakers. It sounds tinny through the TV speakers. It would be a nice blend, except that there's a few millisecond delay between them, so everyone sounds like Darth Vader.
  Reply With Quote
Old 26th September 2010, 08:32 AM   #10
inVain is offline inVain  Indonesia
diyAudio Member
inVain's Avatar
Join Date: May 2009

it's nice that you already bought your dual-gang pot....

but during my past experience, I found out that stepped attenuators has better sonics performance than the log pots....
even if they were made of cheap resistors and rotary switch (in similiar price range)

so my suggestion,
you should try one compared to your pot

  Reply With Quote


adding volume control to my chip ampHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Adding volume control to Lite DAC-AH jaykick Digital Source 9 12th September 2007 07:32 AM
is this the correct way of adding a volume control? jarthel Tubes / Valves 4 30th March 2007 09:32 AM
Adding a Volume Control(PLEASE HELP) jodogzzz Everything Else 0 8th October 2006 11:19 AM

New To Site? Need Help?

All times are GMT. The time now is 02:49 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio