How should I integrate this remote volume control? - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 August 2005, 09:19 AM   #1
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
Question How should I integrate this remote volume control?

I will shortly be building a diy remote volume control kit:

http://www.altronics.com.au/index.as...=item&id=K5026
Click the image to open in full size.

It controls a 20k pot.

I'm currently using an integrated amp, which has pre-out/main in, and I have inserted Behringer Ultracurve in between pre and power amps, which means I can use it to provide more gain. This makes me think, should I bypass having a normal preamp? Could I insert this 20k motorised pot before or after Ultracurve?

It has a +12 and +22 dbu setting which as I understand, alters the gain ...

I have a non working ESP preamp (the one with tone controls), which I could get working and insert it in there perhaps ... (but don't really want the tone controls now) ...

If I inserted this motorised pot in without any preamp, would it then be a passive line level attenuator? I have never been clear on what is the difference with those apparently expensive passive attenuators!
  Reply With Quote
Old 29th August 2005, 12:06 PM   #2
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
It's a good value kit and I've done a few. Never could get the mute to work properly as too touchy on adjustment so the track was cut as suggested in the instructions and the pot varies in quality.... have had a real good one and others crappy. I ended up getting one of the 16mm Alps that Peter Daniel was selling and was very cheap and sounds good.

Motorized Alps pots, 2 x 50K log

Just wire it in after the selector and before your pre out. You can try passive or with your active pre in the existing location. Passives are a strange beast and when they sound good they are great but when they don't.... er.... awful. Impedance matching and all that stuff. The only amp I've ever had luck with a passive was the GC.

Here's a layout but has an active pre.... igonore that and it's a passive.
Attached Images
File Type: jpg opa627 in case all view.jpg (49.0 KB, 458 views)
  Reply With Quote
Old 1st September 2005, 12:18 PM   #3
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
Ok I've built the kit, grabbed some remotes to see if one of them can control it. Fortunately yes, one of them does

However ...

I then programmed the signal that worked into my learning remote, and then tried it. It worked as well, but only for a short time! I disconnected from the power, and after half a minute tried again and it worked for a few moments, then stopped working again. This happened yet one more time ...

but now it doesn't seem to work at all!

Any ideas?

Yes - it has adequate power 12V going to the terminals
Yes - all the connections seem fine

One strange thing - there was a spair MKT cap left over, did you find that as well? Also, does that chrystal thing have a polarity?
  Reply With Quote
Old 1st September 2005, 12:26 PM   #4
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
Now I tried it again and it works just fine!!! .... ahhh how to understand this!
  Reply With Quote
Old 1st September 2005, 01:17 PM   #5
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
Should be 3 100nF MKT's on the PCB. If they are all there, then surplus. There is another 10nF MKT for the motor filtering. 4MHz Crystal can go in any direction.

Just double check the wires running to the motor as sometimes the fine wires break. Once I solder these on I put heatshrink over the joint to act as a sort of strain relief (put the heatshrink on the wire before soldering).

If it happens again, check the voltage at the input terminals and pull out IC1 and measure the voltage between pin 5 and 14 on the socket for roughly 5V.
  Reply With Quote
Old 1st September 2005, 01:38 PM   #6
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
ahhhh that's the cap I was talking about ... so how do I put it in?

I tried it out in my system passively, after the switchbox and before preamp, and it sounded terrible. Apart from very unsteady changes in volume, which seemed to change almost randomly, the overall sound was terrible - distorted like a very cheap amp (ie. 1w) and speakers turned up to their limit. TV speakers would sound good in comparison!

It appears I'll have to do a diy preamp! ... I did one as one of my first electronics projects, however it didn't work

Any ideas why it might sound so bad?
  Reply With Quote
Old 1st September 2005, 02:28 PM   #7
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Quote:
Originally posted by paulspencer
ahhhh that's the cap I was talking about ... so how do I put it in?

I tried it out in my system passively, after the switchbox and before preamp, and it sounded terrible. Apart from very unsteady changes in volume, which seemed to change almost randomly, the overall sound was terrible - distorted like a very cheap amp (ie. 1w) and speakers turned up to their limit. TV speakers would sound good in comparison!

It appears I'll have to do a diy preamp! ... I did one as one of my first electronics projects, however it didn't work

Any ideas why it might sound so bad?

Sounds as if you have too much gain in your system. Maybe you should try without that Behringer, or preset that for a comfortable range on the remote control.

Jan Didden
__________________
I won't make the tactical error to try to dislodge with rational arguments a conviction that is beyond reason - Daniel Dennett
Check out Linear Audio Vol 7!
  Reply With Quote
Old 1st September 2005, 11:47 PM   #8
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
How can there be too much gain? If that were the case, surely the amp would be clipping. However, in this case, the sound is distorted at any volume when the pot is included as a passive attenuator. Not distorted as in the peaks being clipped, but distortion as in the entire signal sounds like AM radio on a cheapie clock radio!

Rabbitz, what do I need to do with that 10nf MKT cap?
  Reply With Quote
Old 2nd September 2005, 12:47 PM   #9
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
The 10nF goes across the motor terminals.... see the pic below.

Too much gain really can make the sound sound harsh and ill defined. Had a Rotel pre amp attached to an AKSA and the Rotel must have had a zillion dB gain as it was full bore about 9 o'clock so I put in a dividing network to attenuate the signal which was OK until I finished my pre amp with 6dB of gain.

Try the passive first with only the source > pot > power amp without any other electronics. Then add one active thing at a time.

Just double check you have the pot wired correctly... looking from the front:
Right pin is IN
Centre pin is OUT
Left pin is GRD
Attached Images
File Type: jpg alpha 20k pot.jpg (61.8 KB, 222 views)
  Reply With Quote
Old 2nd September 2005, 12:59 PM   #10
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
Quote:
Originally posted by paulspencer
[B]How can there be too much gain? If that were the case, surely the amp would be clipping. /B]
Doesn't quite work like that but I believe you can overload the power amp with too much voltage in... so it's not clipping as such. Make sure your Behringer doover is set to the lowest gain as 22dB is a HUGE amount of gain..... a virtual power amp.
  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
Volume control on DVD player remote. Lose resolution at low volume? Circlotron Digital Source 2 10th June 2011 07:20 PM
Remote volume control for existing remote? theAnonymous1 Parts 7 6th August 2007 08:22 AM
The remote control paratactic volume control audio-gd Solid State 33 7th June 2007 11:16 PM
remote control motorised control for volume pot/knob CharlesY Parts 0 25th July 2005 11:12 AM


New To Site? Need Help?

All times are GMT. The time now is 09:42 PM.


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