Commercial Gainclone kit- building instructions - Page 23 - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > Audio Sector

Audio Sector Kits & PC boards from AudioSector

Reply
 
Thread Tools Search this Thread
Old 19th August 2008, 04:28 PM   #221
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
If I ever need heatsinks, I usually buy them locally, surplus.
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 19th August 2008, 07:35 PM   #222
diyAudio Member
 
Join Date: May 2008
Thanks Peter. I did mean the copper bars. Is there a website for the supplier?
  Reply With Quote
Old 19th August 2008, 08:11 PM   #223
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Here it is: http://www.metalsupermarkets.com/

Also, this place stocks copper bars: http://www.mcmaster.com/
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 20th August 2008, 07:31 AM   #224
Ted205 is offline Ted205  United Kingdom
diyAudio Member
 
Ted205's Avatar
 
Join Date: Jun 2008
Quote:
Originally posted by Peter Daniel
The diagram included with kits shows 2 options: parts and connections marked in red are for parallel configuration only, those marked in green are for stereo or bridged setup: http://audiosector.com/lm4780%20amp.pdf

More info was posted on a forum: http://www.diyaudio.com/forums/showt...565#post636565

It is no problem to add larger caps; depending on a system they may bring improvement, but not neccessarily.

the diagram provided shows the jumper in place for parallel work. Looking at the National LM4780 datasheet i need to tie the inputs (in and in ground) for bridged mode so that i only have one input. This suggest i need to put the jumper in place for bridged setup.

can anyone confirm this ?
  Reply With Quote
Old 21st August 2008, 05:37 AM   #225
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
The jumper is in place for parallel setup only. For bridged operation we want to keep inputs and outputs separately, as they are run in opposite phases.
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 21st August 2008, 06:51 PM   #226
Ted205 is offline Ted205  United Kingdom
diyAudio Member
 
Ted205's Avatar
 
Join Date: Jun 2008
but i require only one input per chip. Sorry i'm getting abit confused over the bridged setup.

I understand the schematic in the datasheet where one internal amp is non inverted, the other is inverted resulting in the output opposite phases, doubling the available signal 'swing'.

Looking at the instructions with the kit i can't see how this is achieved.

Sorry if I'm being stupid
  Reply With Quote
Old 21st August 2008, 07:49 PM   #227
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Quote:
Originally posted by Ted205
but i require only one input per chip. Sorry i'm getting abit confused over the bridged setup.

I understand the schematic in the datasheet where one internal amp is non inverted, the other is inverted resulting in the output opposite phases, doubling the available signal 'swing'.

Looking at the instructions with the kit i can't see how this is achieved.
My kit is configured in a such a way, that even in bridged setup none of the amps is inverting: that way, with those boards, you can use half of the kit only, with a single chip wired for stereo operation. Of course, bridged configuration requires balanced signal to the amp, as it will not convert unbalanced to balanced.

If you require one input per chip, you have the option of using each chip in parallel for more current output, or one chip only (non parallel) with two separate channels.

http://www.diyaudio.com/forums/showt...565#post636565
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 24th August 2008, 01:11 AM   #228
F1 FAN is offline F1 FAN  Canada
diyAudio Member
 
Join Date: Jun 2006
If using a 10k pot should I just omit the 22k R2?I will also be including an input cap after the pot and R1 will be 1k.


THanks
  Reply With Quote
Old 24th August 2008, 06:04 AM   #229
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
The 22k input shunt resistor is there for a reason: with simplified GC schematic (and 22k feeedback resistor) it limits the output DC offset.

If you use the coupling cap after the pot, that resisotor is neccessary. If there is no cap, you could omit the R2 resistor, but in case a pot fails the resistor is there for protectioion.
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 24th August 2008, 12:20 PM   #230
CFT is offline CFT  United States
diyAudio Member
 
Join Date: Jul 2006
Location: Hong Kong
Hi Peter,

I understand that the power supply filter caps should be close to the chip's pins.

From your experience, would positioning those caps with PC board traces that are 2 to 3 cm away from the chip make a sonic difference? Just curious.

Thanks!

CFT
  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
Commercial complete Gainclone kit for a beginner? gychang Chip Amps 365 4th October 2011 08:19 AM


New To Site? Need Help?

All times are GMT. The time now is 07:42 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