Newbie GainKlone - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 16th April 2003, 10:32 PM   #1
VoLCoM is offline VoLCoM  Canada
diyAudio Member
 
Join Date: Apr 2003
Location: Saint-Hubert , Quebec
Question Newbie GainKlone

Hi,
I'm starting building a gaincard clone with a LM3875 and i wanted to know if i have to use a for example 40-0-40 or I can use 40-0
because i'm going to power it with Batteries like...2 12V
in series l'll have 24 volt is it enough to power this GainKlone?
and if i must use 40-0-40
how do I do this with batteries?
Attached Images
File Type: jpg sans titre.jpg (50.2 KB, 994 views)
  Reply With Quote
Old 17th April 2003, 12:43 AM   #2
diyAudio Member
 
Steve Eddy's Avatar
 
Join Date: Sep 2002
Location: Sacramento, CA
Default Re: Newbie GainKlone

Quote:
Originally posted by VoLCoM
I'm starting building a gaincard clone with a LM3875 and i wanted to know if i have to use a for example 40-0-40 or I can use 40-0
because i'm going to power it with Batteries like...2 12V
in series l'll have 24 volt is it enough to power this GainKlone?
and if i must use 40-0-40
how do I do this with batteries?
A single 24 volt supply (i.e. 24-0) is really no different in terms of power output than a double 12 volt supply (i.e. 12-0-12). If you're just going to use two 12 volt batteries, then make the supply 12-0-12. But that will only get you about 6 watts or so. If you want more power, you'll need to get another pair of batteries and connect each pair in series so you essntially get a 24-0-24 volt supply. If you get to more batteries again, you can do a 36-0-36 volt supply.

It really all depends on how much power you need.

se
  Reply With Quote
Old 17th April 2003, 06:51 AM   #3
VoLCoM is offline VoLCoM  Canada
diyAudio Member
 
Join Date: Apr 2003
Location: Saint-Hubert , Quebec
Default uh....60watt

I'd like to get 60watt is it possible with a LM3875?

i'd like to make this small and "not heavy" lol. Because I want it to fit in my backpack with 36volt how much power can i get?? i have to mention the amp will not be Stereo. I'll plug the 2 channels of my walkman in the amplifier and the output will be in 1 Speaker and i want it to play very loud!
lol
-Guillaume
  Reply With Quote
Old 17th April 2003, 11:30 AM   #4
Rarkov is offline Rarkov  England
diyAudio Member
 
Rarkov's Avatar
 
Join Date: Aug 2002
Location: North East, UK
Send a message via ICQ to Rarkov Send a message via Skype™ to Rarkov
Hiya,
No, the chips are rated for 56W if my memory recalls...Also the distortion goes sky high when you get anywhere near that level. a +-24V supply is fine. Do the following:

|------ +V
+
12V
-
+
12V
-
|------ 0V
+
12V
-
+
12V
-
|------ -V

Sorry - I know it isn't that clear, but it'll work!

You may have read my recent thread on PICs of my gainclone, but they already play extremely loud. I found that supplying them with 38V did more damage to the sound (and percieved power output) than good. Stick with a 24V supply and use sensetive speakers. That is far more important! Have fun!

Edit:
You can't just tie the two Left and Right signals together by the way...You'll have to use an Opamp mixing circuit to make it Mono. You could make a (still) stereo cheap amp by using the same power supplies etc so no need for extra caps, rectifiers etc. You decide.

Gaz
  Reply With Quote
Old 17th April 2003, 12:47 PM   #5
shyfx is offline shyfx  Australia
diyAudio Member
 
Join Date: Apr 2003
Location: Melbourne, Australia
I hope I am not hijacking the thread here, but on the power supply questions for a gainclone, can you use a transformer that isn't centre tapped and use a circuit like this to get the +, 0, - ?
Click the image to open in full size.

ps; i thought I would post it here because maybe you can use a single battery and power the gainclone with a circuit like that instead of multiple batteries
  Reply With Quote
Old 17th April 2003, 04:19 PM   #6
VoLCoM is offline VoLCoM  Canada
diyAudio Member
 
Join Date: Apr 2003
Location: Saint-Hubert , Quebec
Default ok

Rarkov,
You mean...that i plug 2 12V in Series to Get 24V on the +
and the same on the -
If the batteries are for example 7 000mah this mean that i'll get
for the total 14 000 mah and 24V ???

Can i plug the batteries in the circuit of shyfx???
or i have to change the resistor value?
or I didn'T understand right and these are 2 different ways?
which one is better?
  Reply With Quote
Old 17th April 2003, 06:36 PM   #7
Rarkov is offline Rarkov  England
diyAudio Member
 
Rarkov's Avatar
 
Join Date: Aug 2002
Location: North East, UK
Send a message via ICQ to Rarkov Send a message via Skype™ to Rarkov
Hi,
No you've misunderstood a little. The method with 4 batteries that I explained will give you 7000mah (if that is what one cell is rated at). This would double if they were is parallel, but then you would only get 12V...You see electronics is all about trade offs!

The circuit indicated by shyfx is to give the same effect but only using "one" cell. If you look at the circuit, it produces a virtual ground half way between the full potential of the cell. So for this application you would still need all 4 cells to produce the +-24V. This is why I had "one" in quotation marks! Now this is where I am slightly sketchy - but I think that this also halfs the current, so it would become 3500mah, because it drains both + and - rails from "one" cell instead of two.

There for, I believe that my method is better...but I am ready to be corrected if I am wrong.

At the end of the day, it is your decision.

Gaz
  Reply With Quote
Old 17th April 2003, 07:41 PM   #8
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Btw the inclusion of the 1.5k 'class A' resistor is very controversial. You should build without it first and then try to include it and listen.
  Reply With Quote
Old 17th April 2003, 09:07 PM   #9
Verbal is offline Verbal  Germany
diyAudio Member
 
Join Date: Mar 2003
Location: Aachen
Volcom, check this thread:
Battery-powered supplies

Quote:
I'd like to get 60watt is it possible with a LM3875?
i'd like to make this small and "not heavy" lol. Because I want it to fit in my backpack
Depends on how long and how loud you want it to play. But you should be aware that batteries are heavy. +/-24V,7Ah in SLAs weights 10kg+.

Quote:
but I think that this also halfs the current, so it would become 3500mah, because it drains both + and - rails from "one" cell instead of two.
No, because the "one" is made up from the same number of batteries as the two (i.e. four ), so capacity would still be the same. Don't see the point though, if you're using an even number of batteries why not just take the midpoint.
  Reply With Quote
Old 17th April 2003, 10:29 PM   #10
VoLCoM is offline VoLCoM  Canada
diyAudio Member
 
Join Date: Apr 2003
Location: Saint-Hubert , Quebec
Default batteries

I went at my local electronics center and i have found 3 type of batteries http://www.master-vox.com

12V 18AH Lead Acid (WP18-12) ---$39.00 CAD
12V 6.5AH PANASONIC ( PA-12V65P ) --- $32.00 CAD
12V 7AH (IM-1270) --- $24.95 CAD

I have to carry them in my backpack.....so it must not be dangerous which one should i choose?
i want the amp to play..at leat 2 hours with a 3875 or 3886
  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
My new wooden gainklone DT Chip Amps 8 6th August 2005 02:09 AM
Zen vs. GainKlone MikeW Pass Labs 26 19th June 2003 07:52 PM
gainklone problems, maybe... cowanrg Chip Amps 44 25th February 2003 05:16 PM


New To Site? Need Help?

All times are GMT. The time now is 04:06 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