I just designed an amplifier to power big speakers with small voltage! - Page 10 - 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 18th October 2012, 03:41 PM   #91
diyAudio Member
 
Join Date: Sep 2012
sorry I was talking about a simple 5 volt 800mA DC adapter i never even mentioned wall sockets.. sorry for the confusion.

Last edited by realflow100; 18th October 2012 at 03:43 PM.
  Reply With Quote
Old 18th October 2012, 04:30 PM   #92
diyAudio Member
 
Join Date: Apr 2010
Location: Coffs Harbour
Something like this one maybe?
__________________
Ian
  Reply With Quote
Old 18th October 2012, 05:34 PM   #93
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Quote:
Originally Posted by sofaspud
Here's a spoonful.
Are you sure the diagram matches the text? The emitter decoupler C3 should be omitted; it is not mentioned in the text. The text is a bit confusing about calculating coupling capacitor values. At the input it uses R1 instead of R1 in parallel with R2, and at the output it uses R3 instead of R3 in series with the output load (whatever that is). He assumes a beta of 10, which seems a bit low.

Perhaps this was in the introductory part of the book, so details were skipped over, but it could create as much confusion as it solves if people regard it as definitive.
  Reply With Quote
Old 18th October 2012, 05:38 PM   #94
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
Well, he said he was 15, but I suspect more like 11, 12 yo... just speculating.

By the time I was 15 I had built several Heathkits, including an SB-301 ham band SSB receiver, as well as duplicating a 6146 screen modulated transmitter (novice power, back in the day) from the ARRL handbook by myself.

My first scratch electronic project was a discrete transistor schmitt trigger that my father brought home the part for from an engineer at RCA in NJ where he worked at the time. It did not work. The engineer had made an error in the schematic. I used the Heathkit VTVM that I built to test its action. That was when I was 13, iirc.

But I suppose I had a natural talent for "stuff" so that helps.

I found a local ham who became my mentor, and he gave me my Novice test on his dining room table. He gave me all sorts of help, explanations and parts to complete the transmitter. Also, a ton of back issues of Electronics World, Popular Electronics and QST to read. Learning by doing and absorption.

Everyone is different, but that's how it went for me...
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- [...2SJ74 Toshiba bogus asian parts - beware! ]
  Reply With Quote
Old 18th October 2012, 05:46 PM   #95
diyAudio Member
 
jmillerdoc's Avatar
 
Join Date: Mar 2009
Location: Lawton, OK, USA
No Cal, we are warning a 15y/o newbie NOT to mess with mains or even consider it....Other than that, I don't think it has been mentioned...
Cheers!
  Reply With Quote
Old 18th October 2012, 06:14 PM   #96
diyAudio Member
 
Join Date: Sep 2012
okay I found a bunch more capacitors and I upped the total rating of them all combined to 7200uF's!!
that's quite a bit..
It sure made a big difference!! my subwoofer is causing a mini earthquake! and the low frequencies get down to like 2-4hz!
  Reply With Quote
Old 18th October 2012, 07:08 PM   #97
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
Ok, now my opinion is changed.

I think we have a troll who is playing us...

_-_-bear
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- [...2SJ74 Toshiba bogus asian parts - beware! ]
  Reply With Quote
Old 18th October 2012, 07:11 PM   #98
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
Quote:
Originally Posted by jmillerdoc View Post
No Cal, we are warning a 15y/o newbie NOT to mess with mains or even consider it....
I am aware of that. It was just a 'gentle' reminder from
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  Reply With Quote
Old 18th October 2012, 07:28 PM   #99
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally Posted by Cal Weldon View Post


Direct mains powered equipment discussion is not allowed here.
If this route is being considered, the thread will be closed
and your posting privileges revoked.

It's that serious.
Hi,

Not the issue under discussion. Wall wart powered is OK for a newbie.
Mains powered is not IMO until some proper understanding is exhibited.

Direct mains powered was not mentioned, don't give people ideas ...

rgds, sreten.
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
  Reply With Quote
Old 18th October 2012, 07:41 PM   #100
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally Posted by realflow100 View Post
okay I found a bunch more capacitors and I upped the total rating of them all combined to 7200uF's!!
that's quite a bit..
It sure made a big difference!! my subwoofer is causing a mini earthquake! and the low frequencies get down to like 2-4hz!
Hi,

Please stop spouting nonsense about your build.

Realise you have no idea what the output bias point is, the input impedance is,
the frequency response is, the output power is (very low), and that you could
build something far better if you took any of the sensible advice available.

Your speaker can do nothing like 2 to 4Hz at any useful level.

How to build a decent speaker that works properly is another can of worms
you no doubt also want to pretend you don't need to know, but you do.

rgds, sreten.
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
  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
A small, low-voltage, battery operated amplifier Elvee Headphone Systems 29 6th November 2012 06:13 PM
Big bass from small power johnr66 Subwoofers 6 5th March 2010 03:40 PM
Amplifier to Drive small speakers haseeb Multi-Way 7 30th April 2008 04:24 PM
OB big sonding small speakers inrank Multi-Way 0 23rd July 2006 06:34 PM
Small BIG power for not so high-end class D diy’s Joep Zonnebloem Class D 29 29th April 2005 04:39 PM


New To Site? Need Help?

All times are GMT. The time now is 07:57 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