Amp design - 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 5th January 2006, 08:30 PM   #1
diyAudio Member
 
Join Date: Sep 2005
Location: Melbourne Florida
Lightbulb Amp design

Could anybody give me a hand and take a look at this circuit and give a little creative critisism?? I would greatly apreciate it!Click the image to open in full size.
  Reply With Quote
Old 5th January 2006, 09:00 PM   #2
moamps is offline moamps  Croatia
diyAudio Member
 
Join Date: Oct 2002
Location: Croatia
The Q7 should be NPN type.

Regards,
Milan
  Reply With Quote
Old 5th January 2006, 09:00 PM   #3
Banned
 
Join Date: Mar 2005
Location: Australia
Q7 should be npn

edit=sorry came in secomd
  Reply With Quote
Old 5th January 2006, 09:11 PM   #4
moamps is offline moamps  Croatia
diyAudio Member
 
Join Date: Oct 2002
Location: Croatia
What's the purpose of the Q8?
Why 4k7 for the R15, 19?
C2, C3 may have a higher value.

Regards,
Milan
  Reply With Quote
Old 5th January 2006, 09:36 PM   #5
diyAudio Member
 
darkfenriz's Avatar
 
Join Date: Jun 2004
Location: Warsaw
Same question about q8.
and why lead circuit from output when from vas too?
Beside this it looks nice.
  Reply With Quote
Old 5th January 2006, 09:43 PM   #6
diyAudio Member
 
Join Date: Sep 2005
Location: Melbourne Florida
Default corrections

The original image post should now reflect changes, sometimes I start plopping in components faster then my brain works yes Q7 should be NPN, R15,R19 are 4.7 ohm current limiters, also I made a mistake on R5 it should also be 4.7 ohm it provides the ground path for VR1 to set the offset.
Q8, VR2, R16,R17, D1 and R22 make up the bias cicuit, Q6 provides thermal tracking.
The amp will be biased into class A for a roll off into AB at about 20watts. Thanks and keep the observations coming........
  Reply With Quote
Old 5th January 2006, 10:10 PM   #7
hughmon is offline hughmon  United States
diyAudio Member
 
Join Date: Jun 2004
Location: Los Angeles
Looks like the old Mark V TA1000 design with a few tweaks.
  Reply With Quote
Old 5th January 2006, 11:11 PM   #8
Onra is offline Onra  Germany
diyAudio Member
 
Join Date: Jul 2005
Location: near Frankfurt/M
Hi,
Is there a real connection between the base of Q7 and ground below C4 or is it a misdrawing due to your amendments?
Onra
  Reply With Quote
Old 5th January 2006, 11:31 PM   #9
diyAudio Member
 
Join Date: Sep 2005
Location: Melbourne Florida
Default amp design

To tell you the truth I dont know where it originated from, it was in one of my old books from my school days about 15 years ago, I drew it, but dont remember why, but it looks pretty decent. So I thought I might throw it together just been working out semiconductor choices.
Yes there is a connection from R3 to the juntion of R12 and C4. looks to provide a error correction for DC offset.
  Reply With Quote
Old 5th January 2006, 11:52 PM   #10
Onra is offline Onra  Germany
diyAudio Member
 
Join Date: Jul 2005
Location: near Frankfurt/M
Hi,
if this is an intented connection, it makes R9 absolutely useless and will serve a current of about 450mA through the base of Q7 and R14 to the negative rail.
This would in addition clamp the collector of Q7 near ground and the amp won´t work. The collector of Q7 must be able to swing close to the negative rail.
It has to be a misdrawing ( or the amp is designed for communication by smoke ).
Onra
  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
Collated Design Criteria/dimensions for Ariel ML-TL Design talsius Full Range 1 13th October 2011 05:28 AM
Wilson Watt Puppy Clone Design - Design Review Please soundengine355 Multi-Way 8 15th August 2008 02:07 PM
4th order bandpass, wheel well design :) (design inside) TWOJZ Car Audio 28 13th January 2008 02:56 PM


New To Site? Need Help?

All times are GMT. The time now is 06:55 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