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 17th March 2011, 10:05 AM   #11
sajti is online now sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
And finally the PCB over the heatsink.

Sajti
Attached Images
File Type: jpg 20110316189.jpg (189.1 KB, 655 views)
  Reply With Quote
Old 17th March 2011, 10:30 AM   #12
sajti is online now sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
The power transformer is toroidal, 90VCT, 1000VA, wounded on 1500VA iron for low leakage, and low noise.

Sajti
  Reply With Quote
Old 17th March 2011, 11:43 AM   #13
AKSA is offline AKSA  Australia
diyAudio Member
 
Join Date: Sep 2001
Location: Melbourne, Australia
Beautiful design, Sajti. I see the output buffer is error corrected, wow!

Hugh
__________________
Aspen Amplifiers P/L (Australia)
www.aksaonline.com
  Reply With Quote
Old 17th March 2011, 11:46 AM   #14
sajti is online now sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
Quote:
Originally Posted by AKSA View Post
Beautiful design, Sajti. I see the output buffer is error corrected, wow!

Hugh
Hi Hugh

thanks! Unfortunately the quality of the schematic is not quite good, because I have to reduce the size, for another forum. So there is no error correction at the output. The small transistors are working as overcurrent protection.

Sajti
  Reply With Quote
Old 18th March 2011, 06:31 AM   #15
sajti is online now sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
There are some difference between the posted schematic, and the final PCB. So the small signal stage contains 2SC2240/2SA970 instead the KSC1845/KSA992

Sajti
  Reply With Quote
Old 19th March 2011, 07:26 PM   #16
sajti is online now sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
Some more changes: I reduced the value of the feedback resistors to 4x221ohms. I did it, because of the simulation results. The voltage gain is 2, and the distortion falls to 0.0012%, and the 2nd harmonic is 0.001%, the 3rd is 0.00069%.

Sajti
  Reply With Quote
Old 19th March 2011, 07:54 PM   #17
sajti is online now sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
The final schematic.

Sajti
Attached Images
File Type: png hibrid_pm.png (20.7 KB, 547 views)
  Reply With Quote
Old 20th March 2011, 01:03 AM   #18
AKSA is offline AKSA  Australia
diyAudio Member
 
Join Date: Sep 2001
Location: Melbourne, Australia
I see now, it's a conventional EF3 output stage, with EF input stage to a complex complementary singleton drive via a current mirror and a cascode to the pre-driver. Fascinating protection system! Not simple at all, I assume very high OLG and very low THD? How does it sound, does it make you tap your feet and bring out a smile?

Hugh
__________________
Aspen Amplifiers P/L (Australia)
www.aksaonline.com
  Reply With Quote
Old 20th March 2011, 07:55 AM   #19
sajti is online now sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Vác, Hungary
Quote:
Originally Posted by AKSA View Post
I see now, it's a conventional EF3 output stage, with EF input stage to a complex complementary singleton drive via a current mirror and a cascode to the pre-driver. Fascinating protection system! Not simple at all, I assume very high OLG and very low THD? How does it sound, does it make you tap your feet and bring out a smile?

Hugh
So, the OLG is about 500. It can be higher, but I don't think that it's necessary. The OLG distortion is 0.22%, with 4ohm load, and 300W output. Mainly 3rd harmonic. Interesting that the closed loop distortion contains mainly 2nd harmonic.
The protectione system is my own development, and contains delayed switch ON, overcurrent, overtemperature, low voltage protection. Self reseting, and the amplifier can handle the short circuit for long time.
The circuit based on Marantz PM11, or MA9, but I try to use better passive components.
Not yet listened, I need some more time to build the PSU, and the tube input stage.

Sajti
  Reply With Quote
Old 20th March 2011, 08:13 AM   #20
AKSA is offline AKSA  Australia
diyAudio Member
 
Join Date: Sep 2001
Location: Melbourne, Australia
Make it as linear as possible, then apply minimal feedback? I see around 48dB of loop gain, with very, very low open loop distortion. It should sound very good indeed, and the protection circuits are a tour de force. Congratulations Satji!

Hugh
__________________
Aspen Amplifiers P/L (Australia)
www.aksaonline.com
  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
Hybrid Amplifier Design Luck Chip Amps 32 3rd March 2009 02:43 AM
The Perfect Hybrid Amplifier Stee Solid State 0 27th July 2008 08:03 PM
Hybrid amplifier.. Please help.. DoomPixie Solid State 96 2nd March 2006 02:54 PM
Hybrid amplifier help... DoomPixie Tubes / Valves 83 20th February 2006 01:28 PM
HYBRID POWER AMPLIFIER - Please Help! gianmaria Solid State 40 20th May 2005 01:46 PM


New To Site? Need Help?

All times are GMT. The time now is 08:43 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