TT amp, 200W/8ohm, 701W/2ohm - 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 25th July 2012, 07:44 PM   #1
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Default TT amp, 200W/8ohm, 701W/2ohm

Here is my attempt to construct more powerful amp:
200W on 8ohm load
375W on 4ohm load
701W on 2ohm load
This amps is combination of ThermalTrak and standard ONSEMI power transistors. OPS is a Triple containing two TT pairs and two standard power transistors of the same family. As the power supply is of the same importance (maybe even more) as the amp itself I used Capacitance multiplier situated close to the OPS and the input stage. Input stage and OPS could be powered from different main power supply or from the same one. To facilitate use of the Baker clam input stage capacitance multiplier has 4 to 5V higher output then the OPSís capacitance multiplier. As a bonus OPSís capacitance multiplier contains a loudspeaker protection circuitry.
Those are simulated results:
ULGF = 1.3MHz
RL = 4ohm, Pout=320W
THD1k = 2ppb
THD20k = 0.96ppm (0.90ppm, RL = 8ohm)
THD50k = 13.42ppm
THD100k = 0.014%
RL = 4k, THD20k = 0.81ppm
PM = 61 degree
GM = 15dB

The main goal is to have very short connection between OPS and dedicated power supply. The amp circuitry is quite close to may previous TT amp, and that one plays music for some moths with no problem at all and nicely too.
Attached Images
File Type: jpg DADO-TT-TRIPLE-MPSA18-Cmult-clipping-4ohm.jpg (206.4 KB, 1327 views)
File Type: jpg DADO-TT-TRIPLE-MPSA18-Cmult-clipping-2ohm.jpg (208.7 KB, 1246 views)
File Type: jpg OPS-oneBJT-power-disipation-2ohmload.jpg (211.1 KB, 1080 views)
File Type: jpg DADO-TT-TRIPLE-MPSA18-Cmult-CLG.jpg (241.5 KB, 998 views)
  Reply With Quote
Old 25th July 2012, 07:48 PM   #2
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Here is OPSís C multiplier with the loudspeaker protection. On the main amp schematic OPSís C multiplier was simplified with no loudspeaker protection shown.
No PCB design was not atempted yet.
dado
Attached Images
File Type: jpg Cmult.jpg (195.3 KB, 951 views)
File Type: jpg OPS-oneBJT-power-disipation-2ohmload.jpg (211.1 KB, 254 views)
  Reply With Quote
Old 25th July 2012, 07:51 PM   #3
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
No PCB design was atempted yet, sorry for my bad English.
  Reply With Quote
Old 25th July 2012, 07:52 PM   #4
diyAudio Member
 
Join Date: Sep 2011
Cool to see more people go to greath lengths and detail to create their own pet amp. Good numbers too! Almost sounds like you had a peek at the Power Supply Reservoir Size thread too

Are you close to actual prototype creation or you still have to make the real schematic? (I don't regard simulation schematics the real schematic, so much is omitted ususally)

Edit: Your capacitance multipliers look very interesting; mind you if I would try to incorporate it in my design and see what results it yields?
__________________
Negative Feedback: The Need for Speed

Last edited by MagicBox; 25th July 2012 at 07:59 PM.
  Reply With Quote
Old 25th July 2012, 08:00 PM   #5
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Nothing is omitted here(except main power supply with big caps, similar as I used in my other TT thread) and my actual firs TT amp is very close to the simulation stability wise, distortion was not measured as I donít have the tool yet(planning to use PC and good sound card but always something else is more important).
  Reply With Quote
Old 25th July 2012, 08:18 PM   #6
diyAudio Member
 
Join Date: Sep 2011
Nice, in my schematic there are some parts omitted, most notably decoupling / reservoir caps onboard. When it comes to distortion measurements I was in the same boat as you. I did some research into audio analyzer software and one remarkable piece came out of it: Virtins' Multi-Instrument.

It's not free, it does its job very well (including soundcard calibration and native distortion cancelling) and yields pretty accurate results when used with a decent soundcard. I used the ASIO4ALL driver as the soundcard interface for the tool. I used it to measure MF80, my 80-watts 4Ohm amp, yielding a 10K THD of around 0.00017%. Don't mind the increasing distortion the lower the frequency, the amp has now a big enough feedback cap

Note: When I tried MI, it was rather buggy, so that may be prohibitive to actually buying it for the price ($100 back then)
__________________
Negative Feedback: The Need for Speed
  Reply With Quote
Old 25th July 2012, 08:27 PM   #7
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Look here too, its well reviewed audio software.
  Reply With Quote
Old 25th July 2012, 08:31 PM   #8
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Sorry, here ARTA Home
  Reply With Quote
Old 25th July 2012, 08:42 PM   #9
diyAudio Member
 
Join Date: Sep 2011
Thanks, I'll check it out this weekend I think. I still have the probe attached to MF80 so it'll be quick to hook it up again to the soundcard and see what results I get and will post back when I have some.
__________________
Negative Feedback: The Need for Speed
  Reply With Quote
Old 26th July 2012, 05:30 AM   #10
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Here is OPS's capacitance multiplier power simulation for one MJL4281 transistor at 4 ohm load.
It uses triple EF configuration to complement the same of the OPS.
dado
Attached Images
File Type: jpg OPS-BJT-Cmult-power-disipation-4ohmload.jpg (205.7 KB, 299 views)
  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
Simple, powerful (100W-200W into 8ohm) amplifier schematic needed ddog Solid State 15 11th July 2013 11:04 AM
200W @ 8OHM Class D HiFi Stereo Amp sssuneth Class D 1 27th January 2012 09:23 PM
Can (Elektor) PA300 amp drive 2ohm load goldyrathore Solid State 0 11th June 2010 04:21 PM
8ohm resistor in series with 8ohm speakers for a 16ohm OT? Reidy- Tubes / Valves 8 10th January 2010 11:25 PM
12" 2ohm round Solobaric TS Parameters dok33 Car Audio 1 15th May 2004 09:00 PM


New To Site? Need Help?

All times are GMT. The time now is 03:49 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