Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Another very fast CFA concept
Another very fast CFA concept
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 20th November 2017, 07:07 AM   #101
Lazy Cat is offline Lazy Cat  Slovenia
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Thanks for the internal info. There must be something badly wrong with your reference amplifiers, that’s for sure.

My quote which you probably missed:
Quote:
Originally Posted by Lazy Cat View Post
It's the package of all possible measurements to which amp should be tested and of course, final approval is listening test.
I just stated that FO is faster which is true and that for you is very hard to swallow. Cheers.
  Reply With Quote
Old 20th November 2017, 07:31 AM   #102
Lazy Cat is offline Lazy Cat  Slovenia
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by miro1360 View Post
Another very fast CFA concept
even in simulation and with ccs improvement is not so fast square as yours

... i must working harder, but I am closer ...
Hi miro
In your sch only parasitic capacitances dominate, for the signal source there should be low Z one in use. Usually the cure for capacitance is higher current, so try to tweak interstages and see if there will be an improvement.

Speaking about fast amplifiers, to my experiences the speed and wide bandwidth is important but certainly not the only important feature from amp’s behaviour. Loosing small signal details, maning in micro levels, on its path through interstages is crucial and that measurements rarely show, listening tests do.
Cheers.
  Reply With Quote
Old 20th November 2017, 07:51 AM   #103
daskjdask is offline daskjdask  China
Banned
 
Join Date: Nov 2017
Quote:
Originally Posted by Lazy Cat View Post
Thanks for the internal info. There must be something badly wrong with your reference amplifiers, that’s for sure.
Its kind of like tubes I say, they can have more distrioton perform very bad on scope etc. However sounds better than transistors, similar to comparing good schematics vs poor schematics. Parasitic oscillations/very poor square wave response/poor slew rate in theriotical are not able to be heard. The poor square slew rate would be much above 20khz given its not extremly slow, and 20khz is outside of auditible range, further more speakers don't output 20+khz, there resistance tend to all drop at high freq cus inducatnce.
Parasitic oscillations are also not heard ,eg sine or square with the whole internal area filled up. these components are in MHZ range, not auditble.

The two amps were both head amps, after more than a month of listening on both and many times of direct comparsion on sound quality. Both head amps sounds much better than computer output. However the perfect 20khz square sine response amp refrence, sounded worse than the 20khz amp with better schematic and delibratly made to parasitically oscillate.

Last edited by daskjdask; 20th November 2017 at 07:58 AM.
  Reply With Quote
Old 20th November 2017, 12:52 PM   #104
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
thanks LC, I see it now, with increasing current in interstages are parameters a bit better, ... I'm afraid of overcomplicated designs, it is hard to keep things simple
  Reply With Quote
Old 20th November 2017, 12:58 PM   #105
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
Quote:
Originally Posted by daskjdask View Post
However the perfect 20khz square sine response amp refrence, sounded worse than the 20khz amp with better schematic and delibratly made to parasitically oscillate.
welcome to the club of the same experience ... I personally also stopped interest into super complex designs ... build of bad overcomplication is overpriced and a few transistors in sophisticated simple design sounds often better ...
  Reply With Quote
Old 20th November 2017, 01:34 PM   #106
Lazy Cat is offline Lazy Cat  Slovenia
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by miro1360 View Post
thanks LC, I see it now, with increasing current in interstages are parameters a bit better, ... I'm afraid of overcomplicated designs, it is hard to keep things simple
This is the final SIM from which I started to built new front-end for FO amp (this year's latest version). Reality was not as perfect as SIM, still lot of tweaks were needed, but anyway it was good starting point, also a little proof that my theoretical expectations were correct, at least in the right direction. So never give up, you'll find a sweet spot in your design eventually.
Attached Images
File Type: png AFE FFT-1.png (146.2 KB, 595 views)
  Reply With Quote
Old 20th November 2017, 03:02 PM   #107
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
this is profi is not that best on diyaudio?
..
what was load for that 500kHz square from previous post? I tried it with 8R
  Reply With Quote
Old 20th November 2017, 03:50 PM   #108
Krisfr is offline Krisfr  United States
diyAudio Member
 
Krisfr's Avatar
 
Join Date: Nov 2007
Location: near the House of the Mouse
Quote:
Originally Posted by Lazy Cat View Post
This is the final SIM from which I started to built new front-end for FO amp (this year's latest version). Reality was not as perfect as SIM, still lot of tweaks were needed, but anyway it was good starting point, also a little proof that my theoretical expectations were correct, at least in the right direction. So never give up, you'll find a sweet spot in your design eventually.
Which amp is this, can you show the schmo?

Thanks
__________________
Thanks
Never give a Systems Analyst a screwdriver or hammer
  Reply With Quote
Old 20th November 2017, 04:33 PM   #109
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Quote:
Originally Posted by Lazy Cat View Post
This is the final SIM from which I started to built new front-end for FO amp (this year's latest version). Reality was not as perfect as SIM, still lot of tweaks were needed, but anyway it was good starting point, also a little proof that my theoretical expectations were correct, at least in the right direction. So never give up, you'll find a sweet spot in your design eventually.
I suppose this is preamp looking at the gain.
Here is simulated GW mk3 with boosted power supply to +-24 V.
Your simulation does not show anything below 120 dB, probably because simulation parameters are not set optimally. In that case harmonics are not visible. Here you can see harmonics but all are below 150 dB.
Attached Images
File Type: jpg GW mk3 +-24V FFT.jpg (223.2 KB, 564 views)
  Reply With Quote
Old 8th March 2018, 11:05 PM   #110
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
Default TC 1.0 v2

small update: TC_1.0_v2
- version with bigger output transistors 30MHz (FJL4215/FJL4315)
- improvement in few values (resistors for input transistors, VAS resistors)
- PCB remained small, in cheap size 5x5cm (gerbers included)
... sound is excellent
Attached Images
File Type: jpg TC_01_v2_sch.jpg (384.7 KB, 382 views)
File Type: jpg TC_01_v2_parts_top.jpg (227.0 KB, 381 views)
File Type: jpg TC_01_v2_parts_bottom.jpg (89.2 KB, 345 views)
File Type: jpg image001.jpg (641.8 KB, 203 views)
File Type: jpg image002.jpg (651.3 KB, 204 views)
File Type: jpg image003.jpg (564.5 KB, 151 views)
Attached Files
File Type: pdf TC_01_v2_pcb_top.pdf (9.0 KB, 44 views)
File Type: pdf TC_01_v2_pcb_bottom_mirror.pdf (8.2 KB, 36 views)
File Type: zip gerbers_TC_01_v2_elecrow.zip (100.4 KB, 36 views)
File Type: zip TC_01_v2_BOM.zip (5.4 KB, 39 views)
  Reply With Quote

Reply


Another very fast CFA conceptHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
My New Concept slowikpl Multi-Way 69 31st March 2017 10:37 AM
A fast way to build FAST solhaga Full Range 36 15th December 2012 10:32 AM
Opinions on a Concept monsterevo Solid State 11 8th June 2012 08:46 PM
Help with a concept the joz Subwoofers 14 26th February 2009 07:22 AM
How fast are 'Fast Fuse' and how to identify? bigpanda Solid State 7 22nd March 2005 09:00 PM


New To Site? Need Help?

All times are GMT. The time now is 01:02 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki