|
|||||||
| Home | Forums | Rules | Articles | Store | Gallery | Blogs | Register | Donations | FAQ | Calendar | Search | Today's Posts | Mark Forums Read | Search |
| 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 |
 |
|
|
Thread Tools | Search this Thread |
16th November 2006, 12:57 PM
|
#1 |
|
diyAudio Member
Join Date: Nov 2005
Location: serbia, zajecar
|
bjt/mos (class A) CFP
Hallo good people!
1. When designing class a bjt/mos CFP out stage does the bjt see Cgs or Cgd? 2. In aksa`s "Glass-Harmony" amp, he said that he used 2N5551 bjt with 1K collector load and that`s about 4-5mA bias current. Is that enough for driving IRFP9140 in CFP stage... ?? 3.What is the most important to know when optimising bjt/mos CFP. 4. Does it need bjt base-collector cap and how to calculate the value? cheers! |
|
|
16th November 2006, 03:10 PM
|
#2 |
|
diyAudio Member
Join Date: Nov 2005
Location: serbia, zajecar
|
ANyone knows?
I didn`t found "exact" data in previous threads... |
|
|
|
16th November 2006, 04:12 PM
|
#3 | |
|
diyAudio Member
Join Date: Dec 2005
Location: the north
|
Quote:
How to make a Bipolar + HEXFET foldback device. I am sure it would have some parameters with EXTRAORDINARY PERFORMANCE. You don't see this often. Because the HEXFET people don't use bipolar much and the Bipolar builders do not use HEXFET much, either. Anyway, this is a perfect issue for 'Professor' Pass to answer. He would be the one to know .... Maybe this topic would have better luck in Pass Labs forum lineup
__________________
lineup |
|
|
|
|
16th November 2006, 04:39 PM
|
#4 |
|
diyAudio Member
Join Date: Nov 2005
Location: serbia, zajecar
|
thanks for reply lineup!
Cfp (bjt/mos) is more stable when operating in class a (that`s what I heard) and high local feedback of cfp is good for distortion minimizing, so I think that this combination could be bull`s eye... This kind of CFP IMO is an opposite of IGBT. < base - drain- source> |
|
|
|
16th November 2006, 05:05 PM
|
#5 |
|
Did it Himself
diyAudio Member
Join Date: Nov 2003
Location: Gloucestershire, England, UK
|
Hugh (AKSA) recommends CFP in class-a because it has good distortion and because of class-a you avoid all the turn-off/on problems.
I have built a class-b amp with TIP29C/30C transistors driving IRF540/9540 devices, and it seemed to work well. I didn't test much with loads or waveshapes though. I also had a lot of compensation caps all over the place due to an initial oscillation problem, and I never removed the 'excess' caps to see how it went without them. You cannot calculate the cap values, you have to determine them with the actual board layout and real parts. IMO 2N5551 and 1k is not man enough to drive MOSFETs, maybe Hugh has done some other trick?
__________________
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more |
|
|
|
16th November 2006, 05:56 PM
|
#6 | |
|
diyAudio Member
Join Date: Nov 2005
Location: serbia, zajecar
|
Quote:
so Hugh...? Could you explain this if you have time...? |
|
|
|
|
| Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
| Thread Tools | Search this Thread |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| 1500W RMS Class D PCB - which Class D Driver Chip is it ? | mosfetsound | Class D | 11 | 1st April 2011 11:17 AM |
| Can a Class AB PP amp be said to be operating in Class A at low signal levels? | ray_moth | Tubes / Valves | 19 | 23rd January 2009 07:52 PM |
| How about a round-up of Class A kit power amps, or collectable vintage class A? | Brisso57 | Solid State | 4 | 14th February 2007 10:30 AM |
| New To Site? | Need Help? |
| Page generated in 0.13615 seconds (57.02% PHP - 42.98% MySQL) with 10 queries |
