Tomorrow I will hook both the FX8 and FX9 to my A/B setup and see if there is any audible difference.
someone had expressed a view in peeceebee thread that cfa amps have weaker bass 😉, eagerly waiting to see if its correct or wrong.
reg
prasi
I agreeI have a few Peeceebee's. They have excellent bass response.
'In a non-switching cass AB amplifier an increase in current through one output transistor lowers the current in the other transistor in a non-linear way and such that it will not go to zero. The advantage is that this transistor will not be reversed biased (as will happen in normal class AB) and this makes switching on again much faster.
Steven'
Reffering to the schematic you published here:
http://www.diyaudio.com/forums/soli...imate-fidelity-amplifier-620.html#post4607602
How exactly does it do what you say it does? Or answear this, how can less than 100uA override the VAS current wich is almost always, at least a few mA ( in your case it seams to be almost 9mA )? Or how can you bias 2 Vbe junctions in series with just one diode drop?
Have you tryed the schematic in an simulator and prooved the power transistors are not reverse biased? Because i have tested one of my amps and the reverse bias on the power transistors is very clear. The actual schematic it's self does not matter that much, what matters is the principle of phisics involved, and they say that the upper questions are indeed valid.
I am coming here with this at this late time, just because HpaVictor keeps promoting this principle on a .ro forum as well but neglects to explain it.
Last edited:
Reffering to the schematic you published here:
http://www.diyaudio.com/forums/soli...imate-fidelity-amplifier-620.html#post4607602
How exactly does it do what you say it does? Or answear this, how can less than 100uA override the VAS current wich is almost always, at least a few mA ( in your case it seams to be almost 9mA )? Or how can you bias 2 Vbe junctions in series with just one diode drop?
Have you tryed the schematic in an simulator and prooved the power transistors are not reverse biased? Because i have tested one of my amps and the reverse bias on the power transistors is very clear. The actual schematic it's self does not matter that much, what matters is the principle of phisics involved, and they say that the upper questions are indeed valid.
I am coming here with this at this late time, just because HpaVictor keeps promoting this principle on a .ro forum as well but neglects to explain it.
I never made or simulate NS output stage, there is thread about NS OS:
http://www.diyaudio.com/forums/solid-state/162559-new-class-super-non-switching-need-revival.html
Than you should not be so quick to explain something you cannot back up, as you did in the quote i posted above. You should first try to understant something better yopur self before you suggest it to others. It is quite easy actually ( still reffering to the schematic you have published ), suppose you have an output node connected both to a current source of 100uA pulling up to +5V, and to a current sink of 5mA, pulling down to -5V. Where do you think the output node will be?
Than you should not be so quick to explain something you cannot back up, as you did in the quote i posted above. You should first try to understant something better yopur self before you suggest it to others. It is quite easy actually ( still reffering to the schematic you have published ), suppose you have an output node connected both to a current source of 100uA pulling up to +5V, and to a current sink of 5mA, pulling down to -5V. Where do you think the output node will be?
Somehow I doubt you've got the skills to be schooling Mile. Maybe you should learn some respect, manners and basic operation of spell check.
I never said i did, i just pointed out an error, and the more experianced someone is, the more impact his claims have, thus the more damage a simple error can make. On the other hand one should not take anything at face value, just because someone says it is so, one should try himself to analise that something before he takes it up for granted.Somehow I doubt you've got the skills to be schooling Mile.
As for my typo, i do apologise for it, but i do not see the connection to the subject, nor do i think it is the way to send off someone. I apologise to Mile as well if i offended him but the NS network in his schematic is useless, come to think about it, it's rather harmfull in some way, because it reduces the open loop gain as i see it...
All the best to every one.
Gentlemen, will 2SA1360/2SC3423 also work in place of the BD139/140 in the FX8?
Thanks...
Yes, 2SA1360/2SC3423 will be better to use than BD139/140 in the FX8.
Regards
FX9 pcb PDF files with recommended correction from Mr. Miles.
Can you post Sprint file for this PCB?
Tnx
Can you post Sprint file for this PCB?
Tnx
Sprint file for FX9.
I'm glad some of my makros designs are been using in this section good stuff guys 🙂
Regards
Juan
Your makros helped me a lot.

Regards
Sonal Kunal
Attachments
Last edited:
Hi Mile, at least i think that's right 🙂
Much as i love your thread on the class H amplifier (& i won't forget how you have possibly helped me create something of improved efficiency 😉) you need to bias that thing into class A & then you'll get even more fidelity.
You'll need to parallel output transistors & use huge heatsinks but i feel sure that class A biasing will show you the "ultimate fidelity". Admittedly a well biased class B is good, going OTT is the final hurdle & a rather fascinating transformation...
Bests to you chap & thanks for your posts on lots of interesting stuff, i for one seriously appreciate it 🙂 Oh, i'm sure something will come of your input one day in the not too distant future 😉
Bests, Mark.
Hi 44ct357 ,
could you elaborate on exactly what you intend to convey. just quoting someone's post doesnt convey anything.😉
reg
Prasi
someone had expressed a view in peeceebee thread that cfa amps have weaker bass 😉, eagerly waiting to see if its correct or wrong.
reg
prasi
Some have excellent bass. Deep and taut.
Some have excellen bass. Deep and taut.
Why don't u ask bimo?, he was the one who expressed..or may b I misunderstood his statement. ...I was merely restating someone else's statement.
Reg
Prasi
- Home
- Amplifiers
- Solid State
- 100W Ultimate Fidelity Amplifier