F5 power amplifier

[bogdan_borko]

Originally posted by Assesears



G'Day,

For sale?.

It depends of how many of you are interested and what`s mr.Pass thinks of that idea, it`s his design after all.

[jacco vermeulen]

I'm sure he prefers everyone to party for months on end with hummer and peaking perf board layouts.

[Manu]

Well, posting this after Borkos superb PCBs will make me ridiculous at the face of the whole DIY community...

As an exercice, I tried to copy - shame on me - Admirable Nelson's FW PCB and I am not very satisfied with the result.
Especially the connection between Q5 and input Jfet seems less than convincing on my layout, but my weeny brain cannot find a better way.

Any Idea ...?
Or should I best give up?

Manu

[sandstorm33]

Originally posted by bogdan_borko


It depends of how many of you are interested and what`s mr.Pass thinks of that idea, it`s his design after all.

Perhaps we should send someone to Serbia to snatch Jelina ..to be held for ransom...specifically availability of those beautiful PCBs.

NICE JOB!! Such talent!!(and sooo young).

" and what's mr. Pass thinks of that idea".....

[Zen Mod]

Originally posted by Manu
Well, posting this after Borkos superb PCBs will make me ridiculous at the face of the whole DIY community...

As an exercice, I tried to copy - shame on me - Admirable Nelson's FW PCB and I am not very satisfied with the result.
Especially the connection between Q5 and input Jfet seems less than convincing on my layout, but my weeny brain cannot find a better way.

Any Idea ...?
Or should I best give up?

Manu

I like them

YGFM

[jacco vermeulen]

Originally posted by sandstorm33
NICE JOB

Compared with a couple of years ago even more :beep
Way to go, Bro.

[Zen Mod]

Originally posted by jacco vermeulen


Compared with a couple of years ago even more :beep
Way to go, Bro.

comme ci, comme ça

[bogdan_borko]

Originally posted by jacco vermeulen


Compared with a couple of years ago even more :beep
Way to go, Bro.

Jacco that was very cruel of you

Few days ago I`ve seen one of mine beginner`s post and I`ve blushed

My english is a bit better now, I hope but more important I made a good progress in audio electronics, made my Aleph variation "Krypton": KA30se "KRYPTON" SE class A amplifier

and I`m now deep in developing my low feedback class a hybrid amplifier and I`m happy abou it

Cheers!
Borko.

[rubydac]

My completed project of F5 from Aleph J chssis, I mis understood about parallel 2.4 ohm on the positive site so then I use both site of amplifier

Its sound so beautiful but if I need more power , how do I do ?

Thanks
Rubydac

[EUVL]

> but if I need more power , how do I do ?

If you consider the dissipation on each MOSFET, they are at 24V 1.3A bias -> about 30W. I would not advise you to go beyond that. So more power always means more MOSFETs.

The maximum output is designed at about 20V 2.6A, i.e. optimised for 8ohm load.

If you have a high impedance speaker, you need more drive voltage. Probably easiest is to drive 2x F5 as bridged amps feeding one speaker using balanced input. Maximum power is now optimised for 16 ohm load.

If you have a low impedance speaker, you need more current rather than voltage. You can of course start paralleling matched output devices (e.g. using 2 pairs of MOSFETs will give maximum power at 4 ohm). But paralleling MOSFETs will change the frequency dependent characteristics of the amplifier.


Patrick