F5 power amplifier

[dfdye]

Jack, I was specifically looking for the radial power resistors, but thanks for the extra info! It looks like DK has some alternate parts, so I am pretty sure things will be good.

[Zen Mod]

Originally posted by twitchie


so ... nice weather we've been having lately huh?

yup ...

so ... does anyone know what this thing sounds like yet?

... and also cares to share that with us too?

< scurry away >



someone of course, aside from Papa

(almost 750 posts and nobody has pictures of one completed yet)

Of course, it's summer now in the northern hemisphere and I suspect Steenoe is spending his time out fishing or chasing other slippery objects of his affections

look
HERE

and few posts down

more than 2 yrs ago ;

made by my friend Oly , as result of mine hysteric Babelfish J conundrum ;

as you can see - with all differences , most important one (of many) certainly is difference in feedback arrangement , which is in F5 natural implementation of feedback from toob world

I'm pretty sure that F5 sounds pretty simillar to little Oly's symmetric amp , or vice versa .

so - my conclusion is - it sings pretty much in same league as Babelfish J ( or Aleph J ,whatever ) with minor difference - it's more capable to drive more demanding spks ;

you can place here usual mumbling about preferences/taste for odd vs. even harmonics in THD spectra .....

one more time - you can see what Papa's lateral thinking is ;
ordinary amp designer always look and chase equal impedances on both sides of diff stage ; Papa just neglected diff stage ( or LTP , in any of incarnations ) , making space for something not new , but certainly not seen so lately .

I can write more , but I'm lazy ....... don't count on my awareness what I'm actually writing

edit:

Papa- this time you spoiled my answer ....... while I'm typing .....

[mike_diy]

Originally posted by Zen Mod




look
HERE

and few posts down

more than 2 yrs ago ;

made by my friend Oly , as result of mine hysteric Babelfish J conundrum ;

as you can see - with all differences , most important one (of many) certainly is difference in feedback arrangement , which is in F5 natural implementation of feedback from toob world

I'm pretty sure that F5 sounds pretty simillar to little Oly's symmetric amp ....... while I'm typing .....

Hey Zen Mod did you (or little Oly) build this symmetric amp.

Ot you just

[Zen Mod]

Originally posted by mike_diy


Hey Zen Mod did you (or little Oly) build this symmetric amp.

Ot you just

re-read my post
amp was build in form of prototype , meaning that pcb are
made, populated ,connected to PSU and all settings were done .

I listened to it several hours .

[mike_diy]

Originally posted by Zen Mod


re-read my post
amp was build in form of prototype , meaning that pcb are
made, populated ,connected to PSU and all settings were done .

I listened to it several hours .

Zen Mod, can you please post PCB file for symmetric amp.

Thanks in advance

[Zen Mod]

Originally posted by mike_diy



Zen Mod, can you please post PCB file for symmetric amp.

Thanks in advance

unfortunately - I don't have it .....

but - it's easy for any sort of PtP

[mike_diy]

Originally posted by Zen Mod



unfortunately - I don't have it .....

You monster. I can't believe you destroyed it.



Who is "Oly". Maybe

[Nelson Pass]

Originally posted by Zen Mod
I'm pretty sure that F5 sounds pretty simillar to little Oly's symmetric amp , or vice versa .

so - my conclusion is - it sings pretty much in same league as Babelfish J ( or Aleph J ,whatever ) with minor difference - it's more capable to drive more demanding spks ;

I prototyped that circuit once upon a time, and I was a little
disappointed, but I can attribute that mostly to IR P channels
operated Common Source. Other P channel parts will work better
for this.

Still, I don't expect that it will sound that similar - the diff pairs on
the input do have a different character to them. Relying on (bad)
memory, I think that the F5 has a more extended top end.

[Zen Mod]

Originally posted by Nelson Pass


I prototyped that circuit once upon a time, and I was a little
disappointed, but I can attribute that mostly to IR P channels
operated Common Source. Other P channel parts will work better
for this.
......

yeah,Papa , I learned that lesson form you ; in fact - used parts were IR IRFP140 and Fairchild IRFP9240 ( sorta better complement ? )

Originally posted by Nelson Pass


.......
Still, I don't expect that it will sound that similar - the diff pairs on
the input do have a different character to them. Relying on (bad)
memory, I think that the F5 has a more extended top end.

I meant that I expect that F5 is similar , and certainly better ( what I wrote , if I can trust my bad memory ........ ) ; what one can expect from that Baldrick-like clever feedback arrangement......

I remember - when I was a kidoe - making my first OP based preamp ; first one was anemic ; just later - when I change (maybe even just by mistake , not because of any lucida intervala ) feedback net to low impedance one , funny little OP based thingie almost started to sing ... maybe these audio electrons just prefers easiest paths

so - my conclusion is that - even if I didn't make your (our?) newest toy , I think that I have slight idea how it sounds .... better than little Oly's amp , but similar in character .

regarding Oly's , Plantefeve's and similar amps ...... for me - electronics is somewhat as Jazz - take already well known tune (standard) , make it by your way - you have your tune ; better or worse that other interpretations - another issue , but certainly your

F5 is jewel ; not exactly break-trough as Alephs and SUSY , but certainly example of cunningness .........

is it really easiest to see Buda in details ?

[miguel2]

I am gathering parts for the F5 from Digikey and two issues come up:

1. Digikey carries Dale RN resistors, but at 0.1 and 0.05 W. So, it is better to use these or to use the ones from Yageo?

2. What part number should I use for the thermistors?

Sorry for the questions, but this is not my expertise after all

I remember when I made a Zen V4, parts list included in the article