F5 Headamp ?

[EUVL]

I have taken the liberty to change your spice model as follows :

1. your name and not mine (not my model)
2. gain ~ 5x
3. RLOAD 50R
4. Vout ~3.6V
5. MOSFET bias ~ 150mA instead of 1A
6. DC Offset at Vout < 10mV

After running, press Ctrl L to see THD results.
And I have included a frequency response asc.

Fairchild models are available from their website.
But I suggest you get up to speed with Spice first before attempting those.


Patrick

.

 

[xrk971]

Patrick,
I just got a bag of 5 pairs of 2SJ313/2SK2013. Could the F5HA use these vs IRF610/9610 and would it sound better?

 

[mlackey]

I have taken the liberty to change your spice model as follows

You are very kind to help. Thank you.

Mike

 

[xrk971]

I just realized that the F5 HA with J313/K2013 is kind of like a BA-3 input stage as a headamp (with feedback). So maybe I could follow the BA-3 and use it as a feedback free headamp? Or add feedback... BA-3 has handy trick of tunable balance of H2/H3.

 

[Hikari1]

Ba3 has high output impedence and too much gain. It's not a good headamp, at least not for low impedance phones. I've tried it.

Now the vfet 2 front end on the other hand is promising...

 

[Hikari1]

If you take the ba-3 front end, add feedback like the vfet 2 front end, bias heavy and cross your fingers you may be able to get rid of the output caps and the output impedence would be favorable. Haven't done it but I know someone who has.

 

[EUVL]

Ask Stixx what his ultimate headamp is, having built 15 different ones .....


Patrick

 

[samoloko]

The biggest downside with the 317/337 is still the >3V dropout. especially on lower voltage circuits. We are still talking simple to220 devices with a few caps. Although it would be fun to A/B with a more "fancy" supply - if it did work that is.
i'm quite certain Salas would work - but you may need a small series resistor before the elyt caps, which maybe will degrade some of the performance. But still would be fun to compare.
I will probably remake my boards with LDO + cap multi though, to save some space in my case.

are you really preffer 317/337 series to Salas Shunt reg

 

[Stixx]

are you really preffer 317/337 series to Salas Shunt reg

Read more careful.

 

[xrk971]

Ok, so Stixx, what is your favorite Headamp out of the 15 you have tried?

 

[EUVL]

I was asked by PM about what to do with unmatched JFETs.
Next time I would appreciate that you ask your questions here and not by PM.

For unmatched JFETs you will be able to compensate for the resulting DC offset at the output using the trimmers.
But you will not be able to do much about the increased even harmonic distortion as a result.


Patrick

 

[ammel68]

Ok, so Stixx, what is your favorite Headamp out of the 15 you have tried?

I think you already know what his answer will be.

Just one person's opinion. If there were hundreds of people in agreement on this F5 being the "best" headphone amp, that would be a different story altogether.

 

[pchw]

I think you already know what his answer will be.

Just one person's opinion. If there were hundreds of people in agreement on this F5 being the "best" headphone amp, that would be a different story altogether.

Do you have problem with Patrick? You have expressed your one's opinion not liking this HA in many occasions.

X, this looks like Stixx's new favorite now.

 

[xrk971]

Do you have problem with Patrick? You have expressed your one's opinion not liking this HA in many occasions.

X, this looks like Stixx's new favorite now.

Haha, LOL. The new show: the DAO all FET SE class A HA does look quite splendid indeed, but the simplicity of the F5HA still takes the cake in my opinion.

http://www.diyaudio.com/forums/atta...ne-amplifier-dao-se-public-part-2a-121214.pdf

Funny thing is, I just got a bag of 2SK2013's burning a hole in my pocket lookin' for a project. This may be it...

I don't know anything about the LU104D though...

My hat's off to Patrick for making these fabulous designs available to us. They can clean house with some serious commercial head amps I think.

 

[needtubes]

I don't know anything about the LU104D though...

It's a neat little part. Datasheet here.

Note that when Vgs is -1V or below the characteristic curves resemble a triode tube instead of the usual pentode shape.

 

[ammel68]

Do you have problem with Patrick?

Is it really any of your business if I do or don't? I didn't think so.

We're all here to discuss this headphone amplifier.

Don't try derailing the thread by bringing up personal issues with either me or Patrick.

 

[pchw]

Is it really any of your business if I do or don't? I didn't think so.

We're all here to discuss this headphone amplifier.

Don't try derailing the thread by bringing up personal issues with either me or Patrick.[/QUOTE］
Derail? Yes, I apologize to Patrick and others for last and this post, and no,
I have no personal issue with anyone. I was just puzzled and bothered by your continued jab to this HA in the discussion.

Mods, feel free to remove or to edit last couple posts from me.

 

[cwtim01]

... I was just puzzled and ...

You are not alone

 

[proid]

I don't know about the salas shunt but tried the F5 ha with Lm317/337 + cap multiplier and Jung Super reg and the latter sound much much better. F5 sound ok to my ear, my schiit vali still sound better.

 

[EUVL]

> and the latter sound much much better.....

If it does not oscillate.....

> my schiit vali

If that is the sound you like then the F5 is certainly the wrong one for you.
Personal taste, to which we are all entitled.




Patrick