homemodder,
Those great headphones need and deserve a dedicated amp. What would be your choice of rail voltage and bias current?
That`s the unmistakable, highly GNF seasoned sound of a GNF loaded GNF voltage follower on feed-forward GNF counter-modulated GNF current source. (Accelerated GNF turbo).
Those great headphones need and deserve a dedicated amp. What would be your choice of rail voltage and bias current?
Wavebourn,
OK, the harmonics are gone, actually just transformed and pushed up in frequency, but they are there latently to the ear strongly irritating. Our imaginations cannot be fooled easily. What's left is a clean sound deprived from its spirit and dimensions. This is proven by measurements and expressed in mathematical equations, however the impact of high frequency distortions on the audible range is not subject to discussion at the moment.
OK, the harmonics are gone, actually just transformed and pushed up in frequency, but they are there latently to the ear strongly irritating. Our imaginations cannot be fooled easily. What's left is a clean sound deprived from its spirit and dimensions. This is proven by measurements and expressed in mathematical equations, however the impact of high frequency distortions on the audible range is not subject to discussion at the moment.
Lumba Ogir said:
It is always subject of discussions in this topic.
Harmonics actually not just transformed, they literally gone down.
Our imaginations can be fooled easily. I can "reform" spectral dynamics so solo vocals and instruments will sound "here and now", especially with planar dipole speakers, but trade off will be higher intermodulations.
Why do you think audiophile shops prefer to play solo vocals, violins, and saxophones?
Wavebourn said:
Hi Lineup;
how are you feeling today?
Well, I just drink some more wine today (saturday).
But anyway, I am right now trying to do some 10 kHz analysis.
Settings:
- 12 Volt supply
- Output DC operation point = 4 Volt (as a good recommendation by you)
- Load 32 Ohm
- Constant current in output = 100 mA
- Output level: 566 mV RMS = 10 mW into 32 Ohm's headphone
- Set BD139/IRF610 to contribute the AC currents ratio 1:10
- This means using BD139 + 63 Ohm's emitter resistor
As you know, by changing this resistor, we can change the level of how much the BD139 will assist the MOSFET.
I will post my results later here.
Have a good day, Wavebourn ... with or without WINE
lineup said:
Well, I just drink some more wine today (saturday).
But anyway, I am right now trying to do some 10 kHz analysis.
Settings:
- 12 Volt supply
- Output DC operation point = 4 Volt (as a good recommendation by you)
- Load 32 Ohm
- Constant current in output = 100 mA
- Output level: 566 mV RMS = 10 mW into 32 Ohm's headphone
- Set BD139/IRF610 to contribute the AC currents ratio 1:10
- This means using BD139 + 63 Ohm's emitter resistor
As you know, by changing this resistor, we can change the level of how much the BD139 will assist the MOSFET.
I will post my results later here.
Have a good day, Wavebourn ... with or without WINE
Thank you Lineup;
we had a wonderful time in a campground in a wild redwood forest!
So, you've found already that the amp is frequency independent in audio band, and works well on megahertz frequencies?
Speaking of current ratio, this combination of MOSFET abd BJT I've discovered in another project, designing class A+C+C power amp. The main point was, a FET should start assisting from region of beta droop of a BJT extending linear part of transfer curve on peak currents, but there were other advantages in such topology, so I called it "Tango Pair by Wavebourn" and used in class A amps as well (except power amps I use it now in line level output transformer drivers, in pure class A like in this headphone amp).
Please share what you've found, it is interesting!
Hello Wavebourn
I did really began to explore this output idea of yours.
And note: only by doing virtual simulations. and examine Harm Dist spectrum
Intro: There is a certain balance in contribution among one Bipolar and one MOSFET output transistor
Q4 and Q6 in diagram.
Providing current from positive supply.
------
I Started at 2 extremes.
1. Output without the mosfet only IRF530
2. Output with only the BD139
Then I changed the value R10 and one other helping resistor
to make output be supplied from positive by different shares of bipolar/mosfet.
I provided different % from the BD139 to 'help' the mosfet.
And trying to see what happend to 2nd 3rd 4th harmonics.
From the technical virtual test, I could not see why using 2 different output devices should be soundwise better.
So, I did not publish my results.
Note: Very Important!
All things That work well does not make absolute logic. Not until you can understand it.
For example the X-Concept in Pass amplifiers was said not to work.
On paper and in simulations results indicated this
Until GRollins proved it did work ....
Nowadays it is One of most intresting amplifier series presented by Pass Labs .. end of story.
So, Wavebourn and all other intesrested in this unique design of him,
do not hesitate to try this circuit below.
It may improve listening impression / sound, just as Wavebourn found out and recommend.
Many regards
to one of my few onboard friends, Wavebourn of russian blood
/lineup
I did really began to explore this output idea of yours.
And note: only by doing virtual simulations. and examine Harm Dist spectrum
Intro: There is a certain balance in contribution among one Bipolar and one MOSFET output transistor
Q4 and Q6 in diagram.
Providing current from positive supply.
------
I Started at 2 extremes.
1. Output without the mosfet only IRF530
2. Output with only the BD139
Then I changed the value R10 and one other helping resistor
to make output be supplied from positive by different shares of bipolar/mosfet.
I provided different % from the BD139 to 'help' the mosfet.
And trying to see what happend to 2nd 3rd 4th harmonics.
From the technical virtual test, I could not see why using 2 different output devices should be soundwise better.
So, I did not publish my results.
Note: Very Important!
All things That work well does not make absolute logic. Not until you can understand it.
For example the X-Concept in Pass amplifiers was said not to work.
On paper and in simulations results indicated this
Until GRollins proved it did work ....
Nowadays it is One of most intresting amplifier series presented by Pass Labs .. end of story.
So, Wavebourn and all other intesrested in this unique design of him,
do not hesitate to try this circuit below.
It may improve listening impression / sound, just as Wavebourn found out and recommend.
Many regards
to one of my few onboard friends, Wavebourn of russian blood
/lineup
Attachments
Wavebourn, could you please upgrade the power of this amp and suggest full Class A at about 8 to 10 watts. I would like to try this for active amplification of a pair of Fountek Ribbon Tweeters. They are rated at 94db sensitivity and 7 watts RMS power. I am sure the combination would sound sweet.
Just a question; will dynamics suffer with such a relatively low powered amp?
Thanks.
Just a question; will dynamics suffer with such a relatively low powered amp?
Thanks.
Polish but russian speaking.
Okay, does not change much.
After all we all are human blood. (except for some in-human phreaks )
Wavebourn
I think I once registered at you forum.
But if you have no lineup (or halojoy) I may register again.
Can you check it out and post here result. Thanks.
This forum I mean
Audio, radio, and electronics
Actually, was some hour ago when browsing your website http://wavebourn.com/
I did recall this discussion we had about my and your Class A HeadPhone amplifiers.
Last time I visited forum was a lot of kyrillic stuff I could not understand.
But a diagram or schematic can be intesresting nevertheless.
You website looks better. Think you have upgraded and made it better ...
/your lineup
Okay, does not change much.
After all we all are human blood. (except for some in-human phreaks
)Wavebourn
I think I once registered at you forum.
But if you have no lineup (or halojoy) I may register again.
Can you check it out and post here result. Thanks.
This forum I mean
Audio, radio, and electronics
Actually, was some hour ago when browsing your website http://wavebourn.com/
I did recall this discussion we had about my and your Class A HeadPhone amplifiers.
Last time I visited forum was a lot of kyrillic stuff I could not understand.
But a diagram or schematic can be intesresting nevertheless.
You website looks better. Think you have upgraded and made it better ...
/your lineup
Lineup;
I was tired of modifying of phpBB software, the last time spammers employed real people who used to read graphically presented equations and answered arithmetical questions in order to leave a website URL in the users' list, even though it did not show.
So, now I register by myself only, when I know who is asking.
I'll go and check now.
Anatoliy
I was tired of modifying of phpBB software, the last time spammers employed real people who used to read graphically presented equations and answered arithmetical questions in order to leave a website URL in the users' list, even though it did not show.
So, now I register by myself only, when I know who is asking.
I'll go and check now.
Anatoliy
I noticed this fact.
So, most of posts are by you yourself. And your friends.
Nobody can register unless through you yourself.
I maybe should send you an email and ask ...
Spammers are a drag .. should all be executed by a powerful Nelson Pass endstage.
But there are some way to keep a clean forum .. but it does invlove a lot of programming
and weekly cleanup by manuall hand actions, by moderators.
So, most of posts are by you yourself. And your friends.
Nobody can register unless through you yourself.
I maybe should send you an email and ask ...
Spammers are a drag .. should all be executed by a powerful Nelson Pass endstage.
But there are some way to keep a clean forum .. but it does invlove a lot of programming
and weekly cleanup by manuall hand actions, by moderators.
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