Some headphones can be very good to comparison
Not the cheap one, from Philips International, world model is everywhere, and you can have them.... the cheap model, costing around 5 dollares is reasonable....the mid price unit, the one that cover your ears is very good...difficult to beat with speakers...as they ressonate, have reflections.... and many other problems...the worst is big weigth in movement....damn piston they are!.....and you can have the Best Philips too....but will only pay more money...when the dark gray model will be perfect.
Comparisons made with headphones shows more details, each speaker have their own sonic characteristics, so , one is good with Nad....other with Ned...and some other perfect with Nid (fiction names)...those headphones are more near the flat response...have no reflections, no absortions, no ressonances....well..... very good they are for comparison.
But they are not good to class D...do not ask me why...factories are using normal AB amplifiers to drive headphones....maybe because a lot of Voltage appear in the output wires....they may be afraid of electrocution.... audiophile barbecue.
To compare, you must fix all variables...speaker...just one...monaural..... and them compare.....the problem is that if you change speaker...result can be different...so....headphone will give you more precise informations.
Of course, Senheiser, Beyer, AKG, Neumann, Koss and many others can be good too....i do not know them...but if they make so good microphones, may work very good constructing headphones too.
My audio club had this test.... we put a speaker and call the one to compare and evaluate two amplifiers going to that speaker
We tell the guy:
We want to know, with maximum precision, what is be best sounding amplifier......if he do not ask us one headphone.....hehe.....you are fired!
Speakers were made to match some amplifier, and working together, one compensate the other losses and produce good sound....speaker alone, is something alike "machine to make we turn crazy!"
regards,
Carlos
Not the cheap one, from Philips International, world model is everywhere, and you can have them.... the cheap model, costing around 5 dollares is reasonable....the mid price unit, the one that cover your ears is very good...difficult to beat with speakers...as they ressonate, have reflections.... and many other problems...the worst is big weigth in movement....damn piston they are!.....and you can have the Best Philips too....but will only pay more money...when the dark gray model will be perfect.
Comparisons made with headphones shows more details, each speaker have their own sonic characteristics, so , one is good with Nad....other with Ned...and some other perfect with Nid (fiction names)...those headphones are more near the flat response...have no reflections, no absortions, no ressonances....well..... very good they are for comparison.
But they are not good to class D...do not ask me why...factories are using normal AB amplifiers to drive headphones....maybe because a lot of Voltage appear in the output wires....they may be afraid of electrocution.... audiophile barbecue.
To compare, you must fix all variables...speaker...just one...monaural..... and them compare.....the problem is that if you change speaker...result can be different...so....headphone will give you more precise informations.
Of course, Senheiser, Beyer, AKG, Neumann, Koss and many others can be good too....i do not know them...but if they make so good microphones, may work very good constructing headphones too.
My audio club had this test.... we put a speaker and call the one to compare and evaluate two amplifiers going to that speaker
We tell the guy:
We want to know, with maximum precision, what is be best sounding amplifier......if he do not ask us one headphone.....hehe.....you are fired!
Speakers were made to match some amplifier, and working together, one compensate the other losses and produce good sound....speaker alone, is something alike "machine to make we turn crazy!"
regards,
Carlos
Yves Smolders said:
Hmm, funny !
My problem with the Yamaha is, that it sounds a bit too sweet/warm/soft
for my taste... I'd like it a bit more bright !
I got it much better with better speakercables, but still not happy...
This combined with a slight weakness in bass made me start
building my own amp. But sofar i had no chance to beat the
yamaha, except the bass.
The Yamaha has clean 100watts into 8 ohms, it's quite powerful.
Mike
I have the DSP-AX1 Service Manual
Having interest in schematic, go direct to my adress, because class D forum.
Manual is enormous...79 pages.... i can inform where to download, but have to register....do not have to pay, but have to register.
Related me no problem...but moderators work hard to organize things here...if i start with other subject...we will be moved.
And despite we can understand well the reasons of that actitude...i imagine that this is not agreable to anyone...not for us, and i think not agreable to moderators too.
regards
nanabrother@yahoo.com
Carlos
Having interest in schematic, go direct to my adress, because class D forum.
Manual is enormous...79 pages.... i can inform where to download, but have to register....do not have to pay, but have to register.
Related me no problem...but moderators work hard to organize things here...if i start with other subject...we will be moved.
And despite we can understand well the reasons of that actitude...i imagine that this is not agreable to anyone...not for us, and i think not agreable to moderators too.
regards
nanabrother@yahoo.com
Carlos
OK let the moderators decide if we need to break up this thread.
Thanks, DestroyerX, but I found that AX1 manual floating on the net.
All is in there except the transformer specs. I'm not an electronics expert but there were weird things in there, in the power supply section.
2 differently powered secondaries with bridge rectifiers, coupled together at the rails!
look: D701 and D702 are coupled?
Thanks, DestroyerX, but I found that AX1 manual floating on the net.
All is in there except the transformer specs. I'm not an electronics expert but there were weird things in there, in the power supply section.
2 differently powered secondaries with bridge rectifiers, coupled together at the rails!
look: D701 and D702 are coupled?
Attachments
Those separated supplies are made to avoid interactions
To reduce influence of some rigth channel to left channel, do not mind if front or hear..... better when 2 transformers are used, but this way is even better then one single output.
That lower voltage, normally is used to first stages and to drive transistors, when voltage need to be stable...and the higher voltage is used, normally, to output stages.
But there are people that make this inverted....more voltage in drivers and lower voltage in output.
And this is a very old discussion, alike who started first...the Egg or the Chicken.
regards,
Carlos
To reduce influence of some rigth channel to left channel, do not mind if front or hear..... better when 2 transformers are used, but this way is even better then one single output.
That lower voltage, normally is used to first stages and to drive transistors, when voltage need to be stable...and the higher voltage is used, normally, to output stages.
But there are people that make this inverted....more voltage in drivers and lower voltage in output.
And this is a very old discussion, alike who started first...the Egg or the Chicken.
regards,
Carlos
I have built and tested the UcD180 power amp, using 37V rails, Nichicon KG 4700uF power caps, and unbalanced input.
The module is absolutely stock; no fancy opamp or coupling caps. I would expect Jan-Peter's deluxe version to overcome the criticisms outlined here.
Speakers are custom three way using B&W tweet and mid, reworked Scanspeak 170mm woofer with passive radiator and 3rd order crossover.
Source is Denon 1015 Alpha CD player.
Preamp is my own GK1 tube/SS hybrid.
Verdict: Outstanding impulse/transient response (one of the best I've heard), wonderful bass, very good sound stage, good resolution, some coloration at top end, slight lack of 'body' in midrange, good presence on vocals, a little abrasive in presentation.
The slight abrasiveness to the sound might improve with time; it's only been running 15 hours. It's not as refined as a good Class AB, but the impulse response and very good spatial characteristics make this amp absolutely ideal for HT systems.
Cheers,
Hugh
The module is absolutely stock; no fancy opamp or coupling caps. I would expect Jan-Peter's deluxe version to overcome the criticisms outlined here.
Speakers are custom three way using B&W tweet and mid, reworked Scanspeak 170mm woofer with passive radiator and 3rd order crossover.
Source is Denon 1015 Alpha CD player.
Preamp is my own GK1 tube/SS hybrid.
Verdict: Outstanding impulse/transient response (one of the best I've heard), wonderful bass, very good sound stage, good resolution, some coloration at top end, slight lack of 'body' in midrange, good presence on vocals, a little abrasive in presentation.
The slight abrasiveness to the sound might improve with time; it's only been running 15 hours. It's not as refined as a good Class AB, but the impulse response and very good spatial characteristics make this amp absolutely ideal for HT systems.
Cheers,
Hugh
Thank you Hugh, a friend, Paul said that class D is alike we...
He said sounds good, incredible, impressive...but he is singing in one school to singers...and there he used to sing with some piano "Essenfelder" playing with him....and he said, that this equipment we bougth....all club guys, are good but the piano sound is good, and clear, but seems that came inside a plastic case.
I could understand what he mean, difficult is to transform this effect of sinthetic insulation to words.
We spent one month to perceive.
The sound is beautifull....but.....there are something strange on it.
Carlos
He said sounds good, incredible, impressive...but he is singing in one school to singers...and there he used to sing with some piano "Essenfelder" playing with him....and he said, that this equipment we bougth....all club guys, are good but the piano sound is good, and clear, but seems that came inside a plastic case.
I could understand what he mean, difficult is to transform this effect of sinthetic insulation to words.
We spent one month to perceive.
The sound is beautifull....but.....there are something strange on it.
Carlos
@DestroyerX,
Please check the Ucd400 thread if you want my opinion on the Ucd400AD amplifier modules. They sound wonferful and open on the nautilus 804 speakers.
@AKSA,
The tests I've done compare to yours, except for the "abrasiveness" you mentioned. Compared to my old amp, it's really "free"
At first I was thinking coloration in the high-end as well. Now I'm thinking it's actually the "lack" of added harmonics in the high frequencies (THD in class AB raises at higher freq?) that makes it sound different, or maybe the harmonic distortion is on other places. It is different, but i'm not sure if it's UcD that is colored, or that we are "used" to class-ab sound. After a few hours of listening, the highs seem actually to be "easier" on my ears - not softer in volume, just easier to endure.
Yves
Please check the Ucd400 thread if you want my opinion on the Ucd400AD amplifier modules. They sound wonferful and open on the nautilus 804 speakers.
@AKSA,
The tests I've done compare to yours, except for the "abrasiveness" you mentioned. Compared to my old amp, it's really "free"
At first I was thinking coloration in the high-end as well. Now I'm thinking it's actually the "lack" of added harmonics in the high frequencies (THD in class AB raises at higher freq?) that makes it sound different, or maybe the harmonic distortion is on other places. It is different, but i'm not sure if it's UcD that is colored, or that we are "used" to class-ab sound. After a few hours of listening, the highs seem actually to be "easier" on my ears - not softer in volume, just easier to endure.
Yves
As i bougth a standard home system, for a while i am comparing with those equipments.
And the class D at least "exterminate" others system in power, quality, transparence, punch, and all the names we can find to describe sound.
But, despite having enormous advantage ahead from others.... there is something that i could not describe, and also could not realise exactly what is the "thing" i am feeling.
Something strange....when i discover exactly, i will put the meaning in words.
I am confused.....no doubts that class is wonderfull, problem is to discover what is going on that i feel something strange.
I will keep myself listening and trying to find the cause....no!...i do not feel tired...i can hear it for whole day....not distortion...do not know.
Carlos
And the class D at least "exterminate" others system in power, quality, transparence, punch, and all the names we can find to describe sound.
But, despite having enormous advantage ahead from others.... there is something that i could not describe, and also could not realise exactly what is the "thing" i am feeling.
Something strange....when i discover exactly, i will put the meaning in words.
I am confused.....no doubts that class is wonderfull, problem is to discover what is going on that i feel something strange.
I will keep myself listening and trying to find the cause....no!...i do not feel tired...i can hear it for whole day....not distortion...do not know.
Carlos
Hi Yves, Jan-Peter,
Thank you for your comments; very interesting. You are right, Jan-Peter, about the rising THD beyond 1KHz with Class AB; perhaps the UcD is delivering less distortion which sounds a little less soft, and rounded.
Perhaps I was too critical of the UcD - I apologize!
What improvements can be expected with the chip and cap upgrade?
Cheers,
Hugh
Thank you for your comments; very interesting. You are right, Jan-Peter, about the rising THD beyond 1KHz with Class AB; perhaps the UcD is delivering less distortion which sounds a little less soft, and rounded.
Perhaps I was too critical of the UcD - I apologize!
What improvements can be expected with the chip and cap upgrade?
Cheers,
Hugh
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