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NEWS: PortaCode : The Utimate Battery Powered Headphone Amp - Page 3

post #31 of 86
9/24/07 at 11:29pm
Quote:
Originally Posted by Sovkiller View Post
Two thumbs up for uncle Phil...!!!!


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post #32 of 86
9/25/07 at 1:47am
I dunno about the 3 channel business. I was severely under impressed with the performance of the Meier Opera versus a balanced amp (And really the sound signature in general was kind of just really uninteresting... neutral I suppose but flat and without any sort of the beauty/realness of a really high resolution/high power fully discrete solid state amp)... I haven't heard a 3 channel beta22 versus a 2 channel beta 22 so I don't know if it was just the opera or the 3 channel topology in general... possibly it was just the Opera.

My question is... Phil said that the 3 channel topology gives all/most of the benefits of balanced sound without the negatives. What are the negatives?
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post #33 of 86
9/25/07 at 1:54am
What happened to the link for the image and the comments? Maybe I am confusing this with another post.
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post #34 of 86
9/25/07 at 3:14am
this should sound better than the current headcode home editions out there, first its based on the new 2007 headcode layout, which includes different transistors with a different sound signature, second, there are no wires, everything will be pcb mounted, it should blow away the current home headcode, i had a chance to listen to the 2007 headcode at phil's place when i dropped by, and compare it side by side with the home headcode that was sold by laroccoaudio, a significant difference, more details, bass, all the above, a significant upgrade imho. Phil will also be building a companion power supply for it at some point to make it a home amp, this power supply should be like no other built before it, fully cascoded and regulation like you wouldn't believe. This is the amp everyone been waiting for, believe the hype. I can't wait.
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post #35 of 86
9/25/07 at 3:25am
I do not see how a pcb is going to make it sound better. Point to point has normally been the benchmark. You get more capacitance and other reactions from a pcb. I have friends in the industry who have built prototypes point to point, have been happy and then send out the design for the pcb and did not end up with the same quality of sound, lesser was the result. There can be many reasons for this but when possible I have always built my equipment p to p. Having said this it would be just a wee bit difficult when trying to get something small and it is much slower and labor intensive. Maybe things have changed as I see so many high end amps with pcbs but I think it is more of the labor intensive question, with regards to a larger amp with no real space problems, than the idea that a pcb is better.
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post #36 of 86
9/25/07 at 3:28am
there is no chance of a getting a p to p version of this amp, as it is simply too complex.
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post #37 of 86
9/25/07 at 3:35am
Hey Sergio, when are you getting it? Yeah I know the Duponts on me
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post #38 of 86
9/25/07 at 3:46am
its in the works, you know me.
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post #39 of 86
9/25/07 at 4:00am
How big will it be? The Lisa III is huge already.
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post #40 of 86
9/25/07 at 4:23am
Quote:
Originally Posted by OverlordXenu View Post
How big will it be? The Lisa III is huge already.
Now I didn't know size mattered in transportable audio nirvana. OMG
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post #41 of 86
9/25/07 at 7:28am
Quote:
Originally Posted by jamato8 View Post
I do not see how a pcb is going to make it sound better. Point to point has normally been the benchmark. You get more capacitance and other reactions from a pcb. I have friends in the industry who have built prototypes point to point, have been happy and then send out the design for the pcb and did not end up with the same quality of sound, lesser was the result. There can be many reasons for this but when possible I have always built my equipment p to p. Having said this it would be just a wee bit difficult when trying to get something small and it is much slower and labor intensive. Maybe things have changed as I see so many high end amps with pcbs but I think it is more of the labor intensive question, with regards to a larger amp with no real space problems, than the idea that a pcb is better.
FYI, p2p originally came from tubes when there is high voltage and at times it can sound better with tubes, nevertheless, when the design moves into the SS realm, then p2p sounds substantially worse, it creates lots of RF and lots of other noises that we want to take away from the signal, therefore a high grade PCB is way better then p2p.
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post #42 of 86
9/25/07 at 8:06am

FAQ

(Q) that "I do not see how a pcb is going to make it sound better. Point to point has normally been the benchmark. You get more capacitance and other reactions from a pcb. I have friends in the industry who have built prototypes point to point, have been happy and then send out the design for the pcb and did not end up with the same quality of sound, lesser was the result.

(A) Point to point was used often in the tube era when Printed circuit boards were not available at low cost to use in Consumer Electronics so Point to point wiring upon a steel Chassis became the Standard. Now that low loss Dielectrics is available for printed circuit Board Material and computer Aided design can predict parasitic quite accuracy and the designer can enter these added parasitic components into the CAD program to simulate what the Performance in the real world is like. The problem with most Printed circuit boards is that ether the Material chosen is of low quality and thus having a High dielectric absorption like a poor quality capacitor and or the Designer did not consider parasitics when doing simulation. Audio design is a complete and detailed Mix of both Art and science and thus when dealing with anything as subjective as the perception of a Live Acoustical event far removed in time and space from the point at which it was Created must be evaluated with the Human element so both subjective as well as Objective procedures should be employed and the designer should not be tempted to rely on just one or two variables. I am sure your friend in the Industry has observed a reduction in sound quality when transferring a circuit from Point to point to Printed circuit Board, however this don’t happen to me I bypass point to point after the first breadboard and concentrate on optimizing the system including the PC Board to work in harmony. One big disadvantage of any wiring used anywhere! Even of most of the parts are all upon the PC Board like some of the DIY stuff is the unpredictable parasitic elements from unit to unit since a hard wired point to point construction method has far more positioning changes as well as other unknown’s like the dielectric constant of the wires insulation, Moreover since the actual components are supported by there own long Leeds micro-phonics with point to point is quite common,

(Q) I'm no engineer, but I still don't understand how you can have a bass boost work at all if it isn't in the signal path when its being used to boost bass. I can understand how it could be removed from the signal path when its in the zero position, but when its active, wouldn't it by necessity be in the signal path?"

(A) most tone control circuits are add on circuits and contain additional passive components like Resistors and capacitors in addition to active devices with Voltage gain such as transistors and Operational Amplifier Integrated circuits, this has unexpected consequences like added noise and distortion as well as completely stripping away any possibility of detail present in the Music. The Bass Boost I use on all my headphone Amplifiers are incorporated within the negative feedback loop. By employing tone correction in the negative feedback loop the signal path remains untouched as far as series elements are concerned in the forward signal path. When the Bass boost control is fully counter clockwise on no boost position the bass Boost components are completely Bypassed and thus you have the same situation as if the Amplifier was not equipped with bass boost. The Primary reason that my Bass boost works so well is implementation and paying attention to seemingly insignifigent details like placing the Bass boost components on the output Leg of the feedback loop so as to avoid any added capacitance on the Amplifiers sensitive inverting input.

(Q) I don’t know about the 3-channel business. I was severely under impressed with the performance of the Meier Opera versus a balanced amp (And really the sound signature in general was kind of just really uninteresting... neutral I suppose but flat and without any sort of the beauty/realness of a really high resolution/high power fully discrete solid state amp)... I haven't heard a 3 channel beta22 versus a 2 channel beta 22 so I don't know if it was just the opera or the 3 channel topology in general... possibly it was just the Opera. My question is... Phil said that the 3-channel topology gives all/most of the benefits of balanced sound without the negatives. What are the negatives?

(A) Search the M3,PPA and Headcode threads this topic has been previously belabored to death,
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post #43 of 86
9/25/07 at 9:59am
Thanks Phil!
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post #44 of 86
9/25/07 at 11:03am
Great, thanks for the info.

edit: Mike, who used to, maybe he still does, design some of the dac and amps for Audio Note UK always noted this. Some of the designs needed to use a PCB because of cost restraints and projected end point price. He noted that most always his breadboard design sounded better than the final pcb, even when using some of the very best products available, which Audio Note does have disposal to. I have redesigned pcb to go to p to p and noted an increase in sound quality. Another Mike, the owner of Quicksilver Audio, who has been at this longer than most people I know, also noted the same thing. He uses pcbs but to meet a price point and still prefers p to p. Cary Audio who I used to work with, has the same feelings on this.

Jam
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post #45 of 86
9/25/07 at 1:34pm
Eh, I probably would have been satisfied with a two line explanation. It's cool though.
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