Since im have a past sound enginer experiance and also is musician and use delay a lot i wonder...
Is it a delay fake?
My slowly brain just got open when i read Geoof's
listening test of T-HiFi Micro-TI integrated amplifier.
http://www.tnt-audio.com/ampli/micro-ti_e.html
"Though digital amps have had rave reviews and are without question fabulous value for money they are not perfect. I still feel they are a little grey and soulless, and sometimes I get the feeling that their soundstaging can be just a bit artificial, almost as if they are messing about with phase."
Have sombody messured the channels?
I mean Left and Right together?
It could be very small delays.
Not on on whole spectra.
I dont know.
Just wonder...
Still think its sounds amazing!!
Solve
Is it a delay fake?
My slowly brain just got open when i read Geoof's
listening test of T-HiFi Micro-TI integrated amplifier.
http://www.tnt-audio.com/ampli/micro-ti_e.html
"Though digital amps have had rave reviews and are without question fabulous value for money they are not perfect. I still feel they are a little grey and soulless, and sometimes I get the feeling that their soundstaging can be just a bit artificial, almost as if they are messing about with phase."
Have sombody messured the channels?
I mean Left and Right together?
It could be very small delays.
Not on on whole spectra.
I dont know.
Just wonder...
Still think its sounds amazing!!
Solve
Well, as with most class d amplifiers the output pulse train has to go through a low pass filter to recover the audio information. What is an often undesirable side effect of passing a signal through a filter? You guessed it - phase change. Of course this change should be gradual and only affect the upper end of the audio spectrum if the filter is designed properly.
It doesn't matter if Tripath designed it properly. They just offer you some design guidelines. It's up to the designer to choose to follow them. I've used components based on their filter guidelines (10uH inductors, 0.47uF caps for 4ohm load, 0.27-0.33uF for 8ohm load) and really enjoy what I hear. Certainly doesn't sound like an artificial soundstage to me. That could very well be caused by a poor recording, improperly set up speakers, improperly designed speakers, or the output filter reacting strangely with a certain speaker's crossover.
Do amps normally specify phase delay between channels?
Tripath aside I have listened to a single channel driven by a class d amp for extended periods (only had the one amp).. it sounds like it sounds. The actual phase shift at cut off which is usually well above 20khz is likely to be alot less than in your typical commercial junk, probably more on par with high quality amps with bandwidths of 100kHz, some of which are also likely to use coils in their outputs. Just my guess on the issue.
Tripath aside I have listened to a single channel driven by a class d amp for extended periods (only had the one amp).. it sounds like it sounds. The actual phase shift at cut off which is usually well above 20khz is likely to be alot less than in your typical commercial junk, probably more on par with high quality amps with bandwidths of 100kHz, some of which are also likely to use coils in their outputs. Just my guess on the issue.
Yep, I was just saying listening in mono doesn't change sonics in any significant way.
Back to your regular stereo broadcast:
I actually dont' recall ever seeing such information posted for your "typical" amp either. It would be interesting to do a full comparison across several models, not just tripath.
What's your threshold for considering it off phase anyway.
Back to your regular stereo broadcast:
I actually dont' recall ever seeing such information posted for your "typical" amp either. It would be interesting to do a full comparison across several models, not just tripath.
What's your threshold for considering it off phase anyway.
You realize also that tripath uses a mixed sort of feedback, pre and post filter? Usually that ends up giving you a load sensitive frequency response, so part of that may be due to the speakers used as well... unless they used a zobel?
In case anyone should volunteer to do these tests, I trust almost any well regarded amp would be good for comparison? Perhaps with different loads and zobels.
In case anyone should volunteer to do these tests, I trust almost any well regarded amp would be good for comparison? Perhaps with different loads and zobels.
"What's your threshold for considering it off phase anyway."
I mixed around with an tune in cubase- a tecno song- and changed the time between left and right.
Very small differences before i got the swing i thought,
But, it reminds me about the T-amp i listning to now.
The difference is the whole mix is phased i think.
Just proof me.
I could be wrong.
Solve
I mixed around with an tune in cubase- a tecno song- and changed the time between left and right.
Very small differences before i got the swing i thought,
But, it reminds me about the T-amp i listning to now.
The difference is the whole mix is phased i think.
Just proof me.
I could be wrong.
Solve
Solve said:
Why don't you test it? That way you will know for sure.
I'll try to run my own test as soon as I can. Phase between channels is something I have not tested over a wide frequency range. IIRC, at 1KHz, the channles are in phase on a sawtooth wave.
Testing 2 channels at once on the bridged amps will be tricky, as the outputs can't be tied to ground. Maybe with the scope in differential mode the phase between each positive side could be measured. Or maybe I'll make an resistor bridge and try that.
Something like this:
amp+plus---^^^^---P---^^^^---G---^^^^---amp-minus left
amp+plus---^^^^---P---^^^^---G---^^^^---amp-minus right
Where ---^^^^--- are resistors and P-G stand for scope Probe and Ground.
Easy to check phase between your 2 channel..Just send the same inpuit signal to booth input and with a scope in mode in1-in2 check if you get signal at different frequency! Just make a ''differential'' of booth output...You will see rally fast if they are a phase change of your ''stereo'' amplifier in function of frequency!
Fredos
www.d-amp.com
Fredos
www.d-amp.com
I agree to Fredos suggestion, or if you dont have a scope you can use cheapo CMOS PLL chip like CD4046 or the very popular 2 inputs "EXclussive nor gate" as the phase detector.
If the two channels are not in sync on phase, the o/p of the EXnor will give "high", if in phase, it will give "low". BTW the o/p of the exnor must be filtered out by a RC filter for smoothing ripples.
Regard
ledmania
If the two channels are not in sync on phase, the o/p of the EXnor will give "high", if in phase, it will give "low". BTW the o/p of the exnor must be filtered out by a RC filter for smoothing ripples.
Regard
ledmania
The tripath amps have a free running 300khz (at least in the 2024 chip info that I have poured over) osc. I'm not quite sure of it's function yet, even though I've read some of the technical papers. Could some one point to the full educational info on such, or clear that up for me?
Point being, a item that has clocking system, specifically if it is used in a digitally based re-construction of the signal, will suffer micro phase shift from (ie, x+y= the 'point' of the signal.x is the 'timing'component and is suspect, in terms of timing, therefore it becomes a phase issue) the clocking component. A free running osc used in such a system, depending on it's function, will cause SEVERE micro detail and micro transient issues (positional-locational issues in waveform reconstruction). The devil is in the details.
No mistake, these things are great, as long as the signal is simple. They really fall apart under complex signal loads, IMHO.
I have bought 3 amps so far, to investigate this technology. A sonic impact (2 of them) and modded the crap out of them. Then, the Ref T amp from the same folk. Modded it to the point that I can't sell it to anyone, it's got some semi-secret stuff in it, but it still does this 'thing', during complex passages. One of the secrets to removing this as an issue is, to use a battery system, supposedly. This kinda makes sense, as these are essentially current drive devices. My business partner has the whole max level Red Wine Tripath set-up, as well.
Now, I've got the boards I bought from Brian and am going to make one from scratch, with my own parts choices, again, similar to the ref t amp. I'll give them another shot, but as Conan said in Conan the Barbarian, "This better not be Hagga".
If the loss of detail during complex passages is -still- there, then the whole Tripath thing is a waste of time in my book.
Point being, a item that has clocking system, specifically if it is used in a digitally based re-construction of the signal, will suffer micro phase shift from (ie, x+y= the 'point' of the signal.x is the 'timing'component and is suspect, in terms of timing, therefore it becomes a phase issue) the clocking component. A free running osc used in such a system, depending on it's function, will cause SEVERE micro detail and micro transient issues (positional-locational issues in waveform reconstruction). The devil is in the details.
No mistake, these things are great, as long as the signal is simple. They really fall apart under complex signal loads, IMHO.
I have bought 3 amps so far, to investigate this technology. A sonic impact (2 of them) and modded the crap out of them. Then, the Ref T amp from the same folk. Modded it to the point that I can't sell it to anyone, it's got some semi-secret stuff in it, but it still does this 'thing', during complex passages. One of the secrets to removing this as an issue is, to use a battery system, supposedly. This kinda makes sense, as these are essentially current drive devices. My business partner has the whole max level Red Wine Tripath set-up, as well.
Now, I've got the boards I bought from Brian and am going to make one from scratch, with my own parts choices, again, similar to the ref t amp. I'll give them another shot, but as Conan said in Conan the Barbarian, "This better not be Hagga".
If the loss of detail during complex passages is -still- there, then the whole Tripath thing is a waste of time in my book.
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