I thought you are still in the process of building your Mods? How can you say so much about the sound? And how can you tell whether the amp has a sound of it's own through so imperfect speakers?
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Why do you defend it in a way like you already know how it performs?
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I do know how it performs as I have looked at the measurements. It will be the lowest distortion part of my system therefore will be invisible within its power band. Sorry if this offends your tender subjective tendencies.
Not at all, I am just curious. Because I never found amplifiers that distorted more than speakers in the specs, yet there is usually a very distinct sonic difference when you put them in different systems, even when you change the power cord.
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Modulus-86: Composite amplifier achieving <0.0004 % THD+N.
Not really. Someone wanted to demo a really expensive power cord, and took it out after only a few minutes because he heard how bad it sounded, I did not even have to say a thing. Even the transformer made a difference in the New Class D that I built. So I think you are making this too much of a personal emotion based on narrow range of experience.
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Not really. Someone wanted to demo a really expensive power cord, and took it out after only a few minutes because he heard how bad it sounded, I did not even have to say a thing. Even the transformer made a difference in the New Class D that I built. So I think you are making this too much of a personal emotion based on narrow range of experience.
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Well this could certainly be an interesting project as a potential reference amp, not many alternatives out there in this price/performance ratio.
Looking forward to Toms measurements on PSRR. Possibly a comparison to a non-composite/regular chip amp, and at what level of capacitance the power supply stops being beneficial.
Looking forward to Toms measurements on PSRR. Possibly a comparison to a non-composite/regular chip amp, and at what level of capacitance the power supply stops being beneficial.
Occams razor suggests its more likely that you are confused and hearing things.
Looking at how PSRR is measured, it only tells you how bad the power supply can get... What we really need to know is how the amp and power supply interact, so I would probably like to see how the power supply does under different power levels,. For example, if you did the distortion measurement and also picked off the power supply rails, what would you see?
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Not focusing on the issues, and wanting to attack the person, it shows a very self insecure mentality. Sorry I cannot cure that.
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Komigenie--my hope is not to disparage anyone who wishes to get a subjective evaluation (as, frankly, a listening experience is very subjective, so if something knocks your socks off, awesome!), but that we may have such a different set of holistic preferences as to make any such comparisons useless.
After all, I hope we're all in this hobby as to improve our quality of life. 🙂
No kidding. I've learned long ago that these kinds of threads tend to go through phases of periodic muttering about stuff, then flare up once in a while, only to return to the muttering. That's alright... All I can do is to try to nudge the herd of cats in a more productive direction by sprinkling a few facts and measurements in here and there.
It's all good.
Tom
Tom, here's a question I rarely see mentioned in either the "mid-fi" or "True High Fidelity" worlds, but it should be easy enough to measure, and many would consider it important in these energy-conscious times:
What is the idle (quiescent or no-signal) current draw of the Modulus-86 and the Paralell-86 (at the "standard" +/- 28V supply voltage)?
Likewise, what is the current at full rated output power?
I understand this is likely just the sum of the idle currents of the chips used and maybe a little more for any bias resistors and such, but it would be nice to have a real measurement.
What makes me wonder is my current everyday-listening amp: this 5-channel AV thing:
Technics SA-GX470 Manual - AV Control Stereo Receiver - HiFi Engine
Within days of first use I noticed the top grill above the heatsink was warmer than I expected (especially for low-volume listening), so I put it on my Kill-A-Watt and found it draws 40 watts idling! The user and service manuals only give power consumption at what I presume is full output from all channels.
What is the idle (quiescent or no-signal) current draw of the Modulus-86 and the Paralell-86 (at the "standard" +/- 28V supply voltage)?
Likewise, what is the current at full rated output power?
I understand this is likely just the sum of the idle currents of the chips used and maybe a little more for any bias resistors and such, but it would be nice to have a real measurement.
What makes me wonder is my current everyday-listening amp: this 5-channel AV thing:
Technics SA-GX470 Manual - AV Control Stereo Receiver - HiFi Engine
Within days of first use I noticed the top grill above the heatsink was warmer than I expected (especially for low-volume listening), so I put it on my Kill-A-Watt and found it draws 40 watts idling! The user and service manuals only give power consumption at what I presume is full output from all channels.
Now now, retreat into subjectivism doesn't always mean there isn't a valid engineering issue to address. Just usually. 😉
Most every time I do the maths on green wire loops formed between typical audio components I get common mode error terms 40 or 50dB down from signal for reasonable grounding practice. These are easily moved below subjectively audible levels with most any pseudodifferential or balanced connection. But there's abundant subjective evidence and endless fussing with ground lifts to indicate the 0dB CMRR of unbalanced connections keeps errors in the audible range even in more or less ideal circumstances. Since the loops are formed by power cords, mains wiring, component chassis, connectors, and interconnect shields it follows power cord impedance influences the voltage distribution around the loop. By how much depends on the specific loop structure but generally it's significant as the total power cord impedance in parallel with the interconnect is comparable to that of the interconnect.
There's also abundant evidence the ~40dB CMRR provided by a basic balanced implementation is insufficient for inaudibility in mildly inclement conditions such as not the greatest grounding, mains circuit to mains circuit spans, or not so great audio component implementations. Hence the market for DI boxes and other fix its approaching 100dB CMRR. Usually that much is overkill but maintaining input signal integrity is one reason why the Mod and Parallel, as high end builds, use THAT 1200s.
About 55 mA for MOD86 and 100 mA for the PAR86 as I recall.
It's the idle current plus the load current. I seem to recall the power supply display saying about 1.4 A on the MOD86 at full load. The numbers for PAR86 will be similar under similar conditions.
Tom
Just want to apologize for a bad tone and well jokes that went over the limit. Believe me I would certainly recommend anyone looking for an amplifier in that power class to look at your site. And kudos to the diyaudio army and it's strength 🙄
that was a heavy nudge
that was a heavy nudge
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Yes, loops like these seem to always exist. There was a time when all equipment were Class II, and the power cords were not grounded together, we had discovered that when you plug in the cords in different polarity would result in different sound. Then we measured the voltage levels between there grounds of the equipment and found a significant difference depending on the polarity of the power cords, so we just played around with the power cord polarities till the voltage differences were minimum.
Balanced interface does seem to reduce many issues, in normal home use the ground level difference is minimum, but in longer transmissions, the old balanced method would help preventing ground level differences from creating other problems... the tradeoff is different depending on application.
I noticed the forum administrators did not like the Tapatalk plugin...😀