Amp too good for DIYaudio.

[bmc0]

16bit CDs are perhaps the worst - because distortion increases as the sound level gets lower

If proper dither is used, there's no increase in nonlinear distortion as level falls. Add noise shaping, and you can get ~120dB perceptually-weighted dynamic range with perfect linearity using 16-bit samples at 44.1kHz.

 

[CuteStudio]

If proper dither is used, there's no increase in nonlinear distortion as level falls. Add noise shaping, and you can get ~120dB perceptually-weighted dynamic range with perfect linearity using 16-bit samples at 44.1kHz.

Is this also true for short signals? For example, a midrange signal at 3kHz - say from a snare drum - lasting a few cycles - is there enough time for the dither to blend out the statistical errors?

 

[bmc0]

Is this also true for short signals?

Yep. Here's the spectrum of a 3kHz, 5-cycle tone burst (blackman window, 8k sequence length, flat TPDF dither) at 0dBFS, -40dBFS, and -80dBFS (peak):

The black dotted traces show the spectrum before quantizing to 16-bit. No extra harmonics to be found; only noise.
Same thing with noise shaping:

 

[ShadowFiend]

Welcome to the forum, don't know enough amplifiers to offer a comment but the numbers sure seem impressive.

DIYaudio.com is straight up the worst place I've ever been to regarding audio equipment (ok maybe gearspace is worse, hard to tell). I'm always shocked at how incredibly stupid people are there and how all the stupid people corral behind each other if you ever try to provide any sort of evidence to back up your claims. I don't use the word stupid lightly either, the majority of users there are really anti-science and moderation barely exists. I guess if you're banned you might miss out on the fact that the site is 99% noise and 1% good contet that is buried in 300 page threads. You're going to miss out on planet10 telling you all speakers that aren't full ranges are bad.

Unlike ASR, whose members commit to "proven" science in both positive and negative way, diyaudio is the place for many different groups of diyer. Some want to build something following to the "proven" science. Some want to experience something unconventional. Some just want to build something easy and sound good to specific situation like their music taste. You seems to fail to realize that fact, and try to shove your agenda to them.

The diversity is what makes diyaudio very interesting. I can see unconventional and interesting project there. For amplifier, that is the use of high order feedback loop (TMC, TPC, Cherry), current feedback amplifier or the use of intentional harmonic distortion (Pass). For speaker, it is dipole, line array, omnidirectional, horn, full range, planar/amt/ribbon design, which is fairly absent in ASR since great amount of member by looking at some chart or score just believe 2 way with 5-6" woofer and a dome tweeter is enough. We also should remember that D&D 8C development is originally a thread on diyaudio. And talking about full range speaker, they have their place in diy scene as they are the cheapest, easiest speaker to build fast by inexperience to sound ok. They give you perfect time/phase coherent, which is a rare quality. If the builder's music content focus just on content without too much high, low or loud, then the full range design can give a very decent quality.

 

[Wesseling Audio Lab]

I'd like to understand more on the details of why it was banned. Its hard for me to believe they banned it based on it being a great design. Insulting language is a typical reason for banning or at very least removing posts

The amp from op - board fits on 2U heatsink? Low parts count - Definitely want to try it! $5 for 10 at JLCPCB

 

[Wesseling Audio Lab]

"Unlike ASR, whose members commit to "proven" science in both positive and negative way, diyaudio is the place for many different groups of diyer. Some want to build something following to the "proven" science. Some want to experience something unconventional. Some just want to build something easy and sound good to specific situation like their music taste. You seems to fail to realize that fact, and try to shove your agenda to them."

This is correct!

There is one member that has a full understanding of the science of speaker design but he will defend someone's choices. If one enjoys bass resonance(high Q somewhere in the bass region), he will say its a matter of taste. It can be a little weird.

 

[gwing]

I'd like to understand more on the details of why it was banned. Its hard for me to believe they banned it based on it being a great design. Insulting language is a typical reason for banning or at very least removing posts

The amp from op - board fits on 2U heatsink? Low parts count - Definitely want to try it! $5 for 10 at JLCPCB

A quick browse didn't bring up a reason and the OP seems to be perhaps wriggling around explaining this properly and hasn't even made clear what he means by banned.

AFAIK DIY audio forum doesn't ban designs. It does ban (usually temporarily) members that conduct ab-hominen attacks or otherwise break the forum rules.

However this wasn't just a design published and discussed on the forum but something offered for sale in the 'Vendor's Bazaar'. Given the many safety concerns expressed about the design by DIY forum members it would seems to me commendable if they did actually force the *product* to stop being actually sold commercialy there and I think the design remains available for members to construct or modify as they wish.

 

[Ktacos]

AFAIK DIY audio forum doesn't ban designs. It does ban (usually temporarily) members that conduct ab-hominen attacks or otherwise break the forum rules.

Based off my experience, they actually leave that stuff up a lot of the time.

We also should remember that D&D 8C development is originally a thread on diyaudio.

I see this claimed a lot, but going through that thread, it doesn't seem like a lot of the info is particularly useful for getting to an 8c. I'd argue all the prototypes are dramatically different speakers than the 8c.

Hey I think the site sucks, none of you are ever going to convinced me otherwise so maybe just spend time on something else.

 

[Sir Sanders Zingmore]

A quick browse didn't bring up a reason and the OP seems to be perhaps wriggling around explaining this properly and hasn't even made clear what he means by banned.

Yet another example of brilliant hifi designers stymied by "Big Audio"

 

[ShadowFiend]

I see this claimed a lot, but going through that thread, it doesn't seem like a lot of the info is particularly useful for getting to an 8c. I'd argue all the prototypes are dramatically different speakers than the 8c.

But you can see from even the first post the idea of using the lossy box with slot/hole to get the cardioid like dipersion, and the use of waveguide to control directivity in high frequency. That is the most important characteristic of 8C. Of course you can not get an 8C from this thread but it give you idea, then you can explore and make your owns.

 

[Speedskater]

In the past, DIY audio forum was very firm about banning circuits that used AC voltage in a dangerous way.
(i haven't been following current designs)

 

[Ropeburn]

Unlike ASR, whose members commit to "proven" science in both positive and negative way, diyaudio is the place for many different groups of diyer. Some want to build something following to the "proven" science. Some want to experience something unconventional. Some just want to build something easy and sound good to specific situation like their music taste. You seems to fail to realize that fact, and try to shove your agenda to them.

The diversity...

There is this diversity on ASR too. Almost everyone on here acknowledges the fact that taste and subjective enjoyment is essential when it comes to music.

The main difference is the awareness of that, and the relation to how actual gear scientifically, measurably, provenly behaves. Nobody defends objective nonsense that tries to present subjectivity as fact, but opposes it. The other way around, if you got a specific taste and sound character goal, we try finding scientific and efficient methods to achieve that. Stupid example: you like a bass boost and slight treble rolloff, aka "warm" sound? Magical cables aren't the way, but EQ is. Same with speaker choice and design. You got some hilarious idea and actually like a "bad" design? Go ahead! Just don't present your taste as objective truth, and all is well.

Science and physical truth is a great method to achieve maximum musical enjoyment. It works, for all tastes.

 

[Wesseling Audio Lab]

"The second version is max 200Watt with even better THD = 0.000033 %"

"The third version I am testing at this moment it will output 400Watt. PCB I will publish soon after testing."

I'll wait for more gerber offerings before I order and ship together.

Thank You!

 

[gwing]

Yet another example of brilliant hifi designers stymied by "Big Audio"

Whatever gives you that idea. Where is the evidence for that? Can you quote a post or two?

Simply but I don't believe a word of this without some evidence. DIY audio forum is not a place that rushes to enforce good behaviour and ban things and you could criticise it for being lax in this area rather than draconic. I'm not a mod there nor anyone with more info than is publicly available to members but I've been reading DIY forum, off and on, for something like 20 years now so I have some idea of how it operates.

 

[Koifarm]

Oke, it all starts in 2023 with this thread https://www.diyaudio.com/community/...extremely-low-thd.318372/page-79#post-7510201.
Read the following replies from Koifarm. He was banned after almost been 15 years a member with 500.000 reads of his threads. Only because he had safety critics on an product from a vendor(Neurochrome).

Koifarm lives in my neighborhood and was like a mentor for me. I became also a member at DIYaudio as Monstercre publishing my own threads but also helping members with Koifarms designs. Then I was accused as a suck-puppet and banned without the possibility to defend myself.

Almost all threads I started were removed only my replies in other threads are still there.

I ask Koifarm if I may use his alias, that was no problem because he is never online anymore.

Please keep now your replies on topic about the Trex topology.

 

[Sir Sanders Zingmore]

Whatever gives you that idea. Where is the evidence for that? Can you quote a post or two?

Simply but I don't believe a word of this without some evidence. DIY audio forum is not a place that rushes to enforce good behaviour and ban things and you could criticise it for being lax in this area rather than draconic. I'm not a mod there nor anyone with more info than is publicly available to members but I've been reading DIY forum, off and on, for something like 20 years now so I have some idea of how it operates.

Whatever gives you that idea. Where is the evidence for that? Can you quote a post or two?

Simply but I don't believe a word of this without some evidence. DIY audio forum is not a place that rushes to enforce good behaviour and ban things and you could criticise it for being lax in this area rather than draconic. I'm not a mod there nor anyone with more info than is publicly available to members but I've been reading DIY forum, off and on, for something like 20 years now so I have some idea of how it operates.

??

 

[Sir Sanders Zingmore]

I ask Koifarm if I may use his alias, that was no problem because he is never online anymore.

Why would you use someone else’s alias even with their permission?
IMO it’s against basic etiquette to others as it causes confusion particularly if you’d already been accused of being his sock puppet

 

[Petrushka]

Oke, it all starts in 2023 with this thread https://www.diyaudio.com/community/...extremely-low-thd.318372/page-79#post-7510201.
Read the following replies from Koifarm. He was banned after almost been 15 years a member with 500.000 reads of his threads. Only because he had safety critics on an product from a vendor(Neurochrome).

Koifarm lives in my neighborhood and was like a mentor for me. I became also a member at DIYaudio as Monstercre publishing my own threads but also helping members with Koifarms designs. Then I was accused as a suck-puppet and banned without the possibility to defend myself.

Almost all threads I started were removed only my replies in other threads are still there.

I ask Koifarm if I may use his alias, that was no problem because he is never online anymore.

Please keep now your replies on topic about the Trex topology.

I find this unacceptable, not because it is illegal, but because it is needlessly confusing and misleading.

Also, it takes the form of, “I have a friend who has this problem…”

 

[Sir Sanders Zingmore]

It’s even more confusing because Koifarm says he was banned because he raised safety concerns (reading some of the linked thread though, I’d say he was banned for other reasons). Yet this thread implies it was because his amp was “too good”…

 

[PristineSound]

This thread is all so bizarre.