[Ableza]

That's actually pretty standard - mics since the late 50's have easily hit 140dB or close to it spl handling at 0.5% THD and with SNRs of 90+dB. TLM102 is a good sounding piece of kit, but fairly average in price and specs compared to some other stuff out there. Glad to hear Mike is doing better!

Maybe the studios I've worked in were just too low on the pecking order. AKG condensers with S/N at around 84 db are I think the best I've used, and the most common being the trusty Shure SM57. I don't think I've read the S/N for that workhorse.

 

[wout31]

This is a typical THD graph of a microphone



And yes it is distortion versus SPL.
The most common way of presenting distortion numbers for microphones is to give the SPL number where distortion is 0,5% max.
So in the sample graph that would be some 117 dB
You can see the clipping point at about 128 dB
This is with a single pure frequency, so numbers may rise dramatically with complex sounds in a wide spectrum of frequencies.

Also bear in mind that the threshold for human hearing is far from linear, so distortion in some regions is far more audible /irritating than others.
The graph below shows threshold for a human with "normal" hearing.

 

[Philosoraptor42]

Maybe the studios I've worked in were just too low on the pecking order. AKG condensers with S/N at around 84 db are I think the best I've used, and the most common being the trusty Shure SM57. I don't think I've read the S/N for that workhorse.

Sorry, I was perhaps being a little bit of a mic snob - I do mostly acoustic projects like classical and jazz where people are fussy about mics. Got spoiled working with DPS's and Sennheiser. But if you look even at something like a U40 or M50 from Neumann, a relatively old mic, it's got I believe a S/N of like 90+dB as rated on the spec sheets. In any case, my point was more that THD isn't really a particularly useful measurement for most mics. The relationship between self-noise and total SPL as well as it's frequency response is really what's most useful because it will tell you how hard a mic can be pushed before it starts to get noisy or breakup. Mic clipping is pretty much a no-no. There's really nothing pleasant about it unless you do hard thrash or punk music, and even then, I'd rather distort in post. In my mind, mics, unlike mic pres, compressors, eqs, etc. are the one thing you never really want to clip. It's taken for granted that a mic's THD should be very low, even with a tube mic, because THD generally isn't going to be as much of a factor in the practical sound applications of a mic as other measurements are.

Anyways, I'm being a keyboard warrior at this point... : P

 

[Ableza]

Sorry, I was perhaps being a little bit of a mic snob - I do mostly acoustic projects like classical and jazz where people are fussy about mics. Got spoiled working with DPS's and Sennheiser. But if you look even at something like a U40 or M50 from Neumann, a relatively old mic, it's got I believe a S/N of like 90+dB as rated on the spec sheets. In any case, my point was more that THD isn't really a particularly useful measurement for most mics. The relationship between self-noise and total SPL as well as it's frequency response is really what's most useful because it will tell you how hard a mic can be pushed before it starts to get noisy or breakup. Mic clipping is pretty much a no-no. There's really nothing pleasant about it unless you do hard thrash or punk music, and even then, I'd rather distort in post. In my mind, mics, unlike mic pres, compressors, eqs, etc. are the one thing you never really want to clip. It's taken for granted that a mic's THD should be very low, even with a tube mic, because THD generally isn't going to be as much of a factor in the practical sound applications of a mic as other measurements are.

Anyways, I'm being a keyboard warrior at this point... : P

I own a couple Senn 421's... they are in my drum mic kit.

 

[adydula]

Jason,

Am I incorrect to assume the new Magnis are running class AB?

I was wondering if your not using the coherence circuitry to help reduce the cross over distortion, how do you get such great measurements?

or maybe the question is how much does this AB cross over distortion add to the end result, listening?

Alex

 

[Jason Stoddard]

You can also see why global feedback might be subjectively worse than local, or single-stage feedback, because the global feedback will have the compounded distortion products of many stages of an amp in it whereas a single-stage feedback will only have its own stage's distortion products.

Note that this is not a novel idea. I think I read about this in some AES paper from the 50s or 60s.

Yeah, and in reality almost any discrete design is a mix of techniques: local degeneration or compensation to linearize individual stages, perhaps with cascoding or other distortion-reduction techniques in critical stages, and some negative feedback as well, to get the overall result you're looking for in a reliable product. It's almost never as simple as "no feedback!" versus "max feedback!"

@Jason Stoddard I presume you actually meant next year, given there are only 20 days left this year and most people will be expecting to be on holiday for a few of them!

Yep, duh. Next year.

Question #9 surprised me. It shouldn't but... So far, I've avoided plunking down serious cash for fancy-dancy cables and connectors. My high-school electricity unit dictates my cable choices: larger diameter cables, shorter distances... leads to lower resistance... and that's gooder! BTW - one of my applied science students (in my province, supposedly [applied] < [academic] curriculum.... pshhh, nope) was muttering about cable management while he built his student-circuits. So there's indeed another generation of electricians in the wings! Be patient, Schiit Audio... I'm growing a new crop as fast as I can! Eh.

I wouldn't extrapolate the results of good cabling and jack contact to what has been called "The Big Crazy." It's wayyyy too easy to end up with $15,000 cables and fuses that cost more than a Magni, together with perhaps a salting of magic stones and boxes that "retune the Schumann Resonance" if you go down that path.

That said, yes, both cabling and contacts matter. We experienced many problems with BNC-to-RCA adapters, so we had BNC-to-RCA cables made with good connectors and good cable (again, we're talking Mogami and Neutrik stuff, nothing crazy). And we make sure everything is clean and tight. That's really it.

Jason,

Am I incorrect to assume the new Magnis are running class AB?

I was wondering if your not using the coherence circuitry to help reduce the cross over distortion, how do you get such great measurements?

or maybe the question is how much does this AB cross over distortion add to the end result, listening?

Alex

Magni 3+ is Class AB, no tricks, just like all the previous Magnis. The distortion reduction is mainly from the driver stage, with a bit more from the better devices. That's about it.

Magni Heresy, I assume, is biased Class AB internally, but I really have no idea what's going on in the TI op-amps beyond what their data sheets tell me. And they don't even have simplified circuits, just block diagrams.

 

[adydula]

Thanks for the quick reply!

So what if anything would adding coherence to a Magni do?

:>)

Alex

PS: Please tell Mike we send our best holiday wishes to the old fart!!

 

[Jason Stoddard]

Thanks for the quick reply!

So what if anything would adding coherence to a Magni do?

:>)

Alex

PS: Please tell Mike we send our best holiday wishes to the old fart!!

If you're talking Continuity™, then it would cook the amp real fast. Continuity needs to run at a specific bias level to work, and that bias level is above a normal Class AB bias level. And even then, it loses output due to the sense resistors. So it would be a very hot running, lower powered amp.

Will do with Mike! But I know he reads this thread as well.

 

[Paladin79]

That said, yes, both cabling and contacts matter. We experienced many problems with BNC-to-RCA adapters, so we had BNC-to-RCA cables made with good connectors and good cable (again, we're talking Mogami and Neutrik stuff, nothing crazy). And we make sure everything is clean and tight. That's really it.

While I have to be careful not to use the "C" word, that is a very good approach and one that has served me well.

 

[Ripper2860]

While I have to be careful not to use the "C" word...

What? You can't use the word 'Christmas' in this thread??

 

[Paladin79]

What? You can't use the word 'Christmas' in this thread??

Good guess, but keep Googling.

 

[Ripper2860]

Well, I certainly hope that you were not thinking of using the 'C' word that is often used in reference to "an insulated wire or wires having a protective casing and used for transmitting electrical signals"!!

 

[ScottFree]

Well, I certainly hope that you were not thinking of using the 'C' word that is often used in reference to "an insulated wire or wires having a protective casing and used for transmitting electrical signals"!!

Reminds me of another forbidden word.

 

[adydula]

Thanks Jason....yes I meant to say Continuity tm.....

Merry Christmas Mike!!!

 

[tincanear]

Good guess, but keep Googling.

c r i m p ? with proper tools (including dies matched to the application) and appropriate strain relief onto the cable jacket...

or the other word implying a process involving temperatures trending towards absolute zero???? suddenly i feel a chill...

or another word typically associated with the application of heating edibles (with chemical processes and reactions occurring at the elevated temperatures)?