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Old 8th February 2012, 05:26 PM   #2041
dvv is offline dvv  Serbia
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Quote:
Originally Posted by ThorstenL View Post
Hi,

I am familiar with F&T Cap's and I have no plans to employ them. I selected the Elna's based on my personal preference.

Okay, you buy the beer if we ever meet up... ;-)

Ciao T
With pleasure, Thorsten, with pleasure. And anyway, what's one beer, we need at least three to just get going ... not to mention how fine that stuff ripples down my throat.
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Old 8th February 2012, 05:33 PM   #2042
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Looks like your Economics degree gave you good insight into Ergonomics: rhythmic rows look nice!

Click the image to open in full size.

Yes, you are right about passing school subjects. If you have no passion to what you learn you will never be an Artist.
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Old 8th February 2012, 05:43 PM   #2043
dvv is offline dvv  Serbia
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Quote:
Originally Posted by bcarso View Post
Perhaps a good rule of thumb, but you're neglecting a factor of 2. Energy stored in a capacitor is (E^2*C)/2, in an inductor (I^2*L)/2.

Brad
True, but - aha!!! - I compensated for that by assuming a criminally hard load to drive. If such a load actually existed in form of a real life loudspaker, I think it would soon achieve the dubious glory of being an amp killer. That's actually worse than either the notorious Apogee, or that Infinity Refence from the early 80-ies, which could only be driven by Levinson and Krell amps.

You're right in saying it's a rule of thumb generally, a quick'n'dirty way to work out your apporximate needs on the fly.
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Old 8th February 2012, 05:47 PM   #2044
dvv is offline dvv  Serbia
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Quote:
Originally Posted by Wavebourn View Post
Looks like your Economics degree gave you good insight into Ergonomics: rhythmic rows look nice!

Click the image to open in full size.

Yes, you are right about passing school subjects. If you have no passion to what you learn you will never be an Artist.
Observe the wiring RIPPLE melodically.

My late dad said that, and he was right. Those who just study to pass exams never go beyond being technically educated clerks, effectively.

Passion is what drives us all on towards perfection, a theoretical ideal we know we will never reach, but are drawn to it like moths towards a light.
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Old 8th February 2012, 05:48 PM   #2045
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DVV, if you calculate by ripple voltages you may allow, you can forget about Rules of Dumb and Joules. Joules are needed when you want significant bursts from weak transformer. What is "significant" and "weak" is beyond Rules of Dumb, it needs to be calculated according to limitations of particular design.
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Old 8th February 2012, 05:50 PM   #2046
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Quote:
Originally Posted by dvv View Post
Observe the wiring RIPPLE melodically.
Are you sure your ground wires are soldered optimally?
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Old 8th February 2012, 06:14 PM   #2047
a.wayne is offline a.wayne  United States
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Quote:
Originally Posted by john curl View Post
I tend to use as much capacitance as we can afford in a specific design. I have found that even smaller amps (100W/ch or so) should have at least 20,000 uF/ch, to get the bass right. It is not so much ripple, but return impedance. For my larger amps, maybe 100,000 uF/ch, like the JC-1.
Would 200,000uf/ch in the jc-1 hurt ...?

Quote:
Originally Posted by dvv View Post
Thorsten, without wishing to interfere with your design project, I would strongly suggest you try it out as planned, using Elna caps, but then try again using Fisher & Tausche caps instead.

My money is on the side that says you'll never take those F&T caps out, and certanly not for Elnas.

Forget calculations and ripple factors, the simple fact is that they will give you whatever Elna gives you, PLUS a bass depth and control you will not believe. Especially since they are way cheaper than Elnas.
They make 2 types industrial or the audio, i cannot find the audio brand here in the US. who sells them in the EU..?

Quote:
Originally Posted by dvv View Post
Sorry, all I saw you posted about were tubes, so I assumed you were a dedicated tube guy.
Wave is an dedicated toob guy in the forums only, SS @ home and inside .. TL is the tooob only guy , unlike Wave he hasn't had time to appreciate SS stuff , as yet ...


Quote:
Originally Posted by dvv View Post
The man who installed and mapped the fuel injection system goes to work at Bosch in Stuttgatr, and heads his own team in reseraching of new fuel injection systems. He is completeing his dcotorate in electronics, but his REAL value is in the fact thagt engine oil reaches his shoulders, he's not afraid to get his hands dirty and damn well knows how.
Interesting , my current field .....

Quote:
Originally Posted by dvv View Post
So, my outward appearing standard Yugo ripples from 0 to 62 mph (0-100 km/h) in 6.8 seconds, causing a massive headache to neighboring owners of Audi, BMW, MB and so forth owners. The look on their (дурак) faces in my rear view mirror is priceless!
Yes ...a frighting thought in an Yugo ... Porsche brakes i hope....


Quote:
Originally Posted by dvv View Post

Click the image to open in full size.

my headphone amps, both as wholly bipolar, or with FETs in the input stages and MOSFETs for outputs. Both fully are fully complemetary. Shown is the MOSFET version, those are custom 50 VA transformers, and the power supply is a shunt type reguated power supply. The caps are Fisher & Tausche 4,700 uF/40V types, alternatives are Panasonic types of same specs.

Wayne would love it, headphone amps using 50W complementary power devices for the bipolar (MJE 15030/15031), or 75W for the MOSFET version (IRF 510/9510).
The audio type ..... ? i would modify and put larger transformers , 100va min /ch ....

Quote:
Originally Posted by Wavebourn View Post
DVV, if you calculate by ripple voltages you may allow, you can forget about Rules of Dumb and Joules. Joules are needed when you want significant bursts from weak transformer. What is "significant" and "weak" is beyond Rules of Dumb, it needs to be calculated according to limitations of particular design.
Is 240,000 uf/ch too much for an constant voltage load tolerant amplifier .....
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Old 8th February 2012, 07:15 PM   #2048
Previously: Kuei Yang Wang
 
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Hi,

Quote:
Originally Posted by wahab View Post
AFAIK microphonic effects exist , for caps this is an evidence and has surely been experienced by almost everyone by there.
So, we can illustrate that "audiophile capacitors" that sell at a premium have much lower microphonics than generica and lower distortion (has been measured repeatedly including by D.Self) yet the automatic reaction by a certain kind of believer is to label "audiophile capacitors" automatically, without thinking as "Snakeoil".

Quote:
Originally Posted by wahab View Post
Cables can be important if the amp is not stable , otherwise if the amp is correctly designed their influence is close to zero
in respect of all other existant parameters in the audio chain.
That is patently untrue.

All mains powered equipment is subject to leakage from the mains into chassis and signal ground. Interconnect several pieces of mains powered gear and you will find that chassis potentials differ, after the interconnection currents will flow to equalise the chassis potentials.

The currents will flow though mains cable (earth) and interconnects (ground). Any currents flowing in the interconnects will produce a noise voltage that appears in series with the signal. A very low impedance earth connection on the mains cable can lower this noise voltage by 20dB or more...

Quote:
Originally Posted by wahab View Post
That said , i m somewhat on the expectation about those

"clearly measurables differences in noise floor that a bench
test will not reveal"...

How can something be measurable yet not being revealable , that is
measurable i suppose , by a bench test ??...
The bench test will not reveal these noises because it eliminates their sources quite carefully and only tests a single device, testing a system is possible, but I am unaware of any publication on the subject and even worse, I have not even hear this mentioned.

It helps to have spend ages sitting on a crummy chair in "Testing & Measuring" classes hearing your professor intone "Wer Misst Misst Mist" (who measures measures garbage - literally in german manure) instead of drinking and chasing girls.

Just because a particular measurement does not show a significant result does not mean that the suspected effect does not exist, often it simply means the conditions under which it exists where not re-created.

The opposite is also often observed.

To come back to mains cables, yes, on a system level different mains cables may produce very different levels of noisefloor and these differences may indeed result in audible effects, long before someone notices hum or buzz.

To insist that they cannot do that reveals either a brutal ignorance of even basic electrics (as only Lentz, Coulomb, Kirchhoff and Ohm are needed to illustrate what is really going on) or equally brutal mental blinders that prevent the perception of a really obvious issue coupled with a religious fervour to impose the same blinders on all others, or at least die fighting.

In fact, I have serious problems to allow that anyone who takes the "Mains cables cannot make difference" position ever attended and successfully passed a first year EE course (as everything involved is SO basic). However I had exactly that demonstrated to me so many times, I have generally given up to try to make such people understand and constantly wonder what they teach in universities these days...

Ciao T
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Old 8th February 2012, 07:35 PM   #2049
Previously: Kuei Yang Wang
 
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Hi,

Quote:
Originally Posted by a.wayne View Post
Wave is an dedicated toob guy in the forums only, SS @ home and inside .. TL is the tooob only guy , unlike Wave he hasn't had time to appreciate SS stuff , as yet ...
Funny enough, I designed (and build) probably at least as many Solid State Amp's, Pre's, mixing desks and related miscellanea (arguably mostly studio/pro stuff and mostly 80's and into the early 90's) as I did tube stuff.

Even now I get plenty of Solid State stuff and have currently more solid state amp's in the house than tube Amp's. I had a phase in the early 90's where I was running all solid state, using SLC Batteries to power everything including the poweramp (it was running on a stack of 12pcs 6V/12AH ones)...

But the Amp in my system right now uses tubes. And I prefer to listen to music using it, compared to all the Solid State Gear, which generally makes poor doorstops and catches dust.

To say that I don't appreciate SS stuff is like saying I don't appreciate Lucie Liu or Drew Barrymore and only notice Cameron Diaz.

But if I could only take one of Charlies Angels home it would be Cameron Diaz... If I had all three at home all the time, who knows, who I'd like to spend the most time with. But likely again I'd appreciate one of the ladies by far more than the others.

If solid state stuff floats your boat, go for it. If tubes float your boat, go for it.

As Slartibartfast used to say:

"Perhaps I'm old and tired, but I think that the chances of finding out what's actually going on are so absurdly remote that the only thing to do is to say, 'Hang the sense of it' and keep yourself busy. I'd much rather be happy than right any day."



Ciao T
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Old 8th February 2012, 07:35 PM   #2050
a.wayne is offline a.wayne  United States
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Bench testing don't allow the amplifier to get up and dance like it does when playing music... Hence the measurements are irrelevant unless only for static bench test ...



The micro-phonics is caused by the amplifier dancing too close to the speakers ...... right TL ...
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