Christer said:
I think firing cannons can go over 100db, if you measure close enough.
I am doing due diligence on a professional audio company that makes, among others, sound mixing consoles for live concerts and recording studios right now. dynamics don't seem to be their dominant concern there, shielding (thus noise) is.
and their analog consoles are the benchmark in the industry.
Christer said:
the author is probably saying that as long as a power supply is "decent" (we can all define what that means), it is not important to a well designed amplifiers.
millwood said:
The example was a symphony orchestra, without extramusical
addendums like cannons. It was Wagner, not Tchaikowskys
1812. I don't remember the exact figure, but it was well over
100dB. I don't know where it was measured, but presumably
either amongst the audience or close to the conductor.
That said, I wouldn't personally consider it practical to listen
to such dynamics at home, even if recordings and equipment
permitted. The listening envoronment simply isn't up to it.
If "decent" means a Jung-style super regulator.
millwood said:
haven't done any. I didn't leave my office until about 3am this morning and at 8am I am back.
I have found that I have a better chance if I just guess it blind,
Even if you are guessing and over a large sample it is correct better than 55%, then statistically, something must affecting the result - maybe something psycho-acoustic?
ensen.
millwood said:
Christer said:
Anything that can cause deafness has got to be at least 125dB at 1m. Just ask OSHA or any local hearing test company. If you could record it on good analog tape with some kind of noise reduction and re-expand it for the masters, theoretically, you could max out the range of a 24/96 DAW. Of course, that's provided the mics, ADCs and DACs have the capability.
ensen.
Sure, you can hit 100dB SPL at a concert. I can remember a couple of rock shows I've attended that went quite a bit louder (The Who, ELP). But that's different than saying that there's 100dB of dynamic range- the ambient noise in a concert hall with people in it is pretty high. Movie theaters, too, which is why I always take a blackjack with me to reduce the level of conversations occuring in my vicinity.
The ambient noise level is worst at mariachi shows, since most of us have loaded up on frijoles. And it tends to have a lower frequency spectrum than the noise at classical concerts.
The ambient noise level is worst at mariachi shows, since most of us have loaded up on frijoles. And it tends to have a lower frequency spectrum than the noise at classical concerts.
Upupa Epops said:...second is folloving : in my experience declared current load of output any opamp is data for nothing, because opamp have realy most lower distortion if is not loaded or loaded only to high impedance. In our experiences ( ask for this PMA ) best results give every opamp with output current buffer connected to the feedback loop. PMA use integrated ones ( Buf 634 ), I'm using discrete ones ( similar to the well known W. Jung's )...
Care to post a schem of "your" Jung modification, Upupa?
Cheers,
/cdl
purplepeople said:Dynamics folks... not SNR, although there are many pre/amp combos that give can you >80dB SNR. Besides, even with lots of ambient noise, it's possible to distinguish if the sound comes from outside, next door or the speakers.
[snip]
Dynamic range is defined by the SNR. If you have 40dB SNR, then that's your dynamic range.
Jan Didden
I understood dynamic range as the difference between softest and loudest levels whereas signal-to-noise ratio is the difference between the level of a signal and the level of noise in that signal.
Equipment with 100dB dynamic range may only have 40dB SNR so that at maximum levels, the noise is 60dB. In this case, any volume lower than 40dB and the noise cannot be heard. It would be difficult to get 130dB SNR with 120dB dynamic range as there would be negative noise at just above zero level. More likely, you get equipment with range (often much) greater than SNR.
ensen.
Equipment with 100dB dynamic range may only have 40dB SNR so that at maximum levels, the noise is 60dB. In this case, any volume lower than 40dB and the noise cannot be heard. It would be difficult to get 130dB SNR with 120dB dynamic range as there would be negative noise at just above zero level. More likely, you get equipment with range (often much) greater than SNR.
ensen.purplepeople said:
Dynamic range is the ratio of the loudest signal to the softest signal *that can be resolved*, i.e. before it downs in the noise.
In a linear system dynamic range and SNR are one and the same.
In a non-linear system they can differ, especially when one defines DR in the input signal domain and SNR in the output signal domain. Think compressors and such.
Replacing opamps
Hi all
My CDP has a NJM5532 opamp in the output stage. I am interested in changing this for something better.
I know that opamps like OPA2134 and OPA2604 are drop in replacements physically, however, are any changes to the circuit/surrounding components required or advised?
I am also interested in replacing the dual opamp with two single opamps like OPA627.
Are the Brown Dog adaptors used for this any good?
Do they introduce additional problems by moving the opamps further away from the PCB/groundplane?
Is there another/better way to do this?
Looking at the layout of the components surrounding the opamp in my CDP, it appears that they are spread quite far apart and connected by long traces.
What is likely to happen if you move the opamp to a separate board and construct an identical, but less widespread, circuit around it? The opamp would be further from the main PCB and groundplane but closer to its decoupling caps etc?????
Hi all
My CDP has a NJM5532 opamp in the output stage. I am interested in changing this for something better.
I know that opamps like OPA2134 and OPA2604 are drop in replacements physically, however, are any changes to the circuit/surrounding components required or advised?
I am also interested in replacing the dual opamp with two single opamps like OPA627.
Are the Brown Dog adaptors used for this any good?
Do they introduce additional problems by moving the opamps further away from the PCB/groundplane?
Is there another/better way to do this?
Looking at the layout of the components surrounding the opamp in my CDP, it appears that they are spread quite far apart and connected by long traces.
What is likely to happen if you move the opamp to a separate board and construct an identical, but less widespread, circuit around it? The opamp would be further from the main PCB and groundplane but closer to its decoupling caps etc?????
Re: Replacing opamps
I know that opamps like OPA2134 and OPA2604 are drop in replacements physically, however, are any changes to the circuit/surrounding components required or advised?
I am also interested in replacing the dual opamp with two single opamps like OPA627.
Are the Brown Dog adaptors used for this any good?
Do they introduce additional problems by moving the opamps further away from the PCB/groundplane?
Is there another/better way to do this?
--------------------------------------------------------------------------------
Don't worry, go ahead, the Brown Dogs are fine although I'd like thicker traces.
I personally have never liked the up-with-it 'clean' sound of the 627 and prefer the AD825 current loaded with fets to about 3mA, or the bypassed LM6172. The newer AD opamps are all 12V only.
I know that opamps like OPA2134 and OPA2604 are drop in replacements physically, however, are any changes to the circuit/surrounding components required or advised?
I am also interested in replacing the dual opamp with two single opamps like OPA627.
Are the Brown Dog adaptors used for this any good?
Do they introduce additional problems by moving the opamps further away from the PCB/groundplane?
Is there another/better way to do this?
--------------------------------------------------------------------------------
Don't worry, go ahead, the Brown Dogs are fine although I'd like thicker traces.
I personally have never liked the up-with-it 'clean' sound of the 627 and prefer the AD825 current loaded with fets to about 3mA, or the bypassed LM6172. The newer AD opamps are all 12V only.
Re: Re: Replacing opamps
If making new circuit board, also make new groundplane connected to star ground with a very thick wire. But that's not necessary unless you want to change a lot of the circuit - I would just start replacing opamps
Adding extra decoupling caps close to the opamp will never do any harm, you might consider a combination of two or three sizes in caps, possibly using high-quality (e.g. silver-mica) for the smallest cap (which could be soldered directly between adapter and ground plane).
I would check that there is an output resistor, ~100 ohm or so, between the output of the opamp and the output jacks (there probably is one already), it reduces sensitivity to load capacitance.
I agree with Fmak, Browndogs work fine, and do not bring the opamp much farther away from groundplane etc. I didn't really appreciate the opa627 sound either, stuck with AD825 in my CDP.
The newer AD opamps are 12V, but my ad8610 have survived 15V in my preamp without problems, although it may shorten their life a bit. AD8610/8620 is very nice.
And, as Fmak also suggests, you can current load the opamps.
Good luck - I was happy I replaced my CDP's ne5534's with AD825 that were lying around anyway ;-)
/cdl
Fin said:
If making new circuit board, also make new groundplane connected to star ground with a very thick wire. But that's not necessary unless you want to change a lot of the circuit - I would just start replacing opamps
Fin said:
Adding extra decoupling caps close to the opamp will never do any harm, you might consider a combination of two or three sizes in caps, possibly using high-quality (e.g. silver-mica) for the smallest cap (which could be soldered directly between adapter and ground plane).
I would check that there is an output resistor, ~100 ohm or so, between the output of the opamp and the output jacks (there probably is one already), it reduces sensitivity to load capacitance.
I agree with Fmak, Browndogs work fine, and do not bring the opamp much farther away from groundplane etc. I didn't really appreciate the opa627 sound either, stuck with AD825 in my CDP.
The newer AD opamps are 12V, but my ad8610 have survived 15V in my preamp without problems, although it may shorten their life a bit. AD8610/8620 is very nice.
And, as Fmak also suggests, you can current load the opamps.
Good luck - I was happy I replaced my CDP's ne5534's with AD825 that were lying around anyway ;-)
/cdl
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