Actually there is such an off the shelf solution...it's just not available quite yet
.Dan.
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Actually there is such an off the shelf solution...it's just not available quite yet
Dan.
"Those snakes won't oil themselves."
As a general rule, audio transformers are only used by serious designers where they provide benefits which more than offset their problems. For example, impedance matching (valve OPT), ground isolation or balanced/unbalanced conversion.ginettot61 said:
Some DIYers seem to use transformers where a cap will do the job much better. I'm not sure if this is due to fashion, nostalgia or ignorance. Always remember, a typical cap is much closer to an ideal cap than a typical transformer is to an ideal transformer.
Thanks a lot for the very valuable advice
I can only say now ... "Never Neve"
For my the aim is realism in production ... as true as possible.
I am sure that any gimmick can mask some information.
I like to hear the singer breathing ... the strings swish
So no transformers ... they are also expensive.
Thanks and regards, gino
Lol.
Maybee not magical
Just plain physics.....passively reduce 1/f noise and crap systems can sound natural.
Dan.
Hi and sorry, could you elaborate a little ?
I have noticed one thing. If i short the preamp inputs and raise the volume at max no noise to speak of from the speakers.
If i do the same with the digital sourse with no music ... the noise is very evident.
I am completely sure that this noise is very detrimental for sound.
But i do not know how to get rid of it
If there is indeed a way ... well i would be very interested.
Thanks and regards, gino
Thank you very much. It is the ground isolation that matters me most.For this reason i am seriously thinking to batteries for the preamp.
I think that they should provide isolation between source and the rest of the chain ... and this could be very very beneficial to stop the noise at source level (????)
At least this is my hope ...
So i think that in the end i will use them, even if they are not the best for convenience.
Kind regards, gino
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Hi and sorry, could you elaborate a little ?
I have noticed one thing. If i short the preamp inputs and raise the volume at max no noise to speak of from the speakers.
If i do the same with the digital sourse with no music ... the noise is very evident.
I am completely sure that this noise is very detrimental for sound.
But i do not know how to get rid of it
If there is indeed a way ... well i would be very interested.
Thanks and regards, gino
What is the set up and what explicitly do you mean by digital source, analogue out of a dac to your pre amp?
The reason I pick on "purists" is because I know many extremely intelligent audio engineers that astound me with how many details they've learned how to talk about or engineer, but many of them are so obsessed with the details that they lose perspective on the system as a whole, and what they really want for an audio ecperience.
They worry endlessly about mechanisms that make little or no audible difference, while ignoring things that do make a big difference. They want to believe they know it all and are right, so they avoid areas they don't understand well. I'm generalizing here. Not all audio engineers are like this. But when I watch a guy pay close to $1K for speaker cables, see all the $1K+ preamps out there that have no tone controls, see people pay $50 for a polypropylene cap when you can get a perfectly good polyprop cap same value for $5...
What I see getting less attention is a good understanding of acoustics, phase margin, understanding of the ear-brain mechanism, discussion of the recording process which has all the same problems as the reproduction process (comb filter effects, imaging issues, mic proximity effects, etc.). If you look at the Fletcher-Munson curves, and see what room acoustics do to the sound, not to mention variations in the recording process, I don't see how anyone can think they don't want tone controls.
A salesman came to one of our club meetings and tried to sell his $500 speaker cables. At one point I asked him how one could show the difference between his wire and regular 16AWG AC line cord with test equipment. He said the ear is much more sensitive than the worlds most sensitive test equipment, and you'd have to have a 200 foot length of the wires to be able to measure any difference with today's best test equipment... As someone who calibrated and engineered some of the worlds best test equipment at Tektronix, much of which is NBS traceable (National Bureau of Standards), I could only wonder what this guy was high on... Then someone whipped out $500 and bought one of his cables... Oh well. Is it peer pressure sell-out? I don't know. I guess you've got to let people make their mistakes and learn things their way sometimes.
They worry endlessly about mechanisms that make little or no audible difference, while ignoring things that do make a big difference. They want to believe they know it all and are right, so they avoid areas they don't understand well. I'm generalizing here. Not all audio engineers are like this. But when I watch a guy pay close to $1K for speaker cables, see all the $1K+ preamps out there that have no tone controls, see people pay $50 for a polypropylene cap when you can get a perfectly good polyprop cap same value for $5...
What I see getting less attention is a good understanding of acoustics, phase margin, understanding of the ear-brain mechanism, discussion of the recording process which has all the same problems as the reproduction process (comb filter effects, imaging issues, mic proximity effects, etc.). If you look at the Fletcher-Munson curves, and see what room acoustics do to the sound, not to mention variations in the recording process, I don't see how anyone can think they don't want tone controls.
A salesman came to one of our club meetings and tried to sell his $500 speaker cables. At one point I asked him how one could show the difference between his wire and regular 16AWG AC line cord with test equipment. He said the ear is much more sensitive than the worlds most sensitive test equipment, and you'd have to have a 200 foot length of the wires to be able to measure any difference with today's best test equipment... As someone who calibrated and engineered some of the worlds best test equipment at Tektronix, much of which is NBS traceable (National Bureau of Standards), I could only wonder what this guy was high on... Then someone whipped out $500 and bought one of his cables... Oh well. Is it peer pressure sell-out? I don't know. I guess you've got to let people make their mistakes and learn things their way sometimes.
Hi well now it is a little mess ... a pc and usb dac is my present digital source Honestly I think that is almost impossible to avoid noise from this set-up.
But if i power the pre with a battery i should be able to isolate source and rest of the chain from preamp down. Am i wrong ?
Thanks and regards, gino
If only people would learn from their mistakes! More common is to become an 'evangelist' for the same mistake. Then all you need is a little herding and a new bandwagon develops leaving behind us poor ignorant engineers who prefer to stick to the 'old faith' preached by Ohm and Kirchoff.Bob Richards said:
Ginetto, can you characterize the "noise"? Hum? White noise? Also, can you hear any at the speaker at normal or even high listening levels?
If it's hum, then batteries may help (they may not), but if it's hiss, then batteries are unlikely to make any difference.
Winding the gain to max really only tells you that you have more gain than you need....
If it's hum, then batteries may help (they may not), but if it's hiss, then batteries are unlikely to make any difference.
Winding the gain to max really only tells you that you have more gain than you need....
Hi unfortunately i do not have a scope and anyway i would not know how to use it
I hear the noise when i raise the volume at high level ... let's say that it starts at 1-2 o'clock position... maybe it is hiss ?
But without the source connected the noise is zero even with volume at max.
I think it would be nice to have a similar result also with the source connected.
That is sure ... i never listen with the volume pot in that position
I just like the absence of noise in general
Thanks and regards, gino
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I guess that i should have a scope and send in the signal out from the source ?
In the weekend i will look seriously on ebay ... i have to try at least even if i am quite worried ... i have completely no experience on this kind of things.
But curiosity is huge ... to finally "see" one of those beautiful noise spectra.
I am very curious
Thanks again, gino
A F***ing men Bob
. I also liked your previous post. Too bad there aren't more people like you on here to counter the idi.....ermmm.....mor......uh....misguided 
...Bob... Too bad there aren't more people like you on here to counter the idi.....ermmm.....mor......uh....misguided
I'd love to see a live debate between Bob and one or two of the more vocal "oilers of snakes" around here.
ginetto61,
If I understood well, you have noise at high volume settings when the amplifier it is connected to DAC even if you do not play anything.
It is simple for me. What kind of galvanic isolation do you have between the computer and the DAC?
I suppose that the digital noise from computer are coupled to your DAC output through maybe GND commune connection.
To get rid of it you must use a quality optical isolation, the battery power will not help to much.
In my setup I have remote control of the output volume from DAC and manual control of the amplifier volume. If I do not play anything, I can set to maximum the volume from amplifier and to 0dB the gain from DAC (control from -90dB to +30dB) and I can not hear anything from the speakers. At +30dB there are some little noise.
My DAC have optical isolation between digital input module (USB input chip, source selector, quartz reference oscillators, µController, display) and the analog output module (DAC chip, output reconstruction filters, volume control and analog line drivers).
If I understood well, you have noise at high volume settings when the amplifier it is connected to DAC even if you do not play anything.
It is simple for me. What kind of galvanic isolation do you have between the computer and the DAC?
I suppose that the digital noise from computer are coupled to your DAC output through maybe GND commune connection.
To get rid of it you must use a quality optical isolation, the battery power will not help to much.
In my setup I have remote control of the output volume from DAC and manual control of the amplifier volume. If I do not play anything, I can set to maximum the volume from amplifier and to 0dB the gain from DAC (control from -90dB to +30dB) and I can not hear anything from the speakers. At +30dB there are some little noise.
My DAC have optical isolation between digital input module (USB input chip, source selector, quartz reference oscillators, µController, display) and the analog output module (DAC chip, output reconstruction filters, volume control and analog line drivers).
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