| rinox |
Maybe you know (but I can't find other thread about) that the really sound of every amp coming from PSU ???
Try to connect a switching PSU to your amp (whichever amp) and you' ll be suprised!!
I made a lots of experiments with the support of the guys from Audison (makers of car amps) and the result is that the same amplifier powered by switching PSU sound really surprising.
In dettail we made a try with an old NAD 3020, removed the original PSU, connected the smps to a car battery and voilą...... unbeliveable sound it's not the same amplifier.
The secret of the sound is in PSU!!!!!!!!!
Now the problem is to make a 220/120 Volts SMPS, if someone have some ideas to build it (PC PSU are not good = low voltage) let us know, thanks. |
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| analog_sa |
| quote: | | Try to connect a switching PSU to your amp (whichever amp) and you' ll be suprised!! |
I have been surprised. And not in a pleasant way. |
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| peranders |
| quote: | Originally posted by rinox
The secret of the sound is in PSU!!!!!!!!! |
Congratulations to your new discovery. Not many have made it before you. |
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| thomas997 |
| quote: | Originally posted by rinox
Now the problem is to make a 220/120 Volts SMPS, if someone have some ideas to build it (PC PSU are not good = low voltage) let us know, thanks. |
Someone did some modifications to a computer psu to tie the rails together to get +/-/gnd and to boost the voltage a little.
It might have been posted on here. :confused: |
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| HDTVman |
| quote: | Originally posted by rinox
Maybe you know (but I can't find other thread about) that the really sound of every amp coming from PSU ???
Try to connect a switching PSU to your amp (whichever amp) and you' ll be suprised!!
I made a lots of experiments with the support of the guys from Audison (makers of car amps) and the result is that the same amplifier powered by switching PSU sound really surprising.
In dettail we made a try with an old NAD 3020, removed the original PSU, connected the smps to a car battery and voilą...... unbeliveable sound it's not the same amplifier.
The secret of the sound is in PSU!!!!!!!!!
Now the problem is to make a 220/120 Volts SMPS, if someone have some ideas to build it (PC PSU are not good = low voltage) let us know, thanks. |
The key to performance of any amplifer is the power supply as you point out. I would not how ever say that switch mode supplies are the ultimate. The biggest factor as far as I can tell in the output impedance across the power bandwidth of the amp. Any power supply that has an output impedance at least 100 times lower that the load on the amp across the entire bandwidth will let that amp sound as good as it can. (8 ohm load need PS with output Z=.08 ohms or less. My rules for my stuff.)
The issue with switchers is noise at the switching frequency and harmonics. That's not a problem if the amp is bandwidth limited but can be very bad with a wide bandwidth amp.
If you read the threads on "chip amps" a lot of what goes on with these amps is power supply tuning. I seems like everyone is tuning the caps. They all seem to be looking for the part that give the magic touch to a mass produced IC amp. by playing with the power supply impedance across the frequency spectrum.
Just my 2 cents
BZ |
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| HDTVman |
Any comments on my power supply impedance v frequency ideas?
BZ |
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| carlosfm |
| quote: | Originally posted by HDTVman
Any power supply that has an output impedance at least 100 times lower that the load on the amp across the entire bandwidth will let that amp sound as good as it can. (8 ohm load need PS with output Z=.08 ohms or less. My rules for my stuff.) |
:rolleyes:
| quote: | Originally posted by HDTVman
Any comments on my power supply impedance v frequency ideas? |
Idealy you need a low impedance PSU, extending to very high frequencies.
The impedance of a PSU varies with frequency, as a speaker's impedance changes with frequency too.
Specifying a speaker as "8 ohms" can be as misleading as yor "Z=.08 ohms" impedance for the PSU.
You can't use that "rule" of yours.
Just imagine your rule applied to a PSU for a signal op-amp driving an 100 kohm load.:D |
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| HDTVman |
| quote: | Originally posted by carlosfm
:rolleyes:
Idealy you need a low impedance PSU, extending to very high frequencies.
Yes that is correct.
The impedance of a PSU varies with frequency, as a speaker's impedance changes with frequency too.
Yes, that is what I was refering to as power supply tuning.
Specifying a speaker as "8 ohms" can be as misleading as yor "Z=.08 ohms" impedance for the PSU.
You can't use that "rule" of yours.
Just imagine your rule applied to a PSU for a signal op-amp driving an 100 kohm load.:D |
That was intended as an example of the minimum ratio and although I didn't say so that impedance would be for the entire bandwidth of the amp. A ratio greater than 100 / 1 is not excluded by what I said, in fact that would be better. The key to this is that the power supply impedance needs to be low for the entire frequency spectrum that the amplifer will be expected to deal with.
It's my opinion that the cap swapping that goes on is to pick a part that gives the power supply a impedance v frequency relationship that pleases the experimenter. I build the power supplies for my equipment so that the power supply output impedance is very low more that 2 octives beyond the bandpass of the amplifer in question. I try to make this impedance at least 100 times lower than the speaker loads minimum impedance.
BZ |
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| rinox |
The problem of a normal PSU is that it is connected to main power (120/220 Vac), that isn' t so "clean".
If you have an oscilloscope, you can see that the 50 Hz (I think also 60 Hz) have many mid and high frequency spikes that in some manner "dust" the sound of PSU and of course the sound of the amply connected, this is a fact .
There are many commercial main conditioners, they also works, but they are not capable to totally eliminate mid and high frequency spikes in the udible spectrum.
An SMPS work at higher frenquencies (30-40 Kz) so you simply can't hear these "rumors".
Another good try is to put some inductances in series of the out of PSU like a psu for tubes amps.
A good PSU tube amp is plain of inductances because tubes are very sensible (much more than tansistors) at certain frequencies.
But is quite impossible to make a good inductance when whe speak about some Amperes (tubes use some milliamperes.)
"The sound of tubes" isn' t only for the tubes itself but for the circuit around them.
Meditated people, meditated !!! |
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| rinox |
Only a note....
I wrote abot Bob Carver in another post.
May be you don't know, but many years ago, there was a "battle" between Mark Levinson (now Red Rose) and Bob Carver.
In an audiction room more then 100 persons (audiophilies) was invited to hear, in the same conditions, the same source, the same loudspeakers etc.... two differents amps.
Results... nobody heard differences in sound. (Mark Levinson costed 30 times more then Carver).... maybe PSU ??
I will try to search for this article but I don' t know if I'll find it, we speak about old things (more or less, 20-25 years ago).
Meditate folks, meditate. |
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| analog_sa |
| quote: | | An SMPS work at higher frenquencies (30-40 Kz) so you simply can't hear these "rumors". |
You may not be able to hear but it won't stop these and higher frequency increasing an amps IMD and other distortions. In fact the reason mains supplied circuits sound so vastly different is not so much the presence of lower frequencies in the mains as harmonics going into the MHz range.
It may still be possible to create a good sounding SMPS but judging by the almost complete absence of such supplies in high-end commercial audio it is very difficult. Last year i listened to the latest Chord and against what my friends thought i seemed to like it. So, yes it probably can be done. Certainly not by modding a PC smps.
| quote: | | In an audiction room more then 100 persons (audiophilies) was invited to hear |
A lovely anecdote. Can you really imagine a "100 persons (audiophiles)" in the same room? All of them sharing a sweet spot? It just can't be done.
As i equally dislike the products of both these companies but find Carver's marketing a lot more offensive and annoying i suspect this urban legend was another pitiful sales attempt. |
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| carlosfm |
| quote: | Originally posted by rinox
An SMPS work at higher frenquencies (30-40 Kz) so you simply can't hear these "rumors". |
But you have to band-limit the amp.
Otherwise the switching noise will be very audible, harmonics come all the way down to the audioband.
Also, 30-40khz switching is not appropriate for an audio amp.
It should be higher.
There are some good amps with switching PSUs. |
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| carlosfm |
| quote: | Originally posted by analog_sa
It may still be possible to create a good sounding SMPS but judging by the almost complete absence of such supplies in high-end commercial audio it is very difficult. Last year i listened to the latest Chord and against what my friends thought i seemed to like it. |
Linn has some good sounding amps too, with switching PSUs.
| quote: | Originally posted by analog_sa
Certainly not by modding a PC smps. |
Certainly not.:D |
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| HDTVman |
| quote: | Originally posted by rinox
The problem of a normal PSU is that it is connected to main power (120/220 Vac), that isn' t so "clean".
If you have an oscilloscope, you can see that the 50 Hz (I think also 60 Hz) have many mid and high frequency spikes that in some manner "dust" the sound of PSU and of course the sound of the amply connected, this is a fact . |
Yes, this can be a problem with the simple power supplies many people are building for there DIY projects.
| quote: | [i]There are many commercial main conditioners, they also works, but they are not capable to totally eliminate mid and high frequency spikes in the udible spectrum.
An SMPS work at higher frenquencies (30-40 Kz) so you simply can't hear these "rumors". [/B] |
No, but the amp will be affected. The distortion will be IM as analog_sa said.
| quote: | [i]Another good try is to put some inductances in series of the out of PSU like a psu for tubes amps.
A good PSU tube amp is plain of inductances because tubes are very sensible (much more than tansistors) at certain frequencies.
But is quite impossible to make a good inductance when whe speak about some Amperes (tubes use some milliamperes.)
"The sound of tubes" isn' t only for the tubes itself but for the circuit around them.
Meditated people, meditated !!! [/B] |
If you don't think SS amps can use "inductances in series of the out " of the power supply check out some of the Pass amplifiers.
You can reduce the power line conducted noise with a CLC, or LC, or CRC type power supplies but my choice is a BIG, multi output linear regulated supply for power amps. Each stage has it's own regulator and the current is 2 to 3 time the requirement for that stage. Then properly bypassing is the finishing touch. I know that's expensive but for my own stuff who cares.
Bruce |
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| peranders |
| quote: | Originally posted by rinox
The problem of a normal PSU is that it is connected to main power (120/220 Vac), that isn' t so "clean".
If you have an oscilloscope, you can see that the 50 Hz (I think also 60 Hz) have many mid and high frequency spikes that in some manner "dust" the sound of PSU and of course the sound of the amply connected, this is a fact . |
Don't forget that what you will see on the oscilloscope is the voltage at the probe tip and this is your object PLUS your oscilloscope. In other words: The scope may introduce disturbance and it may also reduce it! You must know your whole measurement setup in order to make any conclusions. |
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| 4fun |
| In this case (powerline) i don't think a high impedance probe will introduce or subtract anything from the actual values. But in other high impedance circuits there is a totally different matter. |
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| TwoSpoons |
Many is the time I've seen a technician with an odd waveform on a scope - measuring some low-impedance circuit. I disconnect their scope probe from the circuit, attach the probe ground clip to the probe tip, and Lo! the odd signal is still there!
High impedance probes make wonderful antennas, even when shorted out. |
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| Luke |
| quote: | May be you don't know, but many years ago, there was a "battle" between Mark Levinson (now Red Rose) and Bob Carver.
In an audiction room more then 100 persons (audiophilies) was invited to hear, in the same conditions, the same source, the same loudspeakers etc.... two differents amps.
Results... nobody heard differences in sound. (Mark Levinson costed 30 times more then Carver).... maybe PSU ??
I will try to search for this article but I don' t know if I'll find it, we speak about old things (more or less, 20-25 years ago). |
I figure that one or more of the following may have caused this phenomena.
1. **** Source.
2. **** speakers.
3. **** amplifiers.
4. **** audiophiles.
:D
Are you trying to tell us that all ampliers sound the same, cos if thats the case, Id like to suggest that all power supplies sound the same too:D
Sorry Im not trying to be rude, but dont understand the post in context to the point you are trying to make regarding power supplies.
regards Arthur
BTW C**P is not a swear word! |
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| Colin |
Nuuk has done some work on switching PSUs here
and Russ Andrews is selling switched mode powerpacks for Tivoli mains radios and portable audio.
Colin |
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| XELB |
| quote: | Originally posted by peranders
Congratulations to your new discovery. Not many have made it before you. |
lol
:rofl:
:D :clown: :clown: :dead: |
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| 4fun |
| quote: | Originally posted by TwoSpoons
Many is the time I've seen a technician with an odd waveform on a scope - measuring some low-impedance circuit. I disconnect their scope probe from the circuit, attach the probe ground clip to the probe tip, and Lo! the odd signal is still there!
High impedance probes make wonderful antennas, even when shorted out. |
Hi!
If you have any waveform while you short probe to ground, well then you must think of that and at least take that into account.
The quality of probes is important....Cheap - Good
antenna ....Expensive (hopefully quality) - Less good antenna.
Measuring really low impedance sources it can be of benefit to connect directly to oscilloscope just to minimise any probe injected stuff.
/ Anders K |
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| sbrads |
| quote: | Originally posted by TwoSpoons
Many is the time I've seen a technician with an odd waveform on a scope - measuring some low-impedance circuit. I disconnect their scope probe from the circuit, attach the probe ground clip to the probe tip, and Lo! the odd signal is still there!
High impedance probes make wonderful antennas, even when shorted out. |
Wind a few turns of the scope's coax cable through a ferrite ring. It won't affect the probe's performance with 'real' signals but it cuts out most of the common mode 'aerial' noise. |
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| davidsrsb |
| quote: | Originally posted by rinox
But is quite impossible to make a good inductance when whe speak about some Amperes (tubes use some milliamperes.)
"The sound of tubes" isn' t only for the tubes itself but for the circuit around them.
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Ever looked inside a Musical Fidelity amp?
The only problem with chokes in transistor amplifiers is that you have to have a high quiescent class AB or class A to provide the minimum load on the LC filter, so no good for chipamps.
Switchers usually have fairly small output caps and are basically cuurent sources with voltage feedback, so the LF output impedance is good, much better than the simple bridge/bulk cap, but the output impeance rises with frequency, the step load response can be poor.
Another problem is the common mode noise current which will end up on the shields of the inputs. I used to design video standards converters for broadcast and we had big problems with this. |
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| :tom:germany: |
Hello
I'm just searching for a SPS for my T-amp (AMP3 from 41Hz.com).
The reason is cause my self builded regulated PSU don't work proberly and I also read that SPSs should sound better with t-amps.
I've found two SPSs now:
http://www2.produktinfo.conrad.com/..._SPS_060_15.pdf
http://www2.produktinfo.conrad.com/...ZTEIL_LPS64.pdf
Voltage, ripple and load are the same. The main differences I can see are efficiency, adjustment range and switching frequency.
Cause of the better efficiency, the higher adjustment range and the cheaper price (45 instead of 55 Euros) I would prefer the first one.
But how important is the switching frequency. The first one I prefer has 50kHz but the second one from ASTEC has 110kHz??
Is that important and if yes which one would be better and why would it be better?
many thanks Tom |
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