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Old 7th November 2012, 01:54 PM   #21
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Location: Coffs Harbour
Lets get this straight.
You are using an external DAC, Right? You adjust the PC for half the volume level and this instructs the DAC to reduce the audio output level, right?
So you are reducing the signal to the amplifier and so the distortion in the sound reduces too. That is what has been described to you here already.

You can switch signals in and out as you please. Combining them seems pointless if you want to listen to them separately.

All you need to do is make 2 simple preamplifier stages with an adjustable gain of around 10. Use a dual OPamp using low supply voltages, if you like.

Feed the undistorted input into the first stage and adjust it to overdrive the second and set the output level of the second to match the undistorted input.

Then feed the output of the second stage into one amplifier channel and the original, undistorted signal is also fed into the other channel.
You will then be comparing original clean input with an overdriven (clipped) one.

Unfortunately, if you want this all to happen like magic with little effort, that's not going to happen. I suspect you'll need to learn some serious electronics and DIY
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Old 7th November 2012, 04:31 PM   #22
aarvin2 is offline aarvin2  Mauritius
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Quote:
Originally Posted by Ian Finch View Post
Lets get this straight.
You are using an external DAC, Right? You adjust the PC for half the volume level and this instructs the DAC to reduce the audio output level, right?
So you are reducing the signal to the amplifier and so the distortion in the sound reduces too. That is what has been described to you here already.

You can switch signals in and out as you please. Combining them seems pointless if you want to listen to them separately.

All you need to do is make 2 simple preamplifier stages with an adjustable gain of around 10. Use a dual OPamp using low supply voltages, if you like.

Feed the undistorted input into the first stage and adjust it to overdrive the second and set the output level of the second to match the undistorted input.

Then feed the output of the second stage into one amplifier channel and the original, undistorted signal is also fed into the other channel.
You will then be comparing original clean input with an overdriven (clipped) one.

Unfortunately, if you want this all to happen like magic with little effort, that's not going to happen. I suspect you'll need to learn some serious electronics and DIY

I think I didn't explain well ok let me try with an illustration sorry I forgot to put the arrows , but I'm sure you know what I mean When I write "Pc Vol" I mean "Windows volume control ", you know, the little speaker on your Taskbar.

Click the image to open in full size.

Here is what I want to do :

Click the image to open in full size.

Does it make any sense guys ?? How could I do this ??

By the way the PC volume(WINDOWS VOLUME CONTROL) is controlling what ?? A pre amp found on the motherboard ?? or does it bypass all this and goes directly to my DAC ??

When it's at 100% what is the electronic element which is actually distorting ??

Last edited by aarvin2; 7th November 2012 at 04:47 PM.
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Old 7th November 2012, 08:22 PM   #23
dsdjoy is offline dsdjoy  Germany
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It is still not clear, what you would like to achieve.

You like the distorted sound for some pieces of musik,
while for other songs you like the undistorted sound ?

You want a switch to switch forth and back between the two variations,
without having to adjust the volume on your amplifier or active-speakers ?

If you want to have something like that, it will be much easier, if you use
plugins like this: Audio tube/valve overdrive plugin (AU, VST) - Voxengo Tube Amp - Voxengo

"The sound this plug-in produces varies from a mild “warm” overdrive to a fuzzy distortion."

Such VST plugins can be loaded for example into J.River Mediacenter and can be applied to the music during playback. You can adjust such plugins or switch them on/off as you like.

If you want to do that in analog hardware, it becomes very difficult:
Without knowing the source of the funny sound you describe, it is not clear if it is distortion, clipping, lack of output power of your DAC or amp at higher levels,...and we are not able to find out by remote diagnostic.

That means probably also, that any analog distortion generator you build, will sound probably fundamentally different from the "funny" sound you have at 100% volume.

My advice: If you would like to compare different distortion figures - since you use a DAC and PC already. Stay at 50% output level and apply sound effects using VST plugins - there are many of them available for free.
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Old 7th November 2012, 08:35 PM   #24
aarvin2 is offline aarvin2  Mauritius
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No actually I am a mixing engineer and I have found that the best tracks, can resist the 100% volume perfectly, while the shitty mixes sounded super harsh and piercing.

I would just like to know how I could create this 100% effect in the analog world. I tried for a long time using different plugins to reproduce this effect but no plugin gave me those results.


I am using a DAC which is connected via USB to my PC. What is the volume control in the task bar actually controlling ?

I assume that USB carries only digital signal , so when the volume control on the taskbar is set at 100% , which electronic part of the DAC is being driven hot ??
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Old 7th November 2012, 09:58 PM   #25
Struth is offline Struth  Canada
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Hi Guys

As others have pointed out, the distortion you described results from some part of the circuit clipping the signal - running out of voltage head room and cutting off what would otherwise be a clean much-taller peak.

Yes, you can simulate this very easily in analog and have it be on a switch. There are several ways to do it.

One method is to simply add diodes in antiparallel to the signal path at a point in the path where you have no control over the signal level. A pot in series with the diodes will allow you to dial in the diode clip sound and provides "compliance" between saturated clipped sounds and fully clean tones. If you wanted to be fancier about it, you would arrange for the clipped path to be buffered from and mixable into the clean path.

An alternate method is to change the supply voltage to a given circuit stage. This is like stepped Power Scaling but without drive compensation because you want to add distortion. The lower voltage mode will clip sooner and provide the distortion you described.

Overdriven stereos, PA systems, mixers,guitar amps, et al clip the signal and put out squared off waves with a predominantly odd-order harmonic profile. It is harsh and fizzy sounding. Most live sound is hugely distorted and presented to the listener at SPLs beyond human compression - should be criminal - which makes it easier than ever to simulate 'live' sound at home: dial volume to '10' and not hear the music.

Some regulatory agencies prescribe measuring maximum output power at 10% THD. This is a visibly distorted sine wave with slightly flattened tops when viewed on a scope.

Have fun
Kevin O'Connor
londonpower.com
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Old 7th November 2012, 10:30 PM   #26
aarvin2 is offline aarvin2  Mauritius
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Quote:
Originally Posted by Struth View Post
Hi Guys

As others have pointed out, the distortion you described results from some part of the circuit clipping the signal - running out of voltage head room and cutting off what would otherwise be a clean much-taller peak.

Yes, you can simulate this very easily in analog and have it be on a switch. There are several ways to do it.

One method is to simply add diodes in antiparallel to the signal path at a point in the path where you have no control over the signal level. A pot in series with the diodes will allow you to dial in the diode clip sound and provides "compliance" between saturated clipped sounds and fully clean tones. If you wanted to be fancier about it, you would arrange for the clipped path to be buffered from and mixable into the clean path.

An alternate method is to change the supply voltage to a given circuit stage. This is like stepped Power Scaling but without drive compensation because you want to add distortion. The lower voltage mode will clip sooner and provide the distortion you described.

Overdriven stereos, PA systems, mixers,guitar amps, et al clip the signal and put out squared off waves with a predominantly odd-order harmonic profile. It is harsh and fizzy sounding. Most live sound is hugely distorted and presented to the listener at SPLs beyond human compression - should be criminal - which makes it easier than ever to simulate 'live' sound at home: dial volume to '10' and not hear the music.

Some regulatory agencies prescribe measuring maximum output power at 10% THD. This is a visibly distorted sine wave with slightly flattened tops when viewed on a scope.

Have fun
Kevin O'Connor
londonpower.com

Kevin thank you sooooo much for sharing your knowledge and this tip !!!! Now i'll get working on it

Wooo hooo!!
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Old 8th November 2012, 03:01 AM   #27
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Quote:
Originally Posted by aarvin2 View Post
......By the way the PC volume(WINDOWS VOLUME CONTROL) is controlling what ?? A pre amp found on the motherboard ?? or does it bypass all this and goes directly to my DAC ??

When it's at 100% what is the electronic element which is actually distorting ??
The cable between the PC and DAC is for digital data, probably in USB format for basic PCs. A DAC converts digital data to analog sound (audio). Logically, the PC volume control can only be a digital command which instructs the DAC to adjust volume in digital format. This results in the volume then being adjusted in audio (analog) format, just like a volume control. Can you follow this?

Once you have sound in audio or analog format, it is passed to your PC speakers which will contain a pre-amp as part of its internal amplifier and analog volume control. That amplifier combination has the necessary gain to drive its loudspeaker under a second (analog) volume control.

You still seem to have difficulty understanding that any signal adjusted too high for the following stage causes clipping distortion. This is exactly what you do by setting the volume on your PC to "high". This is also what Struth has explained again so I guess you must follow the idea.

As an engineer, you will be well aware of this reality and be required to ensure it doesn't happen in live sound, so hopefully this is just a language translation problem.
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Old 10th November 2012, 08:33 AM   #28
aarvin2 is offline aarvin2  Mauritius
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Quote:
Originally Posted by Ian Finch View Post
The cable between the PC and DAC is for digital data, probably in USB format for basic PCs. A DAC converts digital data to analog sound (audio). Logically, the PC volume control can only be a digital command which instructs the DAC to adjust volume in digital format. This results in the volume then being adjusted in audio (analog) format, just like a volume control. Can you follow this?

Once you have sound in audio or analog format, it is passed to your PC speakers which will contain a pre-amp as part of its internal amplifier and analog volume control. That amplifier combination has the necessary gain to drive its loudspeaker under a second (analog) volume control.

You still seem to have difficulty understanding that any signal adjusted too high for the following stage causes clipping distortion. This is exactly what you do by setting the volume on your PC to "high". This is also what Struth has explained again so I guess you must follow the idea.

As an engineer, you will be well aware of this reality and be required to ensure it doesn't happen in live sound, so hopefully this is just a language translation problem.
Thanks a lot for your explanation mate ! things are getting way clearer
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Old 10th November 2012, 10:45 AM   #29
DF96 is offline DF96  England
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Join Date: May 2007
Quote:
Originally Posted by Ian Finch
As an engineer, you will be well aware of this reality and be required to ensure it doesn't happen in live sound, so hopefully this is just a language translation problem.
The English word "engineer" has an unfortunately broad meaning in common usage. In mechanical terms it can mean anything from someone who knows which end of a spanner to hold, to someone who can design build and test an entire engine from scratch with full mathematical underpinning. Similarly in electronics it can mean someone who knows which valve/PCB to swap in a TV when the picture goes funny, to someone who could design the chips in the TV or the antenna it uses.

Some industries have tried to distinguish between operators, fitters, technicians and engineers but this has never trickled down to the general public, who call them all 'engineers'.
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Old 16th November 2012, 10:55 PM   #30
aarvin2 is offline aarvin2  Mauritius
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Join Date: Sep 2012
Quote:
Originally Posted by Struth View Post
Hi Guys

As others have pointed out, the distortion you described results from some part of the circuit clipping the signal - running out of voltage head room and cutting off what would otherwise be a clean much-taller peak.

Yes, you can simulate this very easily in analog and have it be on a switch. There are several ways to do it.

One method is to simply add diodes in antiparallel to the signal path at a point in the path where you have no control over the signal level. A pot in series with the diodes will allow you to dial in the diode clip sound and provides "compliance" between saturated clipped sounds and fully clean tones. If you wanted to be fancier about it, you would arrange for the clipped path to be buffered from and mixable into the clean path.

An alternate method is to change the supply voltage to a given circuit stage. This is like stepped Power Scaling but without drive compensation because you want to add distortion. The lower voltage mode will clip sooner and provide the distortion you described.

Overdriven stereos, PA systems, mixers,guitar amps, et al clip the signal and put out squared off waves with a predominantly odd-order harmonic profile. It is harsh and fizzy sounding. Most live sound is hugely distorted and presented to the listener at SPLs beyond human compression - should be criminal - which makes it easier than ever to simulate 'live' sound at home: dial volume to '10' and not hear the music.

Some regulatory agencies prescribe measuring maximum output power at 10% THD. This is a visibly distorted sine wave with slightly flattened tops when viewed on a scope.

Have fun
Kevin O'Connor
londonpower.com
A last question please Sir, if I create distortion like you have advised , will it affect the life of my speakers and over hear them or burn them ??

I have heard that clipping does affect speakers in a bad way and cause them to blow up, and I am confused as some studio processors like a CLIPPER or Clipping the Analog to Digital converters or the clipping found in distorted rock guitars, don't seem to burn up any speakers

Thanks in advance for helping me out on this!! MERCI BEAUCOUP!!
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