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Analog Kid
Senior Member Joined: 07 Mar 2008 Location: Germany Status: Offline Points: 209 |
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Posted: 13 Jan 2010 at 6:05pm |
So what can you tell us about the upcoming line amps?
When will they be ready? What features will they have? (Tone controls will hopefully be included? ) Edited by Analog Kid - 25 Jan 2010 at 2:01pm |
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Analog Kid
Senior Member Joined: 07 Mar 2008 Location: Germany Status: Offline Points: 209 |
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GSP Audio does not want to discuss unannounced products.
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Graham Slee
Admin Group Retired Joined: 11 Jan 2008 Location: South Yorkshire Status: Offline Points: 16298 |
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I'd love to discuss "unannounced products".
But at the moment I'm still unsure what to announce. Edited by Graham Slee - 16 Feb 2010 at 10:55pm |
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Graham Slee
Admin Group Retired Joined: 11 Jan 2008 Location: South Yorkshire Status: Offline Points: 16298 |
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I have been investigating tone controls and still have a way to go.
The last time I did tone controls was on a post production mixer about 17 years ago. I recall they measured "flat" in the mid positions but how "flat"? Now with the benefit of a simulator, I can see that "flat" can mean a subtle hump, or dip, or even shelving up, or shelving down of the response, where I'd have thought it should be perfectly flat. Obviously the source impedance driving them (buffer stage) and the output impedance of the summing amp (tone control amplifier) they're built around, have a marked effect on this flatness - they influence it, or add to the tone control network impedance. Here I must add I'm talking about the "Americanized" Baxendall type of tone control - I still have to examine the passive solution. I did dig out an old Quad 33 tone control circuit for reference and can see exactly why the tone control defeat switch was so important - it would alter the sound simply because in the centre position there is this hump/dip/shelf which could be as much as 1 or more decibels. I am not saying the Quad 33 was a poor design - hats off to the designer! It was good at the time. My own calculations for a circuit when run exhibited much the same problems. I decided after many hours to take a break from it and then take another look. I will try one or two fixes in the next day or so, and then, if unsuccessful, I will venture down the passive route and report further on my findings. |
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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
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Analog Kid
Senior Member Joined: 07 Mar 2008 Location: Germany Status: Offline Points: 209 |
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The above need some clarification. Why is flatness a concern with tone controls? Just by using tone controls to adjust the treble and bass, you are already manipulating the frequency spectrum of the music, by making the amplifier produce more or less bass and treble, so common sense would say that flatness is not an issue, but maybe I misunderstand something. Edited by Analog Kid - 29 Mar 2010 at 11:51pm |
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less
Senior Member Joined: 27 May 2008 Location: Clevedon Status: Offline Points: 334 |
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I think AK that what you are missing is that some people may not want to use the tone controls all of the time or at all, therefore any change in the signal defeats that goal. I have tone controls on my current amplifier but very rarely use them. I was not aware though, until now, that their prescence might still be affecting the signal (Arcam alpha 9 integrated). Regards Les |
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I don't do mediocrity!
Les Sutherland |
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Graham Slee
Admin Group Retired Joined: 11 Jan 2008 Location: South Yorkshire Status: Offline Points: 16298 |
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Agreed...
If we can show the tone controls result in a flat response when set to their midpoints there should be absolutely no need for a defeat switch - I mean, why have a defeat switch to defeat something that doesn't need defeating? So why did so many amps need defeat switches? Exactly! Because the tone controls never had a flat position no matter where they were set! I don't really like mentioning others but if you model a Quad 33 tone control on a simulator you'll get my drift... So yet again, the hi-fi industry has gone to silly extremes again to cover up for it's inadequacies. If tone controls are designed properly... But then again, in defence of Quad, they didn't have simulators in the day of the 33 (so they couldn't have known). |
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