Unnamed feedback method explored. - Page 3

Mr Evil · 14th November 2004, 08:22 PM

Quote:

Originally posted by janneman

Sorry ! It's just that I am not accustomed to calling someone Evil to his face
Any hint?

Jan Didden

If you want to call me by my real name then you can find it on my website...

djk · 15th November 2004, 04:15 AM

'cheese83' AKA 'miles'

Looks like the classic 'Sandman' circuit ca 1972 (Wireless World).

Mr Evil · 15th November 2004, 11:38 AM

Any schematics or anything for that? After seeing the other Sandman feedback arrangement posted on the first page I searched for more stuff by him, but found almost nothing.

Mr Evil · 15th November 2004, 04:12 PM

I've found my first practical application of this: In my ongoing experimentation with motional feedback for woofers, I've not been able to apply particularly large amounts of feedback without running into stability problems. Using the error correction allows a significantly increased amount of feedback to be applied. Yay!

Tom2 · 15th November 2004, 08:16 PM

Dr. Evil,

In the Nelson Pass SuSy patent, US Patent 5,367,899, see figure 8 (prior art) is the basic Sandman circuit.

Tom

Mr Evil · 15th November 2004, 10:24 PM

Ahhh, interesting. US patent 5,367,899: " System for perfume creation using aroma emission analysis from a living fruit and flower in close proximity"

Had me confused for a minute, but then I saw US patent 5,367,899 instead

Similar, but it's feedforward rather than feedback.

Tom2 · 15th November 2004, 10:52 PM

D'oh!

My mistake. I always thought different amplifiers have unique fragrances.

yes! 5,376,899.

Tom

lumanauw · 23rd November 2004, 06:48 AM

Hi, MrEvil,

I just finished making your feedback idea. It does the job well, but I'm not sure wheter it is making a nice sounding amp.

From my observation, the sound becomes very clean, but the "room effect" disappears. Like classic guitar sounds like it has no resonance room in the wooden guitar cabinet. Too sterile, emotions disappears.

I think this is why amps with 0.00001 THD does not becomes a target for audiophile designers. Some harmonics is needed for "listen-to" audio amps (not measure-to)

Prune · 23rd November 2004, 12:03 PM

Maybe the 'room effect' was nothing but amplifier harmonics.

Mr Evil · 23rd November 2004, 02:10 PM

Indeed. Maybe if someone were to work out exactly what it is that was removed, then a circuit could be designed to deliberately add it back in, but to an adjustable degree. Then maybe any amp could be improved.

15th November 2004, 11:38 AM	#23
Mr Evil diyAudio Member Join Date: Aug 2004 Location: Behind you	Any schematics or anything for that? After seeing the other Sandman feedback arrangement posted on the first page I searched for more stuff by him, but found almost nothing. __________________ http://mrevil.pwp.blueyonder.co.uk/

15th November 2004, 04:12 PM	#24
Mr Evil diyAudio Member Join Date: Aug 2004 Location: Behind you	I've found my first practical application of this: In my ongoing experimentation with motional feedback for woofers, I've not been able to apply particularly large amounts of feedback without running into stability problems. Using the error correction allows a significantly increased amount of feedback to be applied. Yay! __________________ http://mrevil.pwp.blueyonder.co.uk/

15th November 2004, 08:16 PM	#25
Tom2 diyAudio Member Join Date: Jun 2004 Location: Central CA	re: Unnamed feedback method explored Dr. Evil, In the Nelson Pass SuSy patent, US Patent 5,367,899, see figure 8 (prior art) is the basic Sandman circuit. Tom

15th November 2004, 10:24 PM	#26
Mr Evil diyAudio Member Join Date: Aug 2004 Location: Behind you	Ahhh, interesting. US patent 5,367,899: " System for perfume creation using aroma emission analysis from a living fruit and flower in close proximity" Had me confused for a minute, but then I saw US patent 5,367,899 instead Similar, but it's feedforward rather than feedback. __________________ http://mrevil.pwp.blueyonder.co.uk/

15th November 2004, 10:52 PM	#27
Tom2 diyAudio Member Join Date: Jun 2004 Location: Central CA	re: Unnamed feedback method explored D'oh! My mistake. I always thought different amplifiers have unique fragrances. yes! 5,376,899. Tom


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15th November 2004, 04:15 AM	#22
djk diyAudio Member Join Date: Feb 2001 Location: USA	'cheese83' AKA 'miles' Looks like the classic 'Sandman' circuit ca 1972 (Wireless World).

23rd November 2004, 06:48 AM	#28
lumanauw diyAudio Moderator Join Date: Oct 2002 Location: Bandung	Hi, MrEvil, I just finished making your feedback idea. It does the job well, but I'm not sure wheter it is making a nice sounding amp. From my observation, the sound becomes very clean, but the "room effect" disappears. Like classic guitar sounds like it has no resonance room in the wooden guitar cabinet. Too sterile, emotions disappears. I think this is why amps with 0.00001 THD does not becomes a target for audiophile designers. Some harmonics is needed for "listen-to" audio amps (not measure-to)

23rd November 2004, 12:03 PM	#29
Prune Account Disabled Join Date: Mar 2003 Location: Vancouver	Maybe the 'room effect' was nothing but amplifier harmonics.

23rd November 2004, 02:10 PM	#30
Mr Evil diyAudio Member Join Date: Aug 2004 Location: Behind you	Indeed. Maybe if someone were to work out exactly what it is that was removed, then a circuit could be designed to deliberately add it back in, but to an adjustable degree. Then maybe any amp could be improved. __________________ http://mrevil.pwp.blueyonder.co.uk/

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