Commercial Solid State Amps with jumper controlled Modes "without NFB" and "with NFB"

[tiefbassuebertr]

Commercial Solid State Amps with jumper controlled Modes "without NFB" and "with NFB"

The amp under
http://www.lcaudio.com/pdfs/xpcookbook.pdf
haven't G-NFB. The most other use a negative feedback loop
Wich commercial available amp devices without tubes can realize both modes by use of a jumper control bank?

Thank you for advices.

This URLs don't provide any advices:
http://www.diyaudio.com/forums/solid-state/167-end-millenium-amp-opinions.html
http://www.diyaudio.com/forums/soli...ack-called-pax-what-about-vitus-ss-101-a.html
http://www.diyaudio.com/forums/solid-state/28448-there-anybody-built-non-feedback-amplifier.html

 

[DF96]

You can't turn an open-loop amplifier into a feedback amplifier just by slapping on some feedback. These things need to be designed. The tiny exception is if only a very small amount of feedback is used, but in that case it doesn't do very much.

 

[tvrgeek]

No such jumper on the schematic I can find. Check it out.
"Warm tube like sound" Yea, probably 10% distortion. No specifications.
Of course, they don't count degeneration as NFB and speedup caps as being in the circuit.
Who knows what it sounds like, but their marketing is full of do-do.

Nice cabinet with big heat sinks. One could build a decent amp in it.

 

[AndrewT]

the amplifier manufacturer that claims no NFB is telling lies.

 

[Mark Johnson]

The jumper that adds negative feedback is circled in red below. However the feedback is not applied across the entire range of audible frequencies.

 

[Fast Eddie D]

Solid state with no feedback? Hogwash.

User selectable feedback? More hogwash.

How much does the typical consumer know about electronics? They know about as much as the marketing scumbags tell them, that's how much. These are the same people that tell us that an amplifier is "500 + 500 watts RMS" when it only draws 150 watts max from the mains.

It's no different than putting a super loud muffler on a 110 HP el cheapo Korean car. All it does is demonstrate is that the owner is stupid.

 

[tvrgeek]

The jumper that adds negative feedback is circled in red below. However the feedback is not applied across the entire range of audible frequencies.

As that is marked as "DC SERVO" and the circuit is in fact a DC servo, I would not consider that "selectable feedback". Is that feedback? Yes in a technical sense. More BS from a company trying to sell garbage.

 

[alex mm]

END MILLENIUM V4 CLONE

.....find, on russian forum, schematic and PCB for new and improuved Millenium schematic .....
Regards,Alex

 

[Holgi]

.....find, on russian forum, schematic and PCB for new and improuved Millenium schematic .....
Regards,Alex

You're the godfather of PCB layout, Alex...

 

[kouiky]

Another "zero feedback" amplifier? Nonsense. No feedback equals mountains of non linearity, narrow frequency response and moreover amounts to salesmanship. Solid state simply cannot work without feedback. Audiophiles love "no feedback" because the early years of audio press claimed it was the holy grail. Today, if a design doesn't use global feedback but continues to use local feedback, it somehow ends up being labelled as a "zero feedback" design.

 

[Bonsai]

The only guy with some profile still bashing the ZGNF drum out there is CH.

I heard his amp sounds very good. Costs about $16k a pair IIRC

Still, for me his amp is a great pity. A little bit of NFB and it would have sounded a whole lot better.

 

[MiiB]

What is Hawksford error correction, feedback-Feed forward or just a local short FB loop..??

 

[Bigun]

Hawksford is feedback, call it local if you wish but it still uses active devices as an error-amplifier to measure and correct. I view it as negative feedback all the same.

Aspen Amplifiers (Hugh Dean) sells an amplifier without GNF if I remember correctly - and he says it uses a Diamond Buffer output (but not without some clever modifications which may or may not introduce some local feedback). I believe his amplifier was very well received.