No global negative feedback

You know perfectly well that no such test exists.

I fail to follow you.

 

SM,

Well you know the saying : Never argue with an idiot, they simply drag you down to their level and beat you with experience

 

Says the idiot...

 

Then how can we say that NFB has a negative impact on perceived sound quality Markus?

On the other point I was merely highlighting that in this case Antonio seems happy to utilise graphs to demonstrate a measurable impact whereas he is loathe to accept same said forms of measurement when they show no change whatsoever (ie. cables, supports, CD players wtc).

 

When did I say that...

 

Antonio,

Are you accepting the graphs presented by Mr Cheever as evidence of increased upper HD?

 

I'm buying an amp tomorrow with lashings of NFB. In fact it has so much NFB that I'm surprised it doesn't play backwards

I'll let you all know just how nasty and distorted it sounds asap.

 

The graphs are for you, I prefer words...

 

Another Naim Rob?

 

My guess - a chip amp or some Deltecs.

 

Nope - been there and done that three times now.
No more.

I'm buying a 'blameless amplifier' to quote the designer.

 

Ah. Cambridge.

 

Heard a superb Deltec pre/power driving H2s at Martin Clark's a few weeks ago. Could happily live with those but I lack Martin's ability or inclination to repair them when they explode, as it seems many do
Also, too many boxes.

Novel use of feedback though so very much on subject.

 

Spot on Markus.

840A:

 

Hi,

Yes, remove the Sucker. Also, you can try other input valves with less gain, for example the 12AU7 (ECC81) would likely work okay and would lower the gain.

Another thing to try, you can replace C2/4/5 with Mundorf M-Cap Zn or Audyn KP-SN (both are tinfoil types). And re-try triode mode for the output stage.

Ciao T

 

Hi,

The version of this that I build when the articles where out in WW certainly was not to be blamed for good sound, hope you enjoy it....

Ciao T

 

Looks like it's moved on just a tad since then T

 

Thanks Thorsten,

To remove the sucker I have to remove the PCB, quite dangerous, because of whatever connections underneath, C3 I had to cut...

What is the problem with higher gain, I already use SIEMENS E81CC triple mica...

C2/4/5 are WIMAs, I know they are nothing special, but they are not too bad either, so I am told...

I have been using it in triode mode since I tried it again, after removing NFB, as I said then, now it improves the sound without softening bass, particularly significant more body...

Already took many risks, I will wait for a good audio engineer to visit Riga and do those more "complicated" changes, arent you coming to Riga, nice place...

 

I think he's already got a wife Antonio.

 

It is nice to look too...