No global negative feedback

Don't be so stupid. I questioned. I put forward an alternative theory. I asked for proof. None was forthcoming. It still hasn't been. You might not require proof that your audio voodoo works. I do. If I make a false statement I expect someone to pick me up on it. I haven't and no one has.

It hasn't even crossed your mind that the impedence curve of your drive unit might be causing huge frequency anomolies now you've removed NFB. It hasn't crossed your mind that removing NFB increases PSU noise in nearly all instances. You don't want to hear the truth. That's your problem. If it's not the truth prove it - fairly simple proposition.

For trying to offer you some advice, from which you might actually learn something, all I get is childish and petulant posts because your childlike psyche feels your ego is being threatened. It's happened before here. Lowrider arguing from a position of utter ignorance. We all remember what happened then. We were only discussing it last Weekend.

People who buy hifi and think they can improve it despite being utterly ignorant get what they deserve really. An insult to the designer just as a fool would slap salt on food prepared by a world class chef. For the last time the advice is to contact the speaker manufacturer and get a copy of the impedence curve. From that decide whether it is suitable for the intended application. If it isn't consider adding a Zoebel. If it is, buy an amplifier designed by a competent engineer to perform in the manner you want. Choose to ignore it if you like - it's your loss.

 

Gentleman, you can start your bidding...

 

Mic,

For the last time, I listen with my ears, not with my eyes, is it so hard to understand...

So now you discuss about me on weekends, I didnt know I was that important to you...

I am honoured to be included in the same group as 3Dsonics, and Wadiameister, and many other I admire in this forum, unfortunately I need help for all my small mods...

Tuga,

I saw the picture of your room in Schallwand page even posted on my forum:

http://groups.msn.com/hififorfun/_whatsnew.msnw

What speakers are you buying ?

 

From someone who doesn't do blind tests and has an internet site with lots of gloosy photos of his own hifi it's more laughable than difficult to comprehend

 

Are you proud of this pathetic sentence...

 

Actually no - I misspelt the word "glossy".

Still, the rest is pretty spot on.

 

Olá António,

I plan to buy an Audio Note AN-E kit to pair with my forty seven shig system.
When my son is old enough - read less destructive - I might consider DIY widerange boxes or maybe even open baffles... ANs will do for now.

Best,
Ricardo

 

Audio Note must be good, let me know how they sound...

 

O.k.

 

I hardwired triode mode, bypassing the relays, still waiting for the Nichicon replacement CAPs...

My friends now suggest I replace the 12AT7 with 12AU7, lower gain, more linear, 1/4 distortion, all I have to do is put one 47Kohm resistor in paralell with another 30Kohm in the PS...

In AA I have this totally opposite opinions:

 

Contrasting opinions on AA? There's a shock.

Reminds me I must dump the four AT7's that are ruining the performance of my amps. Must tell Neil too.

I say go for it - hell you've started you might as well finish.

PS. Your contributions on AA are enlightening. Where do you cut and paste them from?

 

Can anybody smell smoke?

 

They are indeed, if we compare with yours here...

I bought Siemens E80CC on ebay, they have a bit more gain than 12AU7, might be a better compromise...

 

Anyone seeing a Cayin on Latvian E Bay would be advised to stay well clear.

 

Hi,

You need to realise that to talk about a given valve without context makes no sense at all.

The 12AU7 and 12AT7 are both considered "poor sounding" by many, especially by people who seem to claim 6SN7 "Ueber Alles", which in turn leaves me bemused, as the 12AU7 invariably sounds cleaner and more neutral than the supposedly electrically identical 6SN7, of course if you want traditional, cuddely, "low rez" tube sound that may be what you need.

In your Amplifier, in the context, in the specific circuit, with the specific other valves used (6SN7 & EL34 et al) the 12AU7 is in my view a better choice than the 12AT7. But that's just me.

Ciao T

 

Hi,

That is a good advise, in general and I would think applies not only to E-bay latvia.

But surely you noticed that the Amplifier Antonio has is not from Cayin. If not, could the fact that you two are seemingly talk about completely different amplifiers account for some of the misunderstandings?

Ciao T

 

Thanks,

I am going to try it, apparentely all I have to do is change one resistor, R28, on the PS, my friends wll calculate the right value...

 

Hi,

Best is to adjust this to have the same voltage to ground on what is labelledTP3 (Test Point 3). I'd be tempted to just stick 33k across it and see if I can use VR4 to adjust the rest of the difference.

BTW, try the 12AU7 without the cathode capacitor restored, you may find it reduces noise enough to not need to put the capacitor back at all.

Ciao T

 

Do you mean adjust VR4 disconnected, try, adjust again, and so on ?

33K in parallel or instead of the standard 30K R28 ?

The noise is not listenable from the sofa, my greatest problem is the worst quality of bass without the CAP...

 

Hi,

Measure the voltage on TP3.

Switch off.

Connect 33K in parallel with R28 and fit 12AU7.

Switch on.

Measure voltage on TP3 and try adjsuting it with VR4 to the same as measured before. If the adjustment range is insufficient you need to change the 33K fitted in parallel to R28. If the voltage remains to low fit a lower value, if it is too high fit a higher value.

Interresting. The capacitor would have added distortion and phaseshift at low frequencies, maybe you need to re-tune the subwoofer?

Ciao T