HPS 4.0 phono stage

[analog_sa]

the fet with a lead battery and the op amp type with alkaline.

This alone is sufficient for startling sonic differences. There may be exceptions but in my experience most alkaline batteries sound much better than lead.

 

[Joachim Gerhard]

ok, i give up, the other design is better but i gave it bad conditions

 

[john curl]

Thanks for the precise input. I just wanted to make things clear. It is important to note these factors. Sorry, if I seemed to be too questioning. Some of our messages crossed over, while we were writing new ones.
PS I have no opinion about lead acid and alkaline batteries. I use both.

 

[MJL21193]

...in my experience most alkaline batteries sound much better than lead.

But do you hear the ocean when you hold them up to your ear?

 

[Curly Woods]

But do you hear the ocean when you hold them up to your ear?

You have to use something other than table radios to conduct listening tests or else the results are suspect

 

[MJL21193]

I have several of both type and the last time I checked, they weren't making any sound at all...
Maybe it's just me.

 

[albin]

table radios

Are as magical as anything
I think.
Regards Max Albin

 

[SY]

I've deleted the most recent spate of OT posts. Phono preamps threads will be moved to the appropriate spots.

 

[Lumba Ogir]

syn08,

100% wrong and, funny enough, this comes straight after you mentioned about using NFB in your new designs.

I would prefer, if possible, to confine this kind of crap in the BT thread.

Would you kindly explain what happens to the distortion signal components when they are processed by negative feedback?

 

[john curl]

Higher order AM and FM distortion can be introduced, even as lower order AM distortion is significantly reduced.

 

[Curly Woods]

Higher order AM and FM distortion can be introduced, even as lower order AM distortion is significantly reduced.

So large amounts of negative feedback are to be avoided, correct? I was always told that open loop distortions should be minimized so that lesser amounts of negative feedback would be needed. Is that a true statement or a wives' tale?

 

[john curl]

Sounds like the right approach to me.

 

[syn08]

Higher order AM and FM distortion can be introduced, even as lower order AM distortion is significantly reduced.

So large amounts of negative feedback are to be avoided, correct? I was always told that open loop distortions should be minimized so that lesser amounts of negative feedback would be needed. Is that a true statement or a wives' tale?

Sounds like the right approach to me.

This is 100% wrong, and it was proven thoretically and experimentally to Kingdom Come.

Stop polluting this thread with such crap. One thread (BT) should be enough to accomodate 40 years of chasing ghosts.

 

[Curly Woods]

This is 100% wrong, and it was proven thoretically and experimentally to Kingdom Come.

Stop polluting this thread with such crap. One thread (BT) should be enough to accomodate 40 years of chasing ghosts.

Excuse me but I have always heard this as the truth due to increase in IMD with excessive NFB. Are you say that this does not happen? Where has it been proven? I thought that Matti Otala, among others documented this back in the 70's?

 

[john curl]

Now, what is a myth?

 

[john curl]

Just to be polite about it, were you not, Syn08, the person who was originally going to use an AD797 or its equivalent in output current, to drive a very low resistance feedback network, until we convinced you otherwise? You need a bit more, 'seasoning' still, before calling me 'names'.

 

[Curly Woods]

Bob Cordell does not seem to agree with Otala's agruments from what I have read, but he is one of the few. Does Bob also think that people can not hear TIM? I could not find any reference to this subject.

 

[Joachim Gerhard]

I think it is a good thing when distortion is low and i think circuits with extremely high amounts of feedback can be made to sound good. Again i claim Douglas Self that has researched if there is any low level problem but he did not find anything. In recent years people like Cyryl Bateman and Ed Simon have shown that low level distortion exits in passive parts but they are extremely low level down at least -130dB. if this is audible is open to debate and we should not trample on each other discussing minor things like that. by the way Syn08 i am very happy that you are not leaving us alone here. i think this thread got so popular because it is very controversial and we need you here as the solid rock you seem to be. So john please build two phonostages that measure EXACTLY the same and have the same topology but other parts and play them for me. when i hear a difference i send you some of our famous westfalia ham. i come to the states at the end of november and visit my fellow Allen Perkins so i am in the area.

 

[orjan]

The disagreement is not weather tim could be heard on not, rather what design rules to use to avoid it.

/örjan

 

[Joachim Gerhard]

low pass filtering is the easiest way, but i think otalla whanted to design an amp with high speed that avoids slew limiting by design.