Thermal noise study...

[mrfeedback]

"When soldered correctly added solder will not increase conductivity but will add extra noise IMO."

Extra metal (solder) will surely increase conductivity won't it ?.
Have you done A/B on solder joint volume ?.

Eric.

[fdegrove]

Hi,

Extra metal (solder) will surely increase conductivity won't it ?.

It may increase thermal conductivity,but would it not be better to use other methods for that?

Have you done A/B on solder joint volume ?.

Yes,the general consensus here amongst the audio crew is that once the joint is correctly executed,the less solder used the better.

One should not use solder as a mechanical building block to hold components in place.

Ciao,

[dkemppai]

Originally posted by halojoy
What was the working temp specification of the OP-amp?

It was an LM833N, temp range from -40 to 85 deg C.

I picked 10 to 130F bacause the were easy temps to generate...

[dkemppai]

Originally posted by fdegrove


The broader the frequency response the better,provided you can maintain stabilty from the amps.
Being a vinyl person I don't feel the resonance frequency of tonearm/cartridge should be passed unimpeded.
This will often create a pumping effect on the amp, draining the PSU's energy.
In turn leading to uninvolving,lifeless soundreproduction.

Ciao,

Yeah, but I don't use vinyl... ...at least not yet. I'm not completely sure that CD's are the way to go, being that the standard samling frequency puts the Nyquist at around 22Khz... ...With aliasing and all. Now if we get the standard sampling to around 96Khz or better, then more comfortable with it. (I do like the integrity of a CD, tho)

As for the frequency response, I've found in my own experience that low frequency cutoff is the important one. If the amp has a 45deg phase shift at 20 Hz, it isn't considered gone until 200Hz. Frequency response is partly the reason I've have not played with tube amps. If you're talking transformer coupled speakers, you need a really large transformer to prevent saturation at low frequencies. You also need a low loss core, at high frequencies. Not extremely easy to come up with.

I'd like to play with some tube stuf eventually. My Dad picked up about 3000 tubes, unused new stock (RCA and other big names) a while back. (They were being thrown out!!!) There are a lot of the popular audio tubes there, along with some RF tubes as well. He also grabbed a couple of tube testers. He was mainly interested in the RF tubes, and he'll keep the audio tubes for me. (There is a 4CX1000 with a base... ...that would make a killer amp!!!)

-Dan

[dkemppai]

Originally posted by halojoy
I think the best place to add noise
is in the preamplifier
or already in the CD-player.
This to avoid too high S/N ratio.

SACD suffers from way too high S/N ratio, in my opinion.
140 dB !!!!!
What joy can that bring to da music

There is something to be said for noise. Ever sit in an extermely quite room? The lack of sound is unbearable!!!

-Dan

[fdegrove]

Hi,

Now if we get the standard sampling to around 96Khz or better, then more comfortable with it. (I do like the integrity of a CD, tho)

Absolutely.
I don't understand the part you put between parenthesis though.
IMO the amp should have wide bandwidth at both frequence extremes as would the line stage.

As far as phono goes the highs should be corrected so these don't cause an infinite drop above 20KHz and the lows can pass anything above say 10Hz to 15Hz.
The better the system the lower you can go for phono but on some recordings you can actually hear some low frequency rumble,from the lathe or mastertape perhaps.

I'd like to play with some tube stuf eventually.

Please do,not many of us get an opportunity like that.

Ciao,

[dkemppai]

Originally posted by fdegrove
Hi,



Absolutely.
I don't understand the part you put between parenthesis though.
IMO the amp should have wide bandwidth at both frequence

Ciao,

I mean that CD's don't wear or degrad with time. Because the music is stored digitally, it will never fade (such as with other recording mediums).

Infact, I just talked to my dad today, he's going to keep all of the tubes for me. I know he's been checking on the prices of some of the tubes, and many are in the hundreds of $'s. A rare oppertunity indeed.

It'll be a good while before I start to play with any tubes. As with any project, I usually start to read/think about it ahead of time. (I know this is the wrong forum,but ) Since I'm starting to think of tubes, can you suggest any designs that you prefer?


-Dan

[fdegrove]

Hi,

I mean that CD's don't wear or degrad with time.

Granted CDs don't degrade that much but I find them to be no less fragile than vinyl.
Main problem is that so many people think they can't be damaged and treat them disrespectfully.
Let me state for the record (pun intended) that a vinyl record when well take care of will last at least half a century.

With CD it has been said that the polycarbonate layer may decompose after twenty years.
Admittedly I have not seen it happen yet.

Ciao,