Analog Attenuator?

[PeterSt]

1 hour ago, The Computer Audiophile said:

40 feet isn’t really that long.

 

As long as you realize that any means of analogue attenuation degrades the sound first. 
Indeed 40 feet isn't long, but it is to be tested against a shorter length without aanalogue attenuation or gain (but use a good drive-means first).

 

40 feet of SE cable can easily be totally harmless, BUT use a cable with 5MHz bandwidth capability over more than 300 feet. Next do the math (at say 0.5dB roll off at 1MHz over that distance).

Balanced would be better if the bandwidth is comparable (I don't recall Gotham giving those specs) BUT which also includes the shielding of especially the SE cable (in the end the shielding of the Balanced cable just the same).

And thus remember, start out with an attenuator of any means that I know of, and you can buy cheap cables just the same.

 

I see a lot of apples and oranges here.

 

Something else:

Does anyone want to see the frequency response of a Placette ? You don't want to see that.

The internals of it then ? you definitely don't want to see that.

 

I never could make a satisfying analogue attenuation means. They *all* influence linearity on the frequency response, no matter what type. Voltage control of the D/A chip is the only solution.
Let me add to this that anyone who thinks that a balanced attenuator does not harm THD (wildly) ,,, please explain the "why not" of that. It just can't exist, not even with a differentially setup voltage controlled D/A chip. You can make "a best" all right, but it will always be worse (easily measurable on the THD alone) than a well done digital attenuator (and I mean purely in the digital domain - hence in-software).

 

My 2c.

Peter

 

[PeterSt]

This is not really a serious post - so just as well skip please :

 

20 hours ago, bbosler said:

Many DACs and other sources are perfectly capable of driving a power amp. Many are designed to do just that with a built in volume control. Most, like the Rossini, control the volume in the digital domain so I prefer to do it after the DAC once the D to A is complete.  DCS even recommends avoiding the use of too much digital attenuation.

 

Exactly that won't happen without (severe) THD degradation.

How the remainder of that sentence is consistent with this emphasized part ... hard to see for me. How it is consistent (your message) with the preceding paragraph ... hard to make up (again, for me). Thus :

 

20 hours ago, bbosler said:

If the source is capable of driving the power amp directly, which many of them are, and the power amp has a relatively high input impedance, which most of them do, then all you may achieve by adding an active preamp is to add coloration. Granted, you may prefer that coloration, but it will be there.

 

I surely agree with that. But how to now read the "Many DACs" section, is a bit difficult.

But from your first quote we should conclude that a volume control after the D/A section (in-DAC) is better than digital attenuation (which is NOT the same as in-software, but which could happen at the same level (domain) in-DAC (and then multi-channel ??) ... and which I would like for good principles ... while the VC after the D/A really should be the same as an external VC, often built into pre-amps.

... and which you seem to dislike.

 

Not that anyone will be capable to follow my texts. Ha !

(just saying)

 

[PeterSt]

1 hour ago, acg said:

I feel that I am in a position to comment on much of what has been said in this thread because I have experience with most of the stuff that people have mentioned.

 

Anthony, what a superb post. For others, Anthony may have one of the most exciting systems on the globe. Already the effort he has put in it ... wow.

But Anthony, you are right. When you have too many other sources, the input selector is a must, and with that there will be analogue sources just the same and now you need the analogue volume control.

 

I agree from one of my last escapades that the Muses chip is the better one, and maybe you recall me working on that headphone amp (which ended up as gain stage in the G3 incarnation of your DAC) and how I obtained a "consistently working" version from China somewhere. Well, after it stayed out (shipping) for 3 months, at arrival it did not work. I think it was there where I gave up the headphone amp idea, which also would have been "a best" pre-amp (input selector with VC - no gain).

Maybe I should continue a project like that. I have one cabinet for it as well - haha.

 

 

Btw, I wonder ... @manisandher at some stage told he found a quite transparent pre-amp. I don't recall he shared that publically and I can't find it back in my emails. Mani, could that still be something to go for ?