Is my preamp useless?

Just to give an example,
A 10kohm passive preamp which all solid state sources can drive, has a worst case 2.5kohm output impedance.

In the worst case of 2.5kohm, this passive preamp driving reasonable quality interconnects of 100pf per foot at 2mts long will give a high frequency roll off at -3db @ 106khz!!!

And with just one meter interconnects it is -3db @ 212khz!!!

And this is interconnects of 100pf, if you get good quality ones that are 50pf per foot, the HF roll off point off doubles again
To -3db @ 212khz for 2mts!!
And -3db @ 424khz for 1mt!!

As you can see only dogs and bats can hear this kind of HF filtering.

Cheers George

Here is the graph of a 10kohm passive output impedance.
On the left (vertical axis) is it's output impedance, for the given volume resistance (horizontal axis).
As you can see at half volume rotation it is at the worst 2.5kohm output impedance, either side it's output impedance is lower.

http://i.stack.imgur.com/cVUCc.png

Cheers George

I'm using my PS Audio Direct Steam with a BSG QOL unit (awesome) into a Pass Labs X350.5 Amp.

The BSG QOL unit provides added gain and so much more texture than when I used my former Pass Labs Preamp.

I use the PS Audio Direct Stream volume, and it usually runs between 60 and 65. With the PS Audio High filter engaged, the volume on the PS can run in the high 90's.
However, I prefer to run it without the filter with the volume in the 60's.

The BSG QOL also provides added analog inputs and outputs.
One of the inputs is used for my Denon Home theater pass through in which the Denon controls the volume while playing Blu Rays from my Oppo.

The BSG QOL also has dual analog outputs in which I run my dual JL F113 Subs.

An active pre-amp plays a big part in how a system sounds. It serves as an analog signal processor in a sense in that how all sources used actually sound are affected.

So if you like the sound you gotta give the pre-amp some credit for that.

The option is to take it out and see how each source sounds and perhaps then tweak with that to get the sound you like again.

Either way can work well. If you like teh sound out of teh active pre-amp you have, then be grateful to it for that. It's far from "useless". Unless you try something different that works out even better. Then you might consider putting it out to pasture but still give it its due accolades for a job well done.

I agree that I have not auditioned all the cables that are available. Will the manufacturer make a better cable next year - chances are most likely yes. Isn't advancement in technology supposed to do that? Nordost, Siltech, Shunyata, etc, all come up with new improved cables over a period of some years. Folks have done A-B comparison with the new-old and preferred one of the other. Does it mean that these cables are wrong?
There are tons of users on this forum who use very highly regarded active preamps (probably 3X-10X the cost of my entire system), and have experienced a better sound when their cables were upgraded. Does it mean that all these highly regarded active preamps also have not been designed properly? So which one would you say is wrong: cables or active preamp?

I understand your consternation! It took me a while to get my head around this issue, but to your first question- does this mean that these cables are wrong the simple answer is 'yes'.

What if you had a setup where the cable made no difference in your system and an inexpensive cable sounded just as good a really expensive cable- which is to say that they both played so well it was as if they were simply a direct line to the music? Would that be of interest?

This is what I am talking about when I talk about eliminating interconnect cable artifact. Now if you prefer to throw as much money as you can afford at the cables to get better sound- by all means be my guest. That is one approach and it is the one most commonly used by the 'tons of users on this forum' to which you refer.

But if you want to get off of the interconnect cable merry go round and not have to worry about cables ever again in your whole life then go back and re-read my posts on this thread. That system to allow that has been around for about 60 years and it works really well.