Are passive preamps better?

Lynne

I've got 1.1V sensitivity@22k ohm

I take that to be the amp's specs, right? I.e. it reaches its peak when fed (a max) of 1,1V & its input impedance is 20kOhm. That's not too bad...

But are you saying your players have an "output impedance" of 10kOhm??? That's too high... I must have misunderstood something.

OTOH, 2V output is more than enough to drive the amp -- and then some. You should be able to use a passive attenuator on it.

(BTW, it's called "impedance" when the "resisting" factor changes with frequency; it's called resistance, when the "resisting" factor remians constant whatever the frequency)

We have a cable industry in high end audio based on the experience of audiophiles hearing differences in the cables.

However most audiophiles don't get that the recording/broadcast industry tackled this problem in the late 1940s and early 1950s, the result being the balanced line system.

For decades, audiophiles listened to inexpensive single-ended gear at home. Single-ended cables do not have a termination standard, so to get around the differences in cables that thus resulted, the cable industry began to develop, starting in the late 1970s, lead by Robert Fulton.

But the balanced line system has the advantage of making an inexpensive balanced cable sound as good or better than the best single ended cable (price no object). The first balanced line audio product was introduced to the high end audio world in 1989, possible because of the increased budget allowed in high end audio, but balanced line has had an uphill battle due to audiophiles not really getting why balanced line is an advantage. I hope my explanation here helps; balanced line exists specifically to eliminate cable problems!

BTW the classic passive volume control problem is lack of bass impact at low volumes. Some controls are built to be very low impedance to try to get around this problem, but that low impedance limits the number of front end products that can work with them.

Gregm, ok. Yes, the amps spec is given as 1.1V@22K ohm input impedence. On the CDP, if you meant,"did I read it wrong", apparently not. The HD7600ll's output impedence is given as LINE- 2.0V@10k ohms. I thought the other player was the same, but now I see that a spec is not given. It's an H/K FL8400, one model newer--same DAC, probably the analogue section. So I conclude that it won't work. I am mildly interrested in a City Pulse DAC but I think it has the same spec. But another DAC might be a way to get around it. Otherwise, I assume the Placette active would work. Maybe autoformers? Thanks for the clear, simple explanation of impedence vs resistance.
Atmasphere, I finally got something right. Thanks. I've found a lower cost cable that I like but I probably have $1k in cable easily. For $1k, it probably could have been made balanced. Lynne

Maybe $200.

Hi All,
I am FOR the passives and not against.
There is a simple principle here - the less is more.
An additional circuit is not a benefit to the whole.
The thing is that the output of many of the sources is not
designed to drive the power amplifier directly.
Then there is the problem of impedance matching and that is why some passives use transformers.
A good tube phono pre-map having a cathode follower stage at the output will drive.
So a selector and ladder volume control (Elna, Goldpoint) at the output will be sufficient for a power amplifier with relatively high input impedance and low input sensitivity (0.5V - 1V).
Why add another circuitry in between?
Let's say that the output tube of the phono is 12AX7 and the input tube of the power amp is 12AX7 as well.
Then these circuits probably match very well.
Some do not.
'Everything should be made as simple as possible, but not simpler' - Albert Einstein.