I dont understand passive preamps for turntable setups.

[ceefaxer]

The website doesn't show the A20, so it's hard to say what can be done.

If the Cambridge amp has a volume control, it should work because it has a volume control but he didn't show the model, so that doesn't let us know if that has a pre-out.

its a 551p mm phone preamp and it doesn't have a volume control
my current amp does have a volume control, but the a20 doesn't I don't think....so ahhhh...maybe I do need the p20 pre amp after all....or an active preamp with volume control.

 

[highfigh]

its a 551p mm phone preamp and it doesn't have a volume control
my current amp does have a volume control, but the a20 doesn't I don't think....so ahhhh...maybe I do need the p20 pre amp after all....or an active preamp with volume control.

What does that control on the top of the Cambridge do?

 

[ceefaxer]

its just some awful attempt at branding

 

[killdozzer]

Well, you do need the volume control. If your phono pre-amp doesn't have one, you really can't skip the passive pre-amp. And I saw your pre-amp doesn't have the phono in, so you also need a phono pre-amp.

You can set it up for experiment, but if I were you, I'd go back to tt - cambridge - cambridge. I like it simple. YMMV

 

[ceefaxer]

I like it simple.

Yeah I think your right.

 

[TLS Guy]

So I was looking to upgrade my ancient rubbish setup to an NVA system a friend gifted me. However I really don't understand the benefit of a passive pre amp.

So at the moment my chain is:
TT----cambridge phono preamp-----cambridge amp

If I change to the system a friend has gifted I think it would become:
TT------cambridge Phono preamp----NVA P20 passive pre amp - NVA a20

What I don't understand is what is the P20 doing in this set up? It seems like its just passing on the signal from the phono preamp. But I don't have a clue about this kind of thing.

Are passive preamps more for when you don't need a pre amp, like through some DACs etc.

You can clearly see that unit is just a volume control.

So, unless the output from your phono preamp, which has to be active, is too "hot" for the input of your Cambridge amp, it is superfluous and harmful.

 

[3db]

I hate hate hate absolutely loath the term passive pre-amp. That term is such audiophile BS in its purest form. Anything with the word amp implies amplification which by definition is active. Passive implies no amplification of any kind. A passive selectable attenuator (psa) is a far more accurate term than passive preamp. If the psa count is higher than 4.3, its not audiophile grade and a physician should be consulted. I end my rant. Have a good day everyone!!

 

[PENG]

And more generally. If you only have a turntable with no preamp built in. Is there ever a situation where a passive preamp can be used to the benefit of the final audio.

A phono preamp that has no volume control) may or may not be able to use a so called passive preamp because it would depend on whether its rated output voltage is high enough.

If your phono preamp has volume control and high enough output voltage, you can use with a so called passive preamp too but I can't see how it would be of benefit in terms of "final audio quality" that you are asking about. More components = more chance of increased noise and/or distortions.

I think this seems like a decent summary
The simplest passive pre-amp is an input selector and a volume control. If you use only one source, that is capable of driving your power amp properly, and it has a volume control you probably don’t need a pre-amp.

If you have multiple sources either with or without a volume control or you use a single source which does not have a volume control, but they/it can drive your power amp properly, you need a pre-amp. You can almost certainly use a passive pre-amp.

If you use multiple sources, with or without volume controls, and one or more of them can’t drive your amplifier properly, you need an active pre-amp. A phono stage is an active pre-amp or possibly an active pre-pre-amp.

Sounds about right, at least in generic sense.

In this case, it is straightforward enough that Google is your friend..