Amplification

[Preben Holm]

Hi

What is the normal gain of a power-amp?

And what's the normal gain of a pre-amp?



Best regards

Preben Holm

[Don Pearce]

Preben Holm wrote:
> Hi
>
> What is the normal gain of a power-amp?
>

No single figure, but something around 20 times (26dB) voltage gain
would be normal. It depends on the output power of the amplifier.

> And what's the normal gain of a pre-amp?
>
>

For most inputs (things like CD, tuner etc) no gain is required as they
already present the right level for the power amplifier. If the input is
a microphone, perhaps 40 to 60dB might be needed. For a phono input
there is no answer because of the huge variation of gain with frequency.

d

[Arny Krueger]

"Preben Holm" > wrote in message


> What is the normal gain of a power-amp?

Depends on power output.

Something like 26 dB.

> And what's the normal gain of a pre-amp?

Depends on what kind of inputs it has.

Usually about 20 dB from line level input to main output.

Add about 40 dB @ 1 KHz for a regular moving magnet phono stage.

Really good mic preamps usually have variable gain from 60 dB to zero dB.
Cheap ones take about 10 dB off one or both ends.

[Eeyore]

Preben Holm wrote:

> Hi
>
> What is the normal gain of a power-amp?

What is the normal size of a penis ?

[Eeyore]

Don Pearce wrote:

> Preben Holm wrote:
> > Hi
> >
> > What is the normal gain of a power-amp?
> >
>
> No single figure, but something around 20 times (26dB) voltage gain
> would be normal. It depends on the output power of the amplifier.

31-35dB typically in the case of SR.

Graham

[Don Pearce]

Eeyore wrote:
>
> Don Pearce wrote:
>
>> Preben Holm wrote:
>>> Hi
>>>
>>> What is the normal gain of a power-amp?
>>>
>> No single figure, but something around 20 times (26dB) voltage gain
>> would be normal. It depends on the output power of the amplifier.
>
> 31-35dB typically in the case of SR.
>
> Graham
>

But that would be an unusually high powered amp - not the
run-of-the-mill 50 watt job.

d

[jakdedert]

Eeyore wrote:
>
> Preben Holm wrote:
>
>> Hi
>>
>> What is the normal gain of a power-amp?
>
> What is the normal size of a penis ?
>
Flaccid or fully engorged....?

jak

[Bob Eld]

"Don Pearce" > wrote in message
et...
> Eeyore wrote:
> >
> > Don Pearce wrote:
> >
> >> Preben Holm wrote:
> >>> Hi
> >>>
> >>> What is the normal gain of a power-amp?
> >>>
> >> No single figure, but something around 20 times (26dB) voltage gain
> >> would be normal. It depends on the output power of the amplifier.
> >
> > 31-35dB typically in the case of SR.
> >
> > Graham
> >
>
> But that would be an unusually high powered amp - not the
> run-of-the-mill 50 watt job.
>
> d

Fifty Watts into 8 ohms requries 20 volts RMS. Having a gain of 20 would be
one volt input. That seems pretty typical to me.

[Bob Eld]

"Eeyore" > wrote in message
...
>
>
> Preben Holm wrote:
>
> > Hi
> >
> > What is the normal gain of a power-amp?
>
> What is the normal size of a penis ?


Well, mine use to be 7 inches, 18 cm. But then I got old and it shrunk. I'm
lucky to see 5 inches these days! Oh well, I didn't need that damn thing
anyway.

[Mr.T]

"Preben Holm" > wrote in message
...
> What is the normal gain of a power-amp?
> And what's the normal gain of a pre-amp?

Define "Normal" first.

MrT.

[Eeyore]

Bob Eld wrote:

> "Don Pearce" wrote
> > Eeyore wrote:
> > > Don Pearce wrote:
> > >> Preben Holm wrote:
> > >>>
> > >>> What is the normal gain of a power-amp?
> > >>>
> > >> No single figure, but something around 20 times (26dB) voltage gain
> > >> would be normal. It depends on the output power of the amplifier.
> > >
> > > 31-35dB typically in the case of SR.
> >
> > But that would be an unusually high powered amp - not the
> > run-of-the-mill 50 watt job.
>
> Fifty Watts into 8 ohms requries 20 volts RMS. Having a gain of 20 would be
> one volt input. That seems pretty typical to me.

In pro-audio, a kilowatt or so into 8 ohms isn't unusual. That's another 13dB
on top of your 26 giving 39dB but we tend to use +4dBu input sensitivity, so
knock of another 2dB approx making 37dB voltage gain in this instance..

Graham

[Eeyore]

Bob Eld wrote:

> "Eeyore" wrote
> > Preben Holm wrote:
> > >
> > > What is the normal gain of a power-amp?
> >
> > What is the normal size of a penis ?
>
> Well, mine use to be 7 inches, 18 cm. But then I got old and it shrunk. I'm
> lucky to see 5 inches these days! Oh well, I didn't need that damn thing
> anyway.

Acording for 'sex for the modern girl' or whatever on channel 5, enlargement
creams DO work. They didn't say which make though. Of 3 methods tried it was
the only one that delivered.

Graham

[Preben Holm]

> Define "Normal" first.


I hoped someone could give me a definition of normal in here.

What I'm thinking about is to make this setup (a project):

CD/DVD -> filter (digital) -> preamp -> active speakers.

or

CD/DVD -> filter (digital) -> digital transmission -> advanced active
speakers



But to reduce noise input on cables to speakers, I'm thinking about the
right voltage level.

However to begin with - I wan't sound, so I'm thinking about:

CD/DVD -> preamp -> analog active filter -> active speakers


So for this design, I was thinking about matching the speakers to a
"normal" preamp!


Best
Preben

[Eeyore]

Preben Holm wrote:

> But to reduce noise input on cables to speakers, I'm thinking about the
> right voltage level.

That'll be determined by the signal-to-noise ratio of the sending device.

Read the input voltage specification on the active speakers you have in
mind .... which are ?

Graham

[Eeyore]

Preben Holm wrote:

> > Define "Normal" first.
>
> I hoped someone could give me a definition of normal in here.

Normal output level of a 'proper' CD player is IIRC 2V rms @ 0dBFS.


> What I'm thinking about is to make this setup (a project):
>
> CD/DVD -> filter (digital) -> preamp -> active speakers.

What's the digital filter for ? And is the preamp simply a source selector
?

Graham

[Preben Holm]

>> But to reduce noise input on cables to speakers, I'm thinking about the
>> right voltage level.
>
> That'll be determined by the signal-to-noise ratio of the sending device.
>
> Read the input voltage specification on the active speakers you have in
> mind .... which are ?

... to be built.


It's a project I'm doing on my own - and I'll start by building the
speakers. The whole set-up is a "proof on concept" (do it better) project.

[Preben Holm]

>>> Define "Normal" first.
>> I hoped someone could give me a definition of normal in here.
>
> Normal output level of a 'proper' CD player is IIRC 2V rms @ 0dBFS.
>
>
>> What I'm thinking about is to make this setup (a project):
>>
>> CD/DVD -> filter (digital) -> preamp -> active speakers.
>
> What's the digital filter for ? And is the preamp simply a source selector
> ?

The filter is (so far) a high pass and low pass filter. And of course I
wan't it to be FIR to have linear phase.

The preamp is therefore a 4 channel preamp for up to 2 2-way speakers.
It allows me to make a high order filter without noise input from
components - that's the whole concept of my design idea.

After this project is finished, I would like to extend the project, such
that the signal is digitally transferred to the speakers and thereby
reducing the noise associated with the cables.

"Maybe there will be no difference, but at least fun to do."



Best regards,

Preben Holm