Pre-out vs CDP-out gain ?

[Bevan]

What happens if you plug a cd player strait into a power amp?

I'm guessing volume will be really low. I'm a bit afraid to try it though.

If the pre-out signal that goes from pre-amp to power amp is a higher level signal than that which goes from cdp to pre-amp, what happens if you connect the pre-amp out from one amp into a line-in on another pre amp? I would think that the signal might then be too strong?

Can I connect the front channel pre-outs on an av receiver to one of the line-ins on an integrated amp? I want to integrate my integrated amp into an HT setup, using only the integrated to play cd's, and using it to drive the front speakers when listening to 5.1.

the 2 channel integrated doesnt have a 'unity gain', and I'm hoping I can attach the av receivers out to one of the integrateds line-ins rather than have to disconect the integrated amps pre from it power and plug the av outs to the integrated power section, which would mean physically changing cables each time as opposed to just switching sources on the integrated.

is the tape-in better suited to what i'm guessing is a high level signal?

thanks for any help

b

 

[jcPanny]

Line Out levels

Bevan,
All CD players (like portable ones) offer a line out level and a seperate gain adjustable level (for headphones, etc.). The same sent over dual RCA plugs or the stereo 1/4" jack.

It is my understanding that the signal level of the CD, Tape, and other analog outputs (excluding phono) are all the same range as the Pre-Amp outs. In fact, when a receiver offers a "Pure Direct Mode" it connects the appropriate analog input directly to the amplifier stage without any processing.

Integrated tube amps are basically an amp with a couple selectable inputs for direct connection to a CD player, tape, tuner, etc.

 

[j_garcia]

The problem with connecting directly to an amp is you have no volume control in most cases. The output from a CD, DVD, etc... is assumed to be passed through a preamp. You SHOULD NOT connect a media device directly to an amp.

Integrated amps DO NOT have direct connection to the amp, they are basically an amp with a preamp stage built in, but no processing. The inclusion of a preamp means you can connect any media device's pre-amp level output to an integrated.

Yes, you should be able to use your integrated the way you suggested originally, just like hooking up an external amp. I think tape in is probably the way you want to go, since that will bypass the volume function of the integrated (I believe).

 

[markw]

You're more correct than you give yourself credit for.

The problem with connecting directly to an amp is you have no volume control in most cases.

Very true. Unlress the CD player or the power amp has a volume/gain control. the full output of the CD player will be fed to the amp.

Could get pretty loud pretty quick. ...not a pretty sight.

I think tape in is probably the way you want to go, since that will bypass the volume function of the integrated (I believe).

Again true, but it WILL allow him to avail himself of the preamp functions of his unit. This is a good thing.

Remember a tpe loop is just that. The signal goes out of the unit BEFORE the preamp controls and is returned to the unit at exactly the same place in the circuit.

 

[j_garcia]

Remember a tpe loop is just that. The signal goes out of the unit BEFORE the preamp controls and is returned to the unit at exactly the same place in the circuit.

You're right, but the preamp portion is already being handled by the receiver. That sort of defeats the purpose of putting the integrated in the loop then, though, essentially turning it into just an amp.

How about going digital out from the CD to the receiver, then to the tape loop, and also connect the player via analog to a regular input on the integrated? That way you can switch between the two easily.

 

[Votrax]

What happens if you plug a cd player strait into a power amp?

I'm guessing volume will be really low. I'm a bit afraid to try it though.
b

I'm assuming you're not talking about a home CD player. If you connect the analog output of a CD player to a power amp you would have maximum output. Not a good idea. Most power amps require less than 2V on the input for full output. A CD player delivers that and some since there is no volume control. Here's a pic of the audio signal out the analog right channel of a CD player. The upper red line to the lower red line is 3V peak to peak.

 

[Bevan]

thanks for replies

so plugging a cd player into power amp will cause maximum volume...intersting. i had thought the signal out of the cd player would be of lower volume than out of the preamp.

the preamp must work as a volume attenuator then?

and the tape-in, what is the difference between this and the 'unity gain' or 'HT bypass' that many amps are now marketed as having?

j_garcia, your suggestion is good, cept that my mulitchannel amp is analogue only. but my universal player has two sets of front channel outs so that sould do the trick.

cheers

b