Are all inputs the same?

BuckeyeTim

Are all inputs on a preamp the same? Specifically, on my Adcom? I guess what I am getting at is... I hooked my dvd player audio up to the "Tape 2" input on the pre. For something like that, does it make a difference? Would it be better if it was hooked up to a different input, or are all inputs on a given pre basically the same..phono, tape, aux, etc....?

F1nut

No, they are not all the same. Never connect anything to the phono except a TT. Tape inputs vary from pre to pre, some are ok to use for whatever, but others are not. Best to connect your DVD player to aux.

BuckeyeTim

My tv has no audio outs, so I have to either hook up the dvd to tv with no Adcoms, or remove the cables connecting the audio out from sat receiver to the pre-amp (on the aux) and connect the dvd.....which would mean I can't watch tv with Adcoms.

I just changed cables around tonight but have not tried it out yet. Is it really that big of an issue , and why?

comfortablycurt

I can't see you having any issues. I've got a DVD player hooked up to one of the tape inputs on my Acurus L10...I also have a turntable hooked up to the tuner input(through an outboard phono pre), and I've even got a DVD player hooked up to a CD input.

Should be just fine hooking up your satellite to your pre.

edit-As Jesse said, don't hook anything but a turntable up to the phono input. The phono input amplifies the signal before going to the pre-amp, and hooking up a CD player or DVD player to the phono input could result in some bad juju.

F1nut

Well, try the tape input, it may work for you, but do not use the phono input.

BuckeyeTim

Thanks....but still being curious,....why not the TT in particular? Not looking for a real in depth discussion of the issue...just looking for a basic why. Are the circuits that much different?

F1nut

Yes, different gain.

BuckeyeTim

Thanks guys! Much appreciated

comfortablycurt

As I stated in post #4;)


A turntable puts out a low level, analog signal. This is a much lower level signal than a CD/DVD player puts out, and requires an additional stage of amplification before going through the pre-amp. Since a CD player(digital) is putting out a higher level signal, it doesn't need this additional stage of amplification. I've never hooked up a CDP to my phono stage(for obvious reasons), but I'd imagine the result would be a signal with way too high of a gain level.

BuckeyeTim

Sorry Curt, I missed your post before I responded.. I had started a response to other post and then had to take care of something in the middle of it. I came back and finished and posted it. You had posted in the mean time. Sorry for giving the impression that I had ignored what you said.

Thanks for your comments. I have much to learn.

hearingimpared

BuckeyeTim wrote: »

Thanks....but still being curious,....why not the TT in particular? Not looking for a real in depth discussion of the issue...just looking for a basic why. Are the circuits that much different?

The phono stage input is much, much different than the line level in that it has to take into account the comparitively low voltage outputs of moving magnet & moving coil cartridges. Plus most phono stages have settings inside to set the resistive load for MC cartridges, capacitive & resistive loads for MM cartridges plus they usually have some sort of gain adjustment be it by dip switchs, pots, or straps. Some even allow for custom resistor and/or capacitors.

Hope this helps.

TNRabbit

The phono input also has the RIAA (sp?) equalization built in, which would make anything else connected to it sound like ****.

Bubinga99

TNRabbit wrote: »

The phono input also has the RIAA (sp?) equalization built in, which would make anything else connected to it sound like ****.

Yep, and with RIAA equalization being a 2-step "encode-decode" process, it's also true that if you hooked a turntable up to an external linear preamp at fixed, constant gain to increase the levels to line input levels, and then to your preamp on any line input, it would also sound like ****. Lows would be hugely attenuated and highs hugely boosted.

Here's what the RIAA equalization on the preamp side looks like. This is embedded in the phono stage's signal path:


which is the inverse of what the source material goes through before the master is cut for the vinyl.

Line inputs, on the other hand, are fixed, constant gain versus frequency.

Here's an article with some history and rationale on the RIAA equalization:
http://www.graniteaudio.com/phono/page5.html

Toolfan66

What about a pre with no phono stage like the GFP-750 would it really make a difference what input you use with a external Phono Pre? to me common sense says to use aux input.

The only thing I play with is the passive/active switch.

hearingimpared

I forgot to mention RIAA equalization. Larry use the aux port.

FrankJG

On a Yamaha AX 497, I have these three options to input the audio from the cable television: Tape, MD, and Aux. Is there any difference at all between these three?

heiney9

FrankJG wrote: »

On a Yamaha AX 497, I have these three options to input the audio from the cable television: Tape, MD, and Aux. Is there any difference at all between these three?

See post #2

Hillbilly61

To attempt to summarize, go Tape or Aux, (and CD) if these are RCA connector types. The acceptable incoming line voltages are pretty much compatible. Most pre and integrated amps have multiple inputs of that nature to match the knob setting position on the front of the rig. You can mix/match, but have to remember what specific device is hooked up to the front knob setting. In the past I've used Aux to remember cable for older pre & integrated amps that did not have a specific TV input.

Anything related to Phono is a big no-no for reasons stated above.

FrankJG

Thanks for the advise!