Using a receiver as a phono preamp

[nightflier]

I'm in the process of researching options for a good phono preamp, but while I'm doing that I would like to continue listening to my LP's. Can I use my trusty Onkyo TX8211 (which has a phono input) as a phono preamp temporarily? If so, how do I connect it to my Arcam preamp (which does not have a phono input)?

[ericl]

easy. just connect an interconnect cable to the line out of the receiver into a spare input on the arcam. turn on the onkyo and set it to the phono input when you want to listen. Easy as pie.

-E

[Glen B]

Can I use my trusty Onkyo TX8211 (which has a phono input) as a phono preamp temporarily? If so, how do I connect it to my Arcam preamp (which does not have a phono input)?

That's easy. Your receiver's Tape 1 and Tape 2 outputs (REC) both send a line level signal of whatever input source is selected. Just hookup a pair of interconnects between either one of the receiver's two output jacks and any input of the Arcam preamp. Switch the receiver input to PHONO and enjoy.

[markw]

That's easy. Your receiver's Tape 1 and Tape 2 outputs (REC) both send a line level signal of whatever input source is selected. Just hookup a pair of interconnects between either one of the receiver's two output jacks and any input of the Arcam preamp. Switch the receiver input to PHONO and enjoy.You might want to make sure the volume on the receiver is down and maybe hook up a resister to the speaker outs if you can't switch 'em off.

"Line level" might be interperted as being betweenthe preamp and the power amp stages and this would have the signal pass through the preamp stages of the receiver, which is what you don't want.

[nightflier]

You might want to make sure the volume on the receiver is down and maybe hook up a resister to the speaker outs if you can't switch 'em off.

"Line level" might be interperted as being betweenthe preamp and the power amp stages and this would have the signal pass through the preamp stages of the receiver, which is what you don't want.

Mark,

Could you elaborate. I'm confused about the risks involved. My Arcam is a fairly pricey unit, so I want to be careful. Maybe I'm not understanding what the real difference is between the line outs, ie tape outs, and a preamp out (which the Onkyo TX8211 doesn't have, by the way).

[Glen B]

Mark,

Could you elaborate. I'm confused about the risks involved. My Arcam is a fairly pricey unit, so I want to be careful. Maybe I'm not understanding what the real difference is between the line outs, ie tape outs, and a preamp out (which the Onkyo TX8211 doesn't have, by the way).

There are no risks involved to your Arcam. The volume control of a receiver/preamp/integrated amp usually comes after the phono preamp. The signal going to the tape outputs is taken before the volume control. See the diagram.

[markw]

Mark,

Could you elaborate. I'm confused about the risks involved. My Arcam is a fairly pricey unit, so I want to be careful. Maybe I'm not understanding what the real difference is between the line outs, ie tape outs, and a preamp out (which the Onkyo TX8211 doesn't have, by the way).A Tape out passes the signal just after the phono (pre-pre) amp stage and selection stage. All this is done BEFORE the traditional preamp functions such as volume, balance, tone controls, etc... All of which add additional amplification to the signal.

IOW, by using a "line out" between the preamp and the power amp you will be passing the output of your receiver's preamp stage into the input of your new preamp. This would require you to adjust the volume control on both the receiver, the tone controls WILL have an effect on what's passed to your amp, etc.

While it probably would not damage it, it may not sound as "pure" as you would like. The worst you vould do is overdrive the input stage of your new preamp.

The tape out stage passes the signal to your amp BEFORE all these additional stages. When using a receiver's phono stage, it's always done (at least properly done) via the tape monitors. But, it's your choice.

Addendum: Using Glen's diagram, most "line level" outputs labelled as such are tapped between the "main" and "output" stages. Also, it clearly shows where the tape monitor outout is tapped.

[ericl]

IOW, by using a "line out" between the preamp and the power amp you will be passing the output of your receiver's preamp stage into the input of your new preamp. This would require you to adjust the volume control on both the receiver, the tone controls WILL have an effect on what's passed to your amp, etc.

Line out (short for line-level output) and tape out are the same. pre amp output is called the pre out.

[markw]

Line out (short for line-level output) and tape out are the same. pre amp output is called the pre out.True, they are both referred to as "a "line level" signal, which is generally around 1 volt, and a tape out generally offers this, depending on the level of the source feeding it.

A premp out, while technicaly a line out by virtue of it's not being able to drive speakers, can vary from less than one volt up to about 10 volts depending on the settings of the controls before it.

[nightflier]

True, they are both referred to as "a "line level" signal, which is generally around 1 volt, and a tape out generally offers this, depending on the level of the source feeding it.

A premp out, while technicaly a line out by virtue of it's not being able to drive speakers, can vary from less than one volt up to about 10 volts depending on the settings of the controls before it.

Not that I plan to do this, but theoretically, one could connect a power amp to the tape outputs? Or is the preamp required to regulate the signal?

[markw]

Not that I plan to do this, but theoretically, one could connect a power amp to the tape outputs? Or is the preamp required to regulate the signal?...two things to keep in mind, and they represent both extremes of the same situation..

1) unless the power amp has a gain control, you'll have no control over it's output.

2) the source coming out of the tape monitor may not be at a level sufficient to drive the power amp to it's full potential.

[Glen B]

Not that I plan to do this, but theoretically, one could connect a power amp to the tape outputs? Or is the preamp required to regulate the signal?

In addition to what Mark said -- and going back to my diagram above -- if you were to connect a power amp to the tape out, all you would have is a glorified switch box.

[ericl]

2) the source comoing out of the tape monitor may not be at a level sufficient to drive the power amp to it's full potential.

I thought that a line level signal directly into an amplifier would have way too much gain - meaning that if you connect a line signal directly to an amp the effect is equivalent to having the volume all the way up - and a preamp is needed to lower the gain?

[markw]

I thought that a line level signal directly into an amplifier would have way too much gain - meaning that if you connect a line signal directly to an amp the effect is equivalent to having the volume all the way up - and a preamp is needed to lower the gain? It WILL be running full tilt boogie. I think I pretty much covered that in option 1.

Again, depending on whatever "source" is being used, YMMV. I'd say a lot has to do on hte actual gain of the power amp itself as well. I've heard that some CD players don't put out enough signal to fully frive some power amps to their maximum potential.

As you may know, no one size fits all in this hobby. Personally, I think it's fooliish to attemp something like this without some sort of attenuator somewhere in the circuit.