Can I have 2 preamps?

[bubslewis]

Just finished upgrading crossovers on Maggie 1.6's. Am now considering some of the downstream components. Currently running the maggies from an amp that's fed from the preouts of a Yamaha A/V receiver. For music I use "pure direct" which plays 2 channel and bypasses all sound processing. But also use the maggies as front speakers in an HT setup.

My Question is: Is it possible to put another (higher quality) preamp between the maggie amplifier and the (lower quality) A/V receiver preamp? So the signal would run from the source, thru the A/V preamp, thru a better preamp, to the amp, to the speaker.

If answer to first question is YES, proceed to Question 2:

Question 2: Could I expect any sonic benefit from doing this? Can an additional better preamp improve the signal being fed to it or just do a better job at accurately reproducing the original signal from the A/V preamp?

Additional question: Would a passive preamp be applicable in this situation?

I have to do it this way because I want to use the maggies for both music and HT. Hence I must employ the A/V preamp in order to accomplish this.

[Mr Peabody]

What you would want to do is run your source into the better preamp and then to the power amp, if your power amp allows 2 inputs. If the power amp only allows one input, then your receiver hopefully has a bypass that would allow the signal from your better preamp to pass through it to the power amp. You wouldn't want to run a preamp into just an ordinary input of your receiver or vice versa. A better preamp will yield better sound quality as long as you can get a straight forward path for the signal to go through. I'd be surprised if a receiver had the correct bypass feature because they are assuming you are going to use either the internal amp or a separate power amp, I wouldn't think they'd plan for the receiver being used as just a preamp. If you have not bought your stereo preamp yet, your best bet would be to buy one that has the "unity gain" or "theater bypass" feature on it. Then, you simply run the front L/R preouts of your receiver into the stereo preamp, when using the "bypass" mode of the preamp, it will allow the receivers signal to pass right through to the power amp. Not all, but several manufacturers of stereo preamps offer a theater bypass feature.

What sources do you have? What power amp are you using?

If you still have questions about what I'm talking about feel free to email me. The link is under my profile.

[Feanor]

Just finished upgrading crossovers on Maggie 1.6's. Am now considering some of the downstream components. Currently running the maggies from an amp that's fed from the preouts of a Yamaha A/V receiver. For music I use "pure direct" which plays 2 channel and bypasses all sound processing. But also use the maggies as front speakers in an HT setup.

My Question is: Is it possible to put another (higher quality) preamp between the maggie amplifier and the (lower quality) A/V receiver preamp? So the signal would run from the source, thru the A/V preamp, thru a better preamp, to the amp, to the speaker.

If answer to first question is YES, proceed to Question 2:

Question 2: Could I expect any sonic benefit from doing this? Can an additional better preamp improve the signal being fed to it or just do a better job at accurately reproducing the original signal from the A/V preamp?

Additional question: Would a passive preamp be applicable in this situation?

I have to do it this way because I want to use the maggies for both music and HT. Hence I must employ the A/V preamp in order to accomplish this.

I generally agree with Mr. P.. But let's be clear that it would be point less to run from preamp to the receiver, a configuration he alludes to; any benefit the higher quality preamp would be lost travelling through the receiver, likely even if the receiver does have a "direct" setting.

Secondly the preamp will in no way improve the signal from the receiver, it can just pass it on as-is. But the preamp might prevent signal a certain amount of "damage" to, say, a CD player signal attached directly to it versus to the receiver. So ... if a separate source like a CDP is attached to the preamp (instead of the receiver), and the preamp is in turn attached directly to the power amp, then some sound improvement is possible.

[Mr Peabody]

I think we are on the same page. When I say the preamp would improve sound quality, I mean in comparison to using the receiver's preamp section. If, and that's a big, if, the receiver had a true unity gain bypass, I think it would be one of those things you'd have to try to see how much degradation was done to the signal. In theory, we'd think there would be some but whether it would be noticeable.... A unity gain bypass, called many things by different manufacturers, should pass the signal right through without any contact with un-necessary circuitry. As I stated the best set up would be to get the higher quality preamp with the bypass. That would allow HT sources to go to the receiver and stereo sources to the higher quality preamp, and when using HT the front main speaker signal would pass through the higher quality preamp into the power amp. In theory thins would have the greatest signal preservation without going directly to the power amp. If his power amp will accept 2 inputs then all the discussion is moot, but I've yet to see one that does. Using a switch box would be as bad if not worse than passing it through a receiver.

[Feanor]

...
As I stated the best set up would be to get the higher quality preamp with the bypass. That would allow HT sources to go to the receiver and stereo sources to the higher quality preamp, and when using HT the front main speaker signal would pass through the higher quality preamp into the power amp. In theory thins would have the greatest signal preservation without going directly to the power amp.
....

For example, my Adcom GFP-750 preamp has a "Processor" switch that passes the signal directly from the "Processor In" connectors to output bypassing all gain stages of the Adcom; i.e. volume, balance, etc., are controlled by the "processor" which could well be an A/V receiver.

Interestingly, the Adcom's "Processor" circuitry is a loop with "Processor Out" connectors as well as "In" connectors. Of course, it isn't necessary to connect anything to the "Out" connectors in order to use the "In" connectors. This was designed to accomodate Adcom's own, add-on multichannel processors

[Geoffcin]

Just finished upgrading crossovers on Maggie 1.6's. Am now considering some of the downstream components. Currently running the maggies from an amp that's fed from the preouts of a Yamaha A/V receiver. For music I use "pure direct" which plays 2 channel and bypasses all sound processing. But also use the maggies as front speakers in an HT setup.

My Question is: Is it possible to put another (higher quality) preamp between the maggie amplifier and the (lower quality) A/V receiver preamp? So the signal would run from the source, thru the A/V preamp, thru a better preamp, to the amp, to the speaker.

If answer to first question is YES, proceed to Question 2:

Question 2: Could I expect any sonic benefit from doing this? Can an additional better preamp improve the signal being fed to it or just do a better job at accurately reproducing the original signal from the A/V preamp?

Additional question: Would a passive preamp be applicable in this situation?

I have to do it this way because I want to use the maggies for both music and HT. Hence I must employ the A/V preamp in order to accomplish this.

I run my CD player directly into my passive pre amp. I run the output from the preamp of my AV Receiver's mains into the passive pre also. When I want to listen to music via the CD I am bypassed entirely from the receiver. To run the mains with the receiver requires me to manually switch the preamp to aux. Not a terrible price to pay for having the 3.6's in the HT system.

[bubslewis]

Thanks for responses. I doubt if there is a totally satisfactory solution here.

Mr. Peabody: My B&K 125.2 reference amp for my front maggies does not have dual inputs. Am currently running a standard dvd player, cd player, and turntable thru a Yamaha A/V receiver that does not have a true unity gain bypass. Closest thing in the A/V receiver is the "pure direct" mode that bypasses all sound processing circuits, but still sends the source signal thru the receiver's preamp outputs.

Adding a better preamp in the loop would work electronically, but as Feanor confirmed my suspicions, it would not likely result in any better sound since the source signal would still have to first pass thru the A/V receiver's preamp.

An A/B switch prior to the front maggies amplifier would (seemingly) be the best answer. For music, I would run the cd player and turntable thru the better quality preamp, thru the "A" switch, thru the B&K amp, to the maggies. Volume control would be via the better quality preamp. This bypasses the A/V receiver altogether, so I wouldn't even turn it on.

For movies, I would run the dvd thru the A/V receiver, thru the "B" switch, to the maggie amp, using the A/V receiver for volume control and sound processing for all speakers.

BUT..... Mr. P. indicates that a switch is a really bad audio option. How come?

Geoffcin: How do you control volume when listening to cd's in your setup? I think I understand most of your description, but I can't see where volume control would be if you're using a passive preamp (I didn't think passive preamps had volume controls).

Sorry for all the questions, but I learn so much from this forum.

thx,
Bill

[Geoffcin]

Mr. Peabody: My B&K 125.2 reference amp for my front maggies does not have dual inputs. Am currently running a standard dvd player, cd player, and turntable thru a Yamaha A/V receiver that does not have a true unity gain bypass. Closest thing in the A/V receiver is the "pure direct" mode that bypasses all sound processing circuits, but still sends the source signal thru the receiver's preamp outputs.

Adding a better preamp in the loop would work electronically, but as Feanor confirmed my suspicions, it would not likely result in any better sound since the source signal would still have to first pass thru the A/V receiver's preamp.

An A/B switch prior to the front maggies amplifier would (seemingly) be the best answer. For music, I would run the cd player and turntable thru the better quality preamp, thru the "A" switch, thru the B&K amp, to the maggies. Volume control would be via the better quality preamp. This bypasses the A/V receiver altogether, so I wouldn't even turn it on.

For movies, I would run the dvd thru the A/V receiver, thru the "B" switch, to the maggie amp, using the A/V receiver for volume control and sound processing for all speakers.

BUT..... Mr. P. indicates that a switch is a really bad audio option. How come?

Geoffcin: How do you control volume when listening to cd's in your setup? I think I understand most of your description, but I can't see where volume control would be if you're using a passive preamp (I didn't think passive preamps had volume controls).

Sorry for all the questions, but I learn so much from this forum.

thx,
Bill

OK, that's easy;

All passive preamps have a volume control. If they don't, they are called switchboxes.

The passive preamp controls my PS Audio amp which drives my 3.6's. The analog output from the CD goes directly into the passive pre.

The output from the mains "preamp out" of my receiver goes into the passive preamp. When I use the mains in the HT, I simply set the passive pre's volume to max, which used that way, is for all intensive purposes is a straight wire.

[bubslewis]

OK, that's easy;

All passive preamps have a volume control. If they don't, they are called switchboxes.

The passive preamp controls my PS Audio amp which drives my 3.6's. The analog output from the CD goes directly into the passive pre.

The output from the mains "preamp out" of my receiver goes into the passive preamp. When I use the mains in the HT, I simply set the passive pre's volume to max, which used that way, is for all intensive purposes is a straight wire.

Ahha. This would work for me! Would need a preamp with cd and phono input capability and another good cable. No tone controls necessary on the preamp (is that what makes it "passive'?). Also need to remember to turn the preamp volume back down from max when changing from HT to music.

Thanks muchly,
Bill

[Mr Peabody]

A switch box would have as bad, if not , worse circuits than your receiver. There are some very expensive ones that are said to be high quality but it's still another object in the loop.

I think you have a grasp on what G's set up is, but, if you bought a preamp with the unity gain or "HT bypass", it would be designed for your purpose and you wouldn't have to mess with volume control.

For example, my set up used to be for 2 channel my cdp and turntable went to my Krell integrated which had the "theater through" feature. My DVD and satelite went into a surround processor. The front L/R outs of the processor went into the Krell. When watching HT, I just pushed a button on the Krell which allowed me to use it's power section as a slave to the processor. Either way, passive or HT bypass, would work for you. I'd hate to see you forget that the volume was all the way up sometime when you crank up the ole stereo side though

[bubslewis]

Thanks Mr. P. I've got a pretty clear picture of both yours and Geoffcin's options.

One more question for Geoffcin if you read this. For HT, you said you run thru your aux in your PS2 preamp. Are aux inputs fairly common on preamps these days? Last time I shopped around for a preamp (admittedly that was a long time ago) I didn't recall seeing many with aux inputs.

[Mr Peabody]

I don't want to step on G's toes but until he answers, AUX inputs are still available and even it says something else like "input 1", "cd" or whatever, it is the same type of input. One thing you will have to check on though that is not the same is a phono stage. Most preamps do not come with one anymore but some offer it as an option built in for additional money. There are many outboard units available at various price points. I used the little Creek OBH-8 for some time, it is a giant killer for the money. I think under $200.00 and pure class A circuitry.

[Geoffcin]

Thanks Mr. P. I've got a pretty clear picture of both yours and Geoffcin's options.

One more question for Geoffcin if you read this. For HT, you said you run thru your aux in your PS2 preamp. Are aux inputs fairly common on preamps these days? Last time I shopped around for a preamp (admittedly that was a long time ago) I didn't recall seeing many with aux inputs.

I use the "Tape 1" input on my preamp for HT. It wouldn't matter if I used Tape 2, CD, or any other input as they are all the same, only the labels are different.

[bubslewis]

All the stereo equipment I've used over the years and I never quite realized that the inputs (except phono) were interchangeable. Reminds me of a cartoon strip about the inside of a post office. The front wall had mail slots for local, non-local, out-of-state, international, etc. The second frame showed the back of the wall. All the slots funneled down into one large bag.

Checked out some PS Audio and Arcon preamps on line. Very nice. NOT cheap.

tx,
Bill