Pre-amp output signal booster?

lovinthehd

lovinthehd

Audioholic Jedi
Correct, I have used the .775 amp sensitivity setting, in fact mostly.
I cannot get the amp to clip.

I mainly use it for music and I've had little luck with surround modes. Presumably because most music is 2 channel? So I use that multi channel stereo button often.

I just hooked up the Marantz to my network and poked around in the settings. Found one for input sensitivity that seems to make things come to life.

Haven't hooked up the Crown yet, but I'm hopeful this will cascade a stronger signal to the Crown.
Macbook -> HDMI -> Marantz -> RCA/XLR -> Crown -> Old Telephone Cord -> Polk 60's

(jk) ^
You're using an rca to xlr cable instead of just rca to rca?

Why old telephone cord? What gauge is that?

What gain settings? You have tried max?
 
Verdinut

Verdinut

Audioholic Ninja
The old telephone cord is most probably the cause of the problem. The OP should al least use lamp cord or a bigger gauge wire from amp to speakers if he wants to hear something.
 
M

McChris

Enthusiast
You're using an rca to xlr cable instead of just rca to rca?

Why old telephone cord? What gauge is that?

What gain settings? You have tried max?
Hi, sorry lovinthehd. I was just trying to be funny.
Using regular 14 Gauge speaker wire. :)

I had it at max gain yes, but not since turning up the Marantz setting for input sensitivity. It's kinda late here.

I hadn't heard of XLR before, and I bought it for troubleshooting. Thought maybe magic would happen with that connection. I've since learned it's completely unnecessary unless XLR to XLR, or if you didn't have an option to use RCA's.
 
lovinthehd

lovinthehd

Audioholic Jedi
Hi, sorry lovinthehd. I was just trying to be funny.
Using regular 14 Gauge speaker wire. :)
I was sorta kidding about asking about it, if it's of sufficient gauge it could be fine, not familiar with the stuff, tho.

More curious is using an xlr input on the amp unnecessarily as you have rca input. This could account for the low input level to the amp....use rca to rca....

And what gain settings have you tried? (just saw you'd answered that, it didn't show in the window the first time). What do you mean turning up the Marantz setting for input sensitivity?
 
TLS Guy

TLS Guy

Seriously, I have no life.
Correct, I have used the .775 amp sensitivity setting, in fact mostly.
I cannot get the amp to clip.

I mainly use it for music and I've had little luck with surround modes. Presumably because most music is 2 channel? So I use that multi channel stereo button often.

I just hooked up the Marantz to my network and poked around in the settings. Found one for input sensitivity that seems to make things come to life.

Haven't hooked up the Crown yet, but I'm hopeful this will cascade a stronger signal to the Crown.
Macbook -> HDMI -> Marantz -> RCA/XLR -> Crown -> Old Telephone Cord -> Polk 60's

(jk) ^

* I'll report back if this clears it up, can't do it tonight though. fyi
You need to use 12 or 10 AWG speaker cable.

I think you major misunderstanding is confusing gain structure and raw output power.

Almost certainly the internal amps and the Crown will have a different gain structure.

In any event the difference in loudness by using the Crown amp is 4.8 db. You need a 10 db increase to make your system to seem twice as loud. Your speakers would not tolerate that much power.

To get a system twice as loud as yours would require 1000 watts per channel assuming similar speaker sensitivity. That is were it gets really expensive!
 
M

McChris

Enthusiast
I was sorta kidding about asking about it, if it's of sufficient gauge it could be fine, not familiar with the stuff, tho.

More curious is using an xlr input on the amp unnecessarily as you have rca input. This could account for the low input level to the amp....use rca to rca....

And what gain settings have you tried? (just saw you'd answered that, it didn't show in the window the first time). What do you mean turning up the Marantz setting for input sensitivity?

Haha, I thought maybe you were...

I'm just using it still because it looks cooler than RCA. The cable is actually shorted on pins 2 to 3 (or 1 & 2 ?), basically ground and negative terminal. I suppose it was presumptuous, but I assumed this acted just like the RCA.

I have RCA's and didn't get a better signal with them originally. But I'll try them again.

The setting I found is in the Network GUI. Hooked it up to ethernet and was able to login at 192.168.0.xx. Found more buttons and gadgets to play with. Like this one: (was at 0 db)
 

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lovinthehd

lovinthehd

Audioholic Jedi
Haha, I thought maybe you were...

I'm just using it still because it looks cooler than RCA. The cable is actually shorted on pins 2 to 3 (or 1 & 2 ?), basically ground and negative terminal. I suppose it was presumptuous, but I assumed this acted just like the RCA.

I have RCA's and didn't get a better signal with them originally. But I'll try them again.

The setting I found is in the Network GUI. Hooked it up to ethernet and was able to login at 192.168.0.xx. Found more buttons and gadgets to play with. Like this one: (was at 0 db)
Try the rca to rca again, generally you have a gain difference between balanced (xlr) and unbalanced (rca). You can convert rca to xlr, it's just unnecessary and doesn't really look cooler....at least I never think of a connector as cool looking one way or the other. Useful, perhaps, but cool looking, nah.

The input source level adjustment is to help out if you have sources of varying input level so that when you switch among them the volume stays relatively even. I use that to raise my turntable input up, as it's fairly low. What is your input source?
 
M

McChris

Enthusiast
You need to use 12 or 10 AWG speaker cable.

I think you major misunderstanding is confusing gain structure and raw output power.

Almost certainly the internal amps and the Crown will have a different gain structure.

In any event the difference in loudness by using the Crown amp is 4.8 db. You need a 10 db increase to make your system to seem twice as loud. Your speakers would not tolerate that much power.

To get a system twice as loud as yours would require 1000 watts per channel assuming similar speaker sensitivity. That is were it gets really expensive!
Well that's a bummer. I feel like I was duped by the internet. I wanted to get a powerful amp and then run it with the gains low until I could get some bigger speakers. (forgive me if that's not logical, maybe I don't understand gain).
In the mean time, I figured it would relieve stress on my amp and achieve proper operating power for my polk 60's.

Amazon reviews talked me into it.

I'm not opposed to putting this thing back in it's Amazon box, lol
 
M

McChris

Enthusiast
Try the rca to rca again, generally you have a gain difference between balanced (xlr) and unbalanced (rca). You can convert rca to xlr, it's just unnecessary and doesn't really look cooler....at least I never think of a connector as cool looking one way or the other. Useful, perhaps, but cool looking, nah.

The input source level adjustment is to help out if you have sources of varying input level so that when you switch among them the volume stays relatively even. I use that to raise my turntable input up, as it's fairly low. What is your input source?
HDMI from a macbook Pro into Marantz.

I thought I was golden with input level, actually. I have SpeakerAmp and it can adjust the level too. But it made no difference when I was testing things out the other day.

The poor Crown might not have found a forever home here...
 
lovinthehd

lovinthehd

Audioholic Jedi
Amazon reviews are a lot of hot garbage all too often.

The Polk Monitor 60 spec of max 200 watts (and I don't see much more than a vague reference on the Polk site, which is sort of normal for Polk unfortunately) is likely more a melting point than anything useful...(speaker max wattage is generally not all that useful a spec). T

An external amp can still be useful, just need to keep your expectations in line.

Try this article on gain structure https://www.hometheatershack.com/threads/gain-structure-for-home-theater-getting-the-most-from-pro-audio-equipment-in-your-system.35677/
 
Pogre

Pogre

Audioholic Slumlord
Pogre, I'm thinking that's a factor here as well. I was expecting to have the speaker wind blowing through my hair at 1/4 gain. lol
That actually made me chuckle, then made me think of @Swerd and his forum avatar...

Screenshot_2021-07-24-11-25-34-1_copy_344x93-1.png


When you run Audyssey it's calibrating for a fixed volume level at the main seat so your gain or volume dial position should be the same for a given volume level at your seat before and after adding the amp. Another note about distance since you mentioned it, the distance settings are more to do with timing than actual measured distance and don't always match up accurately.

You said yours is accurate, which is pretty normal but isn't always the case. Especially with subwoofers. If you ever do notice it doesn't match what you measure with a ruler does not necessarily mean it's "wrong". It's likely adjusted for timing purposes and I would leave it alone.
 
Pogre

Pogre

Audioholic Slumlord
Well that's a bummer. I feel like I was duped by the internet. I wanted to get a powerful amp and then run it with the gains low until I could get some bigger speakers. (forgive me if that's not logical, maybe I don't understand gain).
In the mean time, I figured it would relieve stress on my amp and achieve proper operating power for my polk 60's.

Amazon reviews talked me into it.

I'm not opposed to putting this thing back in it's Amazon box, lol
Yeah... internets and fluffy, subjective reviews... pft. Unfortunately there's a lot of woo and magical thinking in this hobby so you gotta be careful and take a lot of it with a grain of salt. Objective measurements and accurate specs will tell you much more.

Bigger speakers in general will have the ability to get louder with less power, but isn't always the case. Sensitivity specs are what's meaningful here. It's a lot more efficient to get higher sensitivity speakers than to throw gobs of power at them. A speaker that's 3 dB more sensitive (say 91 dB compared to 88 dB, both common specs for speakers) is equivalent to doubling your amp power (or more accurately, halving the power requirement to reach the same volume). After that the ability to handle a lot of power is what's relevant for overall speaker wind in your hair volumes.

*Edit: having a more powerful external amp can still provide some benefits. Like you mention it will take some heat off your receiver, and when you do upgrade your speakers you'll have plenty of power for them to play plenty loud.
 
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highfigh

highfigh

Audioholic Slumlord
TLDR;
Trying to hook up a Crown XLi1500 2 channel power amp to the front pre-amp outputs on a Marantz SR5008.
Unimpressed thus far.


I've read that the Crown XLi1500 is a pretty powerful amp for home stereo use, yet when hooked up to my Polk Monitor 60's, they're barely louder than just straight off the AVR.

I upgraded to a Marantz sr5008 (yeah I know it's old, but new to me). My other AVR didn't have pre-amp outputs and I was going to get a line level converter(?), but later read they can introduce noise and that's a shitty way to go. The Marantz has 7 channel pre-amp outs, I've got the Crown hooked to the Front pre-outs.

As I understand it, most AVR's don't live up to the .75 - 1.4 voltage input that the Crown expects for a signal, but some claim that's just fine, it still powers their tower speakers with lots of headroom left.

But me, I have the gains all the way up; and it's not much louder than just coming off the AVR's integrated amp. I've read that I can somehow boost the signal off the pre-amp outputs and then feed that into the Crown to get full potential. I don't fully understand what kind of device does this, or if this is even a viable approach.

Rather than risk damage to my equipment, I thought I'd reach out and ask for advice.

Thanks in advance
Chris
And you're learning that pro gear shouldn't mix with consumer gear. If people refuse to learn about what an amplifier needs WRT input voltage, impedance matching, etc, they'll never be satisfied after being convinced that what they need is something that isn't designed to work with what they have.

RTFM is an acronym that needs to be heeded and if you were to read the manual before buying AND understand it, you wouldn't be having this problem.

A properly matched preamp, power amp and speakers, chosen to achieve the output needed for the application, will produce the desired results. Guesswork will result in poor performance unless the guesses are informed or lucky. Power amplifiers need a certain voltage in order to achieve full output power, but it's not just voltage, its input impedance needs to be a decent match to the output impedance and voltage of whatever feeds it the signal.

"Line level converter"? Is that something you might connect to the Marantz' speaker terminals and convert to line level, like the ones used for a car stereo? You won't find one that properly handles the power output of 100W @8 Ohms.

You really should learn about the technical side of audio- it would save a lot of time, money and frustration. The output from the Crown isn't going to double the output level from the Marantz. I also don't think your speakers are going to be very happy if you hit them with the full output from the Crown for any length of time since they're rated for 200W.

How loud do you want the system to be?
 
highfigh

highfigh

Audioholic Slumlord
There's a lot of confusion about this kind of amplifier and Crown, specifically. Not only are the level controls labeled incorrectly, there's nothing in the .pdf manual about how to properly set them- all it shows is "Input Sensitivity for full rated power at 8 ohms- 0.775V or 1.4V". In reality, full output can only be reached if the controls are turned fully clockwise but if noise is audible, they need to be backed off. Also, amplifier gain is almost always fixed- it's the input level that varies with the position of the controls. This info is used by people who design audio systems for a living and if you call Crown, they will tell you the same (I have called them and they verified this).

DIY is great, if the person does their research. If not, it's just frustrating.
 
Pogre

Pogre

Audioholic Slumlord
And you're learning that pro gear shouldn't mix with consumer gear. If people refuse to learn about what an amplifier needs WRT input voltage, impedance matching, etc, they'll never be satisfied after being convinced that what they need is something that isn't designed to work with what they have.

RTFM is an acronym that needs to be heeded and if you were to read the manual before buying AND understand it, you wouldn't be having this problem.

A properly matched preamp, power amp and speakers, chosen to achieve the output needed for the application, will produce the desired results. Guesswork will result in poor performance unless the guesses are informed or lucky. Power amplifiers need a certain voltage in order to achieve full output power, but it's not just voltage, its input impedance needs to be a decent match to the output impedance and voltage of whatever feeds it the signal.

"Line level converter"? Is that something you might connect to the Marantz' speaker terminals and convert to line level, like the ones used for a car stereo? You won't find one that properly handles the power output of 100W @8 Ohms.

You really should learn about the technical side of audio- it would save a lot of time, money and frustration. The output from the Crown isn't going to double the output level from the Marantz. I also don't think your speakers are going to be very happy if you hit them with the full output from the Crown for any length of time since they're rated for 200W.

How loud do you want the system to be?
I'm guessing things are hooked up and working properly. I think, and op agreed, that expectations weren't realistic and possibly a misunderstanding of calibrated volume levels wrt the position of the volume dial.
 
lovinthehd

lovinthehd

Audioholic Jedi
There's a lot of confusion about this kind of amplifier and Crown, specifically. Not only are the level controls labeled incorrectly, there's nothing in the .pdf manual about how to properly set them- all it shows is "Input Sensitivity for full rated power at 8 ohms- 0.775V or 1.4V". In reality, full output can only be reached if the controls are turned fully clockwise but if noise is audible, they need to be backed off. Also, amplifier gain is almost always fixed- it's the input level that varies with the position of the controls. This info is used by people who design audio systems for a living and if you call Crown, they will tell you the same (I have called them and they verified this).

DIY is great, if the person does their research. If not, it's just frustrating.
The OP found the sensitivity setting switch apparently, it's on the back of the amp....see page 5 of the manual.
 
ski2xblack

ski2xblack

Audioholic Field Marshall
It's too bad that marketing fosters the whole confusion about absolute power and gain structure. If it was all expressed in dbW it would be less impressive on the showroom floor, but cobbling together a system to meet specific goals would be much simpler.
 
highfigh

highfigh

Audioholic Slumlord
It's too bad that marketing fosters the whole confusion about absolute power and gain structure. If it was all expressed in dbW it would be less impressive on the showroom floor, but cobbling together a system to meet specific goals would be much simpler.
I think it's caused more often by reading info on Facebook and other sites where people don't understand what they're dealing with.

Big numbers impress people. That's the reason the major audio companies engaged in their (unfortunate) specs race to the bottom, with all kinds of ridiculous claims.
 
Pogre

Pogre

Audioholic Slumlord
It's too bad that marketing fosters the whole confusion about absolute power and gain structure. If it was all expressed in dbW it would be less impressive on the showroom floor, but cobbling together a system to meet specific goals would be much simpler.
This whole thing about more power making everything sound "better" is even worse with car audio. At least when I was into it. Everyone I remember who was into it too were convinced more expensive, more powerful amps were just as important as speaker choice for sound quality. I believed it, and it carried over to home audio for me until you guys educated me and I learned these things can be objectively measured very accurately.

I get tho, when folks come here with that preconception and don't blame them. Especially when someone is still learning. When everyone around you is telling you what "works" and they even own the gear it's convincing.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Warlord
I think it's caused more often by reading info on Facebook and other sites where people don't understand what they're dealing with.

Big numbers impress people. That's the reason the major audio companies engaged in their (unfortunate) specs race to the bottom, with all kinds of ridiculous claims.
Yep. We’ve all seen these before!!!

Then try explaining to the happy new owner why it really doesn’t work like that
But it says so on the box?!?!?!?!
 
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