Voltage output of preamp outputs (balanced & unbalanced

[chemical]

Concerning voltage output of preamp outputs (balanced & unbalanced).  A long time ago, I bought an Emotiva XPA-5 gen ( well there was no gen as it was the first XPA-5.  Technically it was gen 1, but only after gen 2 arrived.  

Anyway, I connected it to a Harmon Kardon Receiver that was a pretty solid unit.  However, I contacted Lonnie because I had to really turn up the volume to get any power out of it.  I think it was 200/250 watts times 5.  I was only running 2 channels so it was probably closer to 250/300.  Lonnie immediately told me how the voltage of the RCA preamp outs on my HK could severely limit the signal I was getting.  I hadn't thought of this before.  I did remember in car audio that Kenwood would advertise a true 4 volts rms or vrms to it's sub pre-outs.  I noticed some processors today, namely the JBL Synthesis lists the single-ended rca pre's @ 1vrms, 5 max.  And the balanced is listed @ 2VRMS.  For close to 7k, this is surprising as it's listed directly on their website.  I was curious, do we know the voltage rms or max of the SE or balanced XLR output.  If it's 1 volt, I would imagine you would need a DR-3 just to get to XPA-3 sound.  You're basically amplifying a very low signal voltage.  I imagine this would degrade sound and cause all types of issues.  If this has been covered, I am very sorry.  I couldn't find it anywhere.  Hence it is in the stupid question area.  I am also curious about the value represented by the XMC-2, RMC-1L, and RMC-1.  I imagine they are the same on the RMC's since they are both the same circuitry as far as balanced, fully differential on the front 3 channels.  Not sure if it's different on the flagship.  Interesting how these values are often overlooked and yet they are vital as it can make an expensive amp look soft as cottonelle.

Thanks for your patience and understanding with me.  If you are aware of any tech specs, both direct from manufacturer website or from a processor tester like amir or the like, please let me know.  Thanks again.

If the following isn't allowed, just tell me and I will delete or a moderator can fix it according to their rules.  I'm still learning rules.  But, I don't see how this would disparage Emotiva.  Instead, I would like to see it proven that these document enhance the Emotiva brand.

This is from JBL Synthesis concerning their SDP-58  www.jblsynthesis.com/products/electronics/SDP58-.html and here is their voltage claims: 



And from Anthem concerning their AVM-90: products.anthemav.com/avm90/.  Here she is:



Caleb Nathaniel.
cansande

[chemical]

Notice how Anthem only list their max at 11 and no rms or root mean square average, but JBL is 10.7 max, 2vrms. So, one may assume that anthem could be 2 or it could be 4 or 5 I guess. Doubtful since it isn't listed, though.

Me again.

Caleb Nathaniel
cansande

[chemical]

Also, I wonder if a product like a MiniDSP 2 X 4 HD would boost the signal strength to a higher voltage as well as all the other amazing things that product does for a processor with only 1-3 sub precuts. Emotiva doesn't have to worry about this as much. But, it is interesting how you can connect a sub to several different preamps and after adjusting levels they are much quieter or louder depending on VRMS. I had an old picture tube TV that had a sub pre-out that must have had a very high Voltage because that was the best I ever heard my sub back in the day. Who would have thought. So, I guess the question is, would a signal amplifier do the trick on a 1vrms or would it amplify the distortion at an equal ration. This sounds very likely. But, with a dimmer or amplification control, this may do what we want.

[chemical]

I will shut up for the next 60 seconds.

OK, bye.

[chemical]

I lied.

If there is a more appropriate forum or sub-forum please redirect or let me know where to send this thread.

Caleb Nathaniel
cansande

[405x5]

Dec 20, 2023 3:57:01 GMT -5 chemical said:

Concerning voltage output of preamp outputs (balanced & unbalanced).  A long time ago, I bought an Emotiva XPA-5 gen ( well there was no gen as it was the first XPA-5.  Technically it was gen 1, but only after gen 2 arrived.  

Anyway, I connected it to a Harmon Kardon Receiver that was a pretty solid unit.  However, I contacted Lonnie because I had to really turn up the volume to get any power out of it.  I think it was 200/250 watts times 5.  I was only running 2 channels so it was probably closer to 250/300.  Lonnie immediately told me how the voltage of the RCA preamp outs on my HK could severely limit the signal I was getting.  I hadn't thought of this before.  I did remember in car audio that Kenwood would advertise a true 4 volts rms or vrms to its sub pre-outs.  I noticed some processors today, namely the JBL Synthesis lists the single-ended rca pre's @ 1vrms, 5 max.  And the balanced is listed @ 2VRMS.  For close to 7k, this is surprising as it's listed directly on their website.  I was curious, do we know the voltage rms or max of the SE or balanced XLR output.  If it's 1 volt, I would imagine you would need a DR-3 just to get to XPA-3 sound.  You're basically amplifying a very low signal voltage.  I imagine this would degrade sound and cause all types of issues.  If this has been covered, I am very sorry.  I couldn't find it anywhere.  Hence it is in the stupid question area.  I am also curious about the value represented by the XMC-2, RMC-1L, and RMC-1.  I imagine they are the same on the RMC's since they are both the same circuitry as far as balanced, fully differential on the front 3 channels.  Not sure if it's different on the flagship.  Interesting how these values are often overlooked and yet they are vital as it can make an expensive amp look soft as cottonelle.

Thanks for your patience and understanding with me.  If you are aware of any tech specs, both direct from manufacturer website or from a processor tester like amir or the like, please let me know.  Thanks again.

If the following isn't allowed, just tell me and I will delete or a moderator can fix it according to their rules.  I'm still learning rules.  But, I don't see how this would disparage Emotiva.  Instead, I would like to see it proven that these document enhance the Emotiva brand.

This is from JBL Synthesis concerning their SDP-58  www.jblsynthesis.com/products/electronics/SDP58-.html and here is their voltage claims: 

View Attachment

And from Anthem concerning their AVM-90: products.anthemav.com/avm90/.  Here she is:

View Attachment

Caleb Nathaniel.
cansande

Go here first…… You’re pursuing this issue backwards IMHO

support.harmankardon.com/us/en/?basketContents=&basketUrl=https://www.harmankardon.com/cart&_gl=1*kk7ex0*_ga*MTk4NzU1NDU4NC4xNzAzMDc2OTc2*_ga_Y0LVZT4P2X*MTcwMzA4Mzg1OC4yLjAuMTcwMzA4Mzg1OC4wLjAuMA..

[chemical]

I found the support site, but couldn't find any resources on the issue. I wonder if you are referring to the source materials voltage. Otherwise, I don't know what you mean. I see lonnie made a video on it, but it didn't really clear things up other than to say it was one of the most common question when people buy amps and feel they aren't as powerful as they could be.

[405x5]

Dec 20, 2023 14:13:19 GMT -5 chemical said:

I found the support site, but couldn't find any resources on the issue. I wonder if you are referring to the source materials voltage. Otherwise, I don't know what you mean. I see lonnie made a video on it, but it didn't really clear things up other than to say it was one of the most common question when people buy amps and feel they aren't as powerful as they could be.

You may want to try(as you did with Lonnie) getting live with somebody over at Harmon Kardon. Perhaps, as approaching it, the same way you did on the Emotiva side, they may offer up a solution that would be helpful to you. Pairing that Emotiva amplifier with a different receiver processor might end up being the best solution.

[KeithL]

I'm not quite sure exactly what the question is here... so I'm just going to take the time to clarify a few things...

When you talk about amplifiers there are several related things you'll see mentioned.... maximum power, gain, and sometimes voltage sensitivity.

Here's what you need to understand...

Most modern audio power amps don't have a volume control so they have a FIXED GAIN.
For most modern amp models this will be somewhere between about 28 dB and 32 dB; our current models all have a rated gain of 29 dB.
And, since they all have the same gain, if you put the same voltage into one channel of a BasX A3, or one channel of an XPA-DR2, you will get the same power out.
So, for example, if your BasX A3 is putting out 10 watts, with your particular source and speakers, at a certain volume setting...
And you upgrade to an XPA-DR2, with the same source and speakers, at the same volume setting, you will be getting the same 10 watts...

You will be gaining two things by upgrading to that XPA-DR2:

First, since the XPA-DR2 has a higher maximum power, you will be able to turn the level up further, and get a lot more power out, before it clips.
(Once you pass a certain setting on your preamp, the BasX A3 will start to clip, while the XPA-DR2 will keep getting louder cleanly.)
And, since the gain is the same, you will need to send it a higher level input signal to get it to deliver that higher level output signal.
(Since you will need a higher input level to drive it to full power, its "input level required for full output" will be higher. )

Second, music is very dynamic, which means that it may have very short peaks whose level far exceeds the average level.
This means that, depending on the music, if you're playing something loudly, even though it sounds "OK", it may still be clipping a tiny bit on very short high peaks.
And, if you have a more powerful amplifier, you can prevent this from happening, or you'll be able to turn it up louder before it starts to happen.
This is what we perceive as "the amp sounding a bit congested at high volume levels" when we turn a low-powered amp up really loud.
And why a more powerful amplifier will tend to sound better at high listening levels - even when it is not obviously clipping.
This will vary depending on the sort of music you listen to, how dynamic it is, how efficient your speakers are, and a few other details...
However, in general, if a low-powered amplifier "starts to sound a bit off when you turn it way up", getting a more powerful amplifier will usually fix the problem.
(Note, however, that this sort of limit can also occur with speakers, so you need to take the limits of your speakers into account as well.)

Now there are a few things you should know about gain...

The first is that gain is relatively arbitrary...
In design terms, there are certain tradeoffs between gain and noise, and we chose a gain of 29 dB as being "optimum" based on that.
However, it is NOT specifically true that "more gain is better or worse"... it is simply something that is chosen as part of the design process.

The second related thing is that most modern equipment remains relatively clean up to at least near its maximum output level.
In "the old days", the distortion and noise level on many receivers and preamps would increase significantly at very high Volume settings.
And, in those days, it was "conventional wisdom" that "you wanted to avoid turning the level up too high"...
With a few minor exceptions this is NOT true for most modern equipment...
So, with most modern equipment, it really doesn't matter whether the Volume is set to "-30 dB", or "-10 dB", or "59" ....
And it doesn't matter if, due to the different gains involved, you end up with different Volume settings when you change gear. 
As long as you are able to achieve the Volume setting you want, before the control simply "runs out of range", the exact number setting doesn't matter much.

The last thing I'm going to mention here is "the standard non-standard in consumer audio levels".
There is really no single standard for the level of an unbalanced line level audio signal.
There are several standards... but since they are not widely agreed upon... they aren't very standard.
However, in general, most modern audio gear is designed with the requirements and capabilities of other similar audio gear in mind.
(Most gear really is simply designed to work well with any other gear the designers expect that you might use with it.)
So, for example, the pre-outs on your receiver may be "rated at 1V out" but also rated as having a "maximum output of 3V"....
And one of our bigger amps may be rated as "requiring 2.7V in for full output"...
However, in reality, the requirement of our amp is pretty typical, and the guys who designed that receiver designed it to work with "most typical amps"...
So the pre-out on their receiver probably won't actually have any problem driving our amplifier... or any other "relatively normal modern amplifier"...
(The THD or noise may be a tiny bit higher than at its "rated 1V out"... or they may not... but the difference is unlikely to be audible or significant.)

It's kind of like modern gasoline... almost all modern cars will run on "regular gas"...
And all modern receivers, preamps, or pre-pros will run almost all modern amplifiers just fine...
That's why those specs are often not quoted in detail or not given much priority...
(We almost never encounter receivers that can't run our power amps... even among those whose specs seem to be somewhat insufficient.)

The only place you might have trouble would be running a big amp or powered speaker directly from something like the headphone output of a phone...
In many cases those really are limited and do not actually deliver what we might consider "normal consumer levels".
(But, then, the headphone output of your phone is not intended to, expected to, or designed to, drive a big power amp directly.)