Possible to increase RCA output?

[Xcaliber]

Received my new IOM i250 today to power the Polk R200, this amp built like a tank and super excited, currently have it connected to my Denon X1800h main preout, the AVR sort of act like the "preamp" for volume control and I'm using it to decode DTS for movies and to power the surround speakers. Only thing is....the RCA preout from the Denon is a bit of a weak sauce, I had to set the gain (volume) quite high on the i250.

Neither the Denon or the i250 have XLR so what's my best option to increase the preout signal/voltage from my Denon? I tried the Fosi P1 briefly but do not like the faux tube sound, seems to have too much coloration and distortion. I don't need headphone and never use them, just need some sort of RCA amplifier to boost the signal or voltage without introducing load of distortion or noise, I believe these Hypex NC252MP could take up to 4v input.

 

[staticV3]

Neither the Denon or the i250 have XLR so what's my best option to increase the preout signal/voltage from my Denon?

The JDS Atom Amp 2 or Topping L30II can function as high quality preamps to amplify your Denon's preout by up to 13.5 and 16.5dB, respectively.

Yes, they have headphone Amps built-in as well which you don't need.
It is what it is.

 

[DVDdoug]

Only thing is....the RCA preout from the Denon is a bit of a weak sauce, I had to set the gain (volume) quite high on the i250.

What's wrong with that? Usually a volume control is an attenuator so it doesn't make sense to add additional amplification and then attenuate.

 

[Xcaliber]

What's wrong with that? Usually a volume control is an attenuator so it doesn't make sense to add additional amplification and then attenuate.

The issue is, even when the i250 at max, i still have to crank up the Denon's volume way higher than I like, and by doing so, it also ramped up the surround's volume (which i had already set them manually at -12dB, can't go lower) unless i completely disable the surrounds, another problem is, i am not able to utilize the full potential of the amp, leaving a lot of power on the table being untapped since the preout input signal from the denon is too low.

 

[Chrispy]

What pre out on a Denon X 1800? was my first thought, but went looking and wow finally a lower than X3xxx series with a pre-out! Well, L/R at least. Did you run Audyssey to set levels among the various channels and external amp?

 

[radix]

What pre out on a Denon X 1800? was my first thought, but went looking and wow finally a lower than X3xxx series with a pre-out! Well, L/R at least. Did you run Audyssey to set levels among the various channels and external amp?

I've not used the X1800, but other models have a per-channel gain control in the software. But I'd just re-run Audyssey with the amp volume control at full.

EDIT: I meant to say I agree with @Chrispy but pressed submit too soon.

 

[Chrispy]

I've not used the X1800, but other models have a per-channel gain control in the software. But I'd just re-run Audyssey with the amp volume control at full.

EDIT: I meant to say I agree with @Chrispy but pressed submit too soon.

I meant to also ask if levels with various channels (using external amp) were set not just with Audyssey, as manually is another option. Depends on the amp whether I'd want any attenuation....but if boost is the question then yes maximize gain on the amp end.

 

[Xcaliber]

What pre out on a Denon X 1800? was my first thought, but went looking and wow finally a lower than X3xxx series with a pre-out! Well, L/R at least. Did you run Audyssey to set levels among the various channels and external amp?

I know right? the next model up x2800h don't have preout either, just really weird how Denon gave one set of preout on lowest model but nothing for the next step up model, the catch is...only the US model x1800h have the main L/R preout, apparently the EU edition don't have it. (see pictures below)

I set all parameters manually, maybe I should try running the Audyssey again as you've suggested, would be great if I don't have to add another device in the chain.

US x1800h model

EU x1800h model

 

[Chrispy]

I know right? the next model up x2800h don't have preout either, just really weird how Denon gave one set of preout on lowest model but nothing for the next step up model, the catch is...only the US model x1800h have the main L/R preout, apparently the EU edition don't have it. (see pictures below)

I set all parameters manually, maybe I should try running the Audyssey again as you've suggested, would be great if I don't have to add another device in the chain.

US x1800h model
View attachment 358020

EU x1800h model
View attachment 358019

How did you do it manually?

 

[dasdoing]

i still have to crank up the Denon's volume way higher than I like

like Doug said, it makes no sense. unless you hit full open and still want more it doesn't matter where the dial is

 

[restorer-john]

The issue is, even when the i250 at max, i still have to crank up the Denon's volume way higher than I like, and by doing so, it also ramped up the surround's volume (which i had already set them manually at -12dB, can't go lower) unless i completely disable the surrounds, another problem is, i am not able to utilize the full potential of the amp, leaving a lot of power on the table being untapped since the preout input signal from the denon is too low.

Isn't it a Hypex NC-252MP in a box?

The default gain is around 25.5dB with the onboard buffer active.

New boards allow for the gain stage to be bypassed- what is the rated gain of your amplifier from the manufacturer?

Even with the buffer active, it's a bout 4-5dB lower than what you'd be used to.

There's likely a few resistors you could change to higher values (in the FB loop of the opamp) in the front end gain stage to make the amplifier more sensitive.

 

[Xcaliber]

How did you do it manually?

Setup Menu / Speakers / Manual Setup / Levels/ Test Tone Start, and you'll get the menu to setup the dB level on each speaker individually, from -12dB to +12dB.

Isn't it a Hypex NC-252MP in a box?

The default gain is around 25.5dB with the onboard buffer active.

New boards allow for the gain stage to be bypassed- what is the rated gain of your amplifier from the manufacturer?

View attachment 358023

Even with the buffer active, it's a bout 4-5dB lower than what you'd be used to.

There's likely a few resistors you could change to higher values (in the FB loop of the opamp) in the front end gain stage to make the amplifier more sensitive.

Yes sir, it's a Hypex NC252MP. I'm still trying to find out what is the preout gain from this x1800h but haven't found any voltage rating of it yet, i probably should hit up Sipko to see if there's any way I could set it to a higher gain on the board, I don't recall seeing any adjustable gain on these NC252MP, but I know the NCx500, 1ET400A, and Nilai500 all have adjustable variable gain setting on the board, while Apollon and Buckeye, Nord, and few other assemblers have their own buffer stage along with routing the gain settings to the back (or bottom) of the amp to make them more user friendly.


This is the innert of the same i250 but in black casing.

Kinda wish I went with the 1ET400A or NCx500 now, they both have adjustable/variable gain.....

 

[Chrispy]

Setup Menu / Speakers / Manual Setup / Levels/ Test Tone Start, and you'll get the menu to setup the dB level on each speaker individually, from -12dB to +12dB.



Yes sir, it's a Hypex NC252MP. I'm still trying to find out what is the preout gain from this x1800h but haven't found any voltage rating of it yet, i probably should hit up Sipko to see if there's any way I could set it to a higher gain on the board, I don't recall seeing any adjustable gain on these NC252MP, but I know the NCx500, 1ET400A, and Nilai500 all have adjustable variable gain setting on the board, while Apollon and Buckeye, Nord, and few other assemblers have their own buffer stage along with routing the gain settings to the back (or bottom) of the amp to make them more user friendly.


This is the innert of the same i250 but in black casing.

View attachment 358027

Doesn't answer my question.

 

[Xcaliber]

Doesn't answer my question.

your question was how i manually set it up, and this is where i went to change the Front L and R to max +12dB, and set the surround to the lowest possible -12dB. Audyssey is kinda lackluster, they had my surrounds tuned wayyy too loud completely overpowered the front, so i had to set everything manually and this is where i left it currently.

 

[Xcaliber]

like Doug said, it makes no sense. unless you hit full open and still want more it doesn't matter where the dial is

I guess it's one of those thing where I'm simply not used to having to crank up the Denon volume to 60~70 out of 98 with an external amp at MAX gain.


On a side note, can't say i hear any sound quality difference between the Denon's internal amp vs. the NC252MP. Using the Fosi P1 in between them however, added some very noticeable and audible distortion, along with undesirable color.

 

[radix]

I went over the online manual, and they actually do not show the L/R PRE-OUT at all. The picture in the manual only shows sub outs. I did not see them in the text anywhere.

AVR-X1800H

manuals.denon.com

I wonder if they are really supported? Seems wierd.

 

[Xcaliber]

I went over the online manual, and they actually do not show the L/R PRE-OUT at all. The picture in the manual only shows sub outs. I did not see them in the text anywhere.

AVR-X1800H

manuals.denon.com

I wonder if they are really supported? Seems wierd.

You see the "eu" in your link? that's why...all European edition of this amp do not have any L/R pre-out.

Try this link for US edition: https://manuals.denon.com/AVRX1800H/NA/EN/DRDZSYqibytsvl.php

Only the NA (North America) x1800h have the preout, two sets actually, one set for L/R, and another set for Zone2

 

[Xcaliber]

This is the back of my x1800h.

While the predecessor x1700h (the x1800h supposed to replace it) do not have any L/R RCA pre-out either:

Rear panel AVR-X1700H

manuals.denon.com

 

[Chrispy]

your question was how i manually set it up, and this is where i went to change the Front L and R to max +12dB, and set the surround to the lowest possible -12dB. Audyssey is kinda lackluster, they had my surrounds tuned wayyy too loud completely overpowered the front, so i had to set everything manually and this is where i left it currently.

View attachment 358030

Well that's one way, not a very good way, tho. Usually one uses an spl meter to match levels....then tweak. I'd rerun Audyssey and get the $20 Audyssey MultEQ Editor App

 

[Xcaliber]

Well that's one way, not a very good way, tho. Usually one uses an spl meter to match levels....then tweak. I'd rerun Audyssey and get the $20 Audyssey MultEQ Editor App

I don't trust Audyssey, I use REW + Umik1 that i could check for SPL level for either individual speaker or in pair once i got the level dialed in, along with FR sweep, etc. But I have better result to set everything manually, if there's peak and valley in the FR I would try to EQ them out if it bothers me enough, or when absolutely necessary. For whatever reason Audyssey always ramp up my surrounds and end up overpowering the fronts.


The sweep below was when i was playing with REW and tried to compare different crossover setting for the R200 just to see how they would affect the rest of the FR