[Welborne]

Hi Jason, can you tell me if the led volume level indicator is to be trusted with abosolute accuracy?

I am using the Nuforce ia-7 v2 integrated to drive my fullrange speaker on open baffle (running fullrange, no active xover), and using the pre-out ---> dbx active crossover ----> another class-d for driving the 18" woofer. I have hard time in matching the input gain sensitivity of the bass amp with the Nuforce as an integrated amp. I can't get enough bass volume even i have the volume on both of my dbx e-xover and the woofer class-d ALL THE WAY UP, i can't get louder.

The only solution I could think of is to add a passive master volume at the very front and use that to output two separate signals, one to Nuforce and one to the active crossover and not using Nuforce's own pre-out. But this way I rely quite heavily on how accurately the IA-7 's volume indicator is. The manual says they go from -70db to +30db, but this is only indicated by 4 led levels. I need to get an accurate volume matching between woofer amp and the Nuforce,

Can you offer some solution (except switching to another woofer amp..)

[rustydoglim]

The 4 LEDs are very rough indicator and mainly as a guideline (can also be used with the remote to jump from one volume level to another). You can't get enough volume because the IA-7V2 pre-out is volume controlled. If you turn it up, then your IA-7V2 amp output becomes too loud.
Why don't you just use a Y cable to split the source?

[Welborne]

The 4 LEDs are very rough indicator and mainly as a guideline (can also be used with the remote to jump from one volume level to another). You can't get enough volume because the IA-7V2 pre-out is volume controlled. If you turn it up, then your IA-7V2 amp output becomes too loud.
Why don't you just use a Y cable to split the source?

I am thinking about this last solution, but i still need a master volume to control both the nuforce ---> mid+high driver, and the active crossover ---> class-d ----> 18" woofer. The problem seems to be that i have some problem fixing the Nuforce's volume at certain level all the time simply due to lack of number or making on the NF's volume control, unlike the P-9 which has a "db" level in number

[rustydoglim]

The Nuforce IA-7V2 has memory retention feature. If you set to a certain volume you like and turn it off using the remote control  (or volume knob), the volume setting will be memorized. Don't turn it off using the power switch at the back.

[neutralos]

@welborne, if I have understood right - the main problem is to control two separate volume gains.
I think this must be special master control which can learn. We have two different amps which act
different by rising the main gain step by step. If such a master volume control exists I don?t know and usually an active sub means every time a foreign substance in an audio system.

Why don?t you forget the sub amp ?? Use just the Nuforce with matching cables.
Or better:

@Jason, why you don?t recommend two of the Ref 9 V2 ??? aa
Make him a special offer in dealing with his IA-7 V2 ...

[Welborne]

@welborne, if I have understood right - the main problem is to control two separate volume gains.
I think this must be special master control which can learn. We have two different amps which act
different by rising the main gain step by step. If such a master volume control exists I don?t know and usually an active sub means every time a foreign substance in an audio system.

Why don?t you forget the sub amp ?? Use just the Nuforce with matching cables.
Or better:

@Jason, why you don?t recommend two of the Ref 9 V2 ??? aa
Make him a special offer in dealing with his IA-7 V2 ...

Neutralos, in deed I am tempted to own ref.9 v2/v3 one day soon after tasting the IA-7 v2. This is the only brand of class-d/class-ab/even many tube push-pull or singled ended that has a high frequency delicacy reminding me of that of the flea power triode like 45, VT25, monoplate 2a3...I wonder how much better the ref 8 or even ref 9 would be..my goodness

[neutralos]

I think you have too much audio gear to be happy with that situation - at least me couldn?t be happy. I read very good items in your listed collection but try to reduce it to one system. Often means less is more as like in germany people are saying.

[Welborne]

I think you have too much audio gear to be happy with that situation - at least me couldn?t be happy. I read very good items in your listed collection but try to reduce it to one system. Often means less is more as like in germany people are saying.

  you know, i have got rid of most of my stuff already, i use to have more speaker drivers lying around, on shelves etc, and now only the open baffle with the 18" subwoofer.  I do need two amps however, one to drive the fullrange on top and the other to drive the 18" woofer separately. After dealing with active crossover for bass, it is almost impossible for me to go back to a passive crossover. True I need one more amp for the woofer but i i can get rid of many passive components like resistive inductor coil, caps, resistors etc in the crossover. No exotic inductor coil, no matter how expensive they are, can beat an electronic crossover + amp directly coupled to the bass driver in terms of speed and resolution.

[Welborne]

btw, off topic a bit, is it safe (for the amp's life) to leave the IA-7 v2 in standby mode all the time when i finish listening? And sometimes leave it like that for a few days?

[neutralos]

btw, off topic a bit, is it safe (for the amp's life) to leave the IA-7 v2 in standby mode all the time when i finish listening? And sometimes leave it like that for a few days?

I noticed that the amp gets hot even then when no music is playing. So I decided to switch it off over the vol. knob. Further then you don?t hear the typical background radio frequencies out from the speakers.
It?s really a bit disturbing when you don?t listen to music.

[rustydoglim]

If the amp is first powered up, it will be in an unknown state:
http://www.nuforce.com/faq-startup-noise.htm
It is ok to leave it on for days after you listened to some music. But at idle, it still consumes 15W per amp module so it is like leaving a small light on at all time.

[Welborne]

If the amp is first powered up, it will be in an unknown state:
http://www.nuforce.com/faq-startup-noise.htm
It is ok to leave it on for days after you listened to some music. But at idle, it still consumes 15W per amp module so it is like leaving a small light on at all time.

another reason for asking about leaving the amp in standby mode is that the amp sounds much better after 2-3 hours of use and when the top plate is rather warm/hot. I belive mosfet is used inside, and i was told by a few diyer that mosfet only start to sound good when they are hot.

[Taosman]

Jason, I want to bi-amp my IA-7. Or try another amp.
How much gain does the pre-amp portion of the IA-7 produce?
Thanks!

[rustydoglim]

Should be the same as P-8S, 8V RMS on the preamp out (have to reconfigure one of the inputs)