Dx7 pro into purifi 1et400a poweramp

[amper42]

If you were using the RME ADI-2 DAC FS -30db would be much louder as it offers a lot more gain than the Topping dx7pro. With 4V XLR connectors to the Purifi amp I would expect -25dB on the dx7pro to provide sufficient volume. This really isn't a concern, it's just a difference in gain between devices. I would set the dx7pro where it offers sufficient volume and not be too concerned about the number.

 

[Danny247]

If you were using the RME ADI-2 DAC FS -30db would be much louder as it offers a lot more gain than the Topping dx7pro. With 4V XLR connectors to the Purifi amp I would expect -25dB on the dx7pro to provide sufficient volume. This really isn't a concern, it's just a difference in gain between devices. I would set the dx7pro where it offers sufficient volume and not be too concerned about the number.

Thank you, its what I needed to hear

I was looking at the RME adi-2 but the price difference didn't seem worth it for the marginal gains, I may purchase it in the future.

I did see in a previous message on this thread that 1.5v is enough to produce full volume so either rca or xlr should be sufficient from the dx7pro, what would the advantages be at a higher voltage from the RME?

 

[amper42]

Thank you, its what I needed to hear

I was looking at the RME adi-2 but the price difference didn't seem worth it for the marginal gains, I may purchase it in the future.

I did see in a previous message on this thread that 1.5v is enough to produce full volume so either rca or xlr should be sufficient from the dx7pro, what would the advantages be at a higher voltage from the RME?

The RME would allow you to achieve higher volumes at about 5db less on the volume control than the Topping. It's just a gain difference. That's not a big deal. The sound will reach the same levels on the dx7pro. You just need to have it turned up about 5db higher for the same volume. The real advantage of the ADI-2 is built-in EQ and loudness control plus a better remote. But I'm sure you will be happy with the Topping as well.

 

[MaxwellsEq]

Yes it's very loud, but I would expect it to be very loud @ -60dB if it's as powerful as advertised, just thought I maybe doing something wrong

Like running a car that car do 200mph but cant use it for that 99% of the time but nice to know its available

Unfortunately, I think you are confused. The number (i.e. -30), is just information about how much you have attenuated (reduced) the signal from the normal output of 0. Original DACs didn't have attenuators, were always at 0, so had to be fed into preamplifiers to manage the level. At -3dB your DAC is totally unfussed. It's not running out of headroom or anything like that (power amps can have headroom issues).

In other words, you have a total non-problem.

 

[Danny247]

Unfortunately, I think you are confused. The number (i.e. -30), is just information about how much you have attenuated (reduced) the signal from the normal output of 0. Original DACs didn't have attenuators, were always at 0, so had to be fed into preamplifiers to manage the level. At -3dB your DAC is totally unfussed. It's not running out of headroom or anything like that (power amps can have headroom issues).

In other words, you have a total non-problem.

OK thanks, that makes sense for the dac/preamp, so 0db is the full 4v and anything less is all good.

But for the power amp if the gain on the modules is set lower does it mean it hasn't got the extra headroom available, like running at half power? Why not set it to high gain (if available) and know the power us there if needed

 

[MaxwellsEq]

OK thanks, that makes sense for the dac/preamp, so 0db is the full 4v and anything less is all good.

But for the power amp if the gain on the modules is set lower does it mean it hasn't got the extra headroom available, like running at half power? Why not set it to high gain (if available) and know the power us there if needed

Well.... Headroom is not well defined. What it means to many people is that if the music has a sudden increase, the amplifier can easily respond and can quickly recover if there was a musical impulse. For you to be confident this can happen, you need more power "in hand" than you need normally.

If your power amplifier has low gain, that can mean that your DAC may need to be close to 0dB (totally fine, remember) to make the speakers go very loud, than if it has higher gain. It doesn't mean, necessarily that it won't have enough headroom.

Imagine you had a 2000W amplifier with 2dB of gain - you might not get more than a few Watts out of it with the DAC at 0dB! Your "headroom" (power amp capability left in-hand) would be massive but the sound would be quiet. Imagine a 2W amplifier with 100dB of gain, you probably wouldn't get above -70dB on the DAC before you had run completely out of power amp capability and have no "headroom" but the sound might be quite loud if distorted.

 

[Danny247]

Well.... Headroom is not well defined. What it means to many people is that if the music has a sudden increase, the amplifier can easily respond and can quickly recover if there was a musical impulse. For you to be confident this can happen, you need more power "in hand" than you need normally.

If your power amplifier has low gain, that can mean that your DAC may need to be close to 0dB (totally fine, remember) to make the speakers go very loud, than if it has higher gain. It doesn't mean, necessarily that it won't have enough headroom.

Imagine you had a 2000W amplifier with 2dB of gain - you might not get more than a few Watts out of it with the DAC at 0dB! Your "headroom" (power amp capability left in-hand) would be massive but the sound would be quiet. Imagine a 2W amplifier with 100dB of gain, you probably wouldn't get above -70dB on the DAC before you had run completely out of power amp capability and have no "headroom" but the sound might be quite loud if distorted.

Thank for your complete explanation, I will still try and find out if the bufferboards have different gain setting to satisfy my curiosity