How much gain do I need?

[Eleo]

Hi there. I'm trying to use Rew+RePhase+Eq Apo with my current setup: Amazon Music via laptop=>Topping D50s=>Rotel Rb 1552 (sensitivity 1.5 volts)=>Wharfedale Linton. I have built up several filters and noted that with some of them the music sounds a bit recessed. So I thought to insert a preamp between the D50s and the Rotel in order to raise the level of the signal. Now I'm wondering how much gain do I need. If 6 dbs are enough, I could go with Topping A50s. Otherwise, I could choose the A90. Which is the best choice? See attached my Eq Apo filters. Thanks, eleo

 

[trl]

Hi!

If D50s outputs about 2V RMS and Rotel starts clipping after 1.5V RMS why would you need gain for?

Find a decent preamp (I've seen few Schiit measured here with great results) and keep it in unity gain, even passive is channel imbalance is below 0.5dB.

 

[abdo123]

you're applying a headroom of ~-3 dB so your D50s is outputting anything between 1.5-2 Vrms at 0 dBFS.

it's very likely you're clipping the amp and that's why you think dynamics are lacking.

 

[Eleo]

you're applying a headroom of ~-3 dB so your D50s is outputting anything between 1.5-2 Vrms at 0 dBFS.

it's very likely you're clipping the amp and that's why you think dynamics are lacking.

Thank you! But if the filters lower the signal of - say - 6 dbs, is the D50s still outputting 1.5-2 volts?

 

[abdo123]

Thank you! But if the filters lower the signal of - say - 6 dbs, is the D50s still outputting 1.5-2 volts?

halving of volts reduces the amplitude by 6 dB

so if you put -6 dB pre-gain you will never clip the amplifieri think, as your max output would be 1 Volt and the input sensitivity is 1.5 volts.

 

[trl]

-6 dB will cut the voltage in half from 2V RMS to about 1V RMS, check also http://www.sengpielaudio.com/calculator-db.htm.

 

[Eleo]

thank you!!

 

[digitalfrost]

Can you share a screenshot of the EqAPO configuration editor. What is the estimated peak gain? You should at least make this close to 0, but you can also go over that number. In the bass it will most likely clip in the digital domain, but higher up the frequency range it's not likely to.

 

[Eleo]

Can you share a screenshot of the EqAPO configuration editor. What is the estimated peak gain? You should at least make this close to 0, but you can also go over that number. In the bass it will most likely clip in the digital domain, but higher up the frequency range it's not likely to.

Thank you, here they are, Left and Right channel, current preamp: -2.6 db

 

[sailor2005]

I don't think the issue (music sounding a bit "recessed") has to do with gain. It might be the changes in phase and EQ made in Rephase. But we are only getting just a little bit of information here, namely overall gain but nothing else.

 

[digitalfrost]

So...EqAPO tells me my stuff should be clipping, yet it never clips. I can check with the RME drivers. You could try increasing the preamp gain in EqAPO into the red.

The Wharfdales have a sensitivity of 90dB, I cannot imagine they would not be loud enough with that amplifier. If you have the D50s volume already set at 0dB it is very likely your digital gain is simply too low.

 

[abdo123]

So...EqAPO tells me my stuff should be clipping, yet it never clips. I can check with the RME drivers. You could try increasing the preamp gain in EqAPO into the red.

The Wharfdales have a sensitivity of 90dB, I cannot imagine they would not be loud enough with that amplifier. If you have the D50s volume already set at 0dB it is very likely your digital gain is simply too low.

EQAPO does not show peak gain via it’s convolution engine, you have to figure it out on your own during design or by checking for digital clipping.

 

[Eleo]

Thank you again to you all!