Help a brother out, Amp question

[bmwr75]

@Shayne (sorry for the @OP reference previously), where the volume knob is set on your new Emotiva rig means nothing really.  What does matter is that you don't run out of volume knob before you reach the sound pressure level that you desire.

What @SD was eluding to earlier is that it takes twice as much power to increase sound pressure level +3 dB.  For example, your Magnepan 1.6s are 86 dB efficient (assuming this is 1watt/1meter measured), which means:

1 watt = 86 dB sound pressure level
2 watt = 89 dB
4 watt = 92 dB
8 watt = 95 dB
16 watt = 98 dB
32 watt = 101 dB
64 watt = 104 dB
128 watt = 107 dB
256 watt = 110 dB
512 watt = 113 dB

However, the link below says the 86 dB efficiency rating is not at one watt, but rather 2.83 watts, which means the sound pressure scale above is overstated and your speakers would top out at about 106 dB at 300 WPC RMS, the XPA-2 amp rating.

http://www.magnepan.com/review_MG16_by_Johnathan_Valin

[Shayne]

@SD - take breath bud.....you are going to pass out!!  Think I read this thread closely......and see no mention of a Pioneer preamp anywhere.  Did I miss this?

@OP -  there is no such thing as an Emotiva USP-2 preamp (per a Google search).  Maybe that is the problem.  Please list the actual Emotiva preamp and amp models you purchased.  I'm an Emotiva fan and own an XPA-2 amp and XDA-1 dac.

There is no Pioneer gear anywhere in the equation. My bad on the Emotiva model number. For some reason I get the Emotiva model numbers mixed up. USP-1 is the preamp. It's the only 2 channel pre they make. The amp is the XPA-2. With the addition of the tube phono pre, i'm really happy with this setup. Even the fact that the Yaqin phono pre is relatively inexpensive, the built quality seems good and everything about the sound is better. I'm quite surprised. After reading the responses here and talking to some folks it's relieved my concern about the preamp gain situation.

So officially i'm running a Pro-Ject Xpression III table with an AT440mla cart. into a Yaqin Ms22b phono pre, then to the aux 1 input of the Emotiva USP-1, out to the XPA-2 and out to the Magnepan 1.6's. Also, the USP-1 sub out to my Serpent Sound sealed 12" sub which seems to be blending in pretty well set at around the 45hz mark. Everything sounds fantastic. It looks like total shit right now with cables running everywhere and the amp just setting on a piece of plywood on the floor but it sounds great. I'll work on aesthetics later. The only tweaks i'm going to make are speaker placement and some tube rolling in the pre. I'll upload a pic once everything is looking a little better.

[SunnyDaze]

Wow. I completely confused you with Steve.

Sorry man.

[bmwr75]

@shayne - you should have no gain problems with that set up!!  The XPA-2 is a beast.

[bmwr75]

@shayne - you AT440mla phono cartridge is a moving magnet type.  The USP-1 preamp has one phono input, but a switch that selects MM (moving magnet) or MC (moving coil) type cartridge.  MMs are typically high output and MCs typically low output.

Since the addition of an external tube phono preamp connected to an AUX input solved the problem, you might try the phono input again and make sure the switch is set to MM.

[bmwr75]

I should have said try the phono input directly from the turntable (no tube phono preamp).

[Shayne]

I definitely checked to make sure the MM switch was selected when I was using the on-board phono. Still very low output. I had considered using the MC setting but figured it probably over-amplify the signal and cause distortion.