Recommend a budget amp with low gain?

[Bur05XP]

Forgive me if this is the wrong place or has already been discussed here and I have not found it yet. I am building Titans (99db) and my current speakers are also 99db DIYSG speakers. I use a Denon AVR with Emotiva-A300 currently. My listening levels are stupid low, an AVR would suffice, but I am going to run the Titans full range and would prefer to continue with external amp.

My issue is I sit 10 feet away and Audyssey sets my channel levels to -12db (max value), so it can not calibrate correctly. I am wondering if there are a few known lower gain amps available that I've not discovered? The mainstream ones I know, Emotiva, Outlaw etc all have 29db gains. Just saw Buckeye with lower gain, but seem XLR input only and I do require RCA input.

 

[staticV3]

Some options:

-Audiophonics MPA-S125NC RCA (400€)
26dB gain OOTB, but can be modified to 12dB by removing some SMD resistors (see Hypex datasheet)

-Schiit Rekkr ($150)
12dB gain OOTB

-Schiit Gjallahorn ($300)
20dB gain

-Nord Value-Line MP NC122 (£320)
Same deal as the Audiophonics

-Neurochrome Modulus-86 ($400?)
20dB gain

 

[Bur05XP]

Thank you. That MPA-S125NC looks very promising.

 

[staticV3]

Thank you. That MPA-S125NC looks very promising.

They might be willing to do the modification to bypass the buffer for you. Best to ask them via email.

 

[Bur05XP]

Please correct me if I am wrong with some key specs below. On paper, 32w into the Titans is 114db which is ridiculous for me, however, the Titan is an 18" driver with 8" mid-range and compression driver. An Emotiva BasX A2 weighs about 25 pounds, average for a budget stereo amp I'd say. The MPA-S125NC weighs less than 3 pounds. Am I putting too much emphasis on weight? Will it be able to sufficiently drive the Titans with 1-4watts? I know bass takes a lot of power, I have multiple 15" subs with crown xls amps.

Emotiva A2
160 watts RMS per channel; 20 Hz – 20 kHz; THD < 0.1%; into 8 Ohms
250 watts RMS per channel; 1 kHz; THD < 1%; into 4 Ohms.
112 dB; ref rated power; (A-weighted)

MPA-S125NC
2x 37W 8Ω @ 10Hz-20kHz THD=0.0015%
2x125W 4Ω @1Khz THD=1%
SNR 118dB

 

[staticV3]

An Emotiva BasX A2 weighs about 25 pounds, average for a budget stereo amp I'd say. The MPA-S125NC weighs less than 3 pounds. Am I putting too much emphasis on weight?

Yes.

Will it be able to sufficiently drive the Titans with 1-4watts?

Easily.

I know bass takes a lot of power,

But you're looking for just 1-4watts?

 

[Bur05XP]

Yes, I would think so, on paper. I guess ingrained that explosions etc will require impulses of higher wattages beyond what that amp might be capable of, even with average listening volumes at my couch around 75-85db.

One other question if you would not mind assisting me with. I do not understand much what this is saying. I will be using Roku connected to my TV with audio returning to my AVR via HDMI ARC. All of my theater equipment starts from being plugged into an Emotiva CMX (DC Offset Eliminator) which was recommended to me for bad house ground/hum whether snake oil or not. Just want to be positive about this DC free message on the product page.

"This amplifier is DC pass-through , there are no decoupling capacitors at the input.
Be sure that your source is DC free before use."

 

[staticV3]

One other question if you would not mind assisting me with. I do not understand much what this is saying. I will be using Roku connected to my TV with audio returning to my AVR via HDMI ARC. All of my theater equipment starts from being plugged into an Emotiva CMX (DC Offset Eliminator) which was recommended to me for bad house ground/hum whether snake oil or not. Just want to be positive about this DC free message on the product page.

"This amplifier is DC pass-through , there are no decoupling capacitors at the input.
Be sure that your source is DC free before use."

What is the question?

 

[NTK]

Yes, I would think so, on paper. I guess ingrained that explosions etc will require impulses of higher wattages beyond what that amp might be capable of, even with average listening volumes at my couch around 75-85db.

One other question if you would not mind assisting me with. I do not understand much what this is saying. I will be using Roku connected to my TV with audio returning to my AVR via HDMI ARC. All of my theater equipment starts from being plugged into an Emotiva CMX (DC Offset Eliminator) which was recommended to me for bad house ground/hum whether snake oil or not. Just want to be positive about this DC free message on the product page.

The Emotiva CMX is to eliminate the DC offset in your house AC supply. This DC offset can cause problems with the transformer in the amplifier power supply.

"This amplifier is DC pass-through , there are no decoupling capacitors at the input.
Be sure that your source is DC free before use."

The DC in your house AC supply the Emotiva CMX is removing has nothing to do with DC in the signal feeding into your amplifier. DC in the signal feeding into your amplifier (if your signal has it) is a separate problem.

 

[Bur05XP]

Sorry, the question was how do I know if I have DC from the source? Do I, would I, from AVR pre out RCA to this amp? And secondary supplying gear setup to see if the CMX was already taking care of that, as it appears that's not the purpose of that particular device - thanks NTK. So now I need to determine/measure if there is DC. I know an electrician, so I will ask him to stop by when he can.

 

[NTK]

Assuming you don't have access to an oscilloscope or a suitable ADC, this is what I would try.

1. Remove the speaker grill. With the amplifier powered down, carefully note the position of the woofer cone.
2. Power up the amplifier and the rest of your setup, with everything in idle, see if the position of the woofer cone has shifted. If you have a multimeter (DMM), you can also measure if there is any DC voltage across the speaker terminals. Measuring with a DMM is much more sensitive than visual inspection.
3. Just in case your setup implements an idle mode, they may behave differently when there is an active signal. To defeat the idle mode, play a very weak (e.g. -60 dBFS or lower) tone at a high frequency above the woofer cross-over, e.g. 10 kHz, and repeat step 2. However, if measuring with a DMM, the high frequency tone may affect the readings.

If you don't detect any woofer cone position change, or measure any significant DC voltage (<< 0.1 V) across the speaker terminals, you shouldn't have a significant DC problem inherent in your setup.

To prevent any DC or infrasound in your source contents from affecting your speakers, you can use EQ and add a high-pass filter with a cutoff a little lower than the roll off frequency of your woofer. If you are using bass management (e.g. Audyssey), it will automatically take care of the DC and infrasound in your source for your main speakers.

 

[Bur05XP]

Sounds complicated. I am hoping my electrician bud will be able to understand and assist. The AVR is a Denon with Audyssey and I will be running that process after I use REW to best align my multiple subs and adjust MiniDSP 2x4HD first.

Additional question about these two units regarding their input sensitivity. I believe Denon AVR can output from pre-out RCA up to 1.2V which looks much closer to the Audiophonics spec. I believe I know the AVR does not put out constant voltage, volume control and source content determine. But does this mean the gain will be lower on the NORD with all else equal, same volume (IE -30db) on the Denon? They are equally priced in USD and appear equally spec'd if NORD's 2 x 75Wrms 8 Ohms is the same @ 1kHz instead of 20Hz-20kHz. Just trying to see how these stack up against my current amp as well. With their SNR they are not providing the same metrics either that I can tell, if their 118db rating is 1 watt then they best the Emotiva.

MPA-S125NC
125W 4ohm @ 1.17V RMS
(Gain 25.5db listed separately)

NORD VALUE-LINE MP NC122
26dB Voltage Gain Input Sensitivity 2.3Vrms

(Current) Emotiva A-300
150 watts RMS per channel; 20 Hz - 20 kHz; THD < 0.1%; into 8 Ohms
300 watts RMS per channel; 1 kHz; THD < 1%; into 4 Ohms
Input Sensitivity (for rated power; 8Ohm load): 1.2 V.
Gain: 29 dB.
Signal to Noise Ratio (8 Ohm load)
> 120 dB (A-weighted); ref rated power.
> 100 dB (A-weighted); ref 1 watt.

 

[Bur05XP]

It does not appear I needed a new amp. Built the Titans and ran Audyssey which set the trims around -5 to -6 db with the same Emotiva, instead of -12 db with previous speakers.

I do need help with another issue. I use the subwoofer pre out to a MiniDSP HD and then 4 outputs to channels of Crown XLS 1502 amps. I use the .775Vrms input option which states -6dB lower SINAD so 97 dB. My gain knobs for 72dB are usually around 11-1 o'clock. The other setting is 1.4 V for 103dB SINAD.

Considering switching to QSC DCA 1622 with input sensitivity at 4Ω is 1.1 Vrms and SINAD 107 dB. I do hear a feint whine through my subs at idle (noise floor?), so hoping this would help. I beleive the AVR is 1.2 Vrms output so I should be able to drive this to full power, just might need to turn the gain knobs up higher for 72-75dB??