Dayton MA1240a Manuel D’Utilisation

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While the MA1240a has been designed to minimize the possibility 
of hum in the audio system, it is still possible that a hum will oc-
cur in rare circumstances. Its safety grounding can create a path 
for small amounts of 60 Hz energy to travel through the line-level 
audio system. Although not dangerous, this energy can cause 
diffi culty with the auto signal sensing circuit, and at the very least 
will interfere with the quiet enjoyment of your system. The fi rst 
course of action should be trying to make sure that all of the audio 
components are connected to either the same electrical outlet, or 
at least into the same circuit branch. Next, cable TV systems are 
notoriously the culprit, so be sure to try disconnecting all coaxial 
feeds that are connected to the system. If this solves the problem, 
install a coaxial line isolator and reconnect the system. In the very 
worst case, a line-level audio isolator/transformer connected to the 
line-in of the amplifi er will usually solve the problem.

To reduce the risk of electric shock, do not remove cover. No user serviceable parts inside. Refer 
servicing to qualifi ed personnel. To reduce the risk of fi re and shock do not expose unit to rain or 
moisture. The unit should be connected to an earth grounded AC electrical socket. The unit should 
be operated in a well ventilated area.  Minimum clearance is 2 inches from the ventilation openings.

Note: Unit is set at the factory for 120V operation. Be sure to change the fuse (4A rating) before 
switching to 230V operation.

© Dayton Audio

®

Last Revised:  1/7/2015

tel + 937.743.8248

info@daytonaudio.com

705 Pleasant Valley Dr.

Springboro, OH 45066 

USA

Dayton Audio products are constructed by industry experts, and are thoroughly tested before shipment.  Dayton Audio products are warranted for the period of one 

year.  This warranty is limited to manufacturer defects, either in materials or workmanship.  Dayton Audio is not responsible for any consequential on inconsequential 

damage to any other unit or component or the cost for installation or extraction of any component of the audio system.  In the rare case of a product failure, please 

contact your place of purchase or call our Customer Support Department at (937) 743-8248.

There are no other warranties, either express or implied, which extend the foregoing, and there are no warranties of merchantability or fi tness for any particular 

purpose.  The warranty will not cover  incidental or consequential damage due to defective or improper use of products.  This includes but is not limited to burnt 

voice coils, overheating, bent frames, holes in the cone, or broken lead wires.
This warranty gives you specifi c legal rights and you may also have other rights which vary from state to state.
Non-Warranty Service:  If non-warranty service is required, the product may be sent to the Company for repair/replacement, transportation prepaid, by calling (937) 743-8248 

for details, complete instructions, and service fee charges.

Rated Power Output:  

40 watts per channel RMS at 8 ohms 

80 watts per channel RMS at 8 ohms 

 

(8 ohm minimum)

Input Sensitivity: 

380 mV for full output with all level controls at max.

Input Impedance: 

18K ohm

5 Hz to 72 kHz

.005% THD 20 Hz-20 kHz @ 30W (8 ohm)

.010% THD 20 Hz-20 kHz @ 80W (8 ohm)

80 dB

Signal to Noise Ratio: 

105 dB A-weighted

Effi ciency: 63%
Power Requirements: 

115/230 VAC, 60 Hz/50 Hz

Stand-By Power Rating:  115V, 0.264W *
Auto Turn-On Sensitivity:  13.7mV
Dimensions: 

16.7” W x 4” H (including feet) x 14.25” D 

 

33 lbs.