1. Can the Trends Audio TA-10.1 be bridges so that one amp is used
  for each channel?

If you want to use two TA 10.1 you need biwireable speakers so you can connect 
 one TA 10.1 per speaker or one to the bass range posts and one to the 
 high range posts (vertical or horizontal bi-amping). This way power output and
 overall dynamics will increase. Don't forget you can bypass the volume pot 
 via an internal jumper (so the TA 10.1 becomes a pure power amp by all means). 
 Please go to Support to download the document.

2. Which speakers do you recommend with the Trends TA-10 amp. ? 

There are various of speakers suitable for Trends TA-10 no matter bookshelf
 or floor stand speakers. But, since the output power of Trends TA-10 is only 2x15W, 
 it'd better to choose some higher sensitivity speakers, e.g. >87dB. For the impendence, 
 from 4 ohm to 16 ohm is ok. But, 6-8 ohm would be a little bit better.

3. Can I connect my subwoofer to the speaker terminals of this amp ?

Yes, you can connect your passive subwoofer to TA-10 as 2.1 channels in the following 
 conventions: besides the left & right channels connected, connect the +ve of subwoofer
 to TA-10's left +ve terminal and -ve of subwoofer to TA-10's right -ve terminal. 
 But, it is highly recommended to match the speaker’s impedance such that the subwoofer 
 is about half the impedance of the left/right speakers, e.g. 4ohm subwoofer & 8ohm L/R 

4. Can I use an AC adaptor 13,8V 7A for two Trends TA-10 amps ? 

It is ok to use an adaptor 13.8V 7A for two TA-10. But, two 13.8V 3.5A should be better
 (less interference). Beware that the voltage is too high. It is not recommend 
 using power supply up to 14V. So, you should ensure your supply is 13.8V 
 (not higher actually).Specifications

 T-Amp IC  Tripath TA2024 
 Output Power  2 x 15W @ 4ohm
 2 x 10W @ 8ohm 
 Signal-to-Noise Ratio (SNR)  98dB 
 Dynamic Range  98dB 
 IHF-IM Distortion  0.10% @ 1W, 4ohm 
 THD+Noise  "Audiophile" Quality
 0.03% @ 9W, 4ohm
 0.1% @ 11W 4ohm
 0.1% @ 6W 8ohm
 High Power
 10% @ 15W 4ohm
 10% @ 10W 8ohm 
 Power Efficiency  81% @ 15W, 4ohm
 90% @ 10W, 8ohm 
 Input  Audio IN RCA (Left/Right) x 1 
 Power socket (5.5mm/2.1mm) x 1 
 Output  Speaker OUT (Left) x 1 pair (+ / -)
 Speaker OUT (Right) x 1 pair (+ / -) 
 Other Switch & Knob  Power ON/OFF switch x 1 
 Power Indicator (Blue LED) x 1 
 Volume knob x 1 
 Power Supply  DC 12V~13.2V(max.) 
 Dimensions  (W)76mm x (H)46mm x (D)114mm[case only]/150mm[incl. sockets & knob] 
 Weight  500g 
Spec. (AC Adaptor):   
 AC Input  Universal AC 100V-240V / 50~60Hz 
 DC Output  DC 12V / 3A (36W) 
 Ripple & Noise  <=50mV 
 Over-load Protection  105%-150% 
 Over-voltage Protection  115%-150% 
 Dimensions  (L)117mm x (W)48mm x (H)33mm 
 Weight  300g 
Accessories:  3 Pins Power Cord x1 (IEC plug and another plug with different country standards) 
User Guide x1 
Warranty Card x1 
Warranty:  One years parts and labor.  
Regulatory Compliance:  
CE Class B  
FCC Class B  
Canada ICES-003 Class B  

To continuously improve our product, we reserve the rights to change some features and specifications without further notice.