How to add headphones to a T-amp 2020?

[lancsDavid]

help!!!

I bought a little amp - a Lepai LP-2020 (T-amp 2020 class) but I can't find anywhere to plug headphones in

click here to see it (ebay page showing various photos of the device)

i want to plug ipod-style headphones in to it. does anyone know if this is possible?

help appreciated

 

[ratza]

Do it like this:
http://sound.westhost.com/project100.htm

 

[lancsDavid]

cheers dude, but its a bit technical for me

know where i can buy one?

 

[jaycee]

Agreed, although most commercial amps just put 330 ohms in series, and presumably rely on the headphones impedance to perform the function of R2.

 

[jaycee]

cheers dude, but its a bit technical for me

know where i can buy one?

Doubt these are available for sale, but if you have a bit of skill with a soldering iron it's pretty easy to make up.

 

[theAnonymous1]

I see no one has mentioned yet that the output is bridged, meaning there will be VCC/2 on the output when referenced to ground. Sure, a cap in series can solve this, but then what about changing the output filter value for the higher load?

Point: This is a bad choice for a headphone amplifier.

 

[jaycee]

Ah - if the amp is bridged, then headphones cannot be done, as they all have common earth. This would short out your amplifier.

 

[Lucywy]

This is the data sheet about it,I think it can help you:
RCA Input ,Can be plug in with Ipod,MP3/MP4
Mini size easy to installation by DIY without manual, especially good fit for car, motorcycle bike,boat, every where!
Compact Size: 120mm (D) X 147mm (W) X 42mm (H) weight:280g
It has Blue LED light ring round Volume Knob;Bass/Treble tuning.
Aluminum alloy solid case and also easy to distribute the heat.
Speaker output protection
Short-circuit protection
Use SMD components
Latest 2011 New version

Feature:

T-Amp IC Tripath TA2020-20
Output Power of Tripath TA2020:2 x 20W @ 4ohm, 2 x 12W @ 8ohm
Signal-to-Noise Ratio (SNR) 98dB
Dynamic Range 98dB
IHF-IM Distortion 0.1% @ 1W, 4ohm
THD Distortion
0.03% @ 9W, 4ohm
0.1% @ 10W 4ohm
0.1% @ 6W 8ohm
10% @ 23W 4ohm
10% @ 13W 8ohm


Power Efficiency

81% @ 20W, 4ohm, 88% @ 12W, 8ohm

Input Sensitivity 200mV
Audio IN: RCA X1 & 3.5mm earphone jack x 1
Power socket (5.5mm/2.1mm) x 1

Output
Speaker OUT (Left) x 1 pair (+ / -)
Speaker OUT (Right) x 1 pair (+ / -)
Power Indicator (Blue LED) x 1
Power Supply input DC 12V~14.6V5A

Dimensions
(W)147mm x (H)42mm x (D)120mm
Weight 300g
Black

 

[sreten]

Hi,

It doesn't have a headphones output for two reasons :

1) the common earth wiring of headphones is problematic for bridged amplifiers.

2) Its assumed a typical source device would be able to drive headphones directly.

What is the source device ?

rgds, sreten.