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Lepai LP-168HA Amplifier

Published 13 October 2018

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Many DIY builders are looking for a good entry level amplifier that they can use or enhance to suit their own needs. We look at the entry-price Lepai LP-168HA amplifier and see if it is a contender.

Introduction

The Lepai LP-168HA amplifier is advertised as an entry-priced 2.1 channel power amplifier. Although not written on the external case, the vendor markets the amplifier at 2x40 watts of power for the stereo channel, coupled with a 68W sub output. The recommended load impedance is in the range of 2-8Ω, giving plenty of flexibility for parallel woofer combinations.

To our eyes, this is a good-looking amplifier module. The case has the appearance of a small in-car amplifier module and can easily be bolted into a fix to a frame.

Uses for the Lepai LP-168HA

The marketing material describes the amplifier as perfect for computer desks. We also see opportunities for using the module for creating DIY active loudspeakers or converting passive loudspeakers into active loudspeakers. There is also the possibility of using this module to build a DIY TV soundbar or enhance an existing one.

It has taken us a little while to work out how to best use this amplifier. The treble, bass and volume control give the impression that this can be used as a standalone home theatre amplifier. But as they say, the devil is in the details. The pre-amplifier function on this module should be considered as fine-tuning elements of a standalone amplifier. The giveaway to this thinking is that the sub volume is on a different circuit to the stereo volume control. Pre-amplifier functions such as volume and source selection are best left to a dedicate circuit. Many source media such as computers, mobile phones, and MP3 players have volume controls on them. Users may get frustrated using the Lepai LP-168HA in a pre-amp/power amplifier configuration as there is no master-volume on face-plate.

The LP-168HA is quoted as being usable between 9V and 14.4V, and may be run on batteries. As advertised, this module requires you to bring your own power supply. As a DIY kit this is quite acceptable, although you will need to include the price of an external power supply in your build. There are many quality power bricks available online or at your local electronics store. Just make sure that you get the right voltage and ampage capacity for your needs.

TDA7266 Power Amplifiers

The Lepai LP-168HA is marketed as a 2.1 channel amplifier. The engine power for this amplifier are two ST mostfet amplifiers. The main stereo amplifier is driven by the TDA7266S 5+5W stereo Amplifier. The dot-1 portion is driven by the TDA7266M 7W monaural amplifier. There are very few review articles on the sound quality of the TDA7266 modules. The main reference we found was to the Australian electronics magazine, Silicon Chip. This magazine describes the TDA7226 (wayback) as having excellent performance for a small SMD IC. The main case acts as a common heat sink for both TDA7266 components.

Visual Description

 
 
 
 

Performance Review

OldSchoolStereo.com (wayback) has done an excellent job of reviewing the performance ascpects of the Lepai LP-168HA. They point out many of the thinks that we have experienced as well. The lack of master gain control. They also mention other gripes such as the input gain and the crossover control.

Source: BigDWiz Youtube channel

Please note that oldschoolstereo.com, BigDWiz and other authors have not endorsed this article. The video is served directly by YouTube. Please read YouTube's privacy and copyright policy. The opinions expressed may not reflect the opinion of this site.

Lepai LP-168HA DIY Hacks

If you haven't guessed already, we love DIY projects. The Lepai LP-168HA is a flexible package that can be used to integrate larger DIY projects. Opening the package, there may be opportunities to DIY hack the Lepai LP-168HA to improve performance. We haven't tried these hack ourselves so these options only suitable for serious DIYers.

  1. Change out the TDA7266 amplifiers - truth be known, we don't see the point. If you are looking to change these modules then you are probably looking for a different amplifier to start with.
  2. Change out the JRC4558 op-amps - online reviews of these op-amps can be scathing, see Electrosmash (wayback). We don't have the experience to make comment on this but an interesting DIY project would be to pull out the existing op-amp and inserting a range of alternative op-amps (wayback) to see what sound quality improvements can be made.
  3. Upgrade the loudspeaker connections - as you can see from the photos, it didn't take us long to break the bare wire speaker connections. The form factor of the module is very tight. You may want to create a breakout connector to quality Speakon connectors.

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