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Old 7th August 2011, 06:16 AM   #841
lithoc is offline lithoc  Malaysia
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I have one of these running in my home. This unit sound better with tone control, else it sound really dull.

The high is muddle & lack of bass. Definitely not flat.

No mod on this unit yet.

I suspect the tone by pass is affected by the input cap, resistor and out inductor.

If change all components, I'll opt for the better amp selling out there.

I bought this for budget concern.
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Old 7th August 2011, 08:31 AM   #842
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I replaced the stock 4558 op amps in mine with some SOIC LM833s I had in my parts bin. The bad news is that I get noise ("hiss") when the volume is set between about 9 and twelve o'clock and I engage the tone circuit. Then it totally disappears at about 1 o'clock. I can live with it for now. I'm feeding a multi-amp setup thru a distribution preamp with it's own volume control, so the noise isn't a big issue right now. And it doesn't exist at all with the tone disengaged. The good news is the fidelity is improved and it put the reins to that gawdawful high-midrange squeal. I'm running it into a pair of RS Pro LX5s with Peerless 5-1/4" woofer replacements.
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Old 7th August 2011, 01:48 PM   #843
gychang is offline gychang  United States
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Quote:
Originally Posted by lithoc View Post
I have one of these running in my home. This unit sound better with tone control, else it sound really dull.

my experience is opposite, want to be able to disable or take out the tone-control all together, waiting for a simple "upgrade" if someone can give a pictorial lesson (not too good with schematics).
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Old 9th August 2011, 04:48 AM   #844
lithoc is offline lithoc  Malaysia
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Does anyone have the updated schematics for this model (with tone defeat)?

Somewhere in this thread, some1 posted the old version of the schematics.

Thank you
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Old 9th August 2011, 07:09 AM   #845
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You are both referring to post #736. It shows the older schematic with the tone circuit but no defeat switch. gychang, I'm not too good with pictorial lessons. But if you look at the schematic, you'll see that you can bypass the tone circuitry by removing C4 and C2 and placing a 2.2uF capacitor from the C4 negative pad to the C2 positive pad. Do the same with C5 and C3 of the other channel. Be aware that the designators (C4, C5, etc.) are probably different on the newer model, but the mod remains unchanged. Use C9 and C10 instead of C4 and C5 if you want to keep the op amp preamp gain.
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Old 10th August 2011, 01:44 PM   #846
lithoc is offline lithoc  Malaysia
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Hi sofaspud,

Now, my amp , bass is always maxed out all the time (due to listening at low volume).

Is there any way I can increase the bass for this amp?

Which component I need to tweak?
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Old 10th August 2011, 07:21 PM   #847
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If you have the bass maxed all the time and it still isn't enough, I would look at the system as a whole. What kind of speakers are you using? Honestly, I played mine thru some 8" FR and the bass was insufficient. But I never intended to use it without a subwoofer. Have you considered adding a sub? You might be able to gain some low end by changing some caps and/or tweaking the tone circuit, but IMO you'll get better results with a sub. Even 15WRMS is plenty with the Lepai driving 4 or 8 ohm speakers.
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Old 11th August 2011, 02:56 AM   #848
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I just got one of these amps for the hell of it and I had it hooked up to some Polk Audio RTA8TL's ( 6.5" MTM ported) and I was surprised how much bass this little tiny amp put out. It actually sounded better than a Sony ES 2 channel receiver that i had them hooked up to before. Although the Lepai cost $20 more than the Sony
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Old 11th August 2011, 08:22 PM   #849
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Default Lepai Amp and Polk Audio Speakers

Hello, I have a question regarding a computer-bookshelf-speaker-setup.

I'm thinking of getting Polk Audio Monitor 30's series II and a Lepai LP-2020A+ amplifier from Amazon.com (shipped and sold by Parts Express). My question is:

Will this amp be able to handle these 8 ohm speakers efficiently? I won't be blasting these speakers at loud volumes.

All in all, is this a recommended amp for a small computer speaker setup?

Thanks
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Old 11th August 2011, 10:17 PM   #850
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I haven't heard the Polks, but my short answer would be yes.
The specs show a low -3db point of 63Hz and recommended amp power of 20-100W, so I wouldn't expect big bass from the setup. See my last post regarding subwoofers - for me it helps immensely. I usually listen between low 90s (dBC) and high 6os (when I go to sleep). I can play my system all day and all night. It sounds fine at either extreme and never fatigues.
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