Lepai T-Amp with TA2020 - Page 66 - diyAudio
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Old 10th November 2010, 12:35 AM   #651
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Also, can someone clarify exactly which diode needs to be removed.

I've read in one place that the little orange diode in front of the chip needs to be removed, then in another place I saw a picture circling a larger black diode near the capacitor behind the power switch saying to remove it.
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Old 10th November 2010, 01:06 AM   #652
nige838 is offline nige838  United States
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Quote:
Originally Posted by savenger1 View Post
^ I've found they get annoying if you leave them on, picks up mobile phone interference and all kinds of things. Idle power is quite low but it's still best to turn it off.

I seem to have blown both my TA2020's from using them without first removing the zener diode... what a pain. One is totally silent and the other is playing only on one channel and sounds bloody awful.

I suppose it's fair to say they're beyond repair?

I guess a reliable, good sounding amp for $20 is too much to ask...
First off, the Lepai's power switch is wired to put the amp on standby @ around 150mah...you can rewire it if you like...

I've found that this amp can be made to sound amazing if you spend the time

By the way, I wish that there was a way to take all of the relevant information out of this thread and create a thread that only deals with this discussion...
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Old 10th November 2010, 01:18 AM   #653
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Quote:
Originally Posted by savenger1 View Post
Also, can someone clarify exactly which diode needs to be removed.

I've read in one place that the little orange diode in front of the chip needs to be removed, then in another place I saw a picture circling a larger black diode near the capacitor behind the power switch saying to remove it.

can anyone clarify on the correct diode to remove in order for this thing not to fry as soon as the volume is cranked?
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Old 10th November 2010, 06:54 AM   #654
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Location: Örebro, Sweden
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Originally Posted by danerius View Post
Hi. Thinking of replacing the 14 volt zener with a 15 or 16 volt version. Has anyone tried this. Bad idea. Great idea. Dont bother?

Im still using my Lepai at home with a computer smps but its goin in my when Im done modding and wanna make somewhat sure it will work

Regards /Bo
I replaced the zener with a 15 volt. No probs so far. Tried it on some different batteries, one giving out 14.4 volt wich is car alternatorish and no probs so far.
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Old 10th November 2010, 11:42 AM   #655
col is offline col  Australia
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The problem with the Lepai implementation of the TA2020 is that it doesn't have any overshoot diodes. As a result, it should not be run at a voltage over 13.5v. Read the TA2020 datasheet, compare to the Lepai layout:

"Schottky diodes that minimize overshoots of the outputs with respect to VDD during
switching transitions (required for applications where VDD >13.5V). For maximum
effectiveness, these diodes must be located close to the output pins and returned to their
respective VDD pins. Please see Application/Test Circuit for VDD return pin."

col.
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Old 10th November 2010, 02:24 PM   #656
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Quote:
Originally Posted by col View Post
The problem with the Lepai implementation of the TA2020 is that it doesn't have any overshoot diodes. As a result, it should not be run at a voltage over 13.5v. Read the TA2020 datasheet, compare to the Lepai layout:

"Schottky diodes that minimize overshoots of the outputs with respect to VDD during
switching transitions (required for applications where VDD >13.5V). For maximum
effectiveness, these diodes must be located close to the output pins and returned to their
respective VDD pins. Please see Application/Test Circuit for VDD return pin."

col.
Oops... Am I in trouble now?

Regards /Bo
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Old 11th November 2010, 03:55 PM   #657
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Quote:
Originally Posted by savenger1 View Post
can anyone clarify on the correct diode to remove in order for this thing not to fry as soon as the volume is cranked?
The one in front of the chip It should be between pin18(FAULT) and some other pin. It's the only diode in front of the chip I think.
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Old 12th November 2010, 02:34 PM   #658
amuppet is offline amuppet  United Kingdom
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hi gents. simply can't figure this one out. Whether with 8 ohm or 6 ohm (88dB sensitivity) speakers, I can't get sound through a powered-up lepai from an ipod or laptop connected to its 'mp3' input. No clicking, no thump... just nothing. This is true of two lepais I've got. could they really both be dead, despite no fried smell, no apparently damaged components, etc?
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Old 12th November 2010, 11:04 PM   #659
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Location: Illinois
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Originally Posted by amuppet View Post
hi gents. simply can't figure this one out. Whether with 8 ohm or 6 ohm (88dB sensitivity) speakers, I can't get sound through a powered-up lepai from an ipod or laptop connected to its 'mp3' input. No clicking, no thump... just nothing. This is true of two lepais I've got. could they really both be dead, despite no fried smell, no apparently damaged components, etc?
I received one of these Lepai's last Friday and had a similar problem.

First, the blue LED didn't even come on, but I traced that problem quickly to a flaky "free" 2 amp SMPS. I had a good one that I quickly subsituted.

Then the LED came on when I turned the switch on, but no sound! I checked connections and nothing seemed wrong, and then sit down to look at what I needed to do to return the Lepai.

While I was checking on the return policy, all of the sudden the music started playing!

For whatever reason, it takes a few minutes from powering on till the amplifier actually produces an output. The time seems to vary. There's no thump though. Maybe Lepai has made a change to eliminate the thump but in doing so has produced a situation of turn it on Monday and listen to it Tuesday.
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Old 15th November 2010, 08:07 PM   #660
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Default Fenice-10

Hi everybody, excuse me I'm a newbie, I've bought a fenice 10 (tamp 1101b powered with 12v from PC ali) and I've had strange issues.. I've connected it to my acoustimass 2+1. It sounded well but after sometime, no sound come out, but if I connect an mp3 directly to acoustimass they play (at a very low volume obviusly) and if I connect hearphones to the fenice I get sound (at very high vol) How could this be possible? Acoustimass+mp3 work, fenice+herphones work but acoustimass+fenice no? (always using the same cables...) Some Ideas? thank you very much.
P.S. the time they sound, it worked well..
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