Well, I should have added "with a multimeter" to my suggestion. 😉
Happy to see it works now. Congrats!
Happy to see it works now. Congrats!
Cool, That's what I thought after mine worked with my other power supply 🙂 Looking at the reviews on PE's site it looks like some of them were shipped with incorrect power supplies. The latest batch they have reportedly has a different power supply. My guess is that the email support originally sent was wrong in stating that the amp needed around 13.5VDC in order to operate. I have to give it to them though, they quickly offered up a replacement. Glad to do business with them.
My first test with speakers, nothing dead silent. I used my own power supply at 12.26 volts, the original died in the first hour. Let run for about 5 minutes, I get the blue ring and a click. I checked the DC offset again, 85 mv and 0. It goes back to PE today for another unit.
Hey mintos,
You say 2 free amps, I’m not getting the math. Are they still working?
TC
Hey mintos,
You say 2 free amps, I’m not getting the math. Are they still working?
TC
I got one of these (branded Lepai LP-2020A+) about a month ago. Initially it seemed to sound great, and I was happy with the purchase. However, after a while I started to really dislike the sound. Thin, bright, totally lacking presence in bass and even lower mid frequencies. It wasn't at like that at first, it was only slightly thin at first but with ok bass, and I had heard that burn-in would help with that. At first it seemed to, but then things took a 180-degree turn. And apparently many seem enjoying theirs so I'm not sure what to think. It's odd. However, by the time I started disliking the sound I had already ordered a second unit... and it has the same problem. I don't know, maybe I was simply even more deaf than usual for the first week or something 😕
So, anyway, I'm trying to research what could be done to improve the units. Unfortunately I'm not really much of a DIY person, and don't really have appropriate tools for modding things. One thing to do would be to bypass the tone controls, since touching them makes things only sound a lot worse still. Not sure if it'd help with sound quality to bypass them though. Also I've been wondering if perhaps the 12V 2A AC adapter is simply not able to give enough current to the amp, and that's why it sounds so thin and crappy? I don't really understand these things well enough to know if that could be the case. But overall it feels as if something's up with the power side of things, because sometimes turning the volume knob changes volume very little, sometimes more... it feels as if the power supply is really struggling to power the damn thing. Of course, as the power supply is rated for only 12V 2A, and therefore a max of 24W, it can't do the 2x20W the amp unit itself is capable of anyway, but the problem with unreliable volume control is present even at lower volumes.
Other issues I've noticed are that in the first unit the tone control knobs have the indicator in the wrong position - when the control is set to 0, the indicator shows a few notches up. Also, as someone else mentioned, L/R channels are reversed.
If all else fails, I guess I'll just have to try reselling them, as they are I really have no use for them, listening to them makes me think I could just as well poke my ears out 🙁 Changing from them to my "proper" integrated amplifier really brings the music to life in all its glory, and it's truly a night and day difference.
So, anyway, I'm trying to research what could be done to improve the units. Unfortunately I'm not really much of a DIY person, and don't really have appropriate tools for modding things. One thing to do would be to bypass the tone controls, since touching them makes things only sound a lot worse still. Not sure if it'd help with sound quality to bypass them though. Also I've been wondering if perhaps the 12V 2A AC adapter is simply not able to give enough current to the amp, and that's why it sounds so thin and crappy? I don't really understand these things well enough to know if that could be the case. But overall it feels as if something's up with the power side of things, because sometimes turning the volume knob changes volume very little, sometimes more... it feels as if the power supply is really struggling to power the damn thing. Of course, as the power supply is rated for only 12V 2A, and therefore a max of 24W, it can't do the 2x20W the amp unit itself is capable of anyway, but the problem with unreliable volume control is present even at lower volumes.
Other issues I've noticed are that in the first unit the tone control knobs have the indicator in the wrong position - when the control is set to 0, the indicator shows a few notches up. Also, as someone else mentioned, L/R channels are reversed.
If all else fails, I guess I'll just have to try reselling them, as they are I really have no use for them, listening to them makes me think I could just as well poke my ears out 🙁 Changing from them to my "proper" integrated amplifier really brings the music to life in all its glory, and it's truly a night and day difference.
I would like to start modding one of these to make the SQ better. I saw some pics of modified boards, but they're not the same PCBs. Anyone have a parts list what they can replace on these lastest PCBs?
I also got a 12V 6A laptop adapter for 14 bucks. Would it work with these amps?
I also got a 12V 6A laptop adapter for 14 bucks. Would it work with these amps?
I got my replacement amp today from PE. Interesting thing I noted is that on the box the input power is printed as 13.2VDC 2A where the original box it showed 12VDC 2A. However, the amp inside is the same as previous and marked as 12VDC 2A. The power supply that came with the new amp is different than the previous one in that it's slightly larger though the same basic shape and made by Asian Power Devices, has a serial number and a cord that is about 2 feet longer than the other one (Rui Long brand). The more important thing is that it actually puts out 12.19VDC and not 13.44VDC. So even though the label on the box has been changed, the amp and power supply have not and are actually 12VDC. Most importantly is that this one works out of the box 🙂
Now I have 2 working amps thanks to PE and their great customer service (and a spare 12VDC 5A PS I had laying around) 😀
Now I have 2 working amps thanks to PE and their great customer service (and a spare 12VDC 5A PS I had laying around) 😀
Seems that the new LP2020A+ is more sensitive
for disturbances from newest switching power supplies.
My old one (a few month old) don't produce hf noise
out of my speakers with a EcoFriendly-PSU (P0<0.3W),
but the new one does. With an older switching PSU
there's no noise.
for disturbances from newest switching power supplies.
My old one (a few month old) don't produce hf noise
out of my speakers with a EcoFriendly-PSU (P0<0.3W),
but the new one does. With an older switching PSU
there's no noise.
Hi Tvih,
Yes, it sure could very well be your Power supply that is making it sound "thin". The power supply is the KEY with these amps! I've tried many and this one is very good.
Switchmode Power Supply 11-14 volts ADJ 3.5 A power max - eBay (item 250756185604 end time Feb-11-11 06:36:36 PST)
I have many of these Tripath Amps, and have experimented with many power supplies and a bad power supply can make a great amp sound crappy.
I purchased one of these Lepai Amps around a year ago and played it a few times and put it away until about a month ago. I pulled it out and hooked it up to my Pioneer HPM 900's and hooked up my Trends TA-10.1 Amp Power supply that always sounded great. Well the Lepai shocked me with lot's of bass and very Liquid soundstage, even for Tripath amps, (yes, you have to fine toon the bass & treble) but you can get a nice sound there. You just can't turn it up too loud. It really did get me with with it's LIQUIDness 🙂 and it's RESOLUTION in the backgroud, squeaks and stuff. It didn't do it as much with another power supply, 12v 5a one. I think it likes the Trends SMPS.
Yes, it sure could very well be your Power supply that is making it sound "thin". The power supply is the KEY with these amps! I've tried many and this one is very good.
Switchmode Power Supply 11-14 volts ADJ 3.5 A power max - eBay (item 250756185604 end time Feb-11-11 06:36:36 PST)
I have many of these Tripath Amps, and have experimented with many power supplies and a bad power supply can make a great amp sound crappy.
I purchased one of these Lepai Amps around a year ago and played it a few times and put it away until about a month ago. I pulled it out and hooked it up to my Pioneer HPM 900's and hooked up my Trends TA-10.1 Amp Power supply that always sounded great. Well the Lepai shocked me with lot's of bass and very Liquid soundstage, even for Tripath amps, (yes, you have to fine toon the bass & treble) but you can get a nice sound there. You just can't turn it up too loud. It really did get me with with it's LIQUIDness 🙂 and it's RESOLUTION in the backgroud, squeaks and stuff. It didn't do it as much with another power supply, 12v 5a one. I think it likes the Trends SMPS.
I was looking at this power supply, it'd be 5A so at least it would have sufficient current. But of course the quality otherwise and thus effect on sound quality... who knows. The one you linked... well, it's price is the same as the amp itself was, not to mention it'd apparently require tweaking... something I'm not comfortable with, especially in the case of a PSU.
Disturbance sounds like a 1kHz tone
that's maybe demodulated from the HF-noise of
this PSU : Minwa MW3R15GS (1500mA).
There's another switching PSU that
even emitts this sound out of the PSU itselfs
(this power supply produces sound without an amp!):
Minwa MWS9125GS (the best choice for a hammer bass).
I prefer so far: McVoice/MCPower/EDC 2000 (06-0126)
but it seems only available for 230V input.
I use TA-amps only for comparison purpose
(guess, there are The sound reference up to 1000$).
that's maybe demodulated from the HF-noise of
this PSU : Minwa MW3R15GS (1500mA).
There's another switching PSU that
even emitts this sound out of the PSU itselfs
(this power supply produces sound without an amp!):
Minwa MWS9125GS (the best choice for a hammer bass).
I prefer so far: McVoice/MCPower/EDC 2000 (06-0126)
but it seems only available for 230V input.
I use TA-amps only for comparison purpose
(guess, there are The sound reference up to 1000$).
Hi folks, I was wondering if any of you gurus can help me. Parts Express was sold out of these Lepai amps for a little while but they just got new stock last week and I got mine on Friday. I'm using it to run a subwoofer and some old planar speakers (from the Monsoon Planar Media 9 set) that are just lovely and only need a small amp. Anyway, mine works fine out of the box (thank goodness!) and it sounds pretty good, but I am having a couple issues. Oh, btw I haven't opened it up but on the outside it is the same as the newer ones that people have been getting with the tone/direct pass through button.
So, anyway, a few questions for you diy gurus (or anyone who wants to chip in their thoughts):
1) So the one real problem that I had is I was testing how it was driving my speakers and how loud it would go and I slowly turned the volume up to 2pm, and it suddenly went mute, then I turned it back down and the volume came on again. Is this normal, and is there anything I should worry about that I might have damaged? I only have the signal coming from my computer set to 75% so I didn't think I was really risking much to turn the volume only up to 2pm. It still seems to sound pretty good, but I didn't get a chance to listen to the amp for very long before that happened.
2) I'm pretty disappointed with the power levels this thing is putting out. If I even turn the volume up to 12pm I get noticeable distortion. I feel like for 20w rms this is not driving my speakers very hard, I had them jerry rigged to an old cambridge soundworks computer system that put out like 4w rms and I think that was just as loud as this.... So I guess what I am trying to ask is why I am getting the distortion, what is the limiting factor there that is preventing me from cranking up to higher volumes, and if there is something I can do to fix it?
3) Maybe I'm crazy, but the audio signal sounds richer and cleaner if I use the tone feature rather than the 'direct' pass through button. If I use the "direct" button the sound is sort of tinny and a bit flaccid by comparison. Does anyone know why this would be?
4) Do you think swapping out most of the capacitors on this board would help the sound quality much? It gives a nice, clean sound right now at low to medium volumes, but the sound could definitely be a little richer, it is a little thin. I'd probably use some gold nichicon capacitors or something like that. And would capacitor change help with the distortion at higher volumes?
Anyway, thanks a lot for any insight or tips! This thread is really cool and was helpful to me in picking out this amplifier which in most regards is exactly what I needed to get my beloved monsoon sattelites playing beautiful music again after the amplifier on the old sub circuit crapped out. 🙂
So, anyway, a few questions for you diy gurus (or anyone who wants to chip in their thoughts):
1) So the one real problem that I had is I was testing how it was driving my speakers and how loud it would go and I slowly turned the volume up to 2pm, and it suddenly went mute, then I turned it back down and the volume came on again. Is this normal, and is there anything I should worry about that I might have damaged? I only have the signal coming from my computer set to 75% so I didn't think I was really risking much to turn the volume only up to 2pm. It still seems to sound pretty good, but I didn't get a chance to listen to the amp for very long before that happened.
2) I'm pretty disappointed with the power levels this thing is putting out. If I even turn the volume up to 12pm I get noticeable distortion. I feel like for 20w rms this is not driving my speakers very hard, I had them jerry rigged to an old cambridge soundworks computer system that put out like 4w rms and I think that was just as loud as this.... So I guess what I am trying to ask is why I am getting the distortion, what is the limiting factor there that is preventing me from cranking up to higher volumes, and if there is something I can do to fix it?
3) Maybe I'm crazy, but the audio signal sounds richer and cleaner if I use the tone feature rather than the 'direct' pass through button. If I use the "direct" button the sound is sort of tinny and a bit flaccid by comparison. Does anyone know why this would be?
4) Do you think swapping out most of the capacitors on this board would help the sound quality much? It gives a nice, clean sound right now at low to medium volumes, but the sound could definitely be a little richer, it is a little thin. I'd probably use some gold nichicon capacitors or something like that. And would capacitor change help with the distortion at higher volumes?
Anyway, thanks a lot for any insight or tips! This thread is really cool and was helpful to me in picking out this amplifier which in most regards is exactly what I needed to get my beloved monsoon sattelites playing beautiful music again after the amplifier on the old sub circuit crapped out. 🙂
Hi. Last week I bypassed the preamp/tone controls on my Lepai. Replaced it with simple ELNA electrolytic capacitors between the volume pot and R24 + R26. Really simple mod and yes it was a big improvement 🙂 Next up is upgrading the pot
Regards /Bo
PS. Im including a schematic
Regards /Bo
PS. Im including a schematic
Attachments
Mines screwed together so no pix but I have this. Lemme know if u can read it or not
Regards /Bo
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