Mike, looking at the Lepai board pin 22 and 25 are connected with only one cap feeding them both. You might be able to just connect all the overshoot diodes to the same location (going to 22,25). On the other board I have pin 22 and 25 are kept separate, also they have there own capacitor supplying them and each pair of overshoot diodes go to each.
col.
col.
I see what you are saying now... Pins 22, 25, and 27 are all hooked up to VDD, they're all on the same PCB trace, resistance is 0 ohms between them, meaning it's best to connect the diodes straight to the pins, but it doesn't really matter if you get VDD from somewhere else AFAIK.col said:the overshoot diodes might not work because pin 22 and 25 are connected. what happens if voltage from OUTP1 and OUTM1 is returned to pin22 instead of pin 25?
col.
In this case I used VDD for the diodes from near where the power cap is, as it was easier because of the board layout.
for the other two pins I used pins 25 and 27 as the source of VDD...
I'm just about to wire in a Fault LED, then I'll trying powering it up and see if anything happens.
I'm another happy Lepai owner, just saying hi!
I can be lazy as mine right now as mine already masterfully modded by Col!
anyway, its being held in reserve right now until the right set of matching speakers for it fall into my lap.
Good to have this resource all you peoples getting the most of it!
I can be lazy as mine right now as mine already masterfully modded by Col!
anyway, its being held in reserve right now until the right set of matching speakers for it fall into my lap.
Good to have this resource all you peoples getting the most of it!
Hi,
I just purchased a Lepai today, I should get it in 7 to 10 days. I had to get one to check it out. The price is sure right for getting a TA2020 chip amp!
I've got the TA2020 bug with all of these cheap TA2020 Amps out there now! I just received my HLLY TA2020 yesterday!!! Check it out on the other thread. So far it's VERY NICE!
Can't wait to get the Lepai now and see how it sounds. I am also really interested to check out the bass control.
Marc
I just purchased a Lepai today, I should get it in 7 to 10 days. I had to get one to check it out. The price is sure right for getting a TA2020 chip amp!
I've got the TA2020 bug with all of these cheap TA2020 Amps out there now!
I just received my HLLY TA2020 yesterday!!! Check it out on the other thread. So far it's VERY NICE!Can't wait to get the Lepai now and see how it sounds. I am also really interested to check out the bass control.
Marc
Powered up and everything appears to work ok.MikeHunt79 said:
I see what you are saying now... Pins 22, 25, and 27 are all hooked up to VDD, they're all on the same PCB trace, resistance is 0 ohms between them, meaning it's best to connect the diodes straight to the pins, but it doesn't really matter if you get VDD from somewhere else AFAIK.
In this case I used VDD for the diodes from near where the power cap is, as it was easier because of the board layout.
for the other two pins I used pins 25 and 27 as the source of VDD...
I'm just about to wire in a Fault LED, then I'll trying powering it up and see if anything happens.
I guess I won't really know until I try it in the car with 14.4v input.
Pic:
An externally hosted image should be here but it was not working when we last tested it.
just quoting this from the TA2020 evaluation board datasheet. It's not elaborated so well on the TA2020 chip datasheet:
"The figure below is the Tripath TA2020-020 evaluation board. The most critical components on the board are the power supply decoupling capacitors. Capacitors, C674 and C451, must be placed right next to pins 22 (VDD2) and 19 (PGND2) as shown. Similarly, capacitors, C673 and C451B, must be placed right next to pins 25 (VDD1) and 28 (PGND1) as shown. These power supply decoupling capacitors not only help reject power supply noise, but more importantly, absorb voltage spikes on the VDD pins caused by overshoots of the outputs of the amplifiers.
Similarly, schottky diodes, D1, D2, D3 and D4, minimize overshoots with respect to VDD and schottky diodes, D702, D703, D704 and D728, minimize undershoots with respect to power ground. For maximum effectiveness, these diodes must be located close to the output pins and returned to their respective VDD or PGND pins. Diodes D1, D2, D3 and D4 are only required for applications where VDD>13.5V. Voltage overshoots can also be caused by output inductor flyback during high current switching events such as shorted outputs or driving low impedances at high levels. If these capacitors and diodes are not close enough to the pins, electrical overstress to the part can occur, possibly resulting in permanent damage to the TA2020-020."
col.
"The figure below is the Tripath TA2020-020 evaluation board. The most critical components on the board are the power supply decoupling capacitors. Capacitors, C674 and C451, must be placed right next to pins 22 (VDD2) and 19 (PGND2) as shown. Similarly, capacitors, C673 and C451B, must be placed right next to pins 25 (VDD1) and 28 (PGND1) as shown. These power supply decoupling capacitors not only help reject power supply noise, but more importantly, absorb voltage spikes on the VDD pins caused by overshoots of the outputs of the amplifiers.
Similarly, schottky diodes, D1, D2, D3 and D4, minimize overshoots with respect to VDD and schottky diodes, D702, D703, D704 and D728, minimize undershoots with respect to power ground. For maximum effectiveness, these diodes must be located close to the output pins and returned to their respective VDD or PGND pins. Diodes D1, D2, D3 and D4 are only required for applications where VDD>13.5V. Voltage overshoots can also be caused by output inductor flyback during high current switching events such as shorted outputs or driving low impedances at high levels. If these capacitors and diodes are not close enough to the pins, electrical overstress to the part can occur, possibly resulting in permanent damage to the TA2020-020."
col.
Thanks for the info Col, I was only going by the info on the TA2020 datasheet.
I'll have a look at the Eval board datasheet and also the amp6basic schematic and double check everything along with the decoupling caps.
Also, I noticed a 14V zener on the board today, I'm going to check how much voltage the TA2020 gets with an input voltage of 14.4v as I could be doing this mod for no reason...
I'll have a look at the Eval board datasheet and also the amp6basic schematic and double check everything along with the decoupling caps.
Also, I noticed a 14V zener on the board today, I'm going to check how much voltage the TA2020 gets with an input voltage of 14.4v as I could be doing this mod for no reason...
Re: Need help on lepai
Hi msj965
Humming? Sounds like a grounding issue.
Look earlier on in the thread for reference to this.
There are wires grounding the pots that may have dry solder joints or have become detached.
Also the case doesn't like being 'earthed' on earlier models (UK plugs 3rd pin). If it's sat on another metal case i.e. your CDP the grounding of that case can affect it.
It's definately not the input capacitors
Hope that helps
msj965 said:Hello
Just wanna ask how can I eliminate the humming noise on my lepai.I just change the 2x10uf to 2.2uf 250v,Is this the reason why it is making the noise?
Thanks
Hi msj965
Humming? Sounds like a grounding issue.
Look earlier on in the thread for reference to this.
There are wires grounding the pots that may have dry solder joints or have become detached.
Also the case doesn't like being 'earthed' on earlier models (UK plugs 3rd pin). If it's sat on another metal case i.e. your CDP the grounding of that case can affect it.
It's definately not the input capacitors
Hope that helps
Hi,
Plugged in the Lepai with the 4A power supply that came with it. Pretty much junk, I mean it plays but it was a noisey and loud at you sound. I switched it out for the HLLY 4A Samsung Power supply, a much better result! Nice sound, I like my treble flat and also seemed to like it flat with the Lepai. I was able to get some nice bass with this amp by adjusting the bass knob about 1/4 of the way. It was nice to have that bass adjustment! It distorted at 2/3rds volume, so I turned down the bass and turned it up again it went up more before it distorted.
I changed the Samsung out for a 4A power supply I bought awhile ago. This power supply has a deeper black background, but not as quite as widely dispersed as the HLLY power supply, but it gave the Lepai an AWESUME bass sound once I adjusted the bass again for it. Not bad at all!!! It also distorted when I gave it the crank test, but it put out some great sound before that. In fact it has a really nice sound, imo. Now I also have to try the HLLY 2020 Amp with the 4A power supply that I've had for awhile.
Plugged in the Lepai with the 4A power supply that came with it. Pretty much junk, I mean it plays but it was a noisey and loud at you sound. I switched it out for the HLLY 4A Samsung Power supply, a much better result! Nice sound, I like my treble flat and also seemed to like it flat with the Lepai. I was able to get some nice bass with this amp by adjusting the bass knob about 1/4 of the way. It was nice to have that bass adjustment! It distorted at 2/3rds volume, so I turned down the bass and turned it up again it went up more before it distorted.
I changed the Samsung out for a 4A power supply I bought awhile ago. This power supply has a deeper black background, but not as quite as widely dispersed as the HLLY power supply, but it gave the Lepai an AWESUME bass sound once I adjusted the bass again for it. Not bad at all!!! It also distorted when I gave it the crank test, but it put out some great sound before that. In fact it has a really nice sound, imo. Now I also have to try the HLLY 2020 Amp with the 4A power supply that I've had for awhile.
Hi Tripath07 (or anyone else).
I am a little confused with the current requirement of the power supply for the Lepai.
My Lepai LP-2020 came with a budget 12V 1.2A power supply. Given that this would not be enough to create the 2x20watts it is quoted as being capable of (12V x 1.2A < 2x20W), am I simply being shortchanged in output power?
Are there other advantages to moving to a higher amp power supply?
Is 4A sufficient for max power (do you calculate using RMS or PMPO)?
Or is the current not really the issue, but the quality of the power supply?
The reason I ask is that I am going to use a second Lepai as a base for a portable battery powered stereo system for my boat. It will be running off a 12V SLA battery.
I was assuming a 2A fuse was sufficient but should I increase this to 5A?
What is the maximum power draw the amp has?
And any ideas on the approx current draw in standard usage as this will greatly affect battery life? For instance is it normally <0.5A, <1A, between 1-2A etc?
Am learning quickly but not quickly enough...
Much appreciated,
-Vincent
I am a little confused with the current requirement of the power supply for the Lepai.
My Lepai LP-2020 came with a budget 12V 1.2A power supply. Given that this would not be enough to create the 2x20watts it is quoted as being capable of (12V x 1.2A < 2x20W), am I simply being shortchanged in output power?
Are there other advantages to moving to a higher amp power supply?
Is 4A sufficient for max power (do you calculate using RMS or PMPO)?
Or is the current not really the issue, but the quality of the power supply?
The reason I ask is that I am going to use a second Lepai as a base for a portable battery powered stereo system for my boat. It will be running off a 12V SLA battery.
I was assuming a 2A fuse was sufficient but should I increase this to 5A?
What is the maximum power draw the amp has?
And any ideas on the approx current draw in standard usage as this will greatly affect battery life? For instance is it normally <0.5A, <1A, between 1-2A etc?
Am learning quickly but not quickly enough...
Much appreciated,
-Vincent
I'm running one of my Lepai's from 14.4v for most of today and it's been working fine. The Bass is all the way down tho, and zener removed.col said:motorbikevinnie,
I guess if you read the entire thread and buy a half decent multimeter you could work all that out for yourself. one tip though, If you are running off of batteries don't plug it in if the voltage is over 13.2v Worth snipping the little zener diode in half too
col.
Don't blame me if you try this and kill you're TA2020 tho, I've managed to kill one using 14.4v with one...
Hi msj965,
Nice to hear you are from the Twin Cities also! I bought it on-line over a year ago, and had the site bookmarked but my laptop died with the blue screen of death. Anyway, here is the info from the back of it.
GME switching power supply
Model: GFP651DA-1240
INPUT: 1.4A
OUTPUT: 4A
Good luck, I seem to remember it was $23 or so.
Nice to hear you are from the Twin Cities also! I bought it on-line over a year ago, and had the site bookmarked but my laptop died with the blue screen of death. Anyway, here is the info from the back of it.
GME switching power supply
Model: GFP651DA-1240
INPUT: 1.4A
OUTPUT: 4A
Good luck, I seem to remember it was $23 or so.
Hi motorbikevinnie,
The 4A power supply that came with it is junk, so don't feel bad. It is the quality of the supply that counts not the output. It should probably be over 2.5 A output though for 2020 chip amps. A 12v battery will sound the best, imo.
I posted the info, for my other 4A power supply!
The 4A power supply that came with it is junk, so don't feel bad. It is the quality of the supply that counts not the output. It should probably be over 2.5 A output though for 2020 chip amps. A 12v battery will sound the best, imo.
I posted the info, for my other 4A power supply!
I take back what I said, my Lepai kept cutting out at 14.4v.MikeHunt79 said:
I'm running one of my Lepai's from 14.4v for most of today and it's been working fine. The Bass is all the way down tho, and zener removed.
Don't blame me if you try this and kill you're TA2020 tho, I've managed to kill one using 14.4v with one...
I'm going to use a 7812 in order to drop down the voltage a little.
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