Thank you for your help.
Oddly the pcb on 'this' latest version (Red pcb) Lepai is the best thing about it Surprisingly Well made.. In any event there are no visible or measurable breaks.
Only yanked out the wire, the unit didn't fall to the floor or suffer impact.
Subsequently I have removed and resoldered back in ALL the plugs, Reinserting them with a lot more care than the child at the 'factory' managed
Also reflowed All the solder connections on the board.. No luck yet.
Fresh Inductors are in the mails. However all the on board coils show continuity.
I'm Putting this gizmo on the shelf .. for now. Finding it too hard on my nerves considering the very low replacement price
Ordered a fresh/replacement Lepai and a couple more Ta 2020 'chips'.
Really annoying was that the thing was working surprisingly well...
until I broke it.. sigh. Even the turn on/off clicks were barely there.
Time for me to start assembling the Tripath circuit version.
Oddly the pcb on 'this' latest version (Red pcb) Lepai is the best thing about it Surprisingly Well made.. In any event there are no visible or measurable breaks.
Only yanked out the wire, the unit didn't fall to the floor or suffer impact.
Subsequently I have removed and resoldered back in ALL the plugs, Reinserting them with a lot more care than the child at the 'factory' managed
Also reflowed All the solder connections on the board.. No luck yet.Fresh Inductors are in the mails. However all the on board coils show continuity.
I'm Putting this gizmo on the shelf .. for now. Finding it too hard on my nerves considering the very low replacement price
Ordered a fresh/replacement Lepai and a couple more Ta 2020 'chips'
.Really annoying was that the thing was working surprisingly well...
until I broke it.. sigh. Even the turn on/off clicks were barely there.
Time for me to start assembling the Tripath circuit version.
Seems like the datasheet calls for 0.22uF for Co if using 8ohm speaker. So I think I could fit some Wima MKP4 0.22uF 100V or 250V. I'll get both and see which one fits better.
Also forgot to mention that I got another PSU that I could set to 13.5V. It is Mean Well S-40-12
Got it for about 10$ locally from someone that had some for sale but I saw it on dealextreme for about 10$ shipped but you'd have to wait for about a month to get to you. It's passive cooled so no extra noise from it.
I measured about 2.3A draw on some heavy bass track on 8 ohm speakers. This PSU should work nice for 8 ohm speakers as it has 88% efficiency for 12W@8ohm (Vdo 13.5V). That is 27.3W for both channels and psu is 42W rated. Don't know if it will hold on 4ohm at max output as it is 81% efficient at 20W@4ohm. That means 49.4W power from psu when amp puts out 20W on 4 ohm and it can put out 22W@4ohm. If you plan on driving 4 ohm speakers than I don't recommend this PS.
Right now I found all the caps needed so I have every original cap replaced. I don't know yet how well will Co fit but I will post some pics when I get the parts. I have about 7.3mm between holes on diagonal and the replacement i get will have 10mm pin spacing. Will need to bend the pins a bit but should work out well.
Sure fit:
Cdo 0.01uF - Wima FKP2 0.01uF/100V - FKP2D021001I00 (5mm pin spacing)
Cz 0.22uF - Wima MKS2 0.22uF/100V - MKS2D032201C00 (5mm pin spacing)
Cs, Csw, Cd, Ca and the rest of 0.1uF found on board - Wima MKS2 0.1uF/100V - MKS2D031001A00 (5mm pin spacing); these need to be slim enough as sometimes they are mounted next to each other and thicker one won't fit.
To be tested for fitment:
Cz and Co 0.22uF - Wima MKS2 0.22uF/250V - MKS2F032201H00 (5mm pin spacing)
- Wima MKP2 0.22uF/100V - MKP2D032201K00 (5mm pin spacing)
- Wima MKP2 0.22uF/250V - MKP2F032201K00 (5mm pin spacing)
Co (i prefer MKP4 for this slot) - Wima MKP4 0.22uF/100V - MKP4D032203G00 (10mm pin spacing)
- Wima MKP4 0.22uF/250V - MKP4F032203G00 (10mm pin spacing)
Cp and some other 1uF cap found on board - Wima MKS2 1uF/100V - MKS2D041001K00 (5mm pin spacing)
After I source all of them I will take some pictures of the fitment.
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Yesterday I got the Mundorf caps from a local dealer and the inductor kit from 41hz.com arrived. I must say the shipping was real fast, few days. I like the quality of the kit, it's real nice to DIY. I suggest if you get the inductor kit from 41hz.com (and you should, it's up to spec with ta2020 datasheet), do the first core trying as best to get it right. After the first one you will know the right way to wind the other three, and at the end unwind the first one and wind it again just to be sure you did it ok. I received longer wires than people mentioned some time ago. Had no problems with too shorter wire. Also I saw that they put 7-8 wires just in case some of them brake while winding them. I pulled pretty hard (but not too hard) and had no problem. Also be sure to pun some leather strip on your pulling finger so the wire doesn't hurt your skin. At first I thought I could do it but after the first was done so was my finger.
I managed to install the caps and inductors but no time to test it yet. Still to come 0.22uF, 1uF caps replacement. Need to find 2 power caps that add up to about 4400uF for PS. This way I can lower the input caps as well. I think I should put something on the inductors, like heat shrink... The old ones are sealed inside. They feel heavy and look very robust. Still, had to replace them with the recommended ones.
I managed to install the caps and inductors but no time to test it yet. Still to come 0.22uF, 1uF caps replacement. Need to find 2 power caps that add up to about 4400uF for PS. This way I can lower the input caps as well. I think I should put something on the inductors, like heat shrink... The old ones are sealed inside. They feel heavy and look very robust. Still, had to replace them with the recommended ones.
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Looks good .. so far. Nice winds on the coils I often rewind My Toy airplane Brushless motors Thumbs can get sore.
The number of turns = inductance.
Thickness of the wire = Amp capabilities.
The wire used is Varnish insulated.. and the varnish is tough.
Pointless to further encase them in Heat shrink.
That tiny case does present fitting issues though.
Really should 'test' it after ..every.. 'improvement'
IF only to ensure that the latest bit of fooling around' still left it operational.
IF it doesn't work at the end of your 'involvement'.
Finding cause could be a genuine pain.
The number of turns = inductance.
Thickness of the wire = Amp capabilities.
The wire used is Varnish insulated.. and the varnish is tough.
Pointless to further encase them in Heat shrink.
That tiny case does present fitting issues though.
Really should 'test' it after ..every.. 'improvement'
IF only to ensure that the latest bit of fooling around' still left it operational.
IF it doesn't work at the end of your 'involvement'.
Finding cause could be a genuine pain.
I just got home from a friend. He helped me test the amp with a pair of jamo e530 bookshelf speakers. They are 100W@8ohm, 91db(1w/1m). Source was a MacBook pro. First impressions were that mids were very nice but not as open as I wished for, highs were annoying and there was a serious lack of punch from bass. Vocals were clear but flat, dull. Then I tried to make use of the DAC from a M-Audio fast track pro USB sound card and things improved. This time we also used a flac track with Nina Simone. First tracks used for test weren't very good anyway, low quality mp3 rips. So that toned down the highs and mids sound more natural but only a slight improvement on the bass side. There are many things to consider here. Input caps need some burn in time, and output caps are real small and crappy. Those are the original ones and I want to replace them with PP. Many reported dramatic improvement in bass after replacing Co, so I need to wait it out. Piano jazz with vocals sounds divine!
I noticed today that input caps are bypassed by 0.1uF caps. Is that necessary or apropiate value for 2.2uF? Original value installed was 0.22uF but guess the one who put them there thought they were 2.2 as it is written u22 on them. I can remove the 0.1uF bypass or replace it for an apropiate value.
I noticed today that input caps are bypassed by 0.1uF caps. Is that necessary or apropiate value for 2.2uF? Original value installed was 0.22uF but guess the one who put them there thought they were 2.2 as it is written u22 on them. I can remove the 0.1uF bypass or replace it for an apropiate value.
Hey! it at least Works!.. So far so good?
IMO Sound cards are for Video games. As are Hard drive recordings of recordings of recordings. Might as well buy a pair of Skullcandy earbuds and forget the entire Audio Weenie adventure.. Lots easier on one's nerves
Try a Cheap CD player ..even a crappy portable unit for a reasonable assessment ??
Never a believer of Cap burn in.. although some swear to this on their Mothers' grave But then far too many also buy Penis Enlargement pills and creams too
Although I did personally experience Black Gate 'burn in' but that took 'maybe' an hour's time. Not several hundred hours.
One 'could' eliminate those Input caps altogether. There is arguement for that.
As a small experiment in sounds improvements.. or not ??
IMO Sound cards are for Video games. As are Hard drive recordings of recordings of recordings. Might as well buy a pair of Skullcandy earbuds and forget the entire Audio Weenie adventure.. Lots easier on one's nerves
Try a Cheap CD player ..even a crappy portable unit for a reasonable assessment ??
Never a believer of Cap burn in.. although some swear to this on their Mothers' grave
But then far too many also buy Penis Enlargement pills and creams too Although I did personally experience Black Gate 'burn in' but that took 'maybe' an hour's time. Not several hundred hours.
One 'could' eliminate those Input caps altogether. There is arguement for that.
As a small experiment in sounds improvements.. or not ??
I did finish modding my amp
I replaced all but one resistors with Dale ones. All capacitors on board got replaced as well. I finally settled for two Panasonic FM 2200uF/16V for power. I bypassed input/output/power caps with Vishay MKP1837 / 0,01uF caps. Just because I had some. The output caps went on the backside of the pcb between it and the case. It was a very tight fit but I found some Wima caps that were long and thin matched for 8 ohm speakers. I also bypassed the volume pot completely. I used Micrometals core inductors sold by 41hz.com. I have checked all parts with the ta2020 manual so everything will be ok. Also I managed to replace the protection relays with 3A ones that I got from the same company that made the 2A ones that were inside. The best part is that they gave them to me free of charge with free shipping They work great for this application. Massuse is the relay company. Great customer care! With 8 ohm speakers I won't worry over the 3A relays anymore.
Just found out tonight that the two pots on the board are actually trimming pots for the DC offset. I measured the outputs tonight and I had 90mV on one and 230mV on the other! I adjusted both to about 0.5mV. Now the very thin popping sound that I had at power on has now completely disappeared. And the amp is dead quiet at full volume (from my sound source, the amp is at full volume now with bypass). I'm very excited over the result and it was really worth it. I consider this a very good choice for modding as it has enough space inside for modding and it is also very small anyway. I saw that the amp goes for 36$ with free shipping. Even if you replace every component inside you pay 36$ for aluminium case + aluminium knobs + pcb + ta2020 chip + heat sink + connectors and some diodes that will never replace anyway The other amps out there are either too small to fit larger power caps + proper inductors or are more expensive. In the end you should look for nice aluminium case + proper PCB + space for future mods if you decide to buy a ta2020 amp.
I did a listening test with my Fostex fe206e speakers and I got the goose bumps on vocal tracks. This amp blew my mind and I think I made the best deal on audio amp for my needs. The most problematic has been finding/sourcing the capacitors. I had to make sure they fit and also they are good quality. I might experiment some more with a few more input caps. But the rest is perfect and most importantly...it fits!
I use the whole setup with a Meanwell S-40-12 variable smps power supply. I adjusted it to 13.5V. It works perfect and is as cheap as the amp itself.
https://www.meanwell-web.com/images/items/MW/mean_well_ac_dc_power_supply_g1_series_s-15-5.jpg
I replaced all but one resistors with Dale ones. All capacitors on board got replaced as well. I finally settled for two Panasonic FM 2200uF/16V for power. I bypassed input/output/power caps with Vishay MKP1837 / 0,01uF caps. Just because I had some. The output caps went on the backside of the pcb between it and the case. It was a very tight fit but I found some Wima caps that were long and thin matched for 8 ohm speakers. I also bypassed the volume pot completely. I used Micrometals core inductors sold by 41hz.com. I have checked all parts with the ta2020 manual so everything will be ok. Also I managed to replace the protection relays with 3A ones that I got from the same company that made the 2A ones that were inside. The best part is that they gave them to me free of charge with free shipping
They work great for this application. Massuse is the relay company. Great customer care! With 8 ohm speakers I won't worry over the 3A relays anymore.Just found out tonight that the two pots on the board are actually trimming pots for the DC offset. I measured the outputs tonight and I had 90mV on one and 230mV on the other! I adjusted both to about 0.5mV. Now the very thin popping sound that I had at power on has now completely disappeared. And the amp is dead quiet at full volume (from my sound source, the amp is at full volume now with bypass). I'm very excited over the result and it was really worth it. I consider this a very good choice for modding as it has enough space inside for modding and it is also very small anyway. I saw that the amp goes for 36$ with free shipping. Even if you replace every component inside you pay 36$ for aluminium case + aluminium knobs + pcb + ta2020 chip + heat sink + connectors and some diodes that will never replace anyway
The other amps out there are either too small to fit larger power caps + proper inductors or are more expensive. In the end you should look for nice aluminium case + proper PCB + space for future mods if you decide to buy a ta2020 amp.I did a listening test with my Fostex fe206e speakers and I got the goose bumps on vocal tracks. This amp blew my mind and I think I made the best deal on audio amp for my needs. The most problematic has been finding/sourcing the capacitors. I had to make sure they fit and also they are good quality. I might experiment some more with a few more input caps. But the rest is perfect and most importantly...it fits!
I use the whole setup with a Meanwell S-40-12 variable smps power supply. I adjusted it to 13.5V. It works perfect and is as cheap as the amp itself.
https://www.meanwell-web.com/images/items/MW/mean_well_ac_dc_power_supply_g1_series_s-15-5.jpg
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