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Old 15th December 2011, 06:59 AM   #1001
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Join Date: Jun 2009
Wink suggestion !

I use the blue beauty Alps one in all my pre-amp stages. But it is worth to put
it only if you have done all the mods on the Lepai, you will have slightly better channel separation with the blue Alps but don't expect miracles.
On my Lepai i just bypassed the pre stage with 2 2.2uf theta mkp caps and use it as small power amp paired with an external pre-amplifier or ipod/iphone/mp3 player (which have adjustable outputs). I kept Lepai's pre-stage intact for connecting a standalone cd player.
It is a killer small amp after the mods " + plus" it will help you a lot understanding how the 2020 tripath chip works.
All amps should be placed in a basic metal enclosure if you want to put them in a nice wooden box. You may not have EMI interference in your house but if you take your amp elsewhere, you might have problems. Try it first without the metal enclosure & put your ears close to your speakers to see if you hear any weird noises.

Vassilis

Quote:
Originally Posted by Franfj View Post
The one about what I am taking is this http://www.ebay.es/itm/170683788782#ht_1944wt_1117 only 7$

My Lepai volume potentiometer is a piece of crap, its not centered, makes noise using it, and the knob moves in the vertical axis by 1mm u_u

But thinking about it, I think that better will remove one of the tone potentiometers and replace the volume by one of them.

Another question, what do you think about wood enclosures?, I'm thinking about making a simple one, just to improve the amp appearance. Will be needed to make some kind of metallic cover for the amp to avoid EMI?

Last edited by vmed_cha_gr; 15th December 2011 at 07:04 AM.
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Old 15th December 2011, 09:26 AM   #1002
Franfj is offline Franfj  Spain
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Quote:
Originally Posted by vmed_cha_gr View Post
All amps should be placed in a basic metal enclosure if you want to put them in a nice wooden box. You may not have EMI interference in your house but if you take your amp elsewhere, you might have problems. Try it first without the metal enclosure & put your ears close to your speakers to see if you hear any weird noises.

Vassilis

Well now I have some strange interferences in my signal that are coming from the source and cable (a Macbook with a cheap cable that I have at home), probably getting a better cable will improve this…

But anyway I will use a basic metal enclosure inside the wooden box, I asked this because I saw lots of DIY in wooden box without any visible metal EMI shield and just was wondering if for any reason aren't necessary.
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Old 15th December 2011, 01:13 PM   #1003
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Quote:
Originally Posted by Franfj View Post
The one about what I am taking is this http://www.ebay.es/itm/170683788782#ht_1944wt_1117 only 7$

My Lepai volume potentiometer is a piece of crap, its not centered, makes noise using it, and the knob moves in the vertical axis by 1mm u_u

But thinking about it, I think that better will remove one of the tone potentiometers and replace the volume by one of them.

Another question, what do you think about wood enclosures?, I'm thinking about making a simple one, just to improve the amp appearance. Will be needed to make some kind of metallic cover for the amp to avoid EMI?
I have tested rotary pots for volume control and I didn't liked the result. Your ear is logarithm so you better get one log pot for volume control.

Maybe the moving knob is the chassis of the volume knob not tight to its body, mine was a little loose. Just tight it's arms.

On mine units the tone controls were 50kx2 pots. They should work fine.

I love wood enclosures, I have my not-finished-yet Tk2050 on wood and I like the result. In my case I insulated everything but used no metal walls to block EMI and the amp is quiet.

Click the image to open in full size.

I revised the lepai lp2020A+ schematic for the volume pot and decided that if you still have op amps circuit on the board you better not ground the volume pot in the holes or things may get noise and weird. I can't confirm because the board I did the mod have no op amps circuit anymore but you better go for the pcb to ground.

Last edited by Virpz; 15th December 2011 at 01:17 PM.
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Old 16th December 2011, 10:47 PM   #1004
Franfj is offline Franfj  Spain
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Quote:
Originally Posted by Virpz View Post
I have tested rotary pots for volume control and I didn't liked the result. Your ear is logarithm so you better get one log pot for volume control.

Maybe the moving knob is the chassis of the volume knob not tight to its body, mine was a little loose. Just tight it's arms.

On mine units the tone controls were 50kx2 pots. They should work fine.

I love wood enclosures, I have my not-finished-yet Tk2050 on wood and I like the result. In my case I insulated everything but used no metal walls to block EMI and the amp is quiet.

http://i9.photobucket.com/albums/a83...co59232348.jpg

I revised the lepai lp2020A+ schematic for the volume pot and decided that if you still have op amps circuit on the board you better not ground the volume pot in the holes or things may get noise and weird. I can't confirm because the board I did the mod have no op amps circuit anymore but you better go for the pcb to ground.
Nice tip, if I'm not satisfied with the replace I will try to find a logarithmic pot instead of a linear one


Now I have the opamps bypassed, but I was planning to add a switch to be able to use the tone controls when necessary, so I will take note of your tips.

Thanks
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Old 20th December 2011, 02:42 AM   #1005
Cpurdy is offline Cpurdy  United States
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Hi folks Been following the thread here and on several other sites and just wanted to chime in - I've been working on my Lepai 2020+ and was having trouble finding the inductors here in the US.

I just wanted to pass along a good source I located.. a bit higher spec (6A instead of 3A), but seem to fit the bill nicely. Bass seems quite a bit tighter and defined.

Here is the link for the toroids:
10pcs 10uH 6A coil wire wrap toroid inductor choke | eBay

I let the seller know that I would be pointing more folks his way.

For my Mod - I bypassed the op-ams and tone /volume circuit as well as swapped out the power cap for a 10,000uF. Amp is amazing now.

Here is a vid I made just prior to the inductor swap - I'll update it with the final inductor mod soon when I have time.

Lepai Tripath ta2020+ Class-T amp modifications - YouTube
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Old 20th December 2011, 10:49 AM   #1006
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Thumbs up a highly rated amp after the mods

Those inductors will do the job. Here is another one for you : Inductor 10uH 10 uH +/- 10% 5 pcs | eBay i used these ones and moved the sound to another level .

With a rate of 10 i give 10 to this amp. It has become an addiction for me. I listen to music in mid levels with lepai & use my big stereo for high levels

Quote:
Originally Posted by Cpurdy View Post
Hi folks Been following the thread here and on several other sites and just wanted to chime in - I've been working on my Lepai 2020+ and was having trouble finding the inductors here in the US.

I just wanted to pass along a good source I located.. a bit higher spec (6A instead of 3A), but seem to fit the bill nicely. Bass seems quite a bit tighter and defined.

Here is the link for the toroids:
10pcs 10uH 6A coil wire wrap toroid inductor choke | eBay

I let the seller know that I would be pointing more folks his way.

For my Mod - I bypassed the op-ams and tone /volume circuit as well as swapped out the power cap for a 10,000uF. Amp is amazing now.

Here is a vid I made just prior to the inductor swap - I'll update it with the final inductor mod soon when I have time.

Lepai Tripath ta2020+ Class-T amp modifications - YouTube
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Old 21st December 2011, 02:59 AM   #1007
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Join Date: Sep 2011
hi everyone, first pot here. I have 2 Lepai TA2020A+s. unlike most everyone here I need more bass. Is there a way to permanently add bass within the unit, i.e. modify the tone controls, or better yet, add some "resistors" to have it automatically shelve 10 db at 60 hz?

i have 3 systems in my house. The first is computer>lepai>QLN model ones. it seems like i have winamp permanently boosted at 70 hz, with the preamp reduced equally (to offset the gain). that generates adequate bass on my QLNS.

i have a counterpoint SA3000 + SA220 > energy veritas 1.8. (counterpoints handed down to me, i would never spend that much for amps). my fav setup is the lepai into veritas, which has great bass, but those speakers r too big in my home office where i do most of my listening. i guess it shows importance of matching speakers to amp.

the third is a lepai to energy c6s. it's here that the energys are woefully lacking in bass. i've inserted an audiosource eq b/w the cd player and lepai but don't like having the complexity. im also considering buying a behringer digital eq, and toslink the cd player to the behringer (to keep the signal processing in the digital domain), but figure if i did that, might as well buy a onkyo tx 8255. however i do love falling asleep w the lepai on, knowing it's only sipping watts as opposed to old school amps. sorry for posting so much. my main question is on adding a permanent eq bump on the low end.

thanks, James
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Old 21st December 2011, 09:23 AM   #1008
Cpurdy is offline Cpurdy  United States
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Quote:
Originally Posted by vinyl tap View Post
hi everyone, first pot here. I have 2 Lepai TA2020A+s. unlike most everyone here I need more bass. Is there a way to permanently add bass within the unit, i.e. modify the tone controls, or better yet, add some "resistors" to have it automatically shelve 10 db at 60 hz?
...

thanks, James
swap the power cap... The single biggest effect on the amount of bass. The stock cap is way too small. When I replaced that, I went from no bass below about 100hz, to solid, punchy and defined bass all the way down... I actually have been considering re-eq'ing my room...

Also, make sure your power supply is supplying enough current. If I remember, the stock supply is like 12v at 1.2 or 1.5 A... I swapped for 12v, 5A..

The amp runs out of steam and can't push out the low end without these mods..
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Old 21st December 2011, 11:43 AM   #1009
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Join Date: Jun 2009
Default yeap !

I agree.
I put 4700uf on mine & use a 6A/12v power supply. Amazing amp (after the mods of course).

Quote:
Originally Posted by Cpurdy View Post
swap the power cap... The single biggest effect on the amount of bass. The stock cap is way too small. When I replaced that, I went from no bass below about 100hz, to solid, punchy and defined bass all the way down... I actually have been considering re-eq'ing my room...

Also, make sure your power supply is supplying enough current. If I remember, the stock supply is like 12v at 1.2 or 1.5 A... I swapped for 12v, 5A..

The amp runs out of steam and can't push out the low end without these mods..
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Old 21st December 2011, 05:41 PM   #1010
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thanks guys. i did buy a 12v5a & but couldn't tell a big difference. however i didn't crank it. so w a power cap, one can hear a difference even at lower volumes?

i need at least 8 dbs difference..i really believe an eq bump mod would be the trick.

James
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