Lepai T-Amp with TA2020 - Page 86 - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 11th August 2011, 10:13 PM   #851
diyAudio Member
 
Join Date: Aug 2011
Thanks for the reply.

I'm not expecting nor looking for "big bass". I simply want a nice pair of inexpensive speakers that will sound good.

Unless you mean they won't have "big bass" because the speakers are being limited by the Lepai LP-2020A+ amplifier.

I tried cyber-acoustic speakers which came with a 5-1/4" subwoofer (that's right, they classified a 5-1/4" driver as a subwoofer) but it sounded to muddy and the satellite's alone sounded like tiny metal cans.

I also looking at these: http://www.amazon.com/Dayton-B652-2-...3100439&sr=8-1

They may do the job but I am an audio purist and I've had experience with Polk Audio speakers already. Which is how I ended up with the Monitor 30's Series II.
  Reply With Quote
Old 11th August 2011, 10:47 PM   #852
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Quote:
Unless you mean they won't have "big bass" because the speakers are being limited by the Lepai LP-2020A+ amplifier.
I mean both together. It's next to impossible to get lower bass octaves from a bookshelf speaker, and the Lepai is a low-powered amp that can't provide the energy needed. Believe me, you don't want to listen to the Lepai at it's rated 20 or whatever watts.
The Daytons are much less $$ than the Polks, so you could use that extra money for a sub. A 5-1/4" driver is what it is. There's nothing wrong with one in a well-designed sub.
Quote:
but I am an audio purist
Hmmm... well, I am not. Audio for me is not a quest, it's just a journey. Any talk of "purity" contradicts this entire discussion IMO.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 11th August 2011, 11:37 PM   #853
gychang is offline gychang  United States
diyAudio Member
 
Join Date: Feb 2005
Location: Davis, California
there are several different versions of Lepai, I took some pictures of mine and considering upgrade steps suggested on this forum: Modding the Lepai T2020A+ - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com
Attached Images
File Type: jpg 20110811-P1070748.jpg (313.4 KB, 403 views)
File Type: jpg 20110811-P1070749.jpg (256.6 KB, 400 views)
File Type: jpg 20110811-P1070750.jpg (224.2 KB, 388 views)
File Type: jpg 20110811-P1070751.jpg (245.4 KB, 389 views)
__________________
--
Good sound from Davis, CA
  Reply With Quote
Old 12th August 2011, 12:28 AM   #854
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Yes, that's the Lepai version I have. I only replaced the op amps with LM833s and repaired the RCA input ground pin that I accidentally broke when it was out of the case. It got rid of the worst distortion I was hearing so it was a mod well worth the time for me. I've seen stuff like "the output coils aren't big enough" but they're the same as the ps input coil so there must be more to that story. Upgrading caps certainly couldn't hurt. Or increasing the values of the 3! coupling caps. Some of those might even be replaced with jumpers, but I would double check DC measurements and tolerances before attempting that.
I basically working from the assumption that the schematic posted a while back would apply to this version, less the tone switch. I didn't ohm out the switch or much of the board. I chose not to spend too much time and money on a $20 amp.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 12th August 2011, 12:44 AM   #855
diyAudio Member
 
tubelab.com's Avatar
 
Join Date: Jul 2005
Location: South Florida
I got one of these little amps from Parts Express.

I needed some Tolex and a few other parts to finish some guitar speaker cabinets that will be seen in the Hundred Buck Amp Challenge thread.

The Hundred-Buck Amp Challenge

Parts Express wanted $13 to ship my order, but If I spent $18 more I would get free shipping. I guess that made the amp cost $7. SO.....

I brought a chip amp to a tube fight. I have been listening to a Tubelab SSE running KT88's in single ended triode mode making about 8 WPC. For really annoying the neighbors I have Pete Milletts red board making 125 WPC. The speakers are Silver Iris 15 inch coaxial drivers mounted in old Zenith console radios. They are 96 db efficient making them loud enough to hear across the street with the 8 WPC SSE. The 125 WPC amp is rock concert in the living room loud.

I hooked up the Lepai and cranked it up. It sounded much better than I expected right up to the point where the sound instantly turns to mud.....Digital Clipping sucks. "20 WPC" of digital amp is not as loud as 8 WPC of tube amp because you can run the tube amp into clipping without putting your fingers in your ears. Unlike some other posters I have plenty of bass with 15 inch woofers. I played with the tone controls trying to match the tube amps sound at a volume level well below clipping. I wound up with the bass knob at 10 o'clock and the treble knob at 2 o'clock.

For $7 it is a keeper, and I would probably buy one for $20. It will wind up as the amp on my PC for those times when I don't feel like pumping 100 watts worth of heat into the room. Here in Florida, that is 90% of the time.

I don't know why, but my unit came with a Vonage power supply that has obviously been used, very used. It seems to work OK and the LED doesn't blink even when the amp is heavilly hammered into clipping. Wonder what will happen if I play my guitar through this thing.
Attached Images
File Type: jpg T_amp_A.jpg (284.8 KB, 392 views)
__________________
Too much power is almost enough! Turn it up till it explodes - then back up just a little.
  Reply With Quote
Old 12th August 2011, 01:22 AM   #856
gychang is offline gychang  United States
diyAudio Member
 
Join Date: Feb 2005
Location: Davis, California
Quote:
Originally Posted by sofaspud View Post
Yes, that's the Lepai version I have. I only replaced the op amps with LM833s and repaired I chose not to spend too much time and money on a $20 amp.
I agree, simple mod is what I am after. Which part exactly on the picture, and where can I get the replacement part?, (web page).

thanks in advance.
__________________
--
Good sound from Davis, CA
  Reply With Quote
Old 12th August 2011, 02:44 AM   #857
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
The parts I replaced are U1 and U2, the two 8-pin surface mount ICs just above the volume pot in your first picture. I had LM833s handy so that's what I used. Popular audio op amps like the NE5532 and OPA2134 ought to work also. Here is the 5532 page from Digi-Key, but these parts can be obtained most anywhere finer electronic components are found. I didn't take time to measure but just went on the supplies being the split 12VDC input. There's lots of +/-6V op amps to choose from these days.
I've posted some other tips and caveats from my experience going back in this thread a month or so. Nothing too involved, challenging, or expensive. I think it's established that with a good pair of speakers, this little amp can provide quite satisfying listening. Good luck with yours and keep us updated on your progress, questions, and listening opinions.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 12th August 2011, 06:53 AM   #858
diyAudio Member
 
Join Date: Aug 2011
Quote:
Originally Posted by sofaspud View Post
The Daytons are much less $$ than the Polks, so you could use that extra money for a sub. A 5-1/4" driver is what it is. There's nothing wrong with one in a well-designed sub.
Yes, in a well designed sub, but why bother getting a subwoofer with a 5-1/4" driver in it? If you (me in my case) were to by a subwoofer would you put down $80-200 for a well designed "mid-range driver"? I'd want to get something with some good clean, tight, rattle the room bass. That require's a somewhat larger driver than 5-1/4"; however, to make it simple, I don't want a subwoofer. I want a 2.0 setup and for the simplest reason in the world, money. I'm 16, I don't exactly have a general surgeons payroll.

The Dayton's are cheaper because they do lack bass and clarity from what I've read. I trust Polk Audio, they've done nothing but impress me with their speakers.

Quote:
Hmmm... well, I am not. Audio for me is not a quest, it's just a journey. Any talk of "purity" contradicts this entire discussion IMO.
Audio is not a quest for me either, but I'm not going to buy the cheapest look set available on the market. That's all I was getting at.

It all comes down to one thing, do you believe the Lepai will be bottle-necked by the Polk Audio Monitor 30's Series II? I like clean, tight bass. Shouldn't this amp be able to produce that?

No hard feelings. Thanks for responding.
  Reply With Quote
Old 12th August 2011, 08:31 AM   #859
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Quote:
Originally Posted by xxmastermushxx View Post
Yes, in a well designed sub, but why bother getting a subwoofer with a 5-1/4" driver in it?
Because there is a need for it, and it's well-designed.
Quote:
I'd want to get something with some good clean, tight, rattle the room bass.
If you think you can match that output with the Lepai and the Polk speakers, let no one stop you. I've been contemplating a 2nd sub for my system, diy style.
Quote:
I don't want a subwoofer. I want a 2.0 setup and for the simplest reason in the world, money. I'm 16, I don't exactly have a general surgeons payroll.
Duly noted. I wouldn't intentionally steer you wrong.
Quote:
The Dayton's are cheaper because they do lack bass and clarity from what I've read. I trust Polk Audio, they've done nothing but impress me with their speakers.
I mentioned the Dayton's in the context of running them with a sub. If you just want 2.0, the Polks are fine and at a great price. I have some Polk speakers on another PC, and heaven knows I've gotten lots of mileage out of them.
Quote:
Audio is not a quest for me either, but I'm not going to buy the cheapest look set available on the market. That's all I was getting at.
Sorry, I never meant to imply anything of the sort. My point was just that if we're gonna talk purity, the Lepai needs to be coupled with a very efficient pair of wide response speakers. Big budget speakers mostly.
Quote:
It all comes down to one thing, do you believe the Lepai will be bottle-necked by the Polk Audio Monitor 30's Series II? I like clean, tight bass. Shouldn't this amp be able to produce that?
I agree it should. It and thoughtful speaker placement can go a long way IMO.
Quote:
No hard feelings. Thanks for responding.
Not at all. Sorry if I seemed to antagonize. The Lepai sounds surprisingly good when kept below clipping. It should drive the Polks to moderate SPLs. Probably not rattle-the-room SPLs, but a decent system that you can live with and expand upon. Let us know how it comes together.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 12th August 2011, 01:12 PM   #860
gychang is offline gychang  United States
diyAudio Member
 
Join Date: Feb 2005
Location: Davis, California
Quote:
Originally Posted by sofaspud View Post
The parts I replaced are U1 and U2, the two 8-pin surface mount ICs just above the volume pot in your first picture. I had LM833s handy so that's what I used. Popular audio op amps like the NE5532 and OPA2134 ought to work also. Here is the 5532 page from Digi-Key, but these parts can be obtained most anywhere finer electronic components are found.
thanks very useful infomation.
__________________
--
Good sound from Davis, CA
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New ta2020 pcb'S ArjenShenzhen Vendor's Bazaar 98 14th November 2012 11:39 AM
Ta2020 Bengali Class D 0 29th September 2007 05:28 AM
Eb-ta2020 opentop Class D 16 30th May 2005 07:42 AM


New To Site? Need Help?

All times are GMT. The time now is 04:27 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2