Lepai T-Amp with TA2020 - Page 113 - 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 8th April 2012, 07:56 PM   #1121
diyAudio Member
 
Join Date: Feb 2012
Just a heads up, but I connected everything to the battery and damn does this thing BANG, now i'll have to find a way to make it somewhat portable cause I bought a heave Sealed Acid battery.. It plays better from battery then from the regular power supply...
  Reply With Quote
Old 10th April 2012, 02:05 AM   #1122
swon is offline swon  United States
diyAudio Member
 
Join Date: Mar 2012
I'm new to electronics & I'm looking for some help on modding my Lepai TA2020+ into a custom case. I have some basic soldering skills, but mostly I'm looking for some help locating parts and how to use them. Here is what I want to relocate and/or upgrade:

1. Power switch
2. Power LED
3. Tone control switch
4. Treble knob
5. Bass knob
6. Volume knob
7. Power jack
8. Audio input jacks
9. Speaker wire jacks

Basically everything external. So here is my laundry list of questions:

1. Seems like a metal case is recommended for EMI. I would like to build a wood case, so I'm assuming a metal case or metal sheets inside would do the trick. Are there some standard project cases that people like to use?

2. How do I mount the amp board inside the case? In the computer world, I use brass standoffs so that the solder leads don't touch the bare metal of the PC case, but the Lepai doesn't have any mounting holes. Is there a foam pad or something available?

3. I'm assuming I can use pretty much any switches for the power & tone control buttons. Looking at screw-type buttons like this: Momentary N.O. Raised Push Button Switch Black 060-642 Seems pretty straightfoward...drill a hole, mount, wire to the existing switch leads. If I wanted to use an LED switch, where would I wire the LED to?

4. I would like to (1) remove both LEDs from the volume knob, and (2) relocate one of them (using a new LED) to the front of the case. Do I need any particular type of LED, and to remove the second one, do I just de-solder it?

5. Probably the only internal mod I'd be looking at is swapping the power cap for better bass. This thread mentioned using a 4700uF cap with a 12V 6A power supply. Which one to get - 16V, 25V, 35V, or 50V? The Wiki recommends the 16V at minimum.

6. I haven't worked with power supplies outside of ATX computer PSU's. Are there some common, inexpensive internal power supplies for projects like this, instead of using the laptop-style 12V cord?

7. If I wanted to wire in an iPod USB cable for charging (like to a dock on the top of the case), how would I do that?

8. I'm a bit confused on the potentiometers. First of all, how would you mount these to the side of a piece of wood and have it come out the other side? Second, I've seen rotary vs. log pots thrown around. Do you need a specific type of pot for volume vs. tone control? Third, are the shafts standard, and where do you normally get some cool knobs from?

9. I'm assuming the easiest way to relocate the speaker wire jacks is to plug a speaker wire into the rear pushpins, then solder them onto outside-mount 5-way binding posts, correct?

10. For the power jack - I'd also like to relocate this to the rear. Is it a common size, and are there models that have a better mounting system for flush-mounting?

11. For the RCA's, what's the best way to rewire those to some nice flush-mounted jacks on the rear of a custom case?

There was a user on here, eladmi, who did a couple projects similar to what I'd like to do. His thread is here:

Mahagoni iPod Speaker Dock with CHR-70

His website is here:

http://www.wolfeil.de/

Basically relocated all of the knobs/jacks, one of them has an internal power supply, etc. etc. Not much on info on his site or thread though. Any guidance would be appreciated...TIA.
  Reply With Quote
Old 10th April 2012, 02:20 PM   #1123
swon is offline swon  United States
diyAudio Member
 
Join Date: Mar 2012
Here is what I have found so far:

1. LED Power Switch: 20 mm (25/32") mounting hole. Looks like positive, negative, and ground legs - then the LED lights up when it's on. Link:

SPST Automotive Round Rocker Switch w/Blue LED 12V 060-770

2. Pin Switch for Tone on/off: 11.9 mm (15/32") mounting hole. Not quite sure on how to wire this up. I could probably just use the same LED power switch linked above for this as well. Here's a link to the pin switch:

1-5/8" Adjustable Panel Mount Pin Switch 060-794

3. 16VDC 5600uF Power Cap: As recommended in this thread. I already have a 12A 5V power supply for the upgrade.

EEU-FR1C562 Panasonic Electronic Components Aluminum Electrolytic Capacitors - Leaded

I would like to find a good internal power supply at some point and use a standard IEC power jack on the rear:

IEC Power Jack Chassis Mount 090-442

Also still looking for information on wiring in an iPod USB cable for charging a connected iPhone. I believe I'd need something to step down to 5V (USB-spec) from the 12V power supply, something like this?

7805 +5V Voltage Regulator TO-220 7805

4. 2.5mm DC Jack:

2.5mm Panel Mount DC Jack 090-479

5. Chassis-mount RCA Jacks: Pair for stereo input.

Gold RCA Jack Solder Type with Nut Pair 090-278

6. Binding posts: Two pairs of these for left/right speaker outputs.

Gold Binding Post Pair 091-1150

7. Volume Knob: Alps RK27 blue seems to be the hot one, but I'm happy with the existing one if I could figure out how to mount it, unless there is some kind of big increase in quality for a few dollars. Found various knobs on ebay as well. I believe I need a rotary pot for the treble & bass knobs?

It looks like I'll have to decide on drilling holes in a thicker wood material, or doing a thinner front & rear panel and using panel-mount hardware. I'm assuming that all I do is de-solder & remove the old hardware (such as the switches) and then run hookup wire (any recommendations on type/gauge? would speaker wire work?) to the new hardware?
  Reply With Quote
Old 10th April 2012, 03:09 PM   #1124
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
To me, your posts are a bit too difficult/time-consuming to respond to thoroughly. Let me take it a little at a time, starting with the enclosure.
Quote:
It looks like I'll have to decide on drilling holes in a thicker wood material, or doing a thinner front & rear panel and using panel-mount hardware.
This needs to be addressed first. What will the new front panel be, dimension-wise? Until that is answered selecting components isn't really possible. Keep in mind that components aren't designed for thicker wood material; that would seem to require rear-mount with extensions, or panel surface-mount (don't confuse that with surface mount technology SMT).
And you need to decide on the power-in scheme. DC vs AC makes a big difference. Changing things in the future is possible, but it all has to be considered from the start.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine

Last edited by sofaspud; 10th April 2012 at 03:16 PM.
  Reply With Quote
Old 10th April 2012, 04:19 PM   #1125
swon is offline swon  United States
diyAudio Member
 
Join Date: Mar 2012
Quote:
Originally Posted by sofaspud View Post
To me, your posts are a bit too difficult/time-consuming to respond to thoroughly. Let me take it a little at a time, starting with the enclosure.
I tried to make them as organized as possible, but it turned into a wall of text As mentioned, I am a beginner in the electronics scene, so any guidance is appreciated - didn't mean to overwhelm you. Lots of pesky details to learn...there is a significant lack of basic information available, i.e. even on things as basic as how to mount a potentiometer inside a case or what type of potentiometer to use to replace an existing model. Lots of tribal knowledge to seek out. Been doing a lot of reading over the past couple of days. I am going through a book on electronics, but it's mostly theory unfortunately, not practice.

Quote:
This needs to be addressed first. What will the new front panel be, dimension-wise? Until that is answered selecting components isn't really possible. Keep in mind that components aren't designed for thicker wood material; that would seem to require rear-mount with extensions, or panel surface-mount (don't confuse that with surface mount technology SMT).
And you need to decide on the power-in scheme. DC vs AC makes a big difference. Changing things in the future is possible, but it all has to be considered from the start.
I was planning on making a wooden box, similar to vintage receivers/amplifiers, but in a more slimline design (height-wise). However, it sounds like that design won't work, as (1) an internal metal enclosure seems recommended for EMI shielding, and (2) as you mentioned, a lot of stuff is panel-surface mount and won't go through the thicker wood material. So maybe a better option would be to use a metal box and then build a wooden cummerbund around it for the aesthetics.

eladmi has done a few projects similar to what I have in mind - relocating the input/output jacks & controls into a custom case (although he's using a boombox design). See example here:

http://www.wolfeil.de/wp-content/upl...t-1024x598.jpg

Not sure on the DC vs. AC question. Right now I have a Lepai TA2020+ with an upgraded 12V 5A laptop-style power supply. It looks like the easiest option for a custom case install is to relocate the power jack onto a plate surface on the rear of the new case and connect the laptop-style power cable to there. Switching it over to a small internal power supply would be cool, because then I could use a standard 3-prong power jack, but even an inexpensive model from DealExtreme is half the cost of the Lepai, so I don't really know if it'd be worth it to even try.
  Reply With Quote
Old 10th April 2012, 08:18 PM   #1126
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
The Lepai is already in a metal box, and that solves at least a few of the issues.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 10th April 2012, 08:26 PM   #1127
swon is offline swon  United States
diyAudio Member
 
Join Date: Mar 2012
Quote:
Originally Posted by sofaspud View Post
The Lepai is already in a metal box, and that solves at least a few of the issues.
Yeah, I was thinking about that - I supposed to could chop off the top of the case and then just screw the flanges into the larger wood case, and run the wiring from there.

It looks like most panel-mount parts support up to 3/16" thick of material, is that correct in general? I could probably do a thin piece of metal for the front & rear to mount on.
  Reply With Quote
Old 10th April 2012, 08:40 PM   #1128
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Just run the wires through the holes in the front panel, where the original parts have been removed.
3/16" or 5mm sounds about right. That's just an eyeball guess from me - I haven't looked at any part specs to confirm or deny it. It could be made of wood, like that boombox design.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 11th April 2012, 06:45 AM   #1129
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Or the thin panel could be attached to the inside side of the thicker wood, as long as you can get the controls extended beyond the thickness of the wood on the front of the enclosure. That is similar to the way the flush-mounted RCAs would be mounted on the rear.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 11th April 2012, 01:21 PM   #1130
swon is offline swon  United States
diyAudio Member
 
Join Date: Mar 2012
Quote:
Originally Posted by sofaspud View Post
Or the thin panel could be attached to the inside side of the thicker wood, as long as you can get the controls extended beyond the thickness of the wood on the front of the enclosure. That is similar to the way the flush-mounted RCAs would be mounted on the rear.
Ah, I see...drill a hole in the wood and do a flush-style enclosure. Makes sense, as long as the hole is large enough for the plug to fit in...might go that route.

Has anyone mounted one of the 12V power supplies inside a case? They tend to get warm, but not super hot, so I think it'd be OK. One way to do it would be to slice off the wires around the power brick & remove the power brick's shell (or just leave it in there, if it's all epoxied inside - might cause interference without the case on it?), then solder the jack onto the amp and solder the outlet side to the 3-prong IEC jack. Or even easier, just plug in the jack on the amp and hot-glue it on. So essentially a $10 internal power supply with a nice, standard outlet on the rear. Seems doable, maybe if I cut some vent holes in the case.

Or just run a wire to the rear of the case with a replacement 2.5mm power jack for the power brick wire & drill a hole for it. Any special wire requirements for a power jack cable?
  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 04:36 AM.


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