DIY Audio Projects Forum
 NEW  Matt presents bias and operation data for the 6V6 tube in SE operation - 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization.

DIY Audio Projects Forum

Welcome to the DIY Audio Projects Message Forum. Use these forums to discuss Hi-Fi audio and to share your DIY Audio Projects. Registration is free and required to post messages and view the file attachments. Registration will only take a minute and registered users do not see any advertisements. After you have completed the online registration process, check your email (including spam/junk folder) for the verification email to activate your account. New members are under moderation - so your posts will not be visible until approved by a moderator. See the Read Me 1st, Forum RULES and Forum FAQ to get started on the forum.

It is currently 17 Oct 2018, 05:56

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 61 posts ]  Go to page 1, 2, 3, 4, 5 ... 7  Next
Author Message
 Post subject: PAM8403 - 3+3W D-amp
PostPosted: 06 Jan 2017, 10:28 
Offline
User avatar

Joined: 02 Mar 2009, 12:41
Posts: 1063
Location: Vänersborg, Sweden
Having read about the PAM8403 on a Swedish forum I decided to grab a bag from AliExpress and just recently got my ten stereoamps.

At the cost of a few bucks you get ten bare 3W stereo classD amplifier.boards. You have to add connectors, PSU and a chassis.
I got mine from here: AliExpress
Hooks up to a PSU or battery of 3-5V. When I ran my amp from a bench PSU I measured approx 11mA current, but I am not playing at max OP.

This is what they look like:
Attachment:
PAM_01.jpg


And once installed, running on 3,7V:
Attachment:
PAM_02.jpg


I've been plying my Elkie Brooks CDs all afternoon and I am pretty much satisfioed with the quality of sound. On occassions it may sound a bit harsh, but the last hours I haven't been disturbed by anything like that.

This module can go anywhere, toy synths, music boxes, stompboxes, guitar practicing amps or as a backup at home. I just dug up an iPod dock and a cast zinkbox that could make an iPod amp.

The major disadvantage is the size. Installed in a box, connectors, battery and volume pot will require lots of space.


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.


_________________
Magnus

“If you don't know where you are going, any road will get you there.”
―Lewis Carroll


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 08 Jan 2017, 12:08 
Offline
Editor
User avatar

Joined: 28 May 2008, 21:53
Posts: 4565
Location: Winnipeg, CANADA
Quote:
US $1.69 / lot 10 pieces / lot , US $0.17 / piece

What a great price! At 17 cents, that works out to about 6 cents per stereo Watt!

These modules would be great for a wide variety of DIY projects as you mentioned. The 5V supply voltage can make these really handy around computers if it can work well will work from typical 5V USB supply.

Looks like tons of great inexpensive stuff on AliExpress. I may have to try ordering some stuff.

Cheers

_________________
[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 08 Jan 2017, 12:57 
Offline
User avatar

Joined: 02 Mar 2009, 12:41
Posts: 1063
Location: Vänersborg, Sweden
They are also available on eBay and elsewhere. Check for good prices. And as you can get 10 stereo amps at 2 dollars, it's pointless ordering ONE amp only.

I should stress that they sound OK. Been listening for a few days, mostly rock but some jazz and I am happy.


Ed. And I am VERY surprised that this hasn't appeared on the forum before. I can give it a thought to make a sort of Audio Project to be published in here, but I lack a good housing and I cannot find my battery holders (for the 18650 batterie).

_________________
Magnus

“If you don't know where you are going, any road will get you there.”
―Lewis Carroll


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 08 Jan 2017, 20:52 
Offline
User avatar

Joined: 08 Aug 2009, 03:11
Posts: 2229
Location: Chilliwack, BC
IIRC, Elektor had an issue with this chip. Flexible is an understatement!

_________________
-= Gregg =-
* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
Work: Classic Valve Design


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 09 Jan 2017, 09:32 
Offline
Project Author
User avatar

Joined: 04 Jun 2008, 20:59
Posts: 3814
Location: Arizona, USA
Hi, I have not tried these particular amps but ran into an issue with some others. I used them on a TV. Fed the speaker / headphone jack into them and then off to some speakers. Decent sound and all.......that is until the CATV guys showed up at the door. It seemed that the class D amps put out a lot of high frequency switching noise and containated the ground/shield of the CATV. It was sufficient to cause signal degradation on certain channels (ones I do look at) for a block around. When they hooked up the test gear here it was really clear how bad the contaimation was. Just be alert to the possibility.

Good listening
Bruce

_________________
Some of my DIY Tube Amplifier Projects:


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 09 Jan 2017, 12:00 
Offline
User avatar

Joined: 02 Mar 2009, 12:41
Posts: 1063
Location: Vänersborg, Sweden
Hmmmm ... Arizona ... ??!! ... Didn't you wanted a referendum about free pot ...????!!!! And care about distorted TV-channels. Guess it was something like Paradise Hotel or Housewives of Miami on those channels ...


PS. Hav been listening to Natasha (Chesky Labs) in my car for a while and decided to have ago right now. Sounds VERY natural to me.

PPS. I have a tube preamp with a 6R7 tube (grid attached to top of tube), I hardly can use as it picks up noise from cell phones ... :lildevil:

_________________
Magnus

“If you don't know where you are going, any road will get you there.”
―Lewis Carroll


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 12 Jan 2017, 09:23 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4944
Location: Australia
I just received a 15W class D amp module. It fits in a match box. Not sure what to do with it but I'll think of something.

_________________
Projects: "Lagoon" - tube preamp with cathode follower | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "retro-Hiraga" - Jean Hiraga Le Monster
Website: retro-thermionic


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 12 Jan 2017, 10:37 
Offline
User avatar

Joined: 02 Mar 2009, 12:41
Posts: 1063
Location: Vänersborg, Sweden
The problem are the connectors. Where to find microminiature RCA- and 4mm speakerconnectors ..... :confused:

_________________
Magnus

“If you don't know where you are going, any road will get you there.”
―Lewis Carroll


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 23 Jan 2017, 08:53 
Offline
User avatar

Joined: 31 Dec 2008, 15:34
Posts: 441
heja magnus

now when you've got so many of those pam8403 amps, why not try to offer one two channel amp per loudspeaker. you could go even further by splitting each amplifier up in two ( matched with a two way loudspeaker ). one section (L) for the woofer and (R) for the tweeter. use a passive lowpass RC filter at input of the amplifier for the woofer and a passive highpass CR filter for the tweeter. remember to unmount the loudspeakers originally crossover filter. conclussion: four seperate amps serves four speaker units and it only needs to add four 1/4 w resistors and four bipolar caps in the region 1-10 k and 10-100 nF ( offcourse depending of the input impedance ).

try also to add electrolytic caps of 1000-2200 uF as close as possible to the voltage input terminals of the board. it helps to better sound which is needed.

well you're scandinavian, so i know you can do it :wizard:


Top
 Profile  
 
 Post subject: Re: PAM8403 - 3+3W D-amp
PostPosted: 23 Jan 2017, 11:12 
Offline
User avatar

Joined: 02 Mar 2009, 12:41
Posts: 1063
Location: Vänersborg, Sweden
Struggling a bit with something more substantial. A small Hammond cast box with line inputs, speakrer conns, and, most important, the iPod docking station. Switching between the line IP and docking station (and indirectly to the phono connector in the iPod dock).
Didn't have a suitable potentiometer so I used a 100K linear potentiometer where the slider is connected to gnd through an 18K resistor. The result is an almost logarithmic curve. It's in this region I have problems right now. It seems that the potentiometer isn't grounded.

Alsdo, there's a 3,7V batteri inside the box. Pretty tight.

Attachment:
PAM_07.jpg


Attachment:
PAM_09.jpg


Attachment:
PAM_10.jpg


Attachment:
PAM_11.jpg


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.


_________________
Magnus

“If you don't know where you are going, any road will get you there.”
―Lewis Carroll


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 61 posts ]  Go to page 1, 2, 3, 4, 5 ... 7  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
DIY Tube Projects :: DIY Tube Amp Kits :: DIY Speaker Projects :: DIY Solid State Projects :: DIY IC / Op-amp Projects :: DIY Phono Projects :: DIY Cable Projects :: Hi-Fi Audio Schematics
© diyAudioProjects.com - Terms of Service - Privacy Policy