Why are there only disastrous PCB Versions for TDA7293/TDA7294/LM3886 etc. available? - Page 5 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 27th April 2013, 08:27 PM   #41
diyAudio Member
 
chriscam's Avatar
 
Join Date: Jul 2003
Location: Amsterdam
Quote:
Originally Posted by thejohn View Post
If boards or Gerbers were available I'd definitely be interested.
There are 4 boards left, price is 25euro each including VAT ex shipping, leave me a PM if you are interested. An initial english version of the manual is expected coming week. This is the board's schematic :

Click the image to open in full size.
__________________
where solid state amplification is like photography, tubes are for painting. sometimes the best solution is to paint over a photograph.
  Reply With Quote
Old 29th April 2013, 11:15 AM   #42
diyAudio Member
 
chriscam's Avatar
 
Join Date: Jul 2003
Location: Amsterdam
Default Non Disaster Shipment

Folks, the shipping fees for 1 to 25 pcb's with our national PostNL are eu: 18 euro and worldwide: 24 euro. These shipments are insured for a max of 500 euro.
__________________
where solid state amplification is like photography, tubes are for painting. sometimes the best solution is to paint over a photograph.
  Reply With Quote
Old 21st May 2013, 09:33 AM   #43
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by nigelwright7557 View Post
I don't join them !

It is wrong to just join them and that is lazy and cheap design.

Its the same with random earthing of a layout and then wondering why you get hum.

PCB designs is a bit of a black art and get it wrong and your audio sounds like !"!"$
In this case post #473 about
Optimizing TDA7294 Output
provides also a good description.
  Reply With Quote
Old 17th January 2015, 10:52 AM   #44
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by tiefbassuebertr View Post
Maybe the avoidance of PCBs is the best solution - go to
Point 2 Point (no PCB) for TDA7293, TDA7294, TDA7295, TDA7296.
Looks very good - at least at first glance.
Are there commercial amps in this kind on the marked ?
  Reply With Quote
Old 26th July 2015, 02:40 PM   #45
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by tiefbassuebertr View Post
Maybe the avoidance of PCBs is the best solution - go to
Point 2 Point (no PCB) for TDA7293, TDA7294, TDA7295, TDA7296.
Looks very good - at least at first glance.
I still want to know commercial amplifiers, where this kind of building was realized.

Check out this thread concerning parallel mode operation:
About the Jeff Rowland LM3886 amplifiers
  Reply With Quote
Old 28th July 2015, 06:25 PM   #46
tomchr is offline tomchr  United States
diyAudio Member
 
tomchr's Avatar
 
Join Date: Feb 2009
Location: Greater Seattle Area
To answer your original question: The abundance of poor quality PCBs is probably because few people have the experience to lay out a PCB that delivers good performance. Also, many don't bother with measurements, so they're blissfully unaware of how their layout affects the overall performance of the amp.

Point-to-point is an easy way to muck up the layout as well. I measured the performance of various P2P layouts here: LM3886 PCB vs Point-to-Point (with data)

I highly doubt you'll find P2P construction in any commercial design. It's simply too expensive. It's also rather difficult to get consistent performance, so in addition to the high assembly cost, the manufacturer would have to perform extensive testing to ensure that the product was assembled correctly.

Rowland's circuit is interesting. I think some improvements could be had in the PCB, but the circuit looks well executed. Do note the adjustment pot for each channel, however. Paralleling LM3886es is tricky business. Often better results can be had by paralleling the two channels in an LM4780 as the two halves tend to be closer in performance than two LM3886es.

Tom
__________________
Modulus-86: Composite amp achieving 0.000067 % THD. Damn Good 300B, Novar Spud, 21st Century Maida Reg., Filament Reg., etc.
Neurochrome : : Audio - http://www.neurochrome.com - Engineering : : Done : : Right
  Reply With Quote
Old 29th July 2015, 03:42 AM   #47
Mishkaa is offline Mishkaa  United States
diyAudio Member
 
Join Date: Jun 2009
Seems to me there are many advantages of simple-to-understand layouts. Many of these PCB will be first builds. Easy to follow traces are appreciated by new builders. If you can optimize the board and hear a difference then +1.)
  Reply With Quote
Old 29th July 2015, 06:27 AM   #48
tomchr is offline tomchr  United States
diyAudio Member
 
tomchr's Avatar
 
Join Date: Feb 2009
Location: Greater Seattle Area
A good layout can still have easy-to-follow tracks and good assembly instructions. My point is that if you're bothering to design or buy a PCB, why not make it a good one?

Tom
__________________
Modulus-86: Composite amp achieving 0.000067 % THD. Damn Good 300B, Novar Spud, 21st Century Maida Reg., Filament Reg., etc.
Neurochrome : : Audio - http://www.neurochrome.com - Engineering : : Done : : Right
  Reply With Quote
Old 29th July 2015, 10:02 AM   #49
marce is offline marce  United Kingdom
diyAudio Member
 
Join Date: Jun 2007
Location: Blackburn, Lancs
A good layout will not look busy and thus the tracks will be easy to follow, it will flow (as the schematic flows), will be neat and will take consideration of electrical requirements for layout including EMC requirements and current flow/loops
  Reply With Quote
Old 29th July 2015, 01:34 PM   #50
Mishkaa is offline Mishkaa  United States
diyAudio Member
 
Join Date: Jun 2009
I guess I'm really trying to express that there's a 'good enough' point. Refinement? Absolutely! I'm all for it.

'Good enough' like so many things will vary from person to person -almost- as much as it varies from one component's integration to the next. With one op-amp a certain sub-optimal layout might be a non-starter while in others it could be inaudible.

In the case of the LM series and pre-made PCBs my bigger concern would be using a good, solid layout as a teaching tool. "This is why the layout looks as it does". It would also be a good selling point, IMO.

Sonics are important, but more of us knowing what we're about is even more so.
  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
TDA7294 + Power Transistors AMP (TDA7293 to come also) dr frost dk Chip Amps 503 14th August 2015 03:32 PM
TDA7293/TDA7294 - by which commercial integrated Stereo Amps in use ? tiefbassuebertr Chip Amps 12 26th January 2015 11:43 AM
TDA7294 TDA7293 LM3668 Spice micijanus Chip Amps 2 17th August 2014 03:50 PM
Differences between TDA7293 and TDA7294???? Leolabs Chip Amps 1 22nd December 2006 10:12 AM


New To Site? Need Help?

All times are GMT. The time now is 07:15 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2