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thylantyr
11-16-2005, 05:10 PM
I always like to enter 'chip amplifier' debates.

Maybe I only find comedy in this thread?
http://www.htguide.com/forum/showthread.php4?t=16513

ballstothewall
11-16-2005, 05:48 PM
I am confused now....

Your conversation in anythign audo > me....

But it seems to me you just simpified wha they were trying to do, with cheaper and better componets? Pleas explain in idiot's terms...

-Ryan

*edit* So you just shot down their plans of a "chip amp" using standard pro amps, due to the fact that you can get them cheaper than what it would take to do a "chip amp"?

thylantyr
11-16-2005, 06:33 PM
:laugh: :banghead:

There is a long story behind 'chipamps', I would take me 1 hour to do a writeup,
but essentially you can buy something with more power, able to drive lower
impedance and no sacrifice to SQ for the same price or cheaper than these
chipamp projects. You can make these chipamp projects cheaper if you scrounge
for parts and make your own chassis, etc., but they are low powered amplifiers
no matter how you look at it.

Nelson Pass said in a forum post something to the effect "Make a real
amplifier, not a girlyman amplifier".... :) .. I still laugh at that comment.

ballstothewall
11-16-2005, 08:21 PM
Ahhh ok, Thanks

JimJ
11-16-2005, 08:23 PM
:laugh: :banghead:

There is a long story behind 'chipamps', I would take me 1 hour to do a writeup,
but essentially you can buy something with more power, able to drive lower
impedance and no sacrifice to SQ for the same price or cheaper than these
chipamp projects. You can make these chipamp projects cheaper if you scrounge
for parts and make your own chassis, etc., but they are low powered amplifiers
no matter how you look at it.

Nelson Pass said in a forum post something to the effect "Make a real
amplifier, not a girlyman amplifier".... :) .. I still laugh at that comment.

So your beef with them is their low power?

I find it ironic that Pass said that, especially considering the work he's done on the Zen, a "girlyman" amplifier if there ever was one :D

PV Audio
11-16-2005, 09:45 PM
pass labs FTW!!!

thylantyr
11-16-2005, 10:05 PM
So your beef with them is their low power?

I find it ironic that Pass said that, especially considering the work he's done on the Zen, a "girlyman" amplifier if there ever was one :D

The is alot more comedy involving the 'gaincloners'. It's a story to tell someday.
Maybe later I can dig up old rants... Andy Rooney on chipamps :cool:

JimJ
11-16-2005, 10:06 PM
I've never been a fan of the chip's myself...

thylantyr
11-17-2005, 03:21 AM
Crash Course in Gainclone Comedy

A chip amplifier pics;
http://www.tech-diy.com/Chipamps/completed.jpg
http://ludens.cl/Electron/audioamps/TA8215.jpg
http://www.dragons-lair-project.com/tech/virtual/images/ab/amplifer.jpg

This is an amplifier circuit on a die inside a package and to complete the amplifier
circuit you add some extra parts and power supply. These chip amplifiers have
been around for decades, you see them in low budget home stereos. An audiophile would never buy a chip amp product as they prefer a 'discrete design', individual transistors, diodes, etc. see pic;

Four transistors on the heatsink with all the other circuits on the board.
http://www.drachen-audio.com/Images/DA1_100W_audio_amplifier.jpg

A few years ago, this company;
http://www.sakurasystems.com/intro.html

Made a chip amp product called 'Gaincard';
http://www.sakurasystems.com/products/47amp.html

People found out it was an ordinary chip amp design with external power supply.
It's an 'audiophile' amplifier and reviews were good.

When the DIY community at Diyaudio.com found out it was a chip amp everyone
jumped on the 'Gainclone' bandwagon.

[b]The Comedy; They either bought the chip amp, I think it was the LM3875
or got free samples from National Semiconductor, and made their own chip amp,
there is nothing really to make, the amplifier is already designed all you do is add
a few extra parts and power the chip and viola' - you have music.

It's bad enough that all of a sudden these things are cool whereas for
years they were not cool, but it's pretty pathetic to call your LM3875
DIY amplifier a gainclone as if you really cloned something :laugh: :laugh: :laugh:

The gainclones do not look like the Gaincard, they use the same chip amp and
that alone justifies the name 'GainClone' ??? ... It's like me looking inside a
Bryston amplifier and saying 'hey, they use a XYZ transistor, I'm gonna make
an amplifier using this and it's gonna be a ByrstonClone amp, woo hoo! :uhoh: "

Or

I'm gonna buy the crate engine found in a Corvette and install that engine on my
rolling chassis, viola', CorvetteClone car .... /hehe

To make the comedy deeper, people are adding audio voodoo to their chip amp
recipe. Black Gate capacitors for the power supply, don't use >1500uF capacitors
on the +V/-V rails and make sure you use Panasonic FC caps for SQ, don't use
input coupling capacitors, and the gain clone sounds best using the inverting input... something to that effect. Now people are using the 'Carlosfm' snubber'
circuit {1 cap, 1 resistor} on the power supply because it sounds so good :uhoh:
... as if normal power supply decoupling techniques no longer work anymore
as they once did and continue to do in the electronics industry.

The Comedy Continues
Nelson Pass, the world famous amplifier designer decided to apply his patented 'X topology'
to the chip amp, taking two chip amps and offering the DIY minions a new bone to chew on.
Now we have a slurry of Gainclone X amps in the DIY interest, hehehe

If you look at Jeff Roland, uber high end product, they really have a chip amp product too .. rofl

Recently on the HTguide.com forum this was posted;
http://www.twistedpearaudio.com/

Schematic;
http://www.diyaudio.com/forums/attachment.php?postid=609507&stamp=1112280850

This is a funny design. He places an opamp front end and uses the chip amp
as a booster only and he offers a PCB for this design. You need two of these
PCB's for 1 channel, so 4 PCB's for a stereo amp. The design is too 'busy' and
bloated with nonsense, yet the design is praised as being clever and refreshing
when it's really retarded. It's a single LM3886 per PCB.

You can order a LM4780 chip amp with has two LM3886's inside and you
can bridge or parallel the design and make 1 chip per channel which is 'better'
as it's simple. BrianGT makes a good LM4780 PCB for reasonable price.

I've built a four channel LM4780 amplifier recently for a friend with my
own power supply recipe and I did some basic electrical mods and while
these chip amps are cool, they do run hot, they are limited by 35v rails,
limited in power output and considering that it took me a few weeks to
build this and factoring in costs for all the parts, the money spent is not
worth the result. You can get a pro amplifier for about the same money unless
you scrounged for parts to make your chip amp. They are boring amplifiers,
but they do work and sound fine if you live with it's ultra weak power and
headroom.

thylantyr
11-21-2005, 01:27 PM
:laugh: :thumbsdo: :rolleyes:

http://www.diyaudio.com/forums/showthread.php?postid=771831#post771831



What a waste of a nice heatsink for a real amplifier design :laugh: