On Sep 18, 5:30 pm, "AUUDDIIOOO" wrote:
Just wondered on what happened to the Power amp He had.

The SkyWave 2879ABTC was discontinued because of a poor profit margin.
We hated to do it... but with the temperature compensating biasing...
and all the premium components and chassis... it was just too costly
to manufacture. Unlike other companies, we will discontinue a product
before we will cost reduce it to a point that sacrafices quality and
reliability. Sometimes I just go back and look at the photos... just
for old times sake... http://www.telstar-electronics.com/d...9ABTCPhoto.htm
www.telstar-electronics.com

IDIOT
"Telstar Electronics" wrote in message
ups.com...

Hi,

On Wed, 19 Sep 2007 05:55:10 -0700, Telstar Electronics wrote:

The SkyWave 2879ABTC was discontinued because of a poor profit margin.

Raising the price was not an option?

Cheers,
__
Gregg

The SkyWave 2879ABTC was discontinued because of a poor profit margin.
We hated to do it... but with the temperature compensating biasing...
and all the premium components and chassis... it was just too costly
to manufacture.

Why on earth would you put temperature compensating components
into this product. As far as I know no other doorstop on the market
uses them.

On Sep 19, 8:53 pm, wrote:
Why on earth would you put temperature compensating components
into this product. As far as I know no other doorstop on the market
uses them.

Not temp compensating components... temp compensating bias.
www.telstar-electronics.com

On Thu, 20 Sep 2007 02:54:33 -0700, Telstar Electronics
wrote:

On Sep 19, 8:53 pm, wrote:
Why on earth would you put temperature compensating components
into this product. As far as I know no other doorstop on the market
uses them.

Not temp compensating components... temp compensating bias.
www.telstar-electronics.com

Oh...your bias is magical? It uses no components for compensation?

I always suspected your design to be that of an imaginary nature.

On Sep 20, 3:03 pm, wrote:
Oh...your bias is magical? It uses no components for compensation?
I always suspected your design to be that of an imaginary nature.

Not magical... it used the base-emitter voltage drop of an MJE3055T
(mounted directly to heat sink) to track with the 2SC2879 power
transistors. Since it used a transistor with gain... it worked so much
better than just a plain old diode on the sink for tracking. It worked
fantastic... I was able to set set class AB bias ( I chose about
200Ma) on the power transistors... and hold +/-5% collector current
changes from -40 to +100C heat sink temp during amp operation.
www.telstar-electronics.com

On Thu, 20 Sep 2007 17:08:23 -0700, Telstar Electronics
wrote in
. com:

On Sep 20, 3:03 pm, wrote:
Oh...your bias is magical? It uses no components for compensation?
I always suspected your design to be that of an imaginary nature.

Not magical... it used the base-emitter voltage drop of an MJE3055T
(mounted directly to heat sink) to track with the 2SC2879 power
transistors. Since it used a transistor with gain... it worked so much
better than just a plain old diode on the sink for tracking. It worked
fantastic...


How well it works depends on how well you hacked the design from this
link I posted (while pointing out some of the many problems with your
earlier splatterbox):

http://www.ifwtech.co.uk/g3sek/tr-bias/tr-bias1.htm


I was able to set set class AB bias ( I chose about
200Ma) on the power transistors... and hold +/-5% collector current
changes from -40 to +100C heat sink temp during amp operation.


That's interesting. Previously you said your bias scheme can "hold the
500mA bias to 10% from -30 to +85C". It's funny how many times you
have changed the specs. I especially enjoyed the time when you changed
the power output specs three times in one week after you were caught
fabricating them instead of actually measuring them. Oh well, such is
the life of an internet-educated hack.

But alas, there's still one unresolved issue here, Brian.... where's
the schematic?