On Fri, 22 Dec 2006 10:41:50 -0500, "Arny Krueger"
wrote:

"Phil Allison" wrote in message

"gunnet"

Hi, I would like to get some infos on this power amp. I
didn't understand well if it's a tube or solidstate amp?
How many watts has? It's enough for a medium room with
89db floorstanding speaker?



** Tried a Google search for that info?

The schematic:

http://www.geocities.com/quad_esl63/...c/power306.jpg

The owner's manual:

http://www.hifiengine.com/library_mo...cted_model=306


I have two 306s here at the moment.

Which specific circuit features do you think prove that this amplifier is a
current dumping design?

The bridge feeding the load with an inductor in one arm, a capacitor
in the opposite arm and 2 resistors in the remaining arms.

"Eiron" wrote in message

Arny Krueger wrote:

"Phil Allison" wrote in message


"gunnet"

Hi, I would like to get some infos on this power amp. I
didn't understand well if it's a tube or solidstate
amp? How many watts has? It's enough for a medium room
with 89db floorstanding speaker?



** Tried a Google search for that info?

The schematic:

http://www.geocities.com/quad_esl63/...c/power306.jpg

The owner's manual:

http://www.hifiengine.com/library_mo...cted_model=306


I have two 306s here at the moment.


Which specific circuit features do you think prove that
this amplifier is a current dumping design?


That would be the lack of bias current in the output
transistors, the fact that the main output transistors
feed the output through an inductor while the low-power
amp feeds it through a resistor, and all the other
gubbins you find in a current dumping amp.

Thanks for the refresher. Your comments bring back what I read about current
dumping from the days of the 405.

Arny Krueger wrote:

"Eiron" wrote in message


Arny Krueger wrote:


"Phil Allison" wrote in message



"gunnet"


Hi, I would like to get some infos on this power amp. I
didn't understand well if it's a tube or solidstate
amp? How many watts has? It's enough for a medium room
with 89db floorstanding speaker?



** Tried a Google search for that info?

The schematic:

http://www.geocities.com/quad_esl63/...c/power306.jpg

The owner's manual:

http://www.hifiengine.com/library_mo...cted_model=306


I have two 306s here at the moment.


Which specific circuit features do you think prove that
this amplifier is a current dumping design?


That would be the lack of bias current in the output
transistors, the fact that the main output transistors
feed the output through an inductor while the low-power
amp feeds it through a resistor, and all the other
gubbins you find in a current dumping amp.


Thanks for the refresher. Your comments bring back what I read about current
dumping from the days of the 405.

A wonderful thing happens when L3*C8 doesn't quite equal R22*(R24+R25)

--
Eiron.

"borat-steve"
gunnet wrote:

The Quad 306 is a 50wpc solid state power amp from the 1980's to early
90's. It did not use the more common current dumping technology of the
larger 405 or 606 model but is still a very good little power amp none
the less. You should not worry about it driving speakers with 89db
efficiency as this is a very common rating. Used sensibly its ok.
The seller said it was of 1997. Could it be?

No it was discontinued earlier than that as there was a range called 77
came out in about 1994.


** Because the Quad 77 was an integrated amp it did not replace the 306.

( The 77 integrated was not a current dumper, by all accounts. )

Quad also made the 707 power amp at the same time - it WAS a current
dumper.




....... Phil

"Arny Krueger"

Which specific circuit features do you think prove that this amplifier is
a current dumping design?



** The 47 pF cap and the 1.5uH inductor in that output bridge network are
dead give aways - Arny.



BTW

You did not respond to my question about Marsh and Jung a few days ago on
RAT.

Arny wrote:

Marsh and Jung did a wonderful job of running the other way when we
started talking about adding reasonable controls to their purported
listening tests.

I've spoken to both about them about these issues at great length, Jung
more than Marsh.


..... they did some really bad listening tests, tests that had tremendous
potential to produce false positive results. Then abused some existing
well-known facts about capacitors to impress some poorly-educated
amateurs.


** Did either of them *ever* consider that a detailed correction or
retraction of their ( snake oil) capacitor articles was the proper &
responsible thing to do ??

Or were they both utterly devoid of ethics and only concerned for the
welfare of their undeserved reputations ??

IOW, are they are comfortably relying on the hypothesis that until you
publicly admit a mistake, you haven't made one ??




....... Phil

Got no Google on your PC ????
I've got just outlook espress working. And on internet explorer it goes just
one site. You know they don't want you to go surfing instead of working..

But "current dumper" technology what is oppesed to in the other "normal"
amplifier?

In article ,
gunnet wrote:
I've got just outlook espress working.

That's a first, then.

--
*How many roads must a man travel down before he admits he is lost? *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
gunnet wrote:
I've got just outlook espress working.

That's a first, then.

I've learnt to _love_ it when you switch 'identity' with a mail open and
then it seems to close down but refuses to open the other identity!

You learn to use task manager a lot!

And I think it's _really_great_ that it downloads my news again and again.

In article ,
jasee wrote:
Dave Plowman (News) wrote:
In article ,
gunnet wrote:
I've got just outlook espress working.

That's a first, then.

I've learnt to _love_ it when you switch 'identity' with a mail open and
then it seems to close down but refuses to open the other identity!

You learn to use task manager a lot!

And I think it's _really_great_ that it downloads my news again and
again.

I'm only playing with it since I use RISC OS for news and e-mail, but
Thunderbird (free) seems so much better.

--
*Some people are alive only because it's illegal to kill them *

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Dave Plowman (News)
writes
In article ,
jasee wrote:
Dave Plowman (News) wrote:
In article ,
gunnet wrote:
I've got just outlook espress working.

That's a first, then.

I've learnt to _love_ it when you switch 'identity' with a mail open and
then it seems to close down but refuses to open the other identity!

You learn to use task manager a lot!

And I think it's _really_great_ that it downloads my news again and
again.

I'm only playing with it since I use RISC OS for news and e-mail, but
Thunderbird (free) seems so much better.

It is good .. but for a newsreader you cannot beat the old Turnpike ver 5.01
program)
--
Tony Sayer