Having *fixed* the 'high end' 300B SET monos:

http://www.apah69.dsl.pipex.com/show/BothAmps.JPG

http://www.apah69.dsl.pipex.com/show/Together.JPG


....earlier today, I have had a very good opportunity to compare them
with my POS Chinese 300B SET stereo amp:

http://www.apah69.dsl.pipex.com/myhifi/Bez%20T3B-3.JPG


....and I'm sorry to say the Chinky knocks the crap out of them!! (More
if anyone is interested...)

But that's not important....

What is important is that they are (and, I suspect, always have been)
*out of phase* with each other!! And no, before you ask, there's no way
I got the I/P signal wire twisted up!!

Larf? Do ewe not hafta...??

:-)

If their new owner disagrees with me I will post a retraction (or say
so) here, but I'm *pretty certain* - which is a seriously big shame if
it means my little friend who bought the amps originally never heard
them in phase...??

Keith G wrote:
Having *fixed* the 'high end' 300B SET monos:

http://www.apah69.dsl.pipex.com/show/BothAmps.JPG

http://www.apah69.dsl.pipex.com/show/Together.JPG


...earlier today, I have had a very good opportunity to compare them
with my POS Chinese 300B SET stereo amp:

http://www.apah69.dsl.pipex.com/myhifi/Bez%20T3B-3.JPG


...and I'm sorry to say the Chinky knocks the crap out of them!! (More
if anyone is interested...)

But that's not important....

What is important is that they are (and, I suspect, always have been)
*out of phase* with each other!! And no, before you ask, there's no way
I got the I/P signal wire twisted up!!

Larf? Do ewe not hafta...??

:-)

If their new owner disagrees with me I will post a retraction (or say
so) here, but I'm *pretty certain* - which is a seriously big shame if
it means my little friend who bought the amps originally never heard
them in phase...??



One of the many benefits of overall negative feedback in a valve amp is
that it ensures you get the output transformer phased right. With no
overall NF on these amps, they will work equally well either way round.
There's no excuse for sloppy manufacture, but at least with NF, it would
never have left the factory like that. (assuming of course that they
were tested at all)

S.

--
http://audiopages.googlepages.com

"Serge Auckland" wrote

One of the many benefits of overall negative feedback in a valve amp
is that it ensures you get the output transformer phased right. With
no overall NF on these amps, they will work equally well either way
round. There's no excuse for sloppy manufacture, but at least with NF,
it would never have left the factory like that. (assuming of course
that they were tested at all)


OK Serge, where is this going to have happened then?

I'm certain I haven't buggered up the coax signal wires but I'm equally
certain they amps are out of phase, is it likely to be the transformers?
Doesn't help the amps are handed but the speaker connectors are colour
coded red/black/red, so it's not a question of how they are hooked up!

Keith G wrote:
"Serge Auckland" wrote

One of the many benefits of overall negative feedback in a valve amp
is that it ensures you get the output transformer phased right. With
no overall NF on these amps, they will work equally well either way
round. There's no excuse for sloppy manufacture, but at least with NF,
it would never have left the factory like that. (assuming of course
that they were tested at all)


OK Serge, where is this going to have happened then?

I'm certain I haven't buggered up the coax signal wires but I'm equally
certain they amps are out of phase, is it likely to be the transformers?
Doesn't help the amps are handed but the speaker connectors are colour
coded red/black/red, so it's not a question of how they are hooked up!





This isn't something that has changed, they must have been like that
from new. There's no mechanism that will change the phase. Nick's
suggestion is correct, compare the connections in and out of the output
transformer, and see if they are different. It could be that the
transformer connections are identically colour-coded but that the
transformer itself has been wired differently. If so, just reverse the
b+ and 300b anode connections on one amplifier. I suppose you should
find out which amp is out of phase, and reverse the other one, but
unless the new owner is one of these "absolute phase" nuts, it doesn't
matter provided they are both equally phased.

S.

--
http://audiopages.googlepages.com

"Serge Auckland" wrote in message
...
Keith G wrote:
"Serge Auckland" wrote

One of the many benefits of overall negative feedback in a valve amp
is that it ensures you get the output transformer phased right. With
no overall NF on these amps, they will work equally well either way
round. There's no excuse for sloppy manufacture, but at least with
NF, it would never have left the factory like that. (assuming of
course that they were tested at all)


OK Serge, where is this going to have happened then?

I'm certain I haven't buggered up the coax signal wires but I'm
equally certain they amps are out of phase, is it likely to be the
transformers? Doesn't help the amps are handed but the speaker
connectors are colour coded red/black/red, so it's not a question of
how they are hooked up!





This isn't something that has changed, they must have been like that
from new. There's no mechanism that will change the phase.


No, I didn't expect there would be and it's a certainty the first owner
would not have fiddled with them.


Nick's
suggestion is correct, compare the connections in and out of the
output transformer, and see if they are different. It could be that
the transformer connections are identically colour-coded but that the
transformer itself has been wired differently. If so, just reverse the
b+ and 300b anode connections on one amplifier.


As I said earlier (?), they are no longer here. Whether or not the
present owner will want anything done about it (or even agrees) remains
to be seen.

I suppose you should
find out which amp is out of phase, and reverse the other one, but
unless the new owner is one of these "absolute phase" nuts, it doesn't
matter provided they are both equally phased.


Which he can do with the speaker leads!

Keith G wrote:
Having *fixed* the 'high end' 300B SET monos:
If their new owner disagrees with me I will post a retraction (or say
so) here, but I'm *pretty certain* - which is a seriously big shame if
it means my little friend who bought the amps originally never heard
them in phase...??

Like the look of the 300B set monos what are they ?

"Dave xxxx" wrote in message
.uk...
Keith G wrote:
Having *fixed* the 'high end' 300B SET monos:
If their new owner disagrees with me I will post a retraction (or
say
so) here, but I'm *pretty certain* - which is a seriously big shame
if
it means my little friend who bought the amps originally never heard
them in phase...??

Like the look of the 300B set monos what are they ?



Professionally-built Audio Note 'Quest' clones.

In article ,
Keith G wrote:
What is important is that they are (and, I suspect, always have been)
*out of phase* with each other!! And no, before you ask, there's no way
I got the I/P signal wire twisted up!!

Larf? Do ewe not hafta...??

Since valves are basically unbalanced devices, the problem must be in the
output transformer?

--
*Even a blind pig stumbles across an acorn now and again *

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

"Dave Plowman (News)" wrote in message
...
In article ,
Keith G wrote:
What is important is that they are (and, I suspect, always have been)
*out of phase* with each other!! And no, before you ask, there's no
way
I got the I/P signal wire twisted up!!

Larf? Do ewe not hafta...??

Since valves are basically unbalanced devices, the problem must be in
the
output transformer?


I had no suspicion when I had them open (I had never heard them) or I
would have had a good look round - the amps are handed, but I suspect
summat's *not*...??

Keith G wrote:
"Dave Plowman (News)" wrote in message
...

In article ,
Keith G wrote:

What is important is that they are (and, I suspect, always have been)
*out of phase* with each other!! And no, before you ask, there's no
way
I got the I/P signal wire twisted up!!

Larf? Do ewe not hafta...??

Since valves are basically unbalanced devices, the problem must be in
the
output transformer?



I had no suspicion when I had them open (I had never heard them) or I
would have had a good look round - the amps are handed, but I suspect
summat's *not*...??



Just compare the primary and secondary connections from the B+ and 300b
anode, and the speaker connections.

--
Nick