Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

"Tube747"
....

My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?



** The GZ32 has an indirectly heat cathode while the 247 is directly
heated.

The former type has a lower voltage drop for a given current output.

The 247 should work but the HT will be down by 20 volts or so.



........... Phil

On Wed, 28 Jan 2004 11:39:18 +1100, "Phil Allison"
wrote:


"Tube747"
...

My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?



** The GZ32 has an indirectly heat cathode while the 247 is directly
heated.

The former type has a lower voltage drop for a given current output.

The 247 should work but the HT will be down by 20 volts or so.

Phil
The 247 is an S bulb 47 output pentode
or (in Westrex land)
a small filimentary triode
neither make particularly good full wave rectifiers
The 274, which the OP was referring to, is a different teapot full of
pirhana, and will work, but he would loose the advantages of slow
start afforded by the indirectly heated GZ32
M

"me" wrote in message
...
On Wed, 28 Jan 2004 11:39:18 +1100, "Phil Allison"
wrote:


"Tube747"
...

My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?



** The GZ32 has an indirectly heat cathode while the 247 is directly
heated.

The former type has a lower voltage drop for a given current output.

The 247 should work but the HT will be down by 20 volts or so.



Phil
The 247 is an S bulb 47 output pentode
or (in Westrex land)
a small filimentary triode
neither make particularly good full wave rectifiers


** How smartarse - so I made a tiny typo.


The 274, which the OP was referring to, is a different teapot full of
pirhana, and will work, but he would loose the advantages of slow
start afforded by the indirectly heated GZ32


** I have SS diodes in my Quad mk2 - with no problems.




.......... Phil

"Tube747" wrote in message
om...
Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

It draws 3A filament current, GZ32 draws 2A. This may push your quad power
tranny over the edge, they seem to be prone to blowing up so probably a bad
idea.

GZ32 is a far better rectifier than a 5U4/274B. And you should only use
British valves in a British amp!

"Henry007"

"Tube747"


My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?


It draws 3A filament current, GZ32 draws 2A.



** All three sites I checked gave the figure of 2 amps for the 274B.

Care to check on your 3 amp one.





.............. Phil

Tube747 wrote:

Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

Only if you are willing ( And able) to rewire with a 4-pin socket.
Even Phil A didn't bother to tell you that!!!!!!!!!!!!!!!

Good Luck, John Stewart

"John Stewart"

Tube747 wrote:

Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

Only if you are willing ( And able) to rewire with a 4-pin socket.
Even Phil A didn't bother to tell you that!!!!!!!!!!!!!!!


** Wrong again !!!!!!!!

The 274 B has an octal base with the same wiring as the GZ32.

see: http://www.westernelectric.com/274B/specs274Bindex.html

and http://tdsl.duncanamps.com/show.php?des=GZ32



Three strikes and you are out JH.



.............. Phil

Phil Allison wrote:

"John Stewart"

Tube747 wrote:

Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

Only if you are willing ( And able) to rewire with a 4-pin socket.
Even Phil A didn't bother to tell you that!!!!!!!!!!!!!!!

** Wrong again !!!!!!!!

The 274 B has an octal base with the same wiring as the GZ32.

see: http://www.westernelectric.com/274B/specs274Bindex.html

and http://tdsl.duncanamps.com/show.php?des=GZ32

Three strikes and you are out JH.

............. Phil

Is there no end to this man's expertise? Probably not! JLS

Tube747 wrote:
Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747
You can but the voltage drop would lower the power output to about 5 watts.
Phil

Hi Henry007!
I've seen someone selling a tube called 5V4GB and 5V4GT. As I know,
the 5V4GA is the equivalent to the GZ32. What about the 5V4GB and GT?

Thanks Again!


"Henry007" wrote in message ...
"Tube747" wrote in message
om...
Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

It draws 3A filament current, GZ32 draws 2A. This may push your quad power
tranny over the edge, they seem to be prone to blowing up so probably a bad
idea.

GZ32 is a far better rectifier than a 5U4/274B. And you should only use
British valves in a British amp!

"Phil Lawrence" wrote in message
u...
Tube747 wrote:
Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

You can but the voltage drop would lower the power output to about 5
watts.
Phil


** Huh ????????????????????????

20 volts less HT would not do that .



............... Phil

Tube747 wrote:

Hi Henry007!
I've seen someone selling a tube called 5V4GB and 5V4GT. As I know,
the 5V4GA is the equivalent to the GZ32. What about the 5V4GB and GT?

Thanks Again!

"Henry007" wrote in message ...
"Tube747" wrote in message
om...
Hi RATS!
My Quad II amplifier currently using GZ32 rectifier tube. Can 274B
replace the GZ32 on the Quad II amplifier?

Thank you!
Tube747

It draws 3A filament current, GZ32 draws 2A. This may push your quad power
tranny over the edge, they seem to be prone to blowing up so probably a bad
idea.

GZ32 is a far better rectifier than a 5U4/274B. And you should only use
British valves in a British amp!

The 247B is a rectifier and the data is seen at

http://www.westernelectric.com/274B/...74Bgraphs.html

WE state the maximum capacitor input should be 4 uF.
with a standard Quad II its 16 uF, and with 150ma of DC,
the ripple voltage which appears at the CT of the OPT
is about 20v, but with 4 uF it'd
be a very excessive 80v, and hence the lower
B+, also exacebated by the high Ra of the 274B,
and heater current is too high.

Just plugging in a 274B into a Quad II would
result in excessive charge currents in the rectifier,
and the tube would not last long.
GZ 34 and 32 have indirectly heated cathodes,
and a slow turn on character, and the GZ34
can take a 60 uF input cap.

Perhaps you have no intention to mkod your Quad II
amps very much, but for other who might be thinking of it,
here is some info.....

The better thing to do with Quad II if you want the amp to run cooler
and have the same as original operating voltages is to scrap the
tube rectifier the square boxed supply caps ,
and fit SS diodes plus 2 x 470 uF x 450v caps instead, a 10 watt R of 120
ohms to allow a drop from C1 to C1 to be equal to original.
Ripple voltage will then be 20 mV, instead of 20v.
This should allow cleaner sound into lowish value loads which
cause AB operation.
I have used KT88 in lieu of KT66 etc,
with fixed bias, and a plate choke to replace the screen choke
in the existing can and SS diodes, and caps of 60 uF C1 input, and 100 uF C2 filter
cap, with triode connection of the KT88, and 12AU7 LTP PI stage,
and paralleled 12AT7 as input.
I get 20 watts of beautiful class AB into 8 ohms.
The KT88 idle current is 60mA, B+ = 400v.
-bias supply is from two diodes making -400v, then
divided down to where I want it.

I then reversed the socket hold plate for the output tubes,
which allows a better airflow past the sockets, a neater wiring layout,
and drilled 30 x 10mm holes in the bottom cover.
The Turnerised Quad II amps run cooler than the original amps, and nothing
is stressed; the existing gear is just used more efficiently.
Sound is sweet as.
The customer has had these amps for 4 years,
and used them daily in NSW where the summer temps get up to 40c,
or 35c indoors at times.

The heater current for KT88 is 1.8A.
The heater current for KT66 is 1.27A.
The extra heater current for two KT88 is 1.06A.
The extra heater winding power is 6.7 watts.
If the winding losses are 7%, (and Quad would have at least achieved this
figure,) then the *extra* heater winding dissipation is 0.47 watts,
which is unlikely to fry the winding.
In my mod the heaters for the tube rectifier are unused.
Therefore the power tranny has less total power asked of it,
and there isn't a glowing tube radiating heat around to other
components on Quad's toy sized chassis.

Patrick Turner.

** The Turneroid farted:


and heater current is too high.

** Bull**** - it is is still 2amps.



Just plugging in a 274B into a Quad II would
result in excessive charge currents in the rectifier,
and the tube would not last long.


** How long is that then ???



Ripple voltage will then be 20 mV, instead of 20v.
This should allow cleaner sound into lowish value loads which
cause AB operation.


** Another of theTurneroid's asinine supposition. The demented old ****
knows more about suppositories than suppositions.



I have used KT88 in lieu of KT66 etc,


** Here we ****ing go again - the Turneroid has his trumpet out,
blasting away a one note concerto.



The Turnerised Quad II amps run cooler than the original amps, and nothing
is stressed; the existing gear is just used more efficiently.


** Yawn.


Sound is sweet as.


** Courtesy of Peter Walker's ( RIP) clever 1950's design.

Not anything the stinking Turneroid did.




............ Phil

Phil Allison wrote:

** The Turneroid farted:

and heater current is too high.

** Bull**** - it is is still 2amps.

Just plugging in a 274B into a Quad II would
result in excessive charge currents in the rectifier,
and the tube would not last long.

** How long is that then ???

Ripple voltage will then be 20 mV, instead of 20v.
This should allow cleaner sound into lowish value loads which
cause AB operation.

** Another of theTurneroid's asinine supposition. The demented old ****
knows more about suppositories than suppositions.

I have used KT88 in lieu of KT66 etc,

** Here we ****ing go again - the Turneroid has his trumpet out,
blasting away a one note concerto.

The Turnerised Quad II amps run cooler than the original amps, and nothing
is stressed; the existing gear is just used more efficiently.

** Yawn.

Sound is sweet as.

** Courtesy of Peter Walker's ( RIP) clever 1950's design.

Not anything the stinking Turneroid did.

........... Phil

Phil A continues to enlighten us with his superior knowledge of
the English Language!!!!!!!

Good Luck Phil. Cheers, John Stewart

In article , Patrick Turner
wrote:

The better thing to do with Quad II if you want the amp to run cooler
and have the same as original operating voltages is to scrap the
tube rectifier the square boxed supply caps ,
and fit SS diodes plus 2 x 470 uF x 450v caps instead, a 10 watt R of 120
ohms to allow a drop from C1 to C1 to be equal to original.
Ripple voltage will then be 20 mV, instead of 20v.
This should allow cleaner sound into lowish value loads which
cause AB operation.
I have used KT88 in lieu of KT66 etc,
with fixed bias, and a plate choke to replace the screen choke
in the existing can and SS diodes, and caps of 60 uF C1 input, and 100
uF C2 filter
cap, with triode connection of the KT88, and 12AU7 LTP PI stage,
and paralleled 12AT7 as input.
I get 20 watts of beautiful class AB into 8 ohms.
The KT88 idle current is 60mA, B+ = 400v.
-bias supply is from two diodes making -400v, then
divided down to where I want it.

I then reversed the socket hold plate for the output tubes,
which allows a better airflow past the sockets, a neater wiring layout,
and drilled 30 x 10mm holes in the bottom cover.
The Turnerised Quad II amps run cooler than the original amps, and nothing
is stressed; the existing gear is just used more efficiently.
Sound is sweet as.
The customer has had these amps for 4 years,
and used them daily in NSW where the summer temps get up to 40c,
or 35c indoors at times.

The heater current for KT88 is 1.8A.
The heater current for KT66 is 1.27A.
The extra heater current for two KT88 is 1.06A.
The extra heater winding power is 6.7 watts.
If the winding losses are 7%, (and Quad would have at least achieved this
figure,) then the *extra* heater winding dissipation is 0.47 watts,
which is unlikely to fry the winding.
In my mod the heaters for the tube rectifier are unused.
Therefore the power tranny has less total power asked of it,
and there isn't a glowing tube radiating heat around to other
components on Quad's toy sized chassis.

Except with a solid state rectifier running directly inot a 470 uF cap,
which is how I read the description of your modification, the RMS current
in the High Voltage winding is going to be considerably larger than stock,
creating significantly more heat, the exact amount depending on the
resistance of the HV winding.


Regards,

John Byrns


Surf my web pages at, http://users.rcn.com/jbyrns/

John Byrns wrote:

In article , Patrick Turner
wrote:

The better thing to do with Quad II if you want the amp to run cooler
and have the same as original operating voltages is to scrap the
tube rectifier the square boxed supply caps ,
and fit SS diodes plus 2 x 470 uF x 450v caps instead, a 10 watt R of 120
ohms to allow a drop from C1 to C1 to be equal to original.
Ripple voltage will then be 20 mV, instead of 20v.
This should allow cleaner sound into lowish value loads which
cause AB operation.
I have used KT88 in lieu of KT66 etc,
with fixed bias, and a plate choke to replace the screen choke
in the existing can and SS diodes, and caps of 60 uF C1 input, and 100
uF C2 filter
cap, with triode connection of the KT88, and 12AU7 LTP PI stage,
and paralleled 12AT7 as input.
I get 20 watts of beautiful class AB into 8 ohms.
The KT88 idle current is 60mA, B+ = 400v.
-bias supply is from two diodes making -400v, then
divided down to where I want it.

I then reversed the socket hold plate for the output tubes,
which allows a better airflow past the sockets, a neater wiring layout,
and drilled 30 x 10mm holes in the bottom cover.
The Turnerised Quad II amps run cooler than the original amps, and nothing
is stressed; the existing gear is just used more efficiently.
Sound is sweet as.
The customer has had these amps for 4 years,
and used them daily in NSW where the summer temps get up to 40c,
or 35c indoors at times.

The heater current for KT88 is 1.8A.
The heater current for KT66 is 1.27A.
The extra heater current for two KT88 is 1.06A.
The extra heater winding power is 6.7 watts.
If the winding losses are 7%, (and Quad would have at least achieved this
figure,) then the *extra* heater winding dissipation is 0.47 watts,
which is unlikely to fry the winding.
In my mod the heaters for the tube rectifier are unused.
Therefore the power tranny has less total power asked of it,
and there isn't a glowing tube radiating heat around to other
components on Quad's toy sized chassis.

Except with a solid state rectifier running directly into a 470 uF cap,
which is how I read the description of your modification, the RMS current
in the High Voltage winding is going to be considerably larger than stock,
creating significantly more heat, the exact amount depending on the
resistance of the HV winding.

I have used only 60 uF caps in the amp I modded,
but I still think 470 uF for C1 of a CLC network would be OK.

The amps I modded run cooler after 3 hrs.
The losses in the HT winding do not seem to increase that much
more than when running into a tube rectifier.
What you are saying is that since peak charge currents to say 470 uF
than 4 uF caps, and since P = I* x R then higher losses
occur in the main winding of the power tranny.
But the charging pulses don't last as long.
I saw no reason to tediously work out the HT power dissipation,
as spelled out in RDH4, considering the mains voltage
applied here is not a true sine wave anyway, and has a bit
of a flat top ( 3H ) due to thousands of rectifier circuits attatched to the
network.
Anyway, the T rise of the power tranny is due
to both the heat in the core and wire that is due to transformer
inefficiency, *and* the hot tubes in the near vicinity since Quad II
has rather a cramped layout.
Instead of 70mA per output tube of plate current, I have only 50 to 60 mA;
I found I needed less than Walker designed for to get less thd in the first five
watts.

Remove the rectifier tube, and its heater winding and that adds up to a fair bit

of saving on heat production.

Better than using 470 uF caps only, in a CRC network with an R which
reduces possible B+ and also wastes heat in an R of say 120 ohms,
it is better to use a choke, and if C1 is say 60 uF then peak charge currents
are
not much higher than stock, considering there is no need
for the full 70 mA per output tube if trioded KT88 are used.
with a choke of only 2H at 150mA, and C2 = 470 uF,
the ripple at the CT is going to be 15 mV, a vast improvement
on the stock Quad II amp.
If 20mV ripple is permissable at the CT for good class AB operation,
then 47 uF would be fine for C1 with 2 uF and C2 of 470 uF.
I think peak currents could be trimmed down a bit.
If C2 is 940 uF, then L needs only need be 1H.

For those wanting only 15 watts from a Quad II
amp with KT88 in triode, then using the CRC filter method
and cathode bias is simpler and easier, but when Quad II is set to
8 ohm matching, with 8 ohms, the opvs are loaded with only
3.8k a-a, including the winding losses. I have tried using
EL34 as triodes instead of KT66 as stock or triodes,
but the Ra of the EL34 is still rather highish where the
load lines cross the Eg1 = 0V line, so 13 watts is all that's really manageable.

The lower Ra of the KT88 in triode allows slightly greater voltage swing.
KT90EH with heater current of 1.6 amps would even be better still
in triode, with Ra even lower, and still cheaper than
NOS or premium KT66.
KT90 would last awhile, since so little is being asked of them.

I have not bothered to try KT88 or KT90 set up in acoustical
mode as in original Quad II.
Maybe one gets about 35 watts, but watts ain't everything.
As long as idle currents and supply voltages don't result in greater
power draw from the PT than Mr Walker designed for then
I see no reason why the higher power capable tubes can't be used.
The power into 16 ohms will remain nearly the same
as with KT66 EL34 (in acoustical) but because of the greater
signal current swing of the gruntier tubes, the AB power into
lower value loads will be greater, like when you have a 4 ohm load connected to
the
amp when its set for 8 ohm matching.
There is thus a little extra headroom for transients.
With the lowish B+ even 6CM5 would be good in a Quad II.

Patrick Turner.





Regards,

John Byrns

Surf my web pages at, http://users.rcn.com/jbyrns/

"Patrick Turner"

John Byrns wrote:

Except with a solid state rectifier running directly into a 470 uF cap,
which is how I read the description of your modification, the RMS
current
in the High Voltage winding is going to be considerably larger than
stock,
creating significantly more heat, the exact amount depending on the
resistance of the HV winding.


What you are saying is that since peak charge currents to say 470 uF
than 4 uF caps, and since P = I* x R then higher losses
occur in the main winding of the power tranny.
But the charging pulses don't last as long.


** For the same average value, larger and shorter current pulses means the
rms value has gone up.


I saw no reason to tediously work out the HT power dissipation,


** What a stupid olf fart the Turneroid demonstrates himself to be - over
and over and over .

You only need connect a true rms amp meter in series with the AC mains to
see the change in VA.

Using SS diodes with a first filter cap of even 60 uF will likely increase
the *rms* current in the main secondary by 50 % resulting in double the
original copper loss in watts in that winding and a similar increase in the
primary.




........... Phil

Phil Allison wrote:

"Patrick Turner"

John Byrns wrote:

Except with a solid state rectifier running directly into a 470 uF cap,
which is how I read the description of your modification, the RMS
current
in the High Voltage winding is going to be considerably larger than
stock,
creating significantly more heat, the exact amount depending on the
resistance of the HV winding.

What you are saying is that since peak charge currents to say 470 uF
than 4 uF caps, and since P = I* x R then higher losses
occur in the main winding of the power tranny.
But the charging pulses don't last as long.

** For the same average value, larger and shorter current pulses means the
rms value has gone up.

I saw no reason to tediously work out the HT power dissipation,

** What a stupid olf fart the Turneroid demonstrates himself to be - over
and over and over .

You only need connect a true rms amp meter in series with the AC mains to
see the change in VA.

Using SS diodes with a first filter cap of even 60 uF will likely increase
the *rms* current in the main secondary by 50 % resulting in double the
original copper loss in watts in that winding and a similar increase in the
primary.

You will have to explain the tedious calculations to prove
what you say Phil, and if you don't, then just shut up,
and **** off.


But the altered Quad II amp runs cooler Phil.
*cooler*, did you get that? Do you suppose I didn't measure the T rise?

Phil is yet to demonstrate he has any practical expertise as designing
or constructing any valve gear of his own whatsoever.

By Phil's reckoning, raising the C1 value of a CLC power supply to an infinite
value would forever increase the rms currents and the tranny
winding would have to sustain an infinite dissipation.
But of course the summed P and S winding resistance prevents all this from
happening.
60 uF is quite able to be tolerated as C1 in a Quad II tranny.
In Leak amps, I have seen 470 uF used as C1 with no problems,
and they have fairly hot running power trannies in any case,
even in original form.
One can place some series R in series with the caps to dissipate
some heat and limit charge currents, but they don't do very much
except lower B+ to unacceptable levels.
Using C1 = 16 uF gives about 20vrms ripple at C1, and to get
ripple at C2 to 20 mV, with C2 = 940 uF which is a pair of 470 uF paralleled,
then you'd need the L to be 1,000 times the 100 Hz impedance of the 940 uF
at 100 Hz, so ZL = 1700 ohms so L must be 2.7 H, quite doable..
If you place a 0.93 uF 10 ohm series R across the 2.7H L,
then the L part of the CLC becomes a damped resonant circuit,
and the 100 Hz ripple at C2 drops to very much lower levels
than one will get with pure CLC.

I am using this principle quite successsfully in an SE amp
at the moment, with C1 = 470 uF, C2 = 940 uF, L = 850mH,
and R = 10 ohms, and Cshunt = 3 uF.
The ripple is reduced to negligible levels in a 300 mA supply
for a quad of 6CA7 in parallel.
I did first try a solid state regulator, but I went to the CLC method
when I found it simpler, more reliable, and lest wasteful of power
in a series R before the reg, and in the reg heatsink.

Patrick Turner.

"Patrick Turner" wrote in message
...

Phil Allison wrote:

** What a stupid old fart the Turneroid demonstrates himself to be -
over
and over and over .

You only need connect a true rms amp meter in series with the AC mains
to
see the change in VA.

Using SS diodes with a first filter cap of even 60 uF will likely
increase
the *rms* current in the main secondary by 50 % resulting in double the
original copper loss in watts in that winding and a similar increase in
the
primary.


You will have to explain the tedious calculations to prove
what you say Phil,


** No need for any such stupid thing - just do a measurement.


and if you don't, then just shut up, and **** off.


** The Turneroid never, ever, ever tells me what to do.


But the altered Quad II amp runs cooler Phil.


** Then post the proof with rms current measurements before and after.



Phil is yet to demonstrate he has any practical expertise as designing
or constructing any valve gear of his own whatsoever.


** The Turneroid is yet to offer any counter to my technically valid
points.

As ****ing usual.


By Phil's reckoning,


** Here we go - the Turneroid is inventing things that I did *** NOT
****ING SAY ***.



raising the C1 value of a CLC power supply to an infinite
value would forever increase the rms currents and the tranny
winding would have to sustain an infinite dissipation.


** The value of C1 has only a minor effect on the rms current figure,
within the limits of acceptable ripple.

Changing to SS diodes, however, has a marked effect since their conduction
resistance is only a fraction of an ohm.



............ Phil

In article , Patrick Turner
wrote:

Phil Allison wrote:

Using SS diodes with a first filter cap of even 60 uF will likely increase
the *rms* current in the main secondary by 50 % resulting in double the
original copper loss in watts in that winding and a similar increase in the
primary.

You will have to explain the tedious calculations to prove
what you say Phil, and if you don't, then just shut up,
and **** off.

No need for tedious calculations, you said you had to add a series
resistor after the first capacitor to bring the B+ voltage back down to
normal. The higher voltage on the first capacitor implies a shorter
conduction time or angle, which in turn implies higher peak currents, and
shorter conduction times and higher peak currents imply a higher RMS
current from the HV secondary winding resulting in more heating of that
winding. Now of course we need to have the actual wave forms from the
stock and modified Quad II to put precise numbers on this, and it is even
theoretically possible that the RMS current could go down if the wave
forms are pathological, which would be nearly impossible. Why don't you
post some scope photos of the rectifier wave forms before and after, and
we can go from there?

But the altered Quad II amp runs cooler Phil.
*cooler*, did you get that? Do you suppose I didn't measure the T rise?

I didn't hear anyone say the modified amp didn't run cooler, after all you
eliminated the rectifier tube, and the heat produced by its heater, and
losses in the power transformer resulting from the rectifier heater
winding. All that is being said is that the High Voltage secondary will
produce more heat with your modification, that doesn't prevent an overall
reduction in heat.

John


Surf my web pages at, http://users.rcn.com/jbyrns/

"John Byrns"

Patrick Turner


You will have to explain the tedious calculations to prove
what you say Phil, and if you don't, then just shut up,
and **** off.


No need for tedious calculations, you said you had to add a series
resistor after the first capacitor to bring the B+ voltage back down to
normal. The higher voltage on the first capacitor implies a shorter
conduction time or angle, which in turn implies higher peak currents, and
shorter conduction times and higher peak currents imply a higher RMS
current from the HV secondary winding resulting in more heating of that
winding. Now of course we need to have the actual wave forms from the
stock and modified Quad II to put precise numbers on this,


** Attempting to derive an rms value by calculation for some arbitrary
waveform is absurd.

One just measures it !!!!!

True rms DMMs are cheap and plentiful enough even for a tight arse like
the Turneroid.

He will never do it though - the idea in not mentioned in his tube
bigot's bible.





............ Phil

Patrick Turner wrote:

Phil Allison wrote:

"Patrick Turner"

John Byrns wrote:

Except with a solid state rectifier running directly into a 470 uF cap,
which is how I read the description of your modification, the RMS
current
in the High Voltage winding is going to be considerably larger than
stock,
creating significantly more heat, the exact amount depending on the
resistance of the HV winding.

What you are saying is that since peak charge currents to say 470 uF
than 4 uF caps, and since P = I* x R then higher losses
occur in the main winding of the power tranny.
But the charging pulses don't last as long.

** For the same average value, larger and shorter current pulses means the
rms value has gone up.

I saw no reason to tediously work out the HT power dissipation,

** What a stupid olf fart the Turneroid demonstrates himself to be - over
and over and over .

You only need connect a true rms amp meter in series with the AC mains to
see the change in VA.

Using SS diodes with a first filter cap of even 60 uF will likely increase
the *rms* current in the main secondary by 50 % resulting in double the
original copper loss in watts in that winding and a similar increase in the
primary.

You will have to explain the tedious calculations to prove
what you say Phil, and if you don't, then just shut up,
and **** off.

But the altered Quad II amp runs cooler Phil.
*cooler*, did you get that? Do you suppose I didn't measure the T rise?

Phil is yet to demonstrate he has any practical expertise as designing
or constructing any valve gear of his own whatsoever.

By Phil's reckoning, raising the C1 value of a CLC power supply to an infinite
value would forever increase the rms currents and the tranny
winding would have to sustain an infinite dissipation.
But of course the summed P and S winding resistance prevents all this from
happening.
60 uF is quite able to be tolerated as C1 in a Quad II tranny.
In Leak amps, I have seen 470 uF used as C1 with no problems,
and they have fairly hot running power trannies in any case,
even in original form.
One can place some series R in series with the caps to dissipate
some heat and limit charge currents, but they don't do very much
except lower B+ to unacceptable levels.
Using C1 = 16 uF gives about 20vrms ripple at C1, and to get
ripple at C2 to 20 mV, with C2 = 940 uF which is a pair of 470 uF paralleled,
then you'd need the L to be 1,000 times the 100 Hz impedance of the 940 uF
at 100 Hz, so ZL = 1700 ohms so L must be 2.7 H, quite doable..
If you place a 0.93 uF 10 ohm series R across the 2.7H L,
then the L part of the CLC becomes a damped resonant circuit,
and the 100 Hz ripple at C2 drops to very much lower levels
than one will get with pure CLC.

I am using this principle quite successsfully in an SE amp
at the moment, with C1 = 470 uF, C2 = 940 uF, L = 850mH,
and R = 10 ohms, and Cshunt = 3 uF.
The ripple is reduced to negligible levels in a 300 mA supply
for a quad of 6CA7 in parallel.
I did first try a solid state regulator, but I went to the CLC method
when I found it simpler, more reliable, and lest wasteful of power
in a series R before the reg, and in the reg heatsink.

Patrick Turner.

I didn't bother to read all the responses since as usual a 'fog of
bull ****' hung over the whole subject. Anyway, the ultimate peak
& RMS current in the transformer is limited by the winding R &
reflected primary R & the leakage inductance. I've measured lots
of them with a MetraHit 29S Precision DMM that I bought at
tremendous expense. After a certain point increasing the cap
size makes no difference to the peak & RMS currents.

If you wonder what a MetraHit 29S is see the following link.

www.gmc-instruments.com

Cheers, John Stewart

John Byrns wrote:

In article , Patrick Turner
wrote:

Phil Allison wrote:

Using SS diodes with a first filter cap of even 60 uF will likely increase
the *rms* current in the main secondary by 50 % resulting in double the
original copper loss in watts in that winding and a similar increase in the
primary.

You will have to explain the tedious calculations to prove
what you say Phil, and if you don't, then just shut up,
and **** off.

No need for tedious calculations, you said you had to add a series
resistor after the first capacitor to bring the B+ voltage back down to
normal. The higher voltage on the first capacitor implies a shorter
conduction time or angle, which in turn implies higher peak currents, and
shorter conduction times and higher peak currents imply a higher RMS
current from the HV secondary winding resulting in more heating of that
winding. Now of course we need to have the actual wave forms from the
stock and modified Quad II to put precise numbers on this, and it is even
theoretically possible that the RMS current could go down if the wave
forms are pathological, which would be nearly impossible. Why don't you
post some scope photos of the rectifier wave forms before and after, and
we can go from there?

But the altered Quad II amp runs cooler Phil.
*cooler*, did you get that? Do you suppose I didn't measure the T rise?

I didn't hear anyone say the modified amp didn't run cooler, after all you
eliminated the rectifier tube, and the heat produced by its heater, and
losses in the power transformer resulting from the rectifier heater
winding. All that is being said is that the High Voltage secondary will
produce more heat with your modification, that doesn't prevent an overall
reduction in heat.

The use of 60 uF as C1 instead of the stock 16 uF does in fact
increase the heat dissipation in the HT winding. Not much though.
The plate current is 55mA per output tube rather than 70mA
as original.
The 5V GZ32 heater winding isn't used.
The overall effect of having no tube heater in the amp means the mains tranny
gets less radiated heat and runs cooler.
The 230v Quad II mains wiring is 13.3 ohms, and the HT winding is 135ohms,
about 67ohms each side of a CT.

The HT winding has to provide the DC B+ power plus any wastage.
This is about 52 watts.
If the copper losses are 10%, then that 5 watts of heat loss,
and I have not witnessed that raising C1 from 16 uF to 60 uF increases these
losses from 5 to say 18 watts, proportionately to the rise in capacitance,
and by way of using silicon diodes.

But I have given you enough raw data to calculate what losses increase
do in fact occur using formula contained in RDH4.

Methinks the Quad II power tranny has greater core losses
than winding losses, and it is also a potted tranny, whose internals run hotter
than if unpotted, and Mr Walker allowed for this.

The Quad II tranny has to make about 75 watts all up
depending on attached radio tuners etc.
Losses might be 12% at 9 watts, which doesn't explain the
T rise seen in these amps; in stock versions there is a GZ32
and KT66 almost hard against the tranny casing,
so radiated heat pick up to the PT would be 16 watts in my estimate.
Even on a warm summer day, one can still keep a hand on a Quad II PT,
meaning that T is less than 45C and T rise about 15C,
well within a reasonable figure.
Walker's later 405 PTs ran very cool.

Patrick Turner.



John

Surf my web pages at, http://users.rcn.com/jbyrns/

Because Phil Allison writes with such attrocious use
of insults and obscenities, I have ZERO intention
to reply directly to his twaddle, and so I won't confirm or
deny what use I would make of an RMS meter.

I repeat that Phil Allison has never designed and built any tubed equipment
and hence has little practical experience or relevant knowledge
about what he has said is anachronistic engineering.

He has no website, makes no electronic products forsale,
and merely runs a pint sized electronics repair business,
and after what I have read from his keyboard on the Net,
I would never ever take anything to him to be repaired.
He has delusions of granduer about his acedemic qualifications.
He has failed all his 'human communications' exams repeatedly.
I see zero reason to show him the slightest respect.


Phil is a loudmouth grossly immature gutter person who tries to hang out here
simply to see how many brawls and muggings he can perpetuate,
in the mistaken cause of somehow changing the world to a better place,
but he just leaves slimy trails of muddy encounters wherever he goes.

He brings nothing constructive to the discussions
about tube craft.

Patrick Turner.


Phil Allison wrote:

"John Byrns"

Patrick Turner


You will have to explain the tedious calculations to prove
what you say Phil, and if you don't, then just shut up,
and **** off.


No need for tedious calculations, you said you had to add a series
resistor after the first capacitor to bring the B+ voltage back down to
normal. The higher voltage on the first capacitor implies a shorter
conduction time or angle, which in turn implies higher peak currents, and
shorter conduction times and higher peak currents imply a higher RMS
current from the HV secondary winding resulting in more heating of that
winding. Now of course we need to have the actual wave forms from the
stock and modified Quad II to put precise numbers on this,

** Attempting to derive an rms value by calculation for some arbitrary
waveform is absurd.

One just measures it !!!!!

True rms DMMs are cheap and plentiful enough even for a tight arse like
the Turneroid.

He will never do it though - the idea in not mentioned in his tube
bigot's bible.

........... Phil

"John Stewart"


I didn't bother to read all the responses since as usual a 'fog of
bull ****' hung over the whole subject.


** So you missed the facts and post utter bull**** as usual.



Anyway, the ultimate peak
& RMS current in the transformer is limited by the winding R &
reflected primary R & the leakage inductance. I've measured lots
of them with a MetraHit 29S Precision DMM that I bought at
tremendous expense. After a certain point increasing the cap
size makes no difference to the peak & RMS currents.


** The cap size is not the main issue with the increase in rms current
value - the use of SS diodes is.




........... Phil

"Patrick Turner"


Because Phil Allison writes with such attrocious use
of insults and obscenities, I have ZERO intention
to reply directly to his twaddle, and so I won't confirm or
deny what use I would make of an RMS meter.


** So the stinking, lying, top posting, Turneroid pig covers up one of
his his massive blunders yet again by refusing to even look at them. Same
as any autistic cretin there.




I repeat that Phil Allison has never designed and built any tubed
equipment


** Massive ****ing lie - how would the Turneroid know anything like that
???


and hence has little practical experience or relevant knowledge
about what he has said is anachronistic engineering.


** I started out building valve amps at age 14, never been away from them
for long.



He has no website, makes no electronic products forsale,


** So I am a real electronics tech - not a ****ing appliance assembler
with a bloated ego. I run a business repairing professional audio gear -
including valve guitar amps, every day. I design selected things, several
of my designs have been published in Australia's leading electronics
magazine and then taken up by major kit suppliers.

Not self published drivel like all the Turneroid's crap.


I see zero reason to show him the slightest respect.


** The Turneroid is lying, low life scumbag and small time criminal.

He deserves nothing but hatred.




He brings nothing constructive to the discussions
about tube craft.


** Other that correct the GROSS errors made by that Turneroid pig.




............ Phil

Phil Allison wrote:

"John Stewart"

I didn't bother to read all the responses since as usual a 'fog of
bull ****' hung over the whole subject.

** So you missed the facts and post utter bull**** as usual.

I figured that would get your attention!!!
Your part was the 'fog of bull****'.

Anyway, the ultimate peak
& RMS current in the transformer is limited by the winding R &
reflected primary R & the leakage inductance. I've measured lots
of them with a MetraHit 29S Precision DMM that I bought at
tremendous expense. After a certain point increasing the cap
size makes no difference to the peak & RMS currents.

** The cap size is not the main issue with the increase in rms current
value - the use of SS diodes is.

.......... Phil

Read my statement reference limiting values carefully.
I standby what I said. As usual, You didn't bother to think.
Your tongue is faster than your brain. Must be a genetic failure.

Cheers, John Stewart

"John Stewart"
Phil Allison wrote:

I didn't bother to read all the responses since as usual a 'fog of
bull ****' hung over the whole subject.

** So you missed the facts and post utter bull**** as usual.

I figured that would get your attention!!!
Your part was the 'fog of bull****'.


** Bull**** is all you are capable of posting - JS.

You make far too many wild errors and then ACT on those errors.

If you read my posts *properly* you MIGHT learn something.



Anyway, the ultimate peak
& RMS current in the transformer is limited by the winding R &
reflected primary R & the leakage inductance. I've measured lots
of them with a MetraHit 29S Precision DMM that I bought at
tremendous expense. After a certain point increasing the cap
size makes no difference to the peak & RMS currents.

** The cap size is not the main issue with the increase in rms current
value - the use of SS diodes is.

.......... Phil


Read my statement reference limiting values carefully.

** I did - it is correct.


I standby what I said.

** Fine.


As usual, You didn't bother to think.


** That error is **all yours** - for the umpteenth time in the last few
days. If YOU had bothered to read MY posts in this thread then you would
see that the Turneroid's post misrepresented me - as he invariably does.

I *never* said that cap size determined the rms current.

Like the malicious, autistic turd he is the Turneroid WILL NOT post under
someone's actual words - he paraphrases them it to match his delusional
internal thoughts and so presents others words all twisted and wrong. Just
the same as you do.

***** Figured out what a "ground lift switch" is yet ????????

***** Or how many pins a 274B has ????




............ Phil

Phil Allison wrote:

"John Stewart"
Phil Allison wrote:

I didn't bother to read all the responses since as usual a 'fog of
bull ****' hung over the whole subject.

** So you missed the facts and post utter bull**** as usual.

I figured that would get your attention!!!
Your part was the 'fog of bull****'.

** Bull**** is all you are capable of posting - JS.

You make far too many wild errors and then ACT on those errors.

If you read my posts *properly* you MIGHT learn something.


Anyway, the ultimate peak
& RMS current in the transformer is limited by the winding R &
reflected primary R & the leakage inductance. I've measured lots
of them with a MetraHit 29S Precision DMM that I bought at
tremendous expense. After a certain point increasing the cap
size makes no difference to the peak & RMS currents.

** The cap size is not the main issue with the increase in rms current
value - the use of SS diodes is.

.......... Phil


Read my statement reference limiting values carefully.

** I did - it is correct.

I standby what I said.

** Fine.

As usual, You didn't bother to think.

** That error is **all yours** - for the umpteenth time in the last few
days. If YOU had bothered to read MY posts in this thread then you would
see that the Turneroid's post misrepresented me - as he invariably does.

I *never* said that cap size determined the rms current.

Like the malicious, autistic turd he is the Turneroid WILL NOT post under
someone's actual words - he paraphrases them it to match his delusional
internal thoughts and so presents others words all twisted and wrong. Just
the same as you do.

***** Figured out what a "ground lift switch" is yet ????????

***** Or how many pins a 274B has ????

........... Phil

Is this rant an example of Autism or is it just caused by Hawg Cholera?

G'Day, John Stewart

"John Stewart"

G'Day, John Stewart


** Go straight to hell - you stinking, lying Canadian asshole.




.......... Phil

Phil Allison wrote:

"John Stewart"

G'Day, John Stewart

** Go straight to hell - you stinking, lying Canadian asshole.

......... Phil

I love to rattle Phil's chain. Sure glad he ain't here.
That might be dangerous!!!

Oh well, Cheers to all, including Phil

"John Stewart"


I love to rattle Phil's chain.


** The only chain you ever rattle asshole is in the little boy's dunny.




........... Phil

Hi RATs!

Yesterday I got inspired (?) and swapped 6F6G out and 6550 in. Added ~20uF to
C1 and measured 256 volts @ ~40 mA. After listening for a while, I noticed the
current had dropped to ~20 mA and checked the voltage: 150 volts.

Removed 274B and put in Ruby 5U4GC ...
338 Volts @ ~ 60mA.

The 274B is fine, but it can only supply so much.

If you need more, parallel them or use a different tube.

Happy Ears!
Al


Alan J. Marcy
Phoenix, AZ

PWC/mystic/Earhead

TubeGarden wrote:

Hi RATs!

Yesterday I got inspired (?) and swapped 6F6G out and 6550 in. Added ~20uF to
C1 and measured 256 volts @ ~40 mA. After listening for a while, I noticed the
current had dropped to ~20 mA and checked the voltage: 150 volts.

Removed 274B and put in Ruby 5U4GC ...
338 Volts @ ~ 60mA.

The 274B is fine, but it can only supply so much.

If you need more, parallel them or use a different tube.

Happy Ears!
Al

Alan J. Marcy
Phoenix, AZ

PWC/mystic/Earhead

At last, a ray of sunshine. Cheers, John Stewart