My Fellow Rodents,
Can you tell the difference in sound, all things the same except the B+
supply is either solid state or tube? I was thinking of converting my Sound
Valves ST-70i to a tube rectifier. Conversion seems straight forward, but
should I? Is it worth it? Thanks in advance for your opinions.
west

I'm a little puzzled. Normally I get great responses to my questions and am
very grateful. I've learned plenty (mostly, I don't know Jack). However,
I've posted this question about solid state B+ vs. tube rectifier (see
below) a couple of times and have never received one response. Can someone
tell me why? Perhaps this particular subject has been totally exhausted in
the past, or maybe it was the lynchpin of a r.a.t. war? I don't get it.
Maybe I simply need to reword my question. The subject is very important to
me and I do respect this groups opinions. If I can't get this question
answered, then maybe I can get the reason why. Thank you so much.
Cordially,
west

"west" wrote in message
...
My Fellow Rodents,
Can you tell the difference in sound, all things the same except the B+
supply is either solid state or tube? I was thinking of converting my
Sound
Valves ST-70i to a tube rectifier. Conversion seems straight forward, but
should I? Is it worth it? Thanks in advance for your opinions.
west

Ok. I'll answer: yes.

That make you happy? :^)

We here at RAT don't care about psychoacoustics and which way our resistors
are pointed. If you need a highly opinionated answer, go to one of the
fringe audio groups such as Audio Asylum (how aptly named, though I'll
throw in a disclaimer that I've never been). Then, you will finally know
that gold wire is more conductive than copper. :^)

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"west" wrote in message
...

I'm a little puzzled. Normally I get great responses to my questions and
am
very grateful. I've learned plenty (mostly, I don't know Jack). However,
I've posted this question about solid state B+ vs. tube rectifier (see
below) a couple of times and have never received one response. Can someone
tell me why? Perhaps this particular subject has been totally exhausted in
the past, or maybe it was the lynchpin of a r.a.t. war? I don't get it.
Maybe I simply need to reword my question. The subject is very important
to
me and I do respect this groups opinions. If I can't get this question
answered, then maybe I can get the reason why. Thank you so much.
Cordially,
west

"west" wrote in message
...
My Fellow Rodents,
Can you tell the difference in sound, all things the same except the B+
supply is either solid state or tube? I was thinking of converting my
Sound
Valves ST-70i to a tube rectifier. Conversion seems straight forward,
but
should I? Is it worth it? Thanks in advance for your opinions.
west

Tim Williams wrote:

Ok. I'll answer: yes.

That make you happy? :^)

We here at RAT don't care about psychoacoustics and which way our resistors
are pointed. If you need a highly opinionated answer, go to one of the
fringe audio groups such as Audio Asylum (how aptly named, though I'll
throw in a disclaimer that I've never been). Then, you will finally know
that gold wire is more conductive than copper. :^)

Tim

The engineering of either tube or SS rectifier use in the same amp
has been done to death, and a read of the subject
in the Google news group files should answer questions.

I detect no detriment to sound with SS replacements,
usually larger caps can be used with SS diodes, and sound is improved.
B+ rises for SS diodes, so an extra RC fiter stage can be added,
to realize the same B+ value as with a tube rectifier.

Patrick Turner.


--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"west" wrote in message
...

I'm a little puzzled. Normally I get great responses to my questions and
am
very grateful. I've learned plenty (mostly, I don't know Jack). However,
I've posted this question about solid state B+ vs. tube rectifier (see
below) a couple of times and have never received one response. Can someone
tell me why? Perhaps this particular subject has been totally exhausted in
the past, or maybe it was the lynchpin of a r.a.t. war? I don't get it.
Maybe I simply need to reword my question. The subject is very important
to
me and I do respect this groups opinions. If I can't get this question
answered, then maybe I can get the reason why. Thank you so much.
Cordially,
west

"west" wrote in message
...
My Fellow Rodents,
Can you tell the difference in sound, all things the same except the B+
supply is either solid state or tube? I was thinking of converting my
Sound
Valves ST-70i to a tube rectifier. Conversion seems straight forward,
but
should I? Is it worth it? Thanks in advance for your opinions.
west

Hi West,

Well, my opinion is that it matters not a whit, "all things being the
same." But what is "all things the same"?

If you replace a tube rectifier with a solid-state rectifier, and add
the same resistance that the tube would have had, then the B+ voltage
will be exactly the same. There are those who claim to be able to hear a
difference between the two circuits, because one has a tube in it and
the other doesn't. But I'm not one of them, and if I have two supplies
with the same voltage, same ripple, and same output voltage vs. current
behaviour, I would be very very surprised if it did *not* sound the same.

Going the other way -- if a circuit was designed for SS rectifiers,
replacing them with a tube or tubes will be the same as if you added a
resistor in series with each rectifier. Maybe it will work better, but
probably not, since the designer intended the circuit to work in a
certain way.

What can you expect? Approximately the same effect as you'd get from
running your amp from a lower-than-normal line voltage. The gain might
be a little lower, the sound might be a little softer, and prone to
clipping a little earlier (IOW, you'll get less undistorted power out of
it).

Is there a danger to doing this? Possibly. If the input filter capacitor
is too high, it can damage the tube. SS rectifiers have a vanishingly
low series resistance, and can therefore tolerate massive current pulses
compared to tubes. I'm not familiar with the particular circuit you're
proposing to do this with, but I'm assuming it's pretty generic; so
aside from that, there *probably* won't be any other ill effects from
the substitution. However, there *might* be circuits that would suffer
in other ways from the lower supply voltage.

There can be compelling reasons to use tubes in circuit designs.
Included are their inherent soft-start characteristic, built-in
resistance that limits inrush currents and can decrease "buzzing"
(albeit at the expense of regulation), and -- well, frankly I can't
think of anything else at the moment.

But in my opinion this is not one of those "try it and see" situations.
It's not like casual tube rolling, swapping different brands of 12AX7's
for the fun of seeing if you can hear a difference. Changing types of
rectifiers can significantly affect how the power supply behaves -- and
around which the whole rest of the amplifier is designed.

You can *safely* experiment with such things using Duncan Munro's PSUD
II (Power Supply Unit Designer 2). http://www.duncanamps.com

Cheers,
Fred


west wrote:
I'm a little puzzled. Normally I get great responses to my questions and am
very grateful. I've learned plenty (mostly, I don't know Jack). However,
I've posted this question about solid state B+ vs. tube rectifier (see
below) a couple of times and have never received one response. Can someone
tell me why? Perhaps this particular subject has been totally exhausted in
the past, or maybe it was the lynchpin of a r.a.t. war? I don't get it.
Maybe I simply need to reword my question. The subject is very important to
me and I do respect this groups opinions. If I can't get this question
answered, then maybe I can get the reason why. Thank you so much.
Cordially,
west

"west" wrote in message
...

My Fellow Rodents,
Can you tell the difference in sound, all things the same except the B+
supply is either solid state or tube? I was thinking of converting my

Sound

Valves ST-70i to a tube rectifier. Conversion seems straight forward, but
should I? Is it worth it? Thanks in advance for your opinions.
west






--
+--------------------------------------------+
| Music: http://www3.telus.net/dogstarmusic/ |
| Projects: http://dogstar.dantimax.dk |
+--------------------------------------------+

Tim,
I pleased to learn that you only claim but don't really speak for the rest
of the rats. If I had the same disposition as you, there would be the
perfect ingredients for a flame war. Does it make you feel un-cool to be a
gentleman like most on this ng?
west

"Tim Williams" wrote in message
...
Ok. I'll answer: yes.

That make you happy? :^)

We here at RAT don't care about psychoacoustics and which way our
resistors
are pointed. If you need a highly opinionated answer, go to one of the
fringe audio groups such as Audio Asylum (how aptly named, though I'll
throw in a disclaimer that I've never been). Then, you will finally know
that gold wire is more conductive than copper. :^)

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"west" wrote in message
...

I'm a little puzzled. Normally I get great responses to my questions
and
am
very grateful. I've learned plenty (mostly, I don't know Jack). However,
I've posted this question about solid state B+ vs. tube rectifier (see
below) a couple of times and have never received one response. Can
someone
tell me why? Perhaps this particular subject has been totally exhausted
in
the past, or maybe it was the lynchpin of a r.a.t. war? I don't get it.
Maybe I simply need to reword my question. The subject is very important
to
me and I do respect this groups opinions. If I can't get this question
answered, then maybe I can get the reason why. Thank you so much.
Cordially,
west

"west" wrote in message
...
My Fellow Rodents,
Can you tell the difference in sound, all things the same except the
B+
supply is either solid state or tube? I was thinking of converting my
Sound
Valves ST-70i to a tube rectifier. Conversion seems straight forward,
but
should I? Is it worth it? Thanks in advance for your opinions.
west

In fact, the question is: what does it means all the rest being equal? A SS
rectifier will usually provide the following advantages:

- use larger caps
- use no chokes
- supply larger currents
- have greater efficiency
- have a much lower voltage drop

while a tube rectifier will usually

- be less noisy (lower current spikes/less HF noise)
- provide a soft start
- allow using lower voltage filter capacitors (no start-up overvoltage
unless using direct-heating rectifiers with indirect-heating power valves,
ie. 5U4G and EL34)

I'd say that it is only a matter of convenience: space, cost, unit "level",
cost and appearance.
I made a SE amp using a couple of 6L6 UL connected fed by a SS rectifier:
diodes bridge, capacitors (100+40uF), choke (10H), capacitors (100+40uF); it
seems I got rid of all HF rubbish, 'cause it is perfectly silent (a good
choke does magic). This way I kept the unit much smaller and it releases
less heat, so it could fit into the relatively small library of the friend
of mine who commissioned it (we're talking about Italian homes, no NY
multi-million flats...)
I then made a SE 2A3 aimed to the maximum, and aesthetics was important, so
it got a tube rectifier using a NOS Sylvania 5V4G having the same glass bulb
used by the 2A3.
In fact, a 10H choke-input tube rectifier, followed by a 220 uF Elna
Cerafine, followed by a 150R resistor to "fine-tune" the B+, followed by a
100uF Sprague, followed by two 2H chokes, followed by the two halves of a
220uF (x2) Elna Cerafine each feeding a channel.
It took more space to fit the "power station" than to place all the rest of
the stuff, but it looks great.
By the way: using SS You can feed (as an example) four KT88s out of a single
supply, but I know of no tube (at least readily available ones) that can
provide more than 240 mA (5U4G, a direct-heating one, by the way). 5AR4s
are frequently abused, they should pass 160 mA only according to the
original Mullard D/S.
Oh, well, there's the Russian 5Z8S which is able to provide 440 mA and does
not cost a month's wage, but it uses an impossible-to-find 8-pins socket
copied by the Soviets from the one used by WWII German tubes (Telefunken
LS50 and others).

As per the "sonic" properties, I'd say that any well-designed circuit should
do fine. Maybe the larger current-passing capabilities of SS can give it an
advantage in the lower part of the spectrum, but I never made "the same amp"
with a SS and a tube supply just for comparison.

Ciao

Fabio


"Ronald" ha scritto nel messaggio
...
There are those who claim to be able to hear a
difference between the two circuits, because one has a tube in it and
the other doesn't.

In a PP amp there's not much difference since there's cancelation . Even
a relative big ripple on B+ isn't a problem .
But in SE amps there is a big difference in sound . I think it has to do
with
the overshoot of the SS rect. A tube doesn't know how to do this ;-)
So is a PP amp with a good balanced SS rect. circuit I would just add a
tube rect for the pre-amp / driver stages . Use an AZ1 mesh-plate if you
can
!!

But I'm not one of them, and if I have two supplies
with the same voltage, same ripple, and same output voltage vs. current
behaviour, I would be very very surprised if it did *not* sound the
same.

OK , but that voltage and current behaviour would never be the same
between
tubes and SS !! Even if you add 1000 resistors ......
Maybe some super fast SS will come close to a tube , but it'll never be
one
!!
The tonal balance wouldn't be that much (any?) different but there's more
rest
in the sound .

But in my opinion this is not one of those "try it and see" situations.
It's not like casual tube rolling, swapping different brands of 12AX7's
for the fun of seeing if you can hear a difference. Changing types of
rectifiers can significantly affect how the power supply behaves -- and
around which the whole rest of the amplifier is designed.

If you have a pre-amp with a tube rect. start rolling different types and
you'll
be surprised !!

You can *safely* experiment with such things using Duncan Munro's PSUD
II (Power Supply Unit Designer 2). http://www.duncanamps.com

Cheers,
Fred

PSUD is good but sometimes it tolerates a little to much for the first cap
..
So always look to the datasheet also !!

Ronald .





west wrote:
I'm a little puzzled. Normally I get great responses to my questions
and am
very grateful. I've learned plenty (mostly, I don't know Jack).
However,
I've posted this question about solid state B+ vs. tube rectifier (see
below) a couple of times and have never received one response. Can
someone
tell me why? Perhaps this particular subject has been totally
exhausted
in
the past, or maybe it was the lynchpin of a r.a.t. war? I don't get
it.
Maybe I simply need to reword my question. The subject is very
important
to
me and I do respect this groups opinions. If I can't get this
question
answered, then maybe I can get the reason why. Thank you so much.
Cordially,
west

"west" wrote in message
...

My Fellow Rodents,
Can you tell the difference in sound, all things the same except the
B+
supply is either solid state or tube? I was thinking of converting my

Sound

Valves ST-70i to a tube rectifier. Conversion seems straight forward,
but
should I? Is it worth it? Thanks in advance for your opinions.
west






--
+--------------------------------------------+
| Music: http://www3.telus.net/dogstarmusic/ |
| Projects: http://dogstar.dantimax.dk |
+--------------------------------------------+

Hi RATs!

Please do not breathe on the screen

And wash your hands. PCs have feelings, too.

OK. Flames are fun, but, this is audio!

Anything that allows you to listen to music is good. Anything that encourages
you to listen to your system is evil.

Evil is usually more fun than good

Power supply design for audio is pretty simple: no noise and vast headroom.

The rectifier is next to the transformer, which is into the grid (topical!).

This is technically called the sh!tty end of the stick.

The PS filter is where the money should go!

The basic idea is the wall just provides charge to the filter network.

The amp runs on the stored energy in the filter network.

If a new power cable does wonders for the sound, your PS filter network sucks


I use 5U4GB. Oil caps with PP bypass, two chokes per tube, chokes in filament
supplies, bleeder resistors, 20 nF caps from plates of rectifier to ground.

I like the music

Happy Ears!
Al


Alan J. Marcy
Phoenix, AZ

PWC/mystic/Earhead

Hi Al,
My interest is piqued Al. Do you think you can provide a schematic of what
you just described verbally. It sounds like a "no stone unturned system."
west

"TubeGarden" wrote in message
...
Hi RATs!

Please do not breathe on the screen

And wash your hands. PCs have feelings, too.

OK. Flames are fun, but, this is audio!

Anything that allows you to listen to music is good. Anything that
encourages
you to listen to your system is evil.

Evil is usually more fun than good

Power supply design for audio is pretty simple: no noise and vast
headroom.

The rectifier is next to the transformer, which is into the grid
(topical!).

This is technically called the sh!tty end of the stick.

The PS filter is where the money should go!

The basic idea is the wall just provides charge to the filter network.

The amp runs on the stored energy in the filter network.

If a new power cable does wonders for the sound, your PS filter network
sucks


I use 5U4GB. Oil caps with PP bypass, two chokes per tube, chokes in
filament
supplies, bleeder resistors, 20 nF caps from plates of rectifier to
ground.

I like the music

Happy Ears!
Al


Alan J. Marcy
Phoenix, AZ

PWC/mystic/Earhead

Hi RATs!

Sure. (Sent it email)

Happy Ears!
Al


Alan J. Marcy
Phoenix, AZ

PWC/mystic/Earhead

"TubeGarden" wrote in message
...
The rectifier is next to the transformer, which is into the grid
(topical!).

Huh?

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

Hi RATs!

Um, transformer is plugged into the power grid. Not the control grid nor the
screen grid

NYC without electricity, Phoenix without gasoline. What a summer!

Happy Ears!
Al


Alan J. Marcy
Phoenix, AZ

PWC/mystic/Earhead

Silicon diodes have lower foreward resistance than tubes but

And SS has also lower backward resistance the first few mil.sec's after
zero-crossing ...... (overshoot) .