I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

Eusebius wrote:
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

When I was a research student, we used to use large rubber bungs for
such purposes. I don't know where you get them from outside laboratory
suppliers, though, or whether they go up to 2". Home-brewers' supplies
maybe?

Continuing to think laterally, there is a form of dense packing
material that looks like rubberised matted horse-hair. I think I have a
slab somewhere looking for a good home.

You could also try a garage or breaker's yard; I think I've seen big
rubber blocks in cars.

Chris (SE London)

Eusebius wrote:
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier
to avoid microphonics. I need to build up a raised platform on which
to mount two octal valve bases so they are decoupled from the base
plate. Any ideas welcome. I'm in Hammersmith London, so anywhere
local would be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

Rubber door stops any good?
http://www.diytools.co.uk/diy/Main/C...CategoryID=548

--
Sir Benjamin Middlethwaite

The3rd Earl Of Derby wrote:
Eusebius wrote:
I need some small rubber blocks (e.g. 2" x2") for acoustical
isolation - specifically to mount valve (vacuum tube) bases on a
pre-amplifier to avoid microphonics. I need to build up a raised
platform on which to mount two octal valve bases so they are
decoupled from the base plate. Any ideas welcome. I'm in Hammersmith
London, so anywhere local would be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

Rubber door stops any good?
http://www.diytools.co.uk/diy/Main/C...CategoryID=548

Here's some more.
http://www.rosshandling.co.uk/buffers-stops-caps.asp
--
Sir Benjamin Middlethwaite

"Eusebius" wrote in message
ps.com...
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy


I saw a similar request recently in another forum where the suggestion was a
hockey puck. These supposedly cost about a quid each. Any good?

Bob

"Bob Minchin" wrote in message
...

"Eusebius" wrote in message
ps.com...
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy


I saw a similar request recently in another forum where the suggestion was
a
hockey puck. These supposedly cost about a quid each. Any good?

Bob



This was the link quoted
http://www.iceisus.co.uk/store/shop/...s%20and%20tape

Eusebius wrote:

I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

I think 2"x2" will be way too much rubber to mount something as light
as a valve base. It'll be so stiff the sound absorption will be poor.
Try something much lighter.


NT

Eusebius wrote:
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy


Hmm, strange thing to build in this era, however a solid block of
rubber may not help much as the valve itself is so light that the
mechanical resonance will be at a high frequency and below this
frequency there won't be any decoupling. So for isolating say
loudspeaker vibrations which are usually at a few hundred Hz, it may not
be ideal.
You could try to find some stong compression springs that will take the
traditional 4BA bolts screwed in the ends. I think at the time they
used to have special anti-vibration valve holders which were like a flat
disc of phosphor bronze pressed out into a shape something like a flat
gyroscope or chronometer mounting.

john2

Eusebius wrote:
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier
to avoid microphonics. I need to build up a raised platform on which
to mount two octal valve bases so they are decoupled from the base
plate. Any ideas welcome. I'm in Hammersmith London, so anywhere
local would be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

mount the pre amp on a sturdy shelf on the wall

On 18 Aug 2006 09:42:22 -0700, "Eusebius"
wrote:

I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

In the past I've mounted valveholders using rubber grommets in the
chassis holes, obviously with washers behind the nuts to protect the
grommets from the nuts.

--
Frank Erskine
Sunderland

In article ,
john2 writes:
Eusebius wrote:
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

The standard way of doing this was to use a paving stone supported
on an inflated tyre inner tube, but that's for the whole thing, not
just a valve.

You could try to find some stong compression springs that will take the
traditional 4BA bolts screwed in the ends. I think at the time they

You've just created the image in my mind of Eusebius sitting listening
to his loud music, as 4BA nuts are coming loose and launching the valves
into space in the background...

--
Andrew Gabriel

Eusebius wrote:

I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

I would have though you would need to create an isolated platform
(concrete pad perhaps) that you can mount on rubber mounts (e.g part
number RMM7) and fix the electronics to that:

http://www.prestwich.ndirect.co.uk/hdwrrubbersetc.htm

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

I've decided to try a couple of Chinese ceramic octal sockets (heavy)
for the two valve bases, and mounted them on a sheet of solid teflon
about 6mm thick. Just thinking how to attach this to the base plate.
First thoughts are a couple of big bolts say M6, and decouple these
with rubber grommets so they don't touch the teflon.

It then occurred to me that ordinary erasers from stationary shops
might be rather good - the rubber is soft.

I may have to do a few experiments - microphonics are quite severe. The
base for the two octal sockets may have to be heavy - like 10mm alu. I
have another preamp with directly heated triodes (notoriously
microphonic things) where the sockets are mounted on a 4mm alu plate
and that's much better for microphonics.

In article . com,
"Eusebius" writes:
I may have to do a few experiments - microphonics are quite severe. The
base for the two octal sockets may have to be heavy - like 10mm alu. I
have another preamp with directly heated triodes (notoriously
microphonic things) where the sockets are mounted on a 4mm alu plate
and that's much better for microphonics.

Back in my days of playing around with valve amplifiers (before
any of the valve resurgencies), a valve which had gone microphonic
was regarded as dead.

--
Andrew Gabriel

Eusebius wrote:
I need some small rubber blocks (e.g. 2" x2") for acoustical isolation
- specifically to mount valve (vacuum tube) bases on a pre-amplifier to
avoid microphonics. I need to build up a raised platform on which to
mount two octal valve bases so they are decoupled from the base plate.
Any ideas welcome. I'm in Hammersmith London, so anywhere local would
be great.

Chunks of solid rubber may well be sold as some other kind of product
(door stops?) so lateral thinking is welcome. Andy

I think you probably want high density foam rubber as valves are not
that massy.

It won't solve microphony though..thats more down to direct coupling of
the glass and grid stuff. You need an acoustic shroud over the valves
for that.

Or better still, use FETS instead. Valves have some slight advantages in
power amplifiers, none whatsoever in pre-amplifiers. Particullarly hi-fi
ones.

They are marginally nice in gutar amps where non linearity and
microphony adds a little color to a rather dull pickup sound. The non
linearity is easy to fake in solid state, the microphony is not.

Eusebius wrote:
I've decided to try a couple of Chinese ceramic octal sockets (heavy)
for the two valve bases, and mounted them on a sheet of solid teflon
about 6mm thick. Just thinking how to attach this to the base plate.
First thoughts are a couple of big bolts say M6, and decouple these
with rubber grommets so they don't touch the teflon.

It then occurred to me that ordinary erasers from stationary shops
might be rather good - the rubber is soft.

I may have to do a few experiments - microphonics are quite severe. The
base for the two octal sockets may have to be heavy - like 10mm alu. I
have another preamp with directly heated triodes (notoriously
microphonic things) where the sockets are mounted on a 4mm alu plate
and that's much better for microphonics.

Its probably down to valve design rather than mounting.

We used to 'ping' the pre-amp valves in Marshall valve amps with a
fingertip and any that were vile got used in the power amp instead ..all
ECC83 IIRC..some brands were always worse than others.

The Natural Philosopher wrote:

We used to 'ping' the pre-amp valves in Marshall valve amps with a
fingertip and any that were vile got used in the power amp instead ..all
ECC83 IIRC..some brands were always worse than others.

Those were always a bit microphonic though and the heaters need to be
run on DC to avoid hum problems in very low level input stages for gram
pickups and tape heads, etc.

Mullard introduced the EF86 specifically to overcome those two problems.

--
Andy

Back in my days of playing around with valve amplifiers (before
any of the valve resurgencies), a valve which had gone microphonic
was regarded as dead.

Different thing, it isn't malfunction as you rightly refer to - these
directly heated triodes were used in radios in the field and operated
from batteries. The filaments were something like 50mA at 1.4v -
nothing at all. So the filaments were tiny and fragile, and it's these
kind of filaments that tend to sing in a microphonic way. It's a
well-known issue with these particular type of DHTs. Despite this, they
sound so good that all obstacles simply have to be overcome.

It won't solve microphony though..thats more down to direct coupling of

the glass and grid stuff. You need an acoustic shroud over the valves
for that.

Yes, this could well be true (some DHT users report good results), or
failing that some rubber damper rings


Or better still, use FETS instead. Valves have some slight advantages
in
power amplifiers, none whatsoever in pre-amplifiers. Particullarly
hi-fi ones.

Unfortunately this isn't true at the highest levels where you want to
squeeze the ultra details and timbre out of the system. DHTs for all
their many problems just go that little way further in clarity and
tone. You'd have to hear them to know what I'm talking about - they are
so arcane (20s and 30s as well) that there's no body of opinion to
guide your thoughts, so I wouldn't expect you to to believe all this
just on my say-so. .


They are marginally nice in gutar amps where non linearity and
microphony adds a little color to a rather dull pickup sound. The non
linearity is easy to fake in solid state, the microphony is not.

this is another field - stage gear for effects - I'm talking about hifi
as above. As I say, all this is hard to accept without actually hearing
DHTs and there is no production preamp that uses them since they
haven't been made since the 30s and 40s. I don't expect you to believe
anything on faith alone, so I guess we just have to differ on this one.
Andy

Eusebius wrote:

this is another field - stage gear for effects - I'm talking about
hifi as above. As I say, all this is hard to accept without actually
hearing DHTs and there is no production preamp that uses them since
they haven't been made since the 30s and 40s. I don't expect you to
believe anything on faith alone, so I guess we just have to differ on
this one. Andy

have a look he

http://snipurl.com/v6ai

hope that helped ;-)

Eusebius wrote:

It won't solve microphony though..thats more down to direct coupling of

the glass and grid stuff. You need an acoustic shroud over the valves
for that.

Anti-microphony valveholders used to be a fairly readily available
component. Can't you find any to use with the old valves that you're
seeking to use?

Unfortunately this isn't true at the highest levels where you want to
squeeze the ultra details and timbre out of the system. DHTs for all
their many problems just go that little way further in clarity and
tone. You'd have to hear them to know what I'm talking about - they are
so arcane (20s and 30s as well) that there's no body of opinion to
guide your thoughts,

Oh dear... But I'm slightly puzzled, the 1.4 V battery valves you
mention in another post are a post-WW2 thing and were produced well into
the 60s (I well remember buying them new). These had B7G bases. But
you mention octal bases and the 20s and 30s. The 20s was surely the era
of bright emitters (?) and by the 30s we had 2 V and 4 V filaments,
usually run from lead-acid accumulators, until AC mains became common.
I can't recall any octal-based valves with 1.4 V filaments (but ICBW).

[...] so I wouldn't expect you to to believe all this
just on my say-so. .

Well I certainly wouldn't, because you've swallowed a load of tripe.

--
Andy

have a look he http://snipurl.com/v6ai hope that helped ;-)

Great! Nice one. Andy

On Sat, 19 Aug 2006 16:39:50 +0100, Andy Wade
wrote:

I can't recall any octal-based valves with 1.4 V filaments (but ICBW).

Anorak
DAC32
DF33
DK32
DL35
U35
1C5
1H5
/Anorak

TNBAF

:-)

--
Frank Erskine

[...] so I wouldn't expect you to to believe all this just on my say-so. .

Well I certainly wouldn't, because you've swallowed a load of tripe.

Absolutely not - I've been building audio equipment for 25 years, and
using DHTs for preamps is something, like most people, I avoided
because of the complexity of execution (microphony, filaments supplies,
UX4 bases). I've been using them now for about a year, and I wouldn't
go back to indirectly heated tubes. The sound - to me - has more
clarity and better tone/timbre, and the difference isn't subtle. I'm
not in the slightest doubt myself becase I've tried out several
different circuits, abut 6 filament supplies, transformer coupling (PP
and parafeed) and done this in conjunction with three colleagues all of
whom are electronics engineers and are equally crazy about DHTs. We've
done joint listening tests, put circuits on test equipment etc etc.
Once bitten you're smitten. Yes of course it's esoteric, but there we
are. What can I say!

I can't recall any octal-based valves with 1.4 V filaments (but ICBW).
Anorak
DAC32
DF33
DK32
DL35
U35
1C5
1H5
/Anorak

- there's a bucket full. In terms of triodes, there's 1G4, 1E4, 1LE3,
1LF3, VT239. I'm using the 1G4 right now. The flat plate versions seem
to be more microphonic, hence the post.

Eusebius wrote:
[...] so I wouldn't expect you to to believe all this just on my
say-so. .

Well I certainly wouldn't, because you've swallowed a load of tripe.

Absolutely not - I've been building audio equipment for 25 years, and
using DHTs for preamps is something, like most people, I avoided
because of the complexity of execution (microphony, filaments
supplies,
UX4 bases). I've been using them now for about a year, and I wouldn't
go back to indirectly heated tubes. The sound - to me - has more
clarity and better tone/timbre, and the difference isn't subtle. I'm
not in the slightest doubt myself becase I've tried out several
different circuits, abut 6 filament supplies, transformer coupling (PP
and parafeed) and done this in conjunction with three colleagues all
of
whom are electronics engineers and are equally crazy about DHTs. We've
done joint listening tests, put circuits on test equipment etc etc.
Once bitten you're smitten. Yes of course it's esoteric, but there we
are. What can I say!

well at least you didn't say "make it sound / it sounds warm" top marks, fella.

Eusebius wrote:
It won't solve microphony though..thats more down to direct coupling of

the glass and grid stuff. You need an acoustic shroud over the valves
for that.

Yes, this could well be true (some DHT users report good results), or
failing that some rubber damper rings


Or better still, use FETS instead. Valves have some slight advantages
in
power amplifiers, none whatsoever in pre-amplifiers. Particullarly
hi-fi ones.

Unfortunately this isn't true at the highest levels where you want to
squeeze the ultra details and timbre out of the system. DHTs for all
their many problems just go that little way further in clarity and
tone. You'd have to hear them to know what I'm talking about - they are
so arcane (20s and 30s as well) that there's no body of opinion to
guide your thoughts, so I wouldn't expect you to to believe all this
just on my say-so. .



No,. I';ll just go on what my ears, my test instruments, and blind tests
with volunteers told me over many years of designing audio amplifiers
and preamplifiers.

They are marginally nice in gutar amps where non linearity and
microphony adds a little color to a rather dull pickup sound. The non
linearity is easy to fake in solid state, the microphony is not.

this is another field - stage gear for effects - I'm talking about hifi
as above. As I say, all this is hard to accept without actually hearing
DHTs and there is no production preamp that uses them since they
haven't been made since the 30s and 40s. I don't expect you to believe
anything on faith alone, so I guess we just have to differ on this one.
Andy


I think you do not wot whereof you speak. Lots of people have made
directly heated triode and tetrode front ends - you have to to get the
hum down.

PROBABLY more than have made a decent FET preamplifier actually..

MOST people bang in a couple of chips and leave it at that. I did in
fact take it a little further than that. A very few people could tell
the difference, although the test equipment certainly could. Bottles
represented nothing I couldn't do with FETS and standard transistors so
I ditched em. You had to DESGN carefully though. Any fool can avoid
overload with a 250v supply rail. Its less easy with 30v...

Frank Erskine wrote:
On Sat, 19 Aug 2006 16:39:50 +0100, Andy Wade
wrote:

I can't recall any octal-based valves with 1.4 V filaments (but ICBW).

Anorak
DAC32
DF33
DK32
DL35
U35
1C5
1H5
/Anorak

TNBAF

:-)

Those are all post WWII IIRC

Eusebius wrote:
with three colleagues all of whom are electronics engineers and are equally crazy

we had noticed..

about DHTs.

Oh...;-)


We've
done joint listening tests, put circuits on test equipment etc etc.
Once bitten you're smitten. Yes of course it's esoteric, but there we
are. What can I say!


Now invest all the same effort in designing really low noise linear
transistor pre-amps and select your devices for low flicker noise, 1/f
noise and the like, and be rewarded with a completely hum free utterly
linear design with a 1Mhz bandwidth if thats your bag...

.. wrote:
Eusebius wrote:
[...] so I wouldn't expect you to to believe all this just on my
say-so. .
Well I certainly wouldn't, because you've swallowed a load of tripe.

Absolutely not - I've been building audio equipment for 25 years, and
using DHTs for preamps is something, like most people, I avoided
because of the complexity of execution (microphony, filaments
supplies,
UX4 bases). I've been using them now for about a year, and I wouldn't
go back to indirectly heated tubes. The sound - to me - has more
clarity and better tone/timbre, and the difference isn't subtle. I'm
not in the slightest doubt myself becase I've tried out several
different circuits, abut 6 filament supplies, transformer coupling (PP
and parafeed) and done this in conjunction with three colleagues all
of
whom are electronics engineers and are equally crazy about DHTs. We've
done joint listening tests, put circuits on test equipment etc etc.
Once bitten you're smitten. Yes of course it's esoteric, but there we
are. What can I say!

well at least you didn't say "make it sound / it sounds warm" top marks, fella.


Ahh..that elusive valve warmth..finally traced to smooth second harmonic
distortion in the pre-amp, and a moderately high output impedance and
lack of treble from the cast iron output transformer, together with its
ability to run into clip nice and softly so that cloth eared audio buffs
couldn't realise it had..

The Natural Philosopher wrote:
. wrote:
Eusebius wrote:
[...] so I wouldn't expect you to to believe all this just on my
say-so. .
Well I certainly wouldn't, because you've swallowed a load of
tripe.

Absolutely not - I've been building audio equipment for 25 years,
and
using DHTs for preamps is something, like most people, I avoided
because of the complexity of execution (microphony, filaments
supplies,
UX4 bases). I've been using them now for about a year, and I
wouldn't
go back to indirectly heated tubes. The sound - to me - has more
clarity and better tone/timbre, and the difference isn't subtle. I'm
not in the slightest doubt myself becase I've tried out several
different circuits, abut 6 filament supplies, transformer coupling
(PP
and parafeed) and done this in conjunction with three colleagues all
of
whom are electronics engineers and are equally crazy about DHTs.
We've
done joint listening tests, put circuits on test equipment etc etc.
Once bitten you're smitten. Yes of course it's esoteric, but there
we
are. What can I say!

well at least you didn't say "make it sound / it sounds warm" top
marks, fella.


Ahh..that elusive valve warmth..finally traced to smooth second
harmonic distortion in the pre-amp, and a moderately high output
impedance and lack of treble from the cast iron output transformer,
together with its ability to run into clip nice and softly so that cloth
eared audio buffs couldn't realise it had..

since digitised & encoded to a reliable and reproducible collection of
1's and 0's, freely available to everyone else.

aint progress marvellous ?

Eusebius wrote:
[...] so I wouldn't expect you to to believe all this just on my
say-so. .

Well I certainly wouldn't, because you've swallowed a load of tripe.

Absolutely not - I've been building audio equipment for 25 years, and
using DHTs for preamps is something, like most people, I avoided
because of the complexity of execution (microphony, filaments supplies,
UX4 bases). I've been using them now for about a year, and I wouldn't
go back to indirectly heated tubes. The sound - to me - has more
clarity and better tone/timbre, and the difference isn't subtle. I'm
not in the slightest doubt myself becase I've tried out several
different circuits, abut 6 filament supplies, transformer coupling (PP
and parafeed) and done this in conjunction with three colleagues all of
whom are electronics engineers and are equally crazy about DHTs. We've
done joint listening tests, put circuits on test equipment etc etc.
Once bitten you're smitten. Yes of course it's esoteric, but there we
are. What can I say!

The DC voltage drop along the filament will give a spread of grid bias
voltages within the same valve, thus creating a variegated and subtly
shaded palette of coloration...

Ahem. Excuse me.


Now real valves, you don't dare switch on without a blower :-)


--
Ian White

On Sat, 19 Aug 2006 20:36:40 +0100, The Natural Philosopher
wrote:

Frank Erskine wrote:
On Sat, 19 Aug 2006 16:39:50 +0100, Andy Wade
wrote:

I can't recall any octal-based valves with 1.4 V filaments (but ICBW).

Anorak
DAC32
DF33
DK32
DL35
U35
1C5
1H5
/Anorak

TNBAF

:-)

Those are all post WWII IIRC

Yes - so?

--
Frank Erskine

Ahh..that elusive valve warmth..finally traced to smooth second
harmonic
distortion in the pre-amp, and a moderately high output impedance and
lack of treble from the cast iron output transformer, together with its

ability to run into clip nice and softly so that cloth eared audio
buffs
couldn't realise it had..

I'm sorry to say this is recycled ******** from a few decades back.
Even if you updated your knowledge of valve equipment to take in the
developments of the last years in circuit types and complexity (yes,
heavily reliant on ss componants too) it would leave us with the fact
that several professional musicians prefer valve equipment. At this
point you may be tempted to argue that "it's well known that orchestral
musicians are happy listening to music on kitchen radios" but again
this would take you into another well known cul de sac. Don't you think
that serious valve users have heard these arguments about as many times
as professional musicians have been told to get a proper job?

Now invest all the same effort in designing really low noise linear
transistor pre-amps and select your devices for low flicker noise, 1/f
noise and the like, and be rewarded with a completely hum free utterly
linear design with a 1Mhz bandwidth if thats your bag...

I'm a pro musician - sound is my bag. If you're talking test and
measurement equipment I'd agree with you and I'm sure you're very
skilled in your field.

You had to DESGN carefully though. Any fool can avoid overload with a
250v supply rail. Its less easy with 30v...

The skills needed for designing filament supplies - all solid state -
are exactly the skills I'm sure you have. Valve equipment these days
relies a lot on ancilliary circuits full of ss devices and there's a
lot of skill involved in getting the best reults, as with everything
serious. I was totally unprepared for how different six filament
supplies were from each other. I imagined clean DC would be enough, but
it's a lot more profound than that - current sources sound better than
voltage regs, yet voltage regs sound better with CMCs at the end while
current sources sound worse...... I suspect we haven't even come close
to optimum yet. Then there's the CCS circuitry on top of all this for
diff pairs in balanced circuits.

On 19 Aug 2006 17:15:06 -0700, "Eusebius"
wrote:

I'm sorry to say this is recycled ******** from a few decades back.

Yes it really is. Do a double blind test, maybe even thousands of them
and you'll realise that valves no matter what you do with them are
pretty ****ty, music digitised to CD "standards" is pretty ****ty and
vinyl is pretty ****ty.

Gold plated mains plugs anyone?

How about speaker cable at hundreds of quid a metre?

Wooden spikes to stand your amp on?

Green pens for CD's

Crap science, lots of flashing lights/controls and the absence of
flashing lights/controls has sold "hi-fi" to generations of idiots
with more money than sense.

Thank f*ck for live unamplified music.




--

Matt wrote:
On 19 Aug 2006 17:15:06 -0700, "Eusebius"
wrote:

I'm sorry to say this is recycled ******** from a few decades back.

Yes it really is. Do a double blind test, maybe even thousands of them
and you'll realise that valves no matter what you do with them are
pretty ****ty, music digitised to CD "standards" is pretty ****ty and
vinyl is pretty ****ty.

Gold plated mains plugs anyone?

How about speaker cable at hundreds of quid a metre?

Wooden spikes to stand your amp on?

Green pens for CD's

Crap science, lots of flashing lights/controls and the absence of
flashing lights/controls has sold "hi-fi" to generations of idiots
with more money than sense.

Thank f*ck for live unamplified music.

*amen* and pass the ammunition, brother ;-)

goes back to listening to split - groundhogs

Postscript - I mounted the two valve bases on 8mm teflon sheet then
fastened that to M6 bolts via rubber grommetts so the teflon dosn't
touch the bolt. Finally used a chunk of eraser (soft rubber) under each
corner between the teflon sheet and the chassis as damping. Noise is
very well damped and preamp is now quiet in use. Needless to say, it
sounds bloody marvellous. Andy

"Matt" wrote in message
...
On 19 Aug 2006 17:15:06 -0700, "Eusebius"
wrote:

I'm sorry to say this is recycled ******** from a few decades back.

Yes it really is. Do a double blind test, maybe even thousands of them
and you'll realise that valves no matter what you do with them are
pretty ****ty, music digitised to CD "standards" is pretty ****ty and
vinyl is pretty ****ty.

Gold plated mains plugs anyone?

How about speaker cable at hundreds of quid a metre?

Wooden spikes to stand your amp on?

Green pens for CD's

Crap science, lots of flashing lights/controls and the absence of
flashing lights/controls has sold "hi-fi" to generations of idiots
with more money than sense.

Thank f*ck for live unamplified music.

The funniest thing is - when you can (possibly) hear the difference (about
age 19) you can't afford the kit, by the time you can afford the kit
*everyone's* ears have deteriorated so you couldn't tell the difference
anyway. "Esoteric Hi-Fi" - it's better but you just can't hear it.

Cheap mains cable anyone - I'll take two!....

http://tinyurl.com/r3y9b



--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)