Apogee mini dac or Benchmark DAC1
 

"Eeyore" wrote in
message ...


Andy Evans wrote:

You've snipped all the previous content so it's impossible to know what
exactly
you're replying to.

Please use 'inline posting'.
http://en.wikipedia.org/wiki/Bottom_...nline_replying

You currently have all the hallmark signs of an arrogant opinionated
self-obsessed jerk !


And you don't....??

Apogee mini dac or Benchmark DAC1
 

"Eeyore" wrote in
message ...


Andy Evans wrote:

What they are confusing this with is their preference for an
intentionally flawed but
entirely pleasnt and relatively benign form of distortion. Nothing
wrong with their
listening preference but the presentation of this as inherently
superior is utterly
bogus.

The idea that valves are simply "added distortion" and nothing else
could only be made by somebody with a) very little knowledge of modern
valve circuits and how they sound or b) somebody with cloth ears.

There is precious litle 'modern' about any valve circuit. I learnt on them
btw.


Nahh, I doubt that - you post like you've learnt nothing at all.....

Apogee mini dac or Benchmark DAC1
 

"Andy Evans" wrote in message
oups.com...
There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

I've no doubt you know valves from ( ?50s, 60s?, 70s?), but you'd be
very surprised at how much things have changed. Not the function of the
triode itself, which is well known, but the support circuitry is now
quite complex - cascode active loads, constant current sinks etc. - a
whole cuisine of modern ss devices and traditional stuff like glow
tubes. It really is "nouvelle cuisine" if you pardon the expression.
We're not talking Mullard circuits with EF86s and ECC83s any more.



You've got more faith with some of these 'hot under the collar' types than I
have Andy - I take a lot of what they say with a pinch of salt (large one).
Most of 'em have never heard a valve amp and some of the others have only
heard some old *legacy* struggler at best and seem to forget what some of
the transistor equipment from the 70s could sound like.....

Apogee mini dac or Benchmark DAC1
 

On 2006-09-09, Andy Evans wrote:
If the DAC isn't (sufficiently) transparent then putting a valve (tube)
in series with it cannot make the combination transparent. Yet
sometimes I see the T word used to describe
"better" in this context.

Isn't a DAC by definition something with an analogue output stage? ...

No, it's a device with an analogue output (not necessarily an analogue
output *stage*). For example, in the case of current summing DACs the
summing point is sometimes connected directly to a pin on the DAC and you
are expected to supply your own virtual-earth transimpedance amplifier
(valve or SS) if you want a voltage instead of a current output.

So
something must be on the end of it, whether ss circuit,
transformer,capacitor or tube stage. ...

Well, in the audio context a DAC will not (usually) drive a loudspeaker
so you need amplification and/or impedance conversion and/or current
to voltage conversion after the DAC itself. However I can't see the
relevance of this. There is still a very real DAC in the reproduction
chain.

The advantage of a tube stage is
that the output with DC on it can be fed directly into the grid of the
tube, and the DC included in the biasing.

That may be an advantage in certain cases but you still have a DAC
feeding the tube stage (if I have interpreted you correctly) which can
then (as you say) feed the grid of the tube amplifier with DC as well
as the analogue signal.

However that DC is only needed in the case of feeding a tube grid
- it is not usually necessary if feeding other amplifying devices.
Indeed a DAC driving a tube output stage that fed a lot of DC as well
to the output socket would be a dangerous device. (I think I must be
mis-reading something here.)

You can't talk about a DAC as
if there's "nothing" on the end of it.

Of course you can. What do you call the device whose output you connect
directly to the tube output stage?

I am totally puzzled (sorry - I *have* tried to think what the agument
and point is, but I've failed).

--
John Phillips

Apogee mini dac or Benchmark DAC1
 

you still have a DAC feeding the tube stage (if I have interpreted you
correctly) which can then (as you say) feed the grid of the tube
amplifier with DC as well
as the analogue signal.

I think you've misunderstood this. The DAC - or my DAC to be precise -
outputs an analogue signal of about 1.3v AC with about 2v DC
superimposed on it. To eliminate the DC one could put a capacitor at
this point (i.e. "something" on the end of it) But what I'm saying -
and what my setup does - is to put the analogue signal (both AC signal
and DC) directly into the grid of the triode of what we should call the
"line stage". At the output of this line stage, which has some gain, we
have the usual coupling cap and volume control. You can't put the
volume control in front of the grid because of the DC on the signal,
but the tube stage rather neatly incorporates the 2v DC into the bias
requirements of the stage. To be precise, my DAC has a balanced output
into the grids of a diff pair with a CCS under it, so the CCS
determines the current through the stage.

Apogee mini dac or Benchmark DAC1
 

The advantage of a tube stage is that the output with DC on it can be fed
directly into the grid of the tube, and the DC included in the biasing.


Are you claiming this is impossible for non-tube stages? JLS

Bad choice of words - I can see what you mean. Let me rephrase "it's
convenient to go directly into the grid because you don't need a
coupling cap at this point". You're the expert at ss, and I'd be
delighted to see a schematic for a ss solution with no coupling cap.

Apogee mini dac or Benchmark DAC1
 

Jim Lesurf wrote:

In article .com,
Andy Evans wrote:
Precisision and linearity can be measured scientifically and
objectively. The remainder are in the ear and brain of the listener.

So? The purpose of the DAC is to listen to it.

The purpose of the DAC is to reconstruct an analogue waveform as defined by
the series of sample values.

Unforunately due to Mr Evans half-assed method of quoting you mixed his comments
with mine.

I did indeed say " Precisision and linearity can be measured scientifically and

objectively. The remainder are in the ear and brain of the listener ".

And he said " So? The purpose of the DAC is to listen to it. "

Graham

Apogee mini dac or Benchmark DAC1
 

But of course, some DACs may be made so as to alter the results in
specific ways. Hence someone might then prefer this to a result
indistinguishable from the original prior to ADC conversion. :-)

I see all the signs of you being rather sly here, and if I can rephrase
this it looks like "some people prefer colourations to accurate sound",
which we know from a litany of posts about valve equipment. No, I'm
speaking about instrumental timbre which appears to be more faithful
rather than less. I can only ask people posting on this subject to hear
this for themselves, since neither scientific method nor adjectives
will substitute for the actual sound itself.

Apogee mini dac or Benchmark DAC1
 

Jim Lesurf wrote:

In article . com,
Andy
Evans wrote:

The advantage of a tube stage is that the output with DC on it can be fed
directly into the grid of the tube, and the DC included in the biasing.

Are you claiming this is impossible for non-tube stages?

Mr Evans omits to mention that the output on the tube anodes cannot be directly
coupled to the load.

Selective criticism applies as ever with this kind of tortured thinking.

In comparison, an op-amp or discrete transistor 'DAC follower' can indeed be
100% DC coupled.

Graham

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

I've no doubt you know valves from ( ?50s, 60s?, 70s?), but you'd be
very surprised at how much things have changed.

There has been no change whatever. Tube technology peaked in the early 50s.

Not the function of the
triode itself, which is well known, but the support circuitry is now
quite complex - cascode active loads, constant current sinks etc. - a
whole cuisine of modern ss devices and traditional stuff like glow
tubes. It really is "nouvelle cuisine" if you pardon the expression.
We're not talking Mullard circuits with EF86s and ECC83s any more.

Indeed, toobists now use semiconductors to help cure the inherent flaws of
thermionic devices.

Graham

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

Does Mozilla normally put the quoting arrows on the rhs instead of the
left ?

Mozilla means as much to me as King Kong.

So what are you using to post here ? This is what your headers say.

User-Agent:
G2/1.0
X-HTTP-UserAgent:
Mozilla/4.0 (compatible; MSIE 6.0; AOL 9.0; Windows NT 5.1;
SV1),gzip(gfe),gzip(gfe)
X-HTTP-Via:
HTTP/1.1 (Velocity/1.1.1 [uScMs f p eN:t cCMp s ]), HTTP/1.1
Turboweb [los-tc042 8.4.1], HTTP/1.1 cache-los-ad01.proxy.aol.com[C35D1561]
(Traffic-Server/6.1.2 [uScM])


Or are you simply choosing to be perverse ? You would have considerably
greater
credibility if you adhered to Usenet norms.

As an ex musician I'm so used to being an outsider that credibility -
in terms of fitting in with the norm and conventional behaviour - is a
bit of a Fata Morgana. If I'd wanted credibility I'd have become a bank
manager.

Ok. You *are* perverse!

Linux maybe ?

Graham

Apogee mini dac or Benchmark DAC1
 

Keith G wrote:

"Andy Evans" wrote in message
ups.com...
Does Mozilla normally put the quoting arrows on the rhs instead of the
left ?

Mozilla means as much to me as King Kong.

OK, let me help here - Mozilla is the cheese used to make pizzas,

LOL ! Pppffftttttt...... I have some Mozzarella in the fridge though !


King Kong is the Chinese province used to make *British* hifi equipment....

IAG !

Graham

Apogee mini dac or Benchmark DAC1
 

Keith G wrote:

"Eeyore" wrote in
message ...


Andy Evans wrote:

Listening will only tell you what *you* think of it, i.e. subjective
evaluation.

Exactly. That's how most people evaluate products.

Which is fine as far as it goes. Do you expect everyone's listening
preference to be
identical though ? There lies the limitation !


That is no reliable measure of 'goodness' whatever as easily can be
seen from
those who think SET tube amps are great despite shocking failings wrt
precision
and linearity. Graham

Many SET amps sound very good.

So some say. They also produce oodles of intermodulation products which
are most
unmusical. This will easily be revealed by playing 'complex' music, yet
they will
tend to sound excellent on a single instrument, or say a quartet.


please learn to quote properly btw

please learn to be more flexible and stop demanding that other people
obey your own views.

Please pull your head out of your arse !

Interesting to see that, sooner or later, all of you clowns who just don't
*get it* with valves have to result to guttersnipe phraseology....

It had nothing do do with 'toobiness' at all actually.

Graham

Apogee mini dac or Benchmark DAC1
 

Eeyore wrote:
Jim Lesurf wrote:

In article .com,
Andy Evans wrote:
Precisision and linearity can be measured scientifically and
objectively. The remainder are in the ear and brain of the listener.

So? The purpose of the DAC is to listen to it.

The purpose of the DAC is to reconstruct an analogue waveform as defined by
the series of sample values.

Unforunately due to Mr Evans half-assed method of quoting you mixed his comments
with mine.

I did indeed say " Precisision and linearity can be measured scientifically and

objectively. The remainder are in the ear and brain of the listener ".

And he said " So? The purpose of the DAC is to listen to it. "

Graham

I really have to stand up for my quoting here. The above looks like the
Battle of Agincourt on my AOL system - enough arrows to bring down the
cream of the French aristocracy. Hopeless for a quick comment. In
addition although the first comment is attributed the rest are not. And
even worse, AOL hides the whole previous text so you have to click on
it to see it al all - one more click stroke. In ordinary conversation
(you can imagine the oak dinner table and the bottle of Chablis) one
would say something like "to pick up your point about "skin deep" I
believe it was S J Perelman who said that after the USA, even though
politeness in Britain was only skin deep, that was deep enough for
him". One would not repeat the whole previous conversation word for
word. You may see newsgroups as a literary experience, but I consider
them as essentially conversation, and I believe that picking up on a
point somebody makes is quite enough in the omnipresent information
overload of the Net.

Apogee mini dac or Benchmark DAC1
 

Keith G wrote:

"Eeyore" wrote in
message ...


Andy Evans wrote:


Eeyore wrote
!
Precisision and linearity can be measured scientifically and
objectively. The remainder are in the ear and brain of the listener.

So? The purpose of the DAC is to listen to it.

Listening will only tell you what *you* think of it, i.e. subjective
evaluation.
That is no reliable measure of 'goodness' whatever as easily can be seen
from
those who think SET tube amps are great despite shocking failings wrt
precision and linearity.

'Shocking failings'....???

By any established technical standard for sure.


(I love it when you Denial Boys start to talk dirty.....!! :-)

You haven't heard the half of it.

Graham

Apogee mini dac or Benchmark DAC1
 

Keith G wrote:

"Andy Evans" wrote in message
oups.com...
What they are confusing this with is their preference for an
intentionally flawed but
entirely pleasnt and relatively benign form of distortion. Nothing
wrong with their
listening preference but the presentation of this as inherently
superior is utterly bogus.

The idea that valves are simply "added distortion" and nothing else
could only be made by somebody with a) very little knowledge of modern
valve circuits and how they sound or b) somebody with cloth ears.

My suspicion is that a lot of people with strong views on valve kit is that
they haven't actually ever *heard* any......

Certainly doesn't apply in my case.

Graham

Apogee mini dac or Benchmark DAC1
 

Keith G wrote:

"Eeyore" wrote in
message ...

Andy Evans wrote:

You've snipped all the previous content so it's impossible to know what
exactly you're replying to.

Please use 'inline posting'.
http://en.wikipedia.org/wiki/Bottom_...nline_replying

You currently have all the hallmark signs of an arrogant opinionated
self-obsessed jerk !

And you don't....??

You're suggesting that it's arrogant to use and encourage the use of established
Usenet norms ?

They exist for a reason as you'll see when you read another of my posts. Evans's
method of attribution led you to incorrectly attribute part of what I said to
him.

Graham

Apogee mini dac or Benchmark DAC1
 

Keith G wrote:

"Eeyore" wrote in
message ...

Andy Evans wrote:

What they are confusing this with is their preference for an
intentionally flawed but
entirely pleasnt and relatively benign form of distortion. Nothing
wrong with their
listening preference but the presentation of this as inherently
superior is utterly
bogus.

The idea that valves are simply "added distortion" and nothing else
could only be made by somebody with a) very little knowledge of modern
valve circuits and how they sound or b) somebody with cloth ears.

There is precious litle 'modern' about any valve circuit. I learnt on them
btw.

Nahh, I doubt that - you post like you've learnt nothing at all.....

Do continue. What is it you think I do / don't know ( have / haven't learnt )
about valves ?

Graham

Apogee mini dac or Benchmark DAC1
 

Keith G wrote:

"Andy Evans" wrote in message
oups.com...
There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

I've no doubt you know valves from ( ?50s, 60s?, 70s?), but you'd be
very surprised at how much things have changed. Not the function of the
triode itself, which is well known, but the support circuitry is now
quite complex - cascode active loads, constant current sinks etc. - a
whole cuisine of modern ss devices and traditional stuff like glow
tubes. It really is "nouvelle cuisine" if you pardon the expression.
We're not talking Mullard circuits with EF86s and ECC83s any more.

You've got more faith with some of these 'hot under the collar' types than I
have Andy - I take a lot of what they say with a pinch of salt (large one).
Most of 'em have never heard a valve amp and some of the others have only
heard some old *legacy* struggler at best and seem to forget what some of
the transistor equipment from the 70s could sound like.....

Why would I consider the performance of 70s transistor equipment as having any
more weight than legacy tube kit ?

Graham

Apogee mini dac or Benchmark DAC1
 

John Phillips wrote:

On 2006-09-09, Andy Evans wrote:
If the DAC isn't (sufficiently) transparent then putting a valve (tube)
in series with it cannot make the combination transparent. Yet
sometimes I see the T word used to describe
"better" in this context.

Isn't a DAC by definition something with an analogue output stage? ...

No, it's a device with an analogue output (not necessarily an analogue
output *stage*). For example, in the case of current summing DACs the
summing point is sometimes connected directly to a pin on the DAC and you
are expected to supply your own virtual-earth transimpedance amplifier
(valve or SS) if you want a voltage instead of a current output.

Modern DACs are now typically voltage output again. There's no inherent
advantage to be had either way with current or voltage output really.


So something must be on the end of it, whether ss circuit,
transformer,capacitor or tube stage. ...

Well, in the audio context a DAC will not (usually) drive a loudspeaker
so you need amplification and/or impedance conversion and/or current
to voltage conversion after the DAC itself.

Absolutely. There is no avoiding this.


However I can't see the
relevance of this. There is still a very real DAC in the reproduction
chain.

100% true.


The advantage of a tube stage is
that the output with DC on it can be fed directly into the grid of the
tube, and the DC included in the biasing.

That may be an advantage in certain cases but you still have a DAC
feeding the tube stage (if I have interpreted you correctly) which can
then (as you say) feed the grid of the tube amplifier with DC as well
as the analogue signal.

A long-tailed discrete differential pair would work nicely here but you still
have to get rid of the DC output offset from *that* stage !


However that DC is only needed in the case of feeding a tube grid
- it is not usually necessary if feeding other amplifying devices.
Indeed a DAC driving a tube output stage that fed a lot of DC as well
to the output socket would be a dangerous device. (I think I must be
mis-reading something here.)

Exactly right.


You can't talk about a DAC as if there's "nothing" on the end of it.

Of course you can. What do you call the device whose output you connect
directly to the tube output stage?

I am totally puzzled (sorry - I *have* tried to think what the agument
and point is, but I've failed).

Me too.

Graham

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

you still have a DAC feeding the tube stage (if I have interpreted you
correctly) which can then (as you say) feed the grid of the tube
amplifier with DC as well
as the analogue signal.

I think you've misunderstood this. The DAC - or my DAC to be precise -
outputs an analogue signal of about 1.3v AC with about 2v DC
superimposed on it. To eliminate the DC one could put a capacitor at
this point (i.e. "something" on the end of it) But what I'm saying -
and what my setup does - is to put the analogue signal (both AC signal
and DC) directly into the grid of the triode of what we should call the
"line stage". At the output of this line stage, which has some gain, we
have the usual coupling cap

So, you're saying it's OK to have a cap here but not *there* ?


and volume control. You can't put the
volume control in front of the grid because of the DC on the signal,
but the tube stage rather neatly incorporates the 2v DC into the bias
requirements of the stage. To be precise, my DAC has a balanced output
into the grids of a diff pair with a CCS under it, so the CCS
determines the current through the stage.

Meaningless waffle, selective ignorance and obfuscation.

Graham

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

The advantage of a tube stage is that the output with DC on it can be fed
directly into the grid of the tube, and the DC included in the biasing.

Are you claiming this is impossible for non-tube stages? JLS

Bad choice of words - I can see what you mean. Let me rephrase "it's
convenient to go directly into the grid because you don't need a
coupling cap at this point". You're the expert at ss, and I'd be
delighted to see a schematic for a ss solution with no coupling cap.

It's trivially simple.

Graham

Apogee mini dac or Benchmark DAC1
 

On Sat, 09 Sep 2006 16:42:49 +0100, Eeyore
wrote:

There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

I've no doubt you know valves from ( ?50s, 60s?, 70s?), but you'd be
very surprised at how much things have changed.

There has been no change whatever. Tube technology peaked in the early 50s.

Not the function of the
triode itself, which is well known, but the support circuitry is now
quite complex - cascode active loads, constant current sinks etc. - a
whole cuisine of modern ss devices and traditional stuff like glow
tubes. It really is "nouvelle cuisine" if you pardon the expression.
We're not talking Mullard circuits with EF86s and ECC83s any more.

Indeed, toobists now use semiconductors to help cure the inherent flaws of
thermionic devices.


Well, make your mind up! Either valve circuits have changed or they
haven't.

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

But of course, some DACs may be made so as to alter the results in
specific ways. Hence someone might then prefer this to a result
indistinguishable from the original prior to ADC conversion. :-)

I see all the signs of you being rather sly here, and if I can rephrase
this it looks like "some people prefer colourations to accurate sound",

That would seem to be an accurate statement.


which we know from a litany of posts about valve equipment. No, I'm
speaking about instrumental timbre which appears to be more faithful
rather than less. I can only ask people posting on this subject to hear
this for themselves, since neither scientific method nor adjectives
will substitute for the actual sound itself.

Since musical timbre entirely *depends* on rich harmonics to sound good, it's
hardly surpising then that a toob will 'flatter' them is it ?

Graham

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

Eeyore wrote:
Jim Lesurf wrote:

In article .com,
Andy Evans wrote:
Precisision and linearity can be measured scientifically and
objectively. The remainder are in the ear and brain of the listener.

So? The purpose of the DAC is to listen to it.

The purpose of the DAC is to reconstruct an analogue waveform as defined by
the series of sample values.

Unforunately due to Mr Evans half-assed method of quoting you mixed his comments
with mine.

I did indeed say " Precisision and linearity can be measured scientifically and

objectively. The remainder are in the ear and brain of the listener ".

And he said " So? The purpose of the DAC is to listen to it. "

Graham

I really have to stand up for my quoting here. The above looks like the
Battle of Agincourt on my AOL system

AOL ? Good God !


- enough arrows to bring down the
cream of the French aristocracy. Hopeless for a quick comment. In
addition although the first comment is attributed the rest are not. And
even worse, AOL hides the whole previous text so you have to click on
it to see it al all - one more click stroke. In ordinary conversation
(you can imagine the oak dinner table and the bottle of Chablis) one
would say something like "to pick up your point about "skin deep" I
believe it was S J Perelman who said that after the USA, even though
politeness in Britain was only skin deep, that was deep enough for
him". One would not repeat the whole previous conversation word for
word. You may see newsgroups as a literary experience, but I consider
them as essentially conversation, and I believe that picking up on a
point somebody makes is quite enough in the omnipresent information
overload of the Net.

I suggest you use a decent 'newsreader'. Your problems are entirely of your / AOL's
own making.

Graham

Apogee mini dac or Benchmark DAC1
 

Laurence Payne wrote:

On Sat, 09 Sep 2006 16:42:49 +0100, Eeyore
wrote:

There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

I've no doubt you know valves from ( ?50s, 60s?, 70s?), but you'd be
very surprised at how much things have changed.

There has been no change whatever. Tube technology peaked in the early 50s.

Not the function of the
triode itself, which is well known, but the support circuitry is now
quite complex - cascode active loads, constant current sinks etc. - a
whole cuisine of modern ss devices and traditional stuff like glow
tubes. It really is "nouvelle cuisine" if you pardon the expression.
We're not talking Mullard circuits with EF86s and ECC83s any more.

Indeed, toobists now use semiconductors to help cure the inherent flaws of
thermionic devices.

Well, make your mind up! Either valve circuits have changed or they
haven't.

That's a hybrid circuit not a tube one.

Such improvements as exist are due to semiconductor use. Tubes themselves
haven't changed in any significant way since the advent of new types with radar
for the most part ( and also UHF TV ).


Graham

Apogee mini dac or Benchmark DAC1
 

On Sat, 09 Sep 2006 18:09:31 +0100, Eeyore
wrote:

That's a hybrid circuit not a tube one.

So what? What DO you allow? Resistors, caps....?

Apogee mini dac or Benchmark DAC1
 

Well, make your mind up! Either valve circuits have changed or they haven't.

That's a hybrid circuit not a tube one.

It's my experience that "hybrid" amplifiers have both tube and ss
amplification stages, not ss current sinks, active loads etc. It would
be deviating from common practice to call a circuit where the
amplification stages were all tube a "hybrid" circuit, although clearly
as you say the technology is hybrid.

Apogee mini dac or Benchmark DAC1
 

So, you're saying it's OK to have a cap here but not *there* ? EY..

What I'm saying is you eliminate one cap by DC coupling to the grids of
the amplification stage (I believe Jim says you can do this with ss
devices, which is absolutely fine). The conventional way would be
capamplification stagecap.


To be precise, my DAC has a balanced output into the grids of a diff
pair with a CCS under it, so the CCS determines the current through the
stage. AE


Meaningless waffle, selective ignorance and obfuscation. EY...

Well it may be meaningless to you, but I've built four of these so far
and done a range of comparative listening tests over the last 6 months
with a number of colleagues (engineers, if that makes a difference). If
I built them in ignorance and hid them under a tarpaulin I must have
been bloody lucky they all worked.

Apogee mini dac or Benchmark DAC1
 

Laurence Payne wrote:

On Sat, 09 Sep 2006 18:09:31 +0100, Eeyore
wrote:

That's a hybrid circuit not a tube one.

So what? What DO you allow? Resistors, caps....?

Are you being simply obtuse or actually monumentally obtuse ?

Graham

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

Well, make your mind up! Either valve circuits have changed or they haven't.

That's a hybrid circuit not a tube one.

It's my experience that "hybrid" amplifiers have both tube and ss
amplification stages, not ss current sinks, active loads etc. It would
be deviating from common practice to call a circuit where the
amplification stages were all tube a "hybrid" circuit, although clearly
as you say the technology is hybrid.

Thank you. It is indeed a 'hybrid' and nothing wrong with that at all !

Graham

Apogee mini dac or Benchmark DAC1
 

On Sat, 09 Sep 2006 21:07:23 +0100, Eeyore
wrote:

Are you being simply obtuse or actually monumentally obtuse ?

We're discussing your response to:
There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

There's more than a valve in a "valve circuit". Now there may be
solid-state components too.

Apogee mini dac or Benchmark DAC1
 

Laurence Payne wrote:

On Sat, 09 Sep 2006 21:07:23 +0100, Eeyore
wrote:

Are you being simply obtuse or actually monumentally obtuse ?

We're discussing your response to:
There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

There's more than a valve in a "valve circuit". Now there may be
solid-state components too.

Which makes them hybrid, not exclusively valve.

Graham

Apogee mini dac or Benchmark DAC1
 

Andy Evans wrote:

So, you're saying it's OK to have a cap here but not *there* ? EY..

What I'm saying is you eliminate one cap by DC coupling to the grids of
the amplification stage (I believe Jim says you can do this with ss
devices, which is absolutely fine).

Yes, that's entirely fine.


The conventional way would be capamplification stagecap.

It would be ? Do elaborate.


To be precise, my DAC has a balanced output into the grids of a diff
pair with a CCS under it, so the CCS determines the current through the
stage. AE

Good. Excellent design priciples there. I'll venture that the CCS is
semiconductor though.


Meaningless waffle, selective ignorance and obfuscation. EY...

Well it may be meaningless to you, but I've built four of these so far

So ? The products I've designed have sold in hundreds, thousands and tens of
thousands. What's the big deal ?


and done a range of comparative listening tests over the last 6 months
with a number of colleagues (engineers, if that makes a difference).

It might do. Who are those 'engineers' ?


If
I built them in ignorance and hid them under a tarpaulin I must have
been bloody lucky they all worked.

What's your point ?

Graham

Apogee mini dac or Benchmark DAC1
 

On Sat, 09 Sep 2006 21:53:34 +0100, Eeyore
wrote:

We're discussing your response to:
There is precious litle 'modern' about any valve circuit. I learnt on
them btw.

There's more than a valve in a "valve circuit". Now there may be
solid-state components too.

Which makes them hybrid, not exclusively valve.

So who said "exclusively"? We're discussing modern applications of
valves. They're GOING to be hybrid. (They're probably also going to
be snake-oil, but that's another matter.)

Apogee mini dac or Benchmark DAC1
 

"Andy Evans" wrote in
message
oups.com...
I've ended up with this
http://www.cec-web.co.jp/products/dac/dx71mk2_e.html
I am extremely impressed with this unit.

It looks great. To my mind this really is the way to go -
the
DAC-Preamp. All your digital sources go into it and there
you are.

Can you give us a fuller description of how it operates
and sounds, and
in what ways it was better than the other equipment you
had before or
tried out?

I can't find any reviews of this, so the above would be
welcome.


Apologies for the late reply.

What I have been able to achieve with this is to "shorten"
the chain of gear and hopefully keep the signal integrity
more intact. So I now use the CEC as a DAC and a pre-amp
using it's balanced outputs direct to my Australian made
ME850's balanced inputs. So when I feed an AES/EBU (as
opposed to SPDIF) signal to the CEC I can use it's onboard
Clock and the result is IMHO quite spectacular. I really
never thought garden variety red book CDs could sound so
good. I will need to do some DBTs to compare to the
SACD/DVD-A equivalents now to confirm some this of course.

Doing a comparison with my Marantz DV8300 (multi player)
using SPDIF/TOSlink and then through a pre-amp I could not
tell a difference until I swapped the CEC to pre-amp
function as well.

The biggest gain I have noticed is "magically" that
fatiguing CD sound has gone and it has that more natural
SACD/analog sound.

It is still early days and I am still tweaking (playing
around) with this thing but my initial opinion is that it
really is something special.

BTW I am using this to feed the CEC


http://www.creative.com/products/pro...roduct=1 5189

So I can output a AES/EBU digital signal up to 192/24 and
set the preferences to allow for an external clock i.e. the
CEC's. So I keep a faithful digital signal all the way to
DAC/pre-amp.

I hope some of this helps. My suggestion is try to get hold
of a unit and demo it for yourself.

Regards TT

Apogee mini dac or Benchmark DAC1
 

In article .com,
Andy
Evans wrote:
The advantage of a tube stage is that the output with DC on it can be
fed directly into the grid of the tube, and the DC included in the
biasing.


Are you claiming this is impossible for non-tube stages? JLS

Bad choice of words - I can see what you mean. Let me rephrase "it's
convenient to go directly into the grid because you don't need a
coupling cap at this point". You're the expert at ss, and I'd be
delighted to see a schematic for a ss solution with no coupling cap.

IIUC what you are saying the equivalent would be to connect the DAC output
directly to the gate of a FET or base of a transistor, in either case
operating as a gain stage/buffer like the valve. Then fit a dc break cap
following it, just like the valve. Hence so far as I can see there is no
'advantage' for valves here. And it could be just as 'convenient' with
SS devices - if that was what you wanted to do.

Publish the valve circuit you have in mind and I or someone else can
probably give one for essentially the same topology using a SS gain
device.

BTW regardless of valve or SS I would not personally follow a DAC directly
with a gain device. I'd be quite likely to include a passive LPF regardless
of the type of gain device. But perhaps not everyone would bother to do
this, and nothing to do with type of gain device per se.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Apogee mini dac or Benchmark DAC1
 

In article , Eeyore
wrote:


Jim Lesurf wrote:

In article .com,
Andy Evans wrote:
Precisision and linearity can be measured scientifically and
objectively. The remainder are in the ear and brain of the listener.


So? The purpose of the DAC is to listen to it.

The purpose of the DAC is to reconstruct an analogue waveform as
defined by the series of sample values.

Unforunately due to Mr Evans half-assed method of quoting you mixed his
comments with mine.

Sorry for that. I'm afraid it is one of the hazards of trying to make
sense of his postings.

I've also tried to get Andy to learn to show some consideration for others
and adopt the usual conventions for postings. As have others.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Apogee mini dac or Benchmark DAC1
 

I hope some of this helps. My suggestion is try to get hold of a unit
and demo it for yourself.

I'm alright for a DAC, but I do have to get a sound card to input midi
to my computer since I want to put down all my songs in MIDI. 16 track
would be just fine. Do you use yours for home recording off a keyboard?

Apogee mini dac or Benchmark DAC1
 

"Andy Evans" wrote in message
oups.com...
I hope some of this helps. My suggestion is try to get hold of a unit
and demo it for yourself.

I'm alright for a DAC, but I do have to get a sound card to input midi
to my computer since I want to put down all my songs in MIDI. 16 track
would be just fine. Do you use yours for home recording off a keyboard?

No. I have just about finished putting all my CDs on HD. I am using it as
a computer to hi-fi interface. Also because it has a RIAA phono stage as
well I can also transcribe LPs.

I chose it because of the very high pro specs.

Regards TT