On Sat, 20 May 2023 22:20:37 +1000, Andrew <Andrew97d@btinternet.com>
wrote:

> On 18/05/2023 21:04, Tim+ wrote:
>> Tim Streater <tim@streater.me.uk> wrote:
>>> On 18 May 2023 at 10:53:17 BST, "Bob Latham"
>>> <bob@sick-of-spam.invalid> wrote:
>>
>>>> From having a fully working system one day to a crippled one the next
>>>> without warning or choice AND the only way out is buy a new control
>>>> device or a new iPad at £500 or so. That's why I hate Sonos.
>>>
>>> A good reason for eschewing all this bollocks. Same with smart phones
>>> really.
>>>
>> Ha! Gotta love luddites who haven’t a clue about smart phones.
>> Today I was out in the middle of nowhere listening to a bird (unseen)
>> singing it’s heart out. Whipped out my phone and within seconds my phone
>> had identified the bird from its song and provided me with a picture.
>> Try doing that with a dumb phone.

> Try doing that where the mobile signal is rather poor though.

The best of the apps allow you to capture the sound and tell
you which bird it is when you are back in mobils signal range.

> There are still plenty of not-spots and you also need to have
> downloaded the app beforehand and know how to use it.

Hardly rocket science to do either.

>> Any who says that smart phones are bollocks might as well dismiss the
>> internet, digital cameras, and all manner of mind bogglingly useful apps
>> that are well nigh indispensable these days.
>> Yes, I *could* live without them, but I wouldn’t want to live such an
>> impoverished life.

> There are such things as books, and plenty related to birds, insects
> and other stuff.

But nowhere near as convient with an unseen bird or even a seen one.

On Fri, 19 May 2023 06:53:01 -0000 (UTC), RJH wrote:

>> Before lockdown I paid a visit to John Lewis and there was a
>> Sonos rep in the store.
>>
>> I asked him how a single unit could reproduce a proper stereo
>> image. His reply was that there were two speakers in it, a
>> woofer and a tweeter.
>
> Unusual IME - I find the JL sales staff to be pretty knowledgeable.

That was the Sonus rep, not a John Lewis salesperson.

Also hard to see where any tones less that 500Hz or so, come from.

On 09:35 18 May 2023, Trevor Wilson said:
> On 18/05/2023 6:12 pm, The Natural Philosopher wrote:
>> On 18/05/2023 09:07, Tim Streater wrote:
>>> On 18 May 2023 at 09:02:32 BST, "The Natural Philosopher"
>>> <tnp@invalid.invalid> wrote:
>>>> On 17/05/2023 21:38, Tim Streater wrote:
>>>>> On 17 May 2023 at 20:02:00 BST, "Adrian Caspersz"
>>>>> <email@here.invalid> wrote:
>>>>>> On 17/05/2023 13:27, Tim Streater wrote:
>>>>>>> On 17 May 2023 at 13:01:21 BST, "Adrian Caspersz"
>>>>>>> <email@here.invalid> wrote:
>>>>>>>
>>>>>>>> Bluetooth speakers mainly. Streaming.
>>>>>>>
>>>>>>> What's streaming or bluetooth got to do with the sound quality
>>>>>>> that the speaker will generate? You can use bluetooth or
>>>>>>> streaming to supply audio to a tin box but it won't sound very
>>>>>>> good.
>>>>>>>
>>>>>>
>>>>>> A bluetooth speaker is a popular current replacement for a Hifi.
>>>>>
>>>>> A combination of decent speakers with a quality amp is going to
>>>>> be rare in such a device, which is why one might stick to
>>>>> separate speakers, separate amp.
>>>>>
>>>>> Although I suppose it's possible someone might do a proper job,
>>>>> but not much change out of �5k I wouldn't have thought.
>>>>>
>>>> Amplifiers are now at the point where they are more or less
>>>> 'perfect'
>>>
>>> There wasn't a lot wrong with the Quad 33/303 combo I bought in
>>> 1970. No optical or other digital input, of course. Especially when
>>> paired with the IMF RSPM I bought in 1974. Not that I could tell,
>>> these days, of course, but I sure could then.
>>>
>> Quad 303 was relative junk actually.  Had a lot of crossover
>> distortion especially at HF. Many of its contemporaries were in fact
>> better.
>
> **Agreed. The 33/303 were, at best, extremely primitive, poorly
> performing products.

Reconditioned Quad 33/303s certainly go fo a pretty penny. This dealer
is asking �700, although bargain hunters can probably find them for
half the price. I'm not sure I would pay that.

https://audiogold.co.uk/product/quad-33-303/

On 22/05/2023 12:40 am, Pamela wrote:
> On 09:35 18 May 2023, Trevor Wilson said:
>> On 18/05/2023 6:12 pm, The Natural Philosopher wrote:
>>> On 18/05/2023 09:07, Tim Streater wrote:
>>>> On 18 May 2023 at 09:02:32 BST, "The Natural Philosopher"
>>>> <tnp@invalid.invalid> wrote:
>>>>> On 17/05/2023 21:38, Tim Streater wrote:
>>>>>> On 17 May 2023 at 20:02:00 BST, "Adrian Caspersz"
>>>>>> <email@here.invalid> wrote:
>>>>>>> On 17/05/2023 13:27, Tim Streater wrote:
>>>>>>>> On 17 May 2023 at 13:01:21 BST, "Adrian Caspersz"
>>>>>>>> <email@here.invalid> wrote:
>>>>>>>>
>>>>>>>>> Bluetooth speakers mainly. Streaming.
>>>>>>>>
>>>>>>>> What's streaming or bluetooth got to do with the sound quality
>>>>>>>> that the speaker will generate? You can use bluetooth or
>>>>>>>> streaming to supply audio to a tin box but it won't sound very
>>>>>>>> good.
>>>>>>>>
>>>>>>>
>>>>>>> A bluetooth speaker is a popular current replacement for a Hifi.
>>>>>>
>>>>>> A combination of decent speakers with a quality amp is going to
>>>>>> be rare in such a device, which is why one might stick to
>>>>>> separate speakers, separate amp.
>>>>>>
>>>>>> Although I suppose it's possible someone might do a proper job,
>>>>>> but not much change out of £5k I wouldn't have thought.
>>>>>>
>>>>> Amplifiers are now at the point where they are more or less
>>>>> 'perfect'
>>>>
>>>> There wasn't a lot wrong with the Quad 33/303 combo I bought in
>>>> 1970. No optical or other digital input, of course. Especially when
>>>> paired with the IMF RSPM I bought in 1974. Not that I could tell,
>>>> these days, of course, but I sure could then.
>>>>
>>> Quad 303 was relative junk actually.Ā  Had a lot of crossover
>>> distortion especially at HF. Many of its contemporaries were in fact
>>> better.
>>
>> **Agreed. The 33/303 were, at best, extremely primitive, poorly
>> performing products.
>
> Reconditioned Quad 33/303s certainly go fo a pretty penny. This dealer
> is asking £700, although bargain hunters can probably find them for
> half the price. I'm not sure I would pay that.
>
> https://audiogold.co.uk/product/quad-33-303/
>

**Excellent. I have a couple of 33/303 units here, awaiting restoration.
Should earn me a pretty penny.

Just because people want to pay big Bucks for them, doesn't mean they're
good amps though.

--
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Trevor Wilson wrote:
Pamela wrote:
------------------------------------
> >> **Agreed. The 33/303 were, at best, extremely primitive, poorly
> >> performing products.
> >

* The above *opinion* is not one bit accurate.

> > Reconditioned Quad 33/303s certainly go fo a pretty penny. This dealer
> > is asking £700, although bargain hunters can probably find them for
> > half the price. I'm not sure I would pay that.
> >
> > https://audiogold.co.uk/product/quad-33-303/
> >
>
> Just because people want to pay big Bucks for them, doesn't mean they're
> good amps though.
>

* The Quad 303 amp was designed to be used with the Quad ESL57 speaker so had special features needed for that job.

The exact right power output, +/- 33V peak as specified for the speaker - plus a regulated DC supply ensured this did not vary with the mains.
Sharp low frequency roll of below 30Hz removing sub-sonic signals from TTs and LPs.
Capacitor coupled output so never any DC offsets.
Inherent current limiting protecting output transistors from accidental shorts on speaker lines.
All the above combined made it safe driving the input transformer of the ESL57, a load of 0.3 ohms at DC or when driven into low frequency saturation..
Few if any other SS amps of the 303's era included all the same measures and so could misbehave badly or fail or damage the ESL57.
For this reason the 303 continued in production until 1985 when the ESL57 was withdrawn.
Over 94,000 units were sold.

....... Phil

On Mon, 22 May 2023 07:20:46 +1000
Trevor Wilson <trevor@rageaudio.com.au> wrote:

>
> Just because people want to pay big Bucks for them, doesn't mean
> they're good amps though.
>

Quite robust, though. One university student union used them as disco
amps in the early 70s, fitted with jacks instead of DINs.

--
Joe

On Sun, 21 May 2023 15:40:39 +0100, Pamela wrote:

> Reconditioned Quad 33/303s certainly go fo a pretty penny. This
> dealer is asking £700, although bargain hunters can probably find
> them for half the price. I'm not sure I would pay that.
>
> https://audiogold.co.uk/product/quad-33-303/

They have other interesting offers, like the Audiolab 8000A for 750
UKP. The refurb details are impressive.

On 21/05/2023 22:20, Trevor Wilson wrote:
> On 22/05/2023 12:40 am, Pamela wrote:
>> On 09:35  18 May 2023, Trevor Wilson said:
>>> On 18/05/2023 6:12 pm, The Natural Philosopher wrote:
>>>> On 18/05/2023 09:07, Tim Streater wrote:
>>>>> On 18 May 2023 at 09:02:32 BST, "The Natural Philosopher"
>>>>> <tnp@invalid.invalid> wrote:
>>>>>> On 17/05/2023 21:38, Tim Streater wrote:
>>>>>>> On 17 May 2023 at 20:02:00 BST, "Adrian Caspersz"
>>>>>>> <email@here.invalid> wrote:
>>>>>>>> On 17/05/2023 13:27, Tim Streater wrote:
>>>>>>>>> On 17 May 2023 at 13:01:21 BST, "Adrian Caspersz"
>>>>>>>>> <email@here.invalid> wrote:
>>>>>>>>>
>>>>>>>>>> Bluetooth speakers mainly. Streaming.
>>>>>>>>>
>>>>>>>>> What's streaming or bluetooth got to do with the sound quality
>>>>>>>>> that the speaker will generate? You can use bluetooth or
>>>>>>>>> streaming to supply audio to a tin box but it won't sound very
>>>>>>>>> good.
>>>>>>>>>
>>>>>>>>
>>>>>>>> A bluetooth speaker is a popular current replacement for a Hifi.
>>>>>>>
>>>>>>> A combination of decent speakers with a quality amp is going to
>>>>>>> be rare in such a device, which is why one might stick to
>>>>>>> separate speakers, separate amp.
>>>>>>>
>>>>>>> Although I suppose it's possible someone might do a proper job,
>>>>>>> but not much change out of £5k I wouldn't have thought.
>>>>>>>
>>>>>> Amplifiers are now at the point where they are more or less
>>>>>> 'perfect'
>>>>>
>>>>> There wasn't a lot wrong with the Quad 33/303 combo I bought in
>>>>> 1970. No optical or other digital input, of course. Especially when
>>>>> paired with the IMF RSPM I bought in 1974. Not that I could tell,
>>>>> these days, of course, but I sure could then.
>>>>>
>>>> Quad 303 was relative junk actually.Ā  Had a lot of crossover
>>>> distortion especially at HF. Many of its contemporaries were in fact
>>>> better.
>>>
>>> **Agreed. The 33/303 were, at best, extremely primitive, poorly
>>> performing products.
>>
>> Reconditioned Quad 33/303s certainly go fo a pretty penny. This dealer
>> is asking £700, although bargain hunters can probably find them for
>> half the price. I'm not sure I would pay that.
>>
>> https://audiogold.co.uk/product/quad-33-303/
>>
>
> **Excellent. I have a couple of 33/303 units here, awaiting restoration.
> Should earn me a pretty penny.
>
> Just because people want to pay big Bucks for them, doesn't mean they're
> good amps though.
>
Nope. Same with Marshall Valve amps

--
If I had all the money I've spent on drink...
...I'd spend it on drink.

Sir Henry (at Rawlinson's End)

On 22/05/2023 9:13 pm, The Natural Philosopher wrote:
> On 21/05/2023 22:20, Trevor Wilson wrote:
>> On 22/05/2023 12:40 am, Pamela wrote:
>>> On 09:35  18 May 2023, Trevor Wilson said:
>>>> On 18/05/2023 6:12 pm, The Natural Philosopher wrote:
>>>>> On 18/05/2023 09:07, Tim Streater wrote:
>>>>>> On 18 May 2023 at 09:02:32 BST, "The Natural Philosopher"
>>>>>> <tnp@invalid.invalid> wrote:
>>>>>>> On 17/05/2023 21:38, Tim Streater wrote:
>>>>>>>> On 17 May 2023 at 20:02:00 BST, "Adrian Caspersz"
>>>>>>>> <email@here.invalid> wrote:
>>>>>>>>> On 17/05/2023 13:27, Tim Streater wrote:
>>>>>>>>>> On 17 May 2023 at 13:01:21 BST, "Adrian Caspersz"
>>>>>>>>>> <email@here.invalid> wrote:
>>>>>>>>>>
>>>>>>>>>>> Bluetooth speakers mainly. Streaming.
>>>>>>>>>>
>>>>>>>>>> What's streaming or bluetooth got to do with the sound quality
>>>>>>>>>> that the speaker will generate? You can use bluetooth or
>>>>>>>>>> streaming to supply audio to a tin box but it won't sound very
>>>>>>>>>> good.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> A bluetooth speaker is a popular current replacement for a Hifi.
>>>>>>>>
>>>>>>>> A combination of decent speakers with a quality amp is going to
>>>>>>>> be rare in such a device, which is why one might stick to
>>>>>>>> separate speakers, separate amp.
>>>>>>>>
>>>>>>>> Although I suppose it's possible someone might do a proper job,
>>>>>>>> but not much change out of £5k I wouldn't have thought.
>>>>>>>>
>>>>>>> Amplifiers are now at the point where they are more or less
>>>>>>> 'perfect'
>>>>>>
>>>>>> There wasn't a lot wrong with the Quad 33/303 combo I bought in
>>>>>> 1970. No optical or other digital input, of course. Especially when
>>>>>> paired with the IMF RSPM I bought in 1974. Not that I could tell,
>>>>>> these days, of course, but I sure could then.
>>>>>>
>>>>> Quad 303 was relative junk actually.Ā  Had a lot of crossover
>>>>> distortion especially at HF. Many of its contemporaries were in fact
>>>>> better.
>>>>
>>>> **Agreed. The 33/303 were, at best, extremely primitive, poorly
>>>> performing products.
>>>
>>> Reconditioned Quad 33/303s certainly go fo a pretty penny. This dealer
>>> is asking £700, although bargain hunters can probably find them for
>>> half the price. I'm not sure I would pay that.
>>>
>>> https://audiogold.co.uk/product/quad-33-303/
>>>
>>
>> **Excellent. I have a couple of 33/303 units here, awaiting
>> restoration. Should earn me a pretty penny.
>>
>> Just because people want to pay big Bucks for them, doesn't mean
>> they're good amps though.
>>
> Nope.  Same with Marshall Valve amps
>

**I'm pretty certain Phil will chime in with his opinion on Marshall
valve amps. He experience with musical instrument amps is quite extensive.

--
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On 22/05/2023 12:22, Trevor Wilson wrote:
> On 22/05/2023 9:13 pm, The Natural Philosopher wrote:
>> On 21/05/2023 22:20, Trevor Wilson wrote:
>>> On 22/05/2023 12:40 am, Pamela wrote:
>>>> On 09:35  18 May 2023, Trevor Wilson said:
>>>>> On 18/05/2023 6:12 pm, The Natural Philosopher wrote:
>>>>>> On 18/05/2023 09:07, Tim Streater wrote:
>>>>>>> On 18 May 2023 at 09:02:32 BST, "The Natural Philosopher"
>>>>>>> <tnp@invalid.invalid> wrote:
>>>>>>>> On 17/05/2023 21:38, Tim Streater wrote:
>>>>>>>>> On 17 May 2023 at 20:02:00 BST, "Adrian Caspersz"
>>>>>>>>> <email@here.invalid> wrote:
>>>>>>>>>> On 17/05/2023 13:27, Tim Streater wrote:
>>>>>>>>>>> On 17 May 2023 at 13:01:21 BST, "Adrian Caspersz"
>>>>>>>>>>> <email@here.invalid> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Bluetooth speakers mainly. Streaming.
>>>>>>>>>>>
>>>>>>>>>>> What's streaming or bluetooth got to do with the sound quality
>>>>>>>>>>> that the speaker will generate? You can use bluetooth or
>>>>>>>>>>> streaming to supply audio to a tin box but it won't sound very
>>>>>>>>>>> good.
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> A bluetooth speaker is a popular current replacement for a Hifi.
>>>>>>>>>
>>>>>>>>> A combination of decent speakers with a quality amp is going to
>>>>>>>>> be rare in such a device, which is why one might stick to
>>>>>>>>> separate speakers, separate amp.
>>>>>>>>>
>>>>>>>>> Although I suppose it's possible someone might do a proper job,
>>>>>>>>> but not much change out of £5k I wouldn't have thought.
>>>>>>>>>
>>>>>>>> Amplifiers are now at the point where they are more or less
>>>>>>>> 'perfect'
>>>>>>>
>>>>>>> There wasn't a lot wrong with the Quad 33/303 combo I bought in
>>>>>>> 1970. No optical or other digital input, of course. Especially when
>>>>>>> paired with the IMF RSPM I bought in 1974. Not that I could tell,
>>>>>>> these days, of course, but I sure could then.
>>>>>>>
>>>>>> Quad 303 was relative junk actually.Ā  Had a lot of crossover
>>>>>> distortion especially at HF. Many of its contemporaries were in fact
>>>>>> better.
>>>>>
>>>>> **Agreed. The 33/303 were, at best, extremely primitive, poorly
>>>>> performing products.
>>>>
>>>> Reconditioned Quad 33/303s certainly go fo a pretty penny. This dealer
>>>> is asking £700, although bargain hunters can probably find them for
>>>> half the price. I'm not sure I would pay that.
>>>>
>>>> https://audiogold.co.uk/product/quad-33-303/
>>>>
>>>
>>> **Excellent. I have a couple of 33/303 units here, awaiting
>>> restoration. Should earn me a pretty penny.
>>>
>>> Just because people want to pay big Bucks for them, doesn't mean
>>> they're good amps though.
>>>
>> Nope.  Same with Marshall Valve amps
>>
>
> **I'm pretty certain Phil will chime in with his opinion on Marshall
> valve amps. He experience with musical instrument amps is quite extensive.
>
I have one, its relative crap, its worth about £800. I have two sub £100
Fender solid state amps that are in almost every way infinitely better.
--
"Strange as it seems, no amount of learning can cure stupidity, and
higher education positively fortifies it."

- Stephen Vizinczey

On Mon, 22 May 2023 12:38:39 +0100
The Natural Philosopher <tnp@invalid.invalid> wrote:

> On 22/05/2023 12:22, Trevor Wilson wrote:

> >
> > **I'm pretty certain Phil will chime in with his opinion on
> > Marshall valve amps. He experience with musical instrument amps is
> > quite extensive.

> I have one, its relative crap, its worth about £800. I have two sub
> £100 Fender solid state amps that are in almost every way infinitely
> better.

Valve amplifiers used to be favoured because of their distortion and
greater difficulty of destruction, didn't they?

Then later, valve hifi amplifiers came into vogue because they were
stupendously expensive and fashionable.

--
Joe

On Mon 22/05/2023 14:19, Joe wrote:
> On Mon, 22 May 2023 12:38:39 +0100
> The Natural Philosopher <tnp@invalid.invalid> wrote:
>
>> On 22/05/2023 12:22, Trevor Wilson wrote:
>
>>>
>>> **I'm pretty certain Phil will chime in with his opinion on
>>> Marshall valve amps. He experience with musical instrument amps is
>>> quite extensive.
>
>> I have one, its relative crap, its worth about £800. I have two sub
>> £100 Fender solid state amps that are in almost every way infinitely
>> better.
>
> Valve amplifiers used to be favoured because of their distortion and
> greater difficulty of destruction, didn't they?
>
> Then later, valve hifi amplifiers came into vogue because they were
> stupendously expensive and fashionable.
>

The main thing about valve amps is/was that their main distortion is
second harmonic to which the human ear does not object. IMSMC whilst
much above about 0.5% third harmonic sets your teeth on edge, north of
5% second harmonic is just not heard. Indeed a violin produces more
second harmonic than fundamental and speakers equally have relatively
high levels of 2nd and they don't sound too bad do they?

On 23/05/2023 12:53 am, Woody wrote:
> On Mon 22/05/2023 14:19, Joe wrote:
>> On Mon, 22 May 2023 12:38:39 +0100
>> The Natural Philosopher <tnp@invalid.invalid> wrote:
>>
>>> On 22/05/2023 12:22, Trevor Wilson wrote:
>>
>>>>
>>>> **I'm pretty certain Phil will chime in with his opinion on
>>>> Marshall valve amps. He experience with musical instrument amps is
>>>> quite extensive.
>>
>>> I have one, its relative crap, its worth about £800. I have two sub
>>> £100 Fender solid state amps that are in almost every way infinitely
>>> better.
>>
>> Valve amplifiers used to be favoured because of their distortion and
>> greater difficulty of destruction, didn't they?
>>
>> Then later, valve hifi amplifiers came into vogue because they were
>> stupendously expensive and fashionable.
>>
>
> The main thing about valve amps is/was that their main distortion is
> second harmonic to which the human ear does not object.

**SOME humans accept even order harmonics as OK. I and many others, do
not. Less distortion is always better.

IMSMC whilst
> much above about 0.5% third harmonic sets your teeth on edge, north of
> 5% second harmonic is just not heard.

**Not so. It has been generally accepted that, under careful listening
conditions, that humans can perceive around 0.1% THD.

Indeed a violin produces more
> second harmonic than fundamental

**Most musical instruments produce large amounts of harmonics. That does
not suggest that adding extra harmonics is a good thing.

and speakers equally have relatively
> high levels of 2nd and they don't sound too bad do they?

**Nope. High quality speakers typically exhibit low levels of
distortion. In fact, some speakers produce lower levels of distortion
than many valve amps.

https://www.quad-hifi.co.uk/esl-2912/

Distortion (100dB at 1m) Above 1000Hz 0.15%
Above 100Hz 0.5%
Above 50Hz 1.0%

https://www.bowerswilkins.com/en-us/product/loudspeakers/801-d4

Harmonic distortion
2nd and 3rd harmonics (90dB, 1m on axis)
<1% 30Hz - 20kHz
<0.3% 100Hz - 20kHz

--
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Woody wrote:
-----------------------
>
> The main thing about valve amps is/was that their main distortion is
> second harmonic to which the human ear does not object.

** A very old and tired myth.

Single ended valve amps produce mainly 2nd harmonic while push-pull output stages inherently cancel out the 2nd leaving mostly 3rd.
All the well known valve amps are push-pull, class A or class AB.

BTW intermodulation side bands resulting from even 1% 2nd is objectionable.

...... Phil

On 23/05/2023 11:16 am, Phil Allison wrote:
> Woody wrote:
> -----------------------
>>
>> The main thing about valve amps is/was that their main distortion is
>> second harmonic to which the human ear does not object.
>
> ** A very old and tired myth.
>
> Single ended valve amps produce mainly 2nd harmonic while push-pull output stages inherently cancel out the 2nd leaving mostly 3rd.

**Yes. I neglected to add that. Phil is correct. A really high quality
valve amp sounds and measures very similarly to a good quality SS amp.
I've done a few blind tests, using relatively easy to drive speakers and
found that it is virtually impossible to pick a good valve amp (PP) to a
good SS amp.

--
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On 22/05/2023 14:19, Joe wrote:
> On Mon, 22 May 2023 12:38:39 +0100
> The Natural Philosopher <tnp@invalid.invalid> wrote:
>
>> On 22/05/2023 12:22, Trevor Wilson wrote:
>
>>>
>>> **I'm pretty certain Phil will chime in with his opinion on
>>> Marshall valve amps. He experience with musical instrument amps is
>>> quite extensive.
>
>> I have one, its relative crap, its worth about £800. I have two sub
>> £100 Fender solid state amps that are in almost every way infinitely
>> better.
>
> Valve amplifiers used to be favoured because of their distortion and
> greater difficulty of destruction, didn't they?
>
> Then later, valve hifi amplifiers came into vogue because they were
> stupendously expensive and fashionable.
>
The big problem with early transistors were that they were not fast and
could not handle high queisecentt power: that led to under biasing in
audio class B and crossover distortion which sounds horrible at low
signal levels. Especially at higher audio frequencies. The Quad 303 was
an example,. It tested out ok at moderate power at 1Khz, but look at
5hkz and a few hundred mW and it was awful.
Once faster FETS came along and faster transistors this all became a
thing of the past. A bog standard class D chip today will outperform a
Quad 303 or a valve amp any day. For hifi and indeed for guitar *until
you overdrive it*.

Then the valves inherent low feedback/soft clip is a bit more melodious
than a hard clipping tranny amp, but modern guitar amps actually do
signal shaping before clipping anyway, to simulate valve overload. My
'all digital' Fender can produce almost any sound you ask of it.

--
Truth welcomes investigation because truth knows investigation will lead
to converts. It is deception that uses all the other techniques.

On 22/05/2023 15:53, Woody wrote:
> On Mon 22/05/2023 14:19, Joe wrote:
>> On Mon, 22 May 2023 12:38:39 +0100
>> The Natural Philosopher <tnp@invalid.invalid> wrote:
>>
>>> On 22/05/2023 12:22, Trevor Wilson wrote:
>>
>>>>
>>>> **I'm pretty certain Phil will chime in with his opinion on
>>>> Marshall valve amps. He experience with musical instrument amps is
>>>> quite extensive.
>>
>>> I have one, its relative crap, its worth about £800. I have two sub
>>> £100 Fender solid state amps that are in almost every way infinitely
>>> better.
>>
>> Valve amplifiers used to be favoured because of their distortion and
>> greater difficulty of destruction, didn't they?
>>
>> Then later, valve hifi amplifiers came into vogue because they were
>> stupendously expensive and fashionable.
>>
>
> The main thing about valve amps is/was that their main distortion is
> second harmonic

No, it isn't. Not where it counts on a symmetrical class B output stage.

to which the human ear does not object. IMSMC whilst
> much above about 0.5% third harmonic sets your teeth on edge, north of
> 5% second harmonic is just not heard. Indeed a violin produces more
> second harmonic than fundamental and speakers equally have relatively
> high levels of 2nd and they don't sound too bad do they?

Mostly crap. The reason valve amps sound better is that the overload
more gracefully so cloth eared hifi nuts get less high order ODD harmonics.

So 20W valve amplifier operating at 1% distortion will sound better than
a 20W tranny at 1% distortion.

But a 100W tranny operating at 20W will sound better than either.
In hi fi apps.

For guitar work the 20W valve will, all other things being equal,
coupled to a suitable non linear response loudspeaker and cabinet, sound
better than either, especially with negative feedback totally absent, Cf
the VOX AC30.

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 23/05/2023 15:37, The Natural Philosopher wrote:
> On 22/05/2023 15:53, Woody wrote:
>> On Mon 22/05/2023 14:19, Joe wrote:
>>> On Mon, 22 May 2023 12:38:39 +0100
>>> The Natural Philosopher <tnp@invalid.invalid> wrote:
>>>
>>>> On 22/05/2023 12:22, Trevor Wilson wrote:
>>>
>>>>>
>>>>> **I'm pretty certain Phil will chime in with his opinion on
>>>>> Marshall valve amps. He experience with musical instrument amps is
>>>>> quite extensive.
>>>
>>>> I have one, its relative crap, its worth about £800. I have two sub
>>>> £100 Fender solid state amps that are in almost every way infinitely
>>>> better.
>>>
>>> Valve amplifiers used to be favoured because of their distortion and
>>> greater difficulty of destruction, didn't they?
>>>
>>> Then later, valve hifi amplifiers came into vogue because they were
>>> stupendously expensive and fashionable.
>>>
>>
>> The main thing about valve amps is/was that their main distortion is
>> second harmonic
>
> No, it isn't. Not where it counts on a symmetrical class B output stage.

Agreed, a typical push-pull valve stage into a transformer will have odd
harmonics.

A singled ended class A valve output will have even harmonics. But these
are rarely use as they are incredibly inefficient.

<snip>

> For guitar work the 20W valve will, all other things being equal,
> coupled to a suitable non linear response loudspeaker and cabinet, sound
> better than either, especially with negative feedback totally absent, Cf
> the VOX  AC30.

Guitar amplifiers are all about distortion and harmonics!

On 22/05/2023 23:01, Trevor Wilson wrote:
> On 23/05/2023 12:53 am, Woody wrote:
>> On Mon 22/05/2023 14:19, Joe wrote:
>>> On Mon, 22 May 2023 12:38:39 +0100
>>> The Natural Philosopher <tnp@invalid.invalid> wrote:
>>>
>>>> On 22/05/2023 12:22, Trevor Wilson wrote:
>>>
>>>>>
>>>>> **I'm pretty certain Phil will chime in with his opinion on
>>>>> Marshall valve amps. He experience with musical instrument amps is
>>>>> quite extensive.
>>>
>>>> I have one, its relative crap, its worth about £800. I have two sub
>>>> £100 Fender solid state amps that are in almost every way infinitely
>>>> better.
>>>
>>> Valve amplifiers used to be favoured because of their distortion and
>>> greater difficulty of destruction, didn't they?
>>>
>>> Then later, valve hifi amplifiers came into vogue because they were
>>> stupendously expensive and fashionable.
>>>
>>
>> The main thing about valve amps is/was that their main distortion is
>> second harmonic to which the human ear does not object.
>
> **SOME humans accept even order harmonics as OK. I and many others, do
> not. Less distortion is always better.
>
>  IMSMC whilst
>> much above about 0.5% third harmonic sets your teeth on edge, north of
>> 5% second harmonic is just not heard.
>
> **Not so. It has been generally accepted that, under careful listening
> conditions, that humans can perceive around 0.1% THD.
>
>  Indeed a violin produces more
>> second harmonic than fundamental
>
> **Most musical instruments produce large amounts of harmonics. That does
> not suggest that adding extra harmonics is a good thing.
>
>  and speakers equally have relatively
>> high levels of 2nd and they don't sound too bad do they?
>
> **Nope. High quality speakers typically exhibit low levels of
> distortion. In fact, some speakers produce lower levels of distortion
> than many valve amps.
>
> https://www.quad-hifi.co.uk/esl-2912/
>
> Distortion (100dB at 1m)    Above 1000Hz 0.15%
>                 Above 100Hz 0.5%
>                             Above 50Hz 1.0%
>
> https://www.bowerswilkins.com/en-us/product/loudspeakers/801-d4
>
> Harmonic distortion
> 2nd and 3rd harmonics (90dB, 1m on axis)
> <1% 30Hz - 20kHz
> <0.3% 100Hz - 20kHz
>
>
>
>
The problem with loudspeakers in not distortion - at low sound levels
they are excellent - its only when they are pushed to the limits of the
cones travel that distortion increases. It is *resonance*. In practice
you 'hear' the loudspeaker, not the music. This is perfect for electric
guitars, as the loudspeaker is like the sound box of an acoustic guitar,
but is its non ideal for hi fi.
Hence the whole idea behind the KEF Bextrene cones. Stiff, and
inherently 'dead' . And the idea behind multi element speakers, so that
each speakers resonance was not where it was called to operate by the
crossovers.

The adage 'Carbon fibre destroyed the point of Bextrene' has an element
of truth., A good soft spider roll surround CF coned bass/mid range car
speaker is actually better than a KEF unit and can be had for a few
quid. Or Kevlar honeycomb.
Tweeters haven't changed much and plastic or metal domes are almost
universal with maybe silk cloth domes for mid ranges.
I personally will always be a fan of compressions drivers into loaded
horns, and some of the JBL style mid range and tweeter horns we used in
disco and PA applications were way cleaner sounding than almost any HiFi
setup except perhaps Quad ELS, but could still kick out 115dB on the
dance floor.
And at very high power - well above domestic listening levels -
distortion does become an issue as cones and diaphragms get pushed to
the limits of their travel - compression drivers operate at far higher
pressures and lower movements and do not distort at very high power indeed.

But for domestic use a good selection of 3 ways bass/mid/tweeter is very
adequate.,

--
Climate Change: Socialism wearing a lab coat.

On 24/05/2023 12:37 am, The Natural Philosopher wrote:
> On 22/05/2023 15:53, Woody wrote:
>> On Mon 22/05/2023 14:19, Joe wrote:
>>> On Mon, 22 May 2023 12:38:39 +0100
>>> The Natural Philosopher <tnp@invalid.invalid> wrote:
>>>
>>>> On 22/05/2023 12:22, Trevor Wilson wrote:
>>>
>>>>>
>>>>> **I'm pretty certain Phil will chime in with his opinion on
>>>>> Marshall valve amps. He experience with musical instrument amps is
>>>>> quite extensive.
>>>
>>>> I have one, its relative crap, its worth about £800. I have two sub
>>>> £100 Fender solid state amps that are in almost every way infinitely
>>>> better.
>>>
>>> Valve amplifiers used to be favoured because of their distortion and
>>> greater difficulty of destruction, didn't they?
>>>
>>> Then later, valve hifi amplifiers came into vogue because they were
>>> stupendously expensive and fashionable.
>>>
>>
>> The main thing about valve amps is/was that their main distortion is
>> second harmonic
>
> No, it isn't. Not where it counts on a symmetrical class B output stage.

**Correct.

>
> to which the human ear does not object. IMSMC whilst
>> much above about 0.5% third harmonic sets your teeth on edge, north of
>> 5% second harmonic is just not heard. Indeed a violin produces more
>> second harmonic than fundamental and speakers equally have relatively
>> high levels of 2nd and they don't sound too bad do they?
>
> Mostly crap. The reason valve amps sound better is that the overload
> more gracefully so cloth eared hifi nuts get less high order ODD harmonics.

**Somewhat crap. The reason why SOME valve amps are preferred over SOME
SS amps is due to their overload characteristics. There have been and
still several schemes that very effectively allow for 'soft' Voltage
limiting (aka: clipping) in SS amps. Some schemes include:

* A limiting circuit placed outside the feedback loop. (NAD et al)
* A system which ensures that output devices are never allowed to
saturate, combined with zero global NFB. (ME et al)
* Some pro amps I've seen use a PTC element outside the feedback loop.
* Digital systems also can be used.

In fact, I've measured a few high(ish) global NFB, push pull valve
amps that exhibit quite brutal clipping character.

>
> So 20W valve amplifier operating at 1% distortion will sound better than
> a 20W tranny at 1% distortion.

**Again: That is a pretty broad claim, which is not necessarily true.

>
> But a 100W tranny operating at 20W will sound better than either.
> In hi fi apps.
>
> For guitar work the 20W valve will, all other things being equal,
> coupled to a suitable non linear response loudspeaker and cabinet, sound
> better than either, especially with negative feedback totally absent, Cf
> the VOX  AC30.
>

**Again: That is a pretty broad claim, which is not necessarily true.

--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

On 24/05/2023 12:51 am, The Natural Philosopher wrote:
> On 22/05/2023 23:01, Trevor Wilson wrote:
>> On 23/05/2023 12:53 am, Woody wrote:
>>> On Mon 22/05/2023 14:19, Joe wrote:
>>>> On Mon, 22 May 2023 12:38:39 +0100
>>>> The Natural Philosopher <tnp@invalid.invalid> wrote:
>>>>
>>>>> On 22/05/2023 12:22, Trevor Wilson wrote:
>>>>
>>>>>>
>>>>>> **I'm pretty certain Phil will chime in with his opinion on
>>>>>> Marshall valve amps. He experience with musical instrument amps is
>>>>>> quite extensive.
>>>>
>>>>> I have one, its relative crap, its worth about £800. I have two sub
>>>>> £100 Fender solid state amps that are in almost every way infinitely
>>>>> better.
>>>>
>>>> Valve amplifiers used to be favoured because of their distortion and
>>>> greater difficulty of destruction, didn't they?
>>>>
>>>> Then later, valve hifi amplifiers came into vogue because they were
>>>> stupendously expensive and fashionable.
>>>>
>>>
>>> The main thing about valve amps is/was that their main distortion is
>>> second harmonic to which the human ear does not object.
>>
>> **SOME humans accept even order harmonics as OK. I and many others, do
>> not. Less distortion is always better.
>>
>>   IMSMC whilst
>>> much above about 0.5% third harmonic sets your teeth on edge, north
>>> of 5% second harmonic is just not heard.
>>
>> **Not so. It has been generally accepted that, under careful listening
>> conditions, that humans can perceive around 0.1% THD.
>>
>>   Indeed a violin produces more
>>> second harmonic than fundamental
>>
>> **Most musical instruments produce large amounts of harmonics. That
>> does not suggest that adding extra harmonics is a good thing.
>>
>>   and speakers equally have relatively
>>> high levels of 2nd and they don't sound too bad do they?
>>
>> **Nope. High quality speakers typically exhibit low levels of
>> distortion. In fact, some speakers produce lower levels of distortion
>> than many valve amps.
>>
>> https://www.quad-hifi.co.uk/esl-2912/
>>
>> Distortion (100dB at 1m)    Above 1000Hz 0.15%
>>                  Above 100Hz 0.5%
>>                              Above 50Hz 1.0%
>>
>> https://www.bowerswilkins.com/en-us/product/loudspeakers/801-d4
>>
>> Harmonic distortion
>> 2nd and 3rd harmonics (90dB, 1m on axis)
>> <1% 30Hz - 20kHz
>> <0.3% 100Hz - 20kHz
>>
>>
>>
>>
> The problem with loudspeakers in not distortion - at low sound levels
> they are excellent

**That's correct. And it is (non-linear) distortion that we are
discussing. Modern, high quality speakers can exhibit lower levels of
distortion than many valve amps.

- its only when they are pushed to the limits of the
> cones travel that distortion increases. It is *resonance*. In practice
> you 'hear' the loudspeaker, not the music. This is perfect for electric
> guitars, as the loudspeaker is like the sound box of an acoustic guitar,
> but is its non ideal for hi fi.

**Not relevant to the discussion. High quality speakers are built to
address the issues surrounding enclosure problems.

> Hence the whole idea behind the KEF Bextrene cones. Stiff, and
> inherently 'dead' . And the idea behind multi element speakers, so that
> each speakers resonance was not where it was called to operate by the
> crossovers.

**Of course. And irrelevant to the discussion.

--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

The Natural Philosopher wrote:
---------------------------------------------------
>
> >
> The big problem with early transistors were that they were not fast and
> could not handle high queisecentt power: that led to under biasing in
> audio class B and crossover distortion which sounds horrible at low
> signal levels.

** Amplifiers that used Germanium output transistors and / or driver transformers had those issues.
The arrival of Silicon output and driver devices soon put and end to crossover issues.

> The Quad 303 was an example.

** That 100%, absolute bullshit.

You obviously have ZERO *real* knowledge of the Quad 303 or any other amplifier.

...... Phil

Fredxx wrote:
---------------------
>
> A singled ended class A valve output will have even harmonics. But these
> are rarely use as they are incredibly inefficient.
>

** Really ?
A single ended amp using an output transformer has a max efficiency of 50%.
So does a p-p class A one.
Class B can achieve 78%, at least in theory.

The big difference is with the power dissipated at low and no output.
It is at maximum with class A and near zero with class B.

....... Phil

The Natural Philosopher wrote:
-------------------------------------------------
> >
> >
> I personally will always be a fan of compressions drivers into loaded
> horns, and some of the JBL style mid range and tweeter horns we used in
> disco and PA applications were way cleaner sounding than almost any HiFi
> setup except perhaps Quad ELS, but could still kick out 115dB on the
> dance floor.
> And at very high power - well above domestic listening levels -
> distortion does become an issue as cones and diaphragms get pushed to
> the limits of their travel - compression drivers operate at far higher
> pressures and lower movements and do not distort at very high power indeed.
>
>
** The very high air pressures generated in the throats of such drivers sets a limit on the SPLs that can produce cleanly.

FYI:
Air itself becomes severley non-linear at such levels ( circa 160 dB SPL ) which typically corresponds to *less* that the rated power input of the same drivers. A notable example being with JBL " ring radiators".
Rated at 20W input, severe distortion sets in at 10 W and further increases in power input produce only increasing 3rd harmonic with no increase in overall SPL.

...... Phil

Trevor Wilson wrote:
----------------------------------
>
> **Somewhat crap. The reason why SOME valve amps are preferred over SOME
> SS amps is due to their overload characteristics. There have been and
> still several schemes that very effectively allow for 'soft' Voltage
> limiting (aka: clipping) in SS amps.
> (snip)
> In fact, I've measured a few high(ish) global NFB, push pull valve
> amps that exhibit quite brutal clipping character.
>

* Peak clipping is not something that a hi-fi amp ought to be doing on music program.
However and luckily it is mostly inaudible.

I once owned a 40wpc SS stereo amp that included a fast peak clipping indicator - using it with my Quad ESL57s.
A red LED for each channel would flash brightly on a brief ( < 1mS) clipping of the output signal.
The LEDs could be flashing every few seconds on some CDs, when played loudly, with no audible disturbance.

....... Phil