[Angus Kerr]

OK,

In the realm of a 20 channel (or so) mixer with built in effects, we are able to get:

Allen & Heath
Soundcraft
Behringer
Mackie
Wharfdale

Any experiences as to quality? Ruggedness? Longevity?

This mixer is going to be used for family and friends get togethers maybe a few times a year. The instrumentation will be:
Drumkit (fully miked up for recording purposes - at least 7)
Bass Guitar
Electric Guitar (s)
Acoustic Guitar (s)
Vocal (s)
Violin (s)
Keyboards

16 channels is adequate, I think, and we need them all to be mic pres, as we'll be plugging in DI's on stage. We'll use the other channels for backing tracks (If necessary) and background music between performances.

Onboard Effects is a must, since we don't want extra outboard gear, and we'll be feeding directly to powered speakers (RCF 12" ART 712A) and one 15" Turbosound sub, so we can keep the gear count to a minimum. Our monitoring will be done via 2 Behringer B115W powered speakers. Yes, Behringer, the brand all audio snobs like to bash! They were not my first choice, but came up on special at such a ridiculous price, it was stupid to not buy them.

I own a Behringer mixer, bless its heart. It's had two power supply recaps, an internal dust and lubrication overhaul, and I had to replace faulty ram chips on the noisy onboard effects in its 10 year lifetime. It just does a routing job in my home studio. I tolerate it. It was good value though.

I also have a Mackie 1604VLZ, which needs an overhaul, and on which the channel preamps sound remarkably NOT the same. Mackie seems to me to be a wee bit overpriced. This mixer is not reliable enough to be used in a gig IMO - scratchy switches, dead channels etc. - why we are looking for a new one.

I've not used Allen and Heath or Soundcraft directly, but am leaning in their way as they both have a good reputation and have products where the format fits our needs. The particular desk we are looking at is the Allen and Heath ZED-22FX My only complaint would be only 2 pre-fader sends, so only 2 monitor mixes, and no subgroups.

Thoughts? Experiences?

Have a splendid weekend,

-Angus.

[Frank Stearns]

Angus Kerr writes:

OK,

In the realm of a 20 channel (or so) mixer with built in effects, we are ab=
le to get:

Allen & Heath
Soundcraft
Behringer
Mackie
Wharfdale

I'd add one more to the list -- the little baby analog Yamaha consoles (MG series,
or its successor -- MGX? MGC? Can't remember. The come with a wide range of input
counts, 10 to 32, if memory serves, though not all of those inputs have mic
inputs; some are stereo-paired.)

Any experiences as to quality? Ruggedness? Longevity?

I've had the 16 and 12 input MGs consoles for monitoring location recording, both
are more than 10 years old and simply continue to work, though I will say the PFL
switches are getting kinda crusty. Sonically they're okay; but I don't use them
for anything other than monitoring the multitrack on location. But, Yamaha has been
at this for 40 years, they have design and build down pretty well.

The new MG successor has built in comp and FX.

At these price points the brands are probably all roughly the same in
terms performance, and also expect them to be mostly "disposable". I'd look
at it in terms of what kind of deal you can get for the features you want, and how
easy any given brand is to obtain where you are.

I'd be very disinclined to buy ANY of these used. Behringer still makes me shudder,
even though I did recently purchase the Ultracurve EQ and it hasn't caught fire
yet.

YMMV.

Frank
Mobile Audio

--

[Scott Dorsey]

Angus Kerr wrote:
In the realm of a 20 channel (or so) mixer with built in effects, we are ab=
le to get:

Allen & Heath
Soundcraft
Behringer
Mackie
Wharfdale

Any experiences as to quality? Ruggedness? Longevity?

The A&H Mix Wizard is reasonably rugged. The EQ is good, most of them have
EQ bypass switches (which are your salvation when someone is using the same
mike for vocal and flute), you don't have to mute unused channels to keep
the noise down. The effects are kind of cheesy and you can hear the mike
preamp character changing as you adjust the trim, but considering the price
it's hard to complain.

I am not impressed with the current Mackie or Behringer lines.

I have not used any of the Wharfdale mixers or any of the current Soundcraft
mixers, but I would definitely audition a Soundcraft mixer.

I might suggest you consider outboard effects.

You might also consider a small digital console like the Presonus, if you
are looking for onboard effects anyway.

I also have a Mackie 1604VLZ, which needs an overhaul, and on which the cha=
nnel preamps sound remarkably NOT the same. Mackie seems to me to be a wee =
bit overpriced. This mixer is not reliable enough to be used in a gig IMO -=
scratchy switches, dead channels etc. - why we are looking for a new one.

If you're willing to put in an afternoon with some cramolin you might just
be able to clean it up.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[PStamler]

I'll second Frank's suggestion that you take a look at Yamahas. Among modestly-priced mixers, I've found that they have the most intuitive user interface, which is an important plus if you're running it on two hours' sleep. They take a lickin' and keep on tickin', too.

Peace,
Paul

[Mike Rivers[_2_]]

On 10/9/2015 10:19 AM, Angus Kerr wrote:

In the realm of a 20 channel (or so) mixer with built in effects, we
are able to get:

Allen & Heath Soundcraft Behringer Mackie Wharfdale

Any experiences as to quality? Ruggedness? Longevity?

Wharfdale isn't well known for mixers here in the US. As I recall,
they're actually made by someone else but I can't remember who. With the
possible exception of Behringer (that I've not yet learned to trust for
ruggedness and longevity), I'd say that quality, ruggedness, and
longevity are about the same and fairly good if you get a good one. But
there are so many parts, mostly the cheapest parts they can get away
with, mostly assembled by machine that no matter how much a company
brags about its quality assurance, you can still get one from any
manufacturer that you'll curse.

The problem is that none of those mixers are made to last a lifetime.
Your Mackie 1604 VLZ must be at least 15 years old, and Mackie has
learned a lot about designing mixers in that time. But lately their
efforts have been in digital mixers (as, for a matter of fact, same with
Soundcraft and A&H). Mackie's FX series mixers (if they even still make
them) are crummier in many respects than their mixers that are just mixers.

16 channels is adequate, I think, and we need them all to be mic
pres, as we'll be plugging in DI's on stage. We'll use the other
channels for backing tracks (If necessary) and background music
between performances.

Most mixers of this ilk have a "Tape" input that doesn't count as a
channel and is routed to the main output bus so you can use it for
incidental music between performances. You do have to count your
channels carefully though. Most have adopted a channel count convention
that includes less than the full number of mic inputs, and several
stereo line level inputs with one fader for each pair of stereo
channels. A Mackie 1604 has 16 inputs with mic preamps for all channels.
A 1642 has 8 channels with mic preamps and 4 stereo line input channels
(4 faders, 4 stereo sources).

Onboard Effects is a must, since we don't want extra outboard gear,

As long as you stick with an analog mixer, you're shooting yourself in
the foot here.

Although I know it isn't what you're asking for, and I hate to try to
drag someone kicking and screaming into the world of digital mixers, I
think you might do well with a PreSonus StudioLive. Because they're
digital, they don't have a lot of mechanical parts so about the only
thing to fail prematurely are power supply components - an none last
forever. It has a lot of features you haven't asked for, but you might
grow to like some of them, like the ability to mix remotely if you don't
have room for a typical FOH setup, mix your monitors from the stage
using an iPad, record direct to a computer via Firewire 800 or
(optinally) Dante or AVB. The effects sound better than just pretty
good, there are graphic EQs on every output, and even I who am
accustomed to having a knob for every function managed to use one
without too much trouble when I had to. You'll have to be careful that
it doesn't stay in the closet between family gatherings and gets
"stored" in your studio.

Think about it. I figure than any of them have an equally good chance of
lasting 10 years of moderate use, none of them have any better chance
than the others of lasting much longer.


--
For a good time, visit http://mikeriversaudio.wordpress.com

[Mike Rivers[_2_]]

On 10/9/2015 11:04 AM, Frank Stearns wrote:
I'd add one more to the list -- the little baby analog Yamaha consoles (MG series,
or its successor -- MGX? MGC? Can't remember.

Right - I forget about those because I've never actually worked with
one. They keep changing model numbers, some with effects, some without.
I did have one here for a short while several years back. It worked OK
but had a lot of plastic. Made me wonder how it would hold up if not
handled carefully.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[Peter Larsen[_3_]]

On 09-10-2015 15:19, Angus Kerr wrote:
OK,

In the realm of a 20 channel (or so) mixer with built in effects, we are able to get:

Allen & Heath
Soundcraft
Behringer
Mackie
Wharfdale

Any experiences as to quality? Ruggedness? Longevity?

This mixer is going to be used for family and friends get togethers maybe a few times a year. The instrumentation will be:
Drumkit (fully miked up for recording purposes - at least 7)
Bass Guitar
Electric Guitar (s)
Acoustic Guitar (s)
Vocal (s)
Violin (s)
Keyboards

16 channels is adequate, I think, and we need them all to be mic pres, as we'll be plugging in DI's on stage. We'll use the other channels for backing tracks (If necessary) and background music between performances.

Souncraft GB2-16R looks to the point with 6 auxes.

And their newer stuff is as sweet sounding as their old comparing to the
actual market average sonic performance.

-Angus.

Kind regards

Peter Larsen

[geoff]

On 10/10/2015 4:04 a.m., Frank Stearns wrote:
for the features you want, and how
easy any given brand is to obtain where you are.

I'd be very disinclined to buy ANY of these used. Behringer still makes me shudder,
even though I did recently purchase the Ultracurve EQ and it hasn't caught fire
yet.

YMMV.

Frank
Mobile Audio



For a contrary POV I'd suggest that any of those brands would be just
fine for the purpose outlined.

I'd draw the line at Peavey though. I used to fixed those. Or try to ...

geoff

[Phil Allison[_4_]]

Mike Rivers wrote:


Allen & Heath Soundcraft Behringer Mackie Wharfdale

Any experiences as to quality? Ruggedness? Longevity?

Wharfdale isn't well known for mixers here in the US. As I recall,
they're actually made by someone else but I can't remember who.


** The Wharfedale brand was bought by the Taiwanese Chang brothers in about 2000 and changed to "Wharfedale Pro" in order to badge their Chinese made line of budget PA and DJ equipment with a once famous name.

The parent company is IAG, owned by the Changs. They also bought the Quad brand and continue to make new versions of their famous 1953 valve amp and 1980s electrostatic speakers.

The marketing strategy is similar to Behringer, except using famous brands to give instant fake cred.

The small "Wharfedale Pro" mixers and powered speakers I have seen were typical of budget Chinese manufacture - IOW nothing is built to last.

Of the brands mentioned, only Allen & Heath stands out as better then the rest in terms of component and build quality, despite a most of it being Chinese.



..... Phil

[Angus Kerr]

On Saturday, October 10, 2015 at 7:45:51 AM UTC+2, Phil Allison wrote:
Mike Rivers wrote:


Allen & Heath Soundcraft Behringer Mackie Wharfdale

Any experiences as to quality? Ruggedness? Longevity?

Wharfdale isn't well known for mixers here in the US. As I recall,
they're actually made by someone else but I can't remember who.


** The Wharfedale brand was bought by the Taiwanese Chang brothers in about 2000 and changed to "Wharfedale Pro" in order to badge their Chinese made line of budget PA and DJ equipment with a once famous name.

The parent company is IAG, owned by the Changs. They also bought the Quad brand and continue to make new versions of their famous 1953 valve amp and 1980s electrostatic speakers.

The marketing strategy is similar to Behringer, except using famous brands to give instant fake cred.

The small "Wharfedale Pro" mixers and powered speakers I have seen were typical of budget Chinese manufacture - IOW nothing is built to last.

Of the brands mentioned, only Allen & Heath stands out as better then the rest in terms of component and build quality, despite a most of it being Chinese.



.... Phil

I only mentioned Wharfedale as it is part of the tranche of budget semi pro equipment available (as is Samson). Although, remembering the Wharfedale brand as a venerable highly respected hi-fi brand from the sixties (?), I became extremely suspicious of the new Wharfedale stuff, having seen it recently first in low class, vulgar plastic boom boxes in budget hifi stores, and now 'Pro' equipment such as powered speakers and mixers.

Much as we ridicule Behringer equipment, I bet most of us have at least one piece of nasty Behringer gear that does the job.

My hidden Behringer Stash (opening myself up to ridicule here )
2 DI Boxes
20 Channel analogue mixer
Composer Compressor
Multigate
2 Powered speakers (which don't sound half bad - I mean they at least have compression driven horns the 1000W sounds more to me like maybe 300RMS if that)

Back to topic:

We don't have a lot of choice here, because our currency has devalued 40% this year against the dollar and we have to take what we can get of old stock and get the saving before the new pricing comes in....

So A&H 22 with 16 pres would not be my first choice due to limited monitoring capability and lack of subgroups, the Soundcraft would be better with marginal aux sends and subgroups.

As regards the QuadII, I hope that the version they are selling now is as good as the 53 version. When I was at school the English teacher used to play us music appreciation classes, with a Shure V15 cartridge, Thorens belt drive turntable, Quad Preamp, and QuadII valve amps driving Electrostatic speakers. At least my ears were good enough then to hear how good it all was. I always loved the Quad styling, the preamp was just fantastic looking.

-Angus.

[Angus Kerr]

On Saturday, October 10, 2015 at 7:30:10 AM UTC+2, geoff wrote:
On 10/10/2015 4:04 a.m., Frank Stearns wrote:
for the features you want, and how
easy any given brand is to obtain where you are.

I'd be very disinclined to buy ANY of these used. Behringer still makes me shudder,
even though I did recently purchase the Ultracurve EQ and it hasn't caught fire
yet.

YMMV.

Frank
Mobile Audio



For a contrary POV I'd suggest that any of those brands would be just
fine for the purpose outlined.

I'd draw the line at Peavey though. I used to fixed those. Or try to ...

geoff

Unfortunately, I've never liked Peavey stuff - I don't really know why.

-Angus.

[Angus Kerr]

On Friday, October 9, 2015 at 10:09:24 PM UTC+2, Mike Rivers wrote:
As long as you stick with an analog mixer, you're shooting yourself in
the foot here.

Although I know it isn't what you're asking for, and I hate to try to
drag someone kicking and screaming into the world of digital mixers, I
think you might do well with a PreSonus StudioLive. Because they're
digital, they don't have a lot of mechanical parts so about the only
thing to fail prematurely are power supply components - an none last
forever. It has a lot of features you haven't asked for, but you might
grow to like some of them, like the ability to mix remotely if you don't
have room for a typical FOH setup, mix your monitors from the stage
using an iPad, record direct to a computer via Firewire 800 or
(optinally) Dante or AVB. The effects sound better than just pretty
good, there are graphic EQs on every output, and even I who am
accustomed to having a knob for every function managed to use one
without too much trouble when I had to. You'll have to be careful that
it doesn't stay in the closet between family gatherings and gets
"stored" in your studio.

Think about it. I figure than any of them have an equally good chance of
lasting 10 years of moderate use, none of them have any better chance
than the others of lasting much longer.

Thanks for the heads up. I have mentioned this to my partner in crime (the guy with the money), but the smallest in this group is a quasi 16 channels which unfortunately for the money, will leave us short changed with mic pres. But I'm definitely going to hunt for a used one. Hope they are also Android compatible? I'm all Android, I don't i-Anything.

-Angus.

[geoff]

On 10/10/2015 10:17 p.m., Angus Kerr wrote:
On Saturday, October 10, 2015 at 7:30:10 AM UTC+2, geoff wrote:
On 10/10/2015 4:04 a.m., Frank Stearns wrote:
for the features you want, and how
easy any given brand is to obtain where you are.

I'd be very disinclined to buy ANY of these used. Behringer still makes me shudder,
even though I did recently purchase the Ultracurve EQ and it hasn't caught fire
yet.

YMMV.

Frank
Mobile Audio



For a contrary POV I'd suggest that any of those brands would be just
fine for the purpose outlined.

I'd draw the line at Peavey though. I used to fixed those. Or try to ...

geoff

Unfortunately, I've never liked Peavey stuff - I don't really know why.

-Angus.



Make that "fortunately" ;-)

geoff

[Phil Allison[_4_]]

Angus Kerr wrote:





** The Wharfedale brand was bought by the Taiwanese Chang brothers in about 2000 and changed to "Wharfedale Pro" in order to badge their Chinese made line of budget PA and DJ equipment with a once famous name.

The parent company is IAG, owned by the Changs. They also bought the Quad brand and continue to make new versions of their famous 1953 valve amp and 1980s electrostatic speakers.

The marketing strategy is similar to Behringer, except using famous brands to give instant fake cred.

The small "Wharfedale Pro" mixers and powered speakers I have seen were typical of budget Chinese manufacture - IOW nothing is built to last.

Of the brands mentioned, only Allen & Heath stands out as better then the rest in terms of component and build quality, despite a most of it being Chinese.




I only mentioned Wharfedale as it is part of the tranche of budget semi pro equipment available (as is Samson).


** Please give Samson a big miss !!



As regards the QuadII, I hope that the version they are selling now is as good as the 53 version.


** By all accounts is it, staffers from Quad in the UK oversaw and approved the design of the "Quad II Classic" - which btw is certainly not cheap.


When I was at school the English teacher used to play us music
appreciation classes, with a Shure V15 cartridge, Thorens belt
drive turntable, Quad Preamp, and QuadII valve amps driving
Electrostatic speakers.


** How lucky can you get.



.... Phil

[Mike Rivers[_2_]]

On 10/10/2015 5:33 AM, Angus Kerr wrote:
But I'm definitely going to hunt for a used one [PreSonus
StudioLive]. Hope they are also Android compatible? I'm all Android,
I don't i-Anything.

I'm all Android, too, and unfortunately the mixer manufacturers have not
bothered with the likes of us. The only glimmer of hope is that the new
Soundcraft mixer-in-a-stage-box has its remote control program built in
to the firmware in the form of a web page, so you can talk to it with
anything that has a Web browser. I think the new MOTU Ultra Lite AVB
also uses this technique, so maybe it'll catch on. But unfortunately a
used or even new (as of today) PreSonus mixer's remote control will only
talk to an iGadget.



--
For a good time, visit http://mikeriversaudio.wordpress.com

[Les Cargill[_4_]]

geoff wrote:
On 10/10/2015 10:17 p.m., Angus Kerr wrote:
On Saturday, October 10, 2015 at 7:30:10 AM UTC+2, geoff wrote:
On 10/10/2015 4:04 a.m., Frank Stearns wrote:
for the features you want, and how
easy any given brand is to obtain where you are.

I'd be very disinclined to buy ANY of these used. Behringer still
makes me shudder,
even though I did recently purchase the Ultracurve EQ and it hasn't
caught fire
yet.

YMMV.

Frank
Mobile Audio



For a contrary POV I'd suggest that any of those brands would be just
fine for the purpose outlined.

I'd draw the line at Peavey though. I used to fixed those. Or try to ...

geoff

Unfortunately, I've never liked Peavey stuff - I don't really know why.

-Angus.



Make that "fortunately" ;-)

geoff


Peavey has made some pretty good consoles, or so at least I have heard.

--
Les Cargill

[Angus Kerr]

On Saturday, October 10, 2015 at 1:19:04 PM UTC+2, Phil Allison wrote:
Angus Kerr wrote:


I only mentioned Wharfedale as it is part of the tranche of budget semi pro equipment available (as is Samson).


** Please give Samson a big miss !!

No intention of purchasing Samson, but I thought for completeness, that I shouldn't leave them out!



As regards the QuadII, I hope that the version they are selling now is as good as the 53 version.


** By all accounts is it, staffers from Quad in the UK oversaw and approved the design of the "Quad II Classic" - which btw is certainly not cheap.


When I was at school the English teacher used to play us music
appreciation classes, with a Shure V15 cartridge, Thorens belt
drive turntable, Quad Preamp, and QuadII valve amps driving
Electrostatic speakers.


** How lucky can you get.

I got luckier, I worked a holiday job, as I mentioned before, for the late David Manley when he was starting a high-end hifi business in Parktown, Johannesburg, circa 1981-1982. My 16-17 year old ears got to hear those Williamson Monoblock Valve (Tube) Amps (that I rewired) that he bought in a job lot in their full flow, full glory, into Seas DD Towers, Magneplanars, Electrostatic Speakers, with his Thorens TD125 Turntable with SME tonearm and I think Shure V15 cartridge. Yamaha Preamps - occassionally a Yamaha Class A Power Amp for reference, a huge thing as well. Dark side of the Moon Original Master, Direct to Disc recordings, Direct Metal Cuttings, all of this I got to experience. I've never heard sound like that since, although the Quad II's and electrostatic speakers were good. But what he had and showed me, was sublime, almost divine. I'd kill for a pair of those Williamson Point One Monoblocks, with KT66 power tubes. God they sounded amazing. BJT's and everything else I've heard in the next 33 years of my life were fatiguing, and never sounded close. Not even in the same ball park. We probably heard stuff then that not even the mastering engineer heard, so much was the detail revealed.

-Angus.


... Phil

[Phil Allison[_4_]]

Angus Kerr wrote:


I'd kill for a pair of those Williamson Point One Monoblocks,
with KT66 power tubes. God they sounded amazing.



** The Williamson amplifier is certainly famous, but not a manufactured product - like Quad, Leak etc.

It was instead a DIY design, published in the UK magazine Wireless World in April and May of 1947. The designer was employed by the MOV valve company, makers of the KT66.

https://en.wikipedia.org/wiki/Williamson_amplifier

Because of follow up articles, various maker's transformers being used and popular modifications like "ultra-linear" connection of the output valves many, quite different "Williamsons" were built.

The Quad II mono amp was however made in large numbers (circa 90,000) remaining essentially the same for a period of 18 years. I own and restored an early example that, with no amplifier modifications, exceeds the original specs.

Maybe keep an eye out for a restored pair.


.... Phil

[Angus Kerr]

On Sunday, October 11, 2015 at 8:30:31 AM UTC+2, Phil Allison wrote:
Angus Kerr wrote:


I'd kill for a pair of those
-correction- Leak (Williamson) Point One Monoblocks,
with KT66 power tubes. God they sounded amazing.



** The Williamson amplifier is certainly famous, but not a manufactured product - like Quad, Leak etc.

It was instead a DIY design, published in the UK magazine Wireless World in April and May of 1947. The designer was employed by the MOV valve company, makers of the KT66.

https://en.wikipedia.org/wiki/Williamson_amplifier

Because of follow up articles, various maker's transformers being used and popular modifications like "ultra-linear" connection of the output valves many, quite different "Williamsons" were built.

You are indeed correct.

What I meant to say, was Leak. They were Leak Point One amps, he must have bought at least 50 scrapped ones with the transformers intact.

The reason I said Williamson, was that as I was lead to believe, that Leak amplifier used a Williamson design. We tended to refer to them as Williamsons. David obviously modified the circuitry and design; one thing I remember was using silicon diodes instead of the rectifier tube.

The Quad II mono amp was however made in large numbers (circa 90,000) remaining essentially the same for a period of 18 years. I own and restored an early example that, with no amplifier modifications, exceeds the original specs.

Maybe keep an eye out for a restored pair.

I'd love to own *any* Valve (Tube) Power Amp. They sound gorgeous.
And they look cool.

... Phil

-Angus.

[Phil Allison[_4_]]

Angus Kerr wrote:



https://en.wikipedia.org/wiki/Williamson_amplifier

Because of follow up articles, various maker's transformers being
used and popular modifications like "ultra-linear" connection of
the output valves many, quite different "Williamsons" were built.


You are indeed correct.

What I meant to say, was Leak. They were Leak Point One amps,
he must have bought at least 50 scrapped ones with the transformers intact.

The reason I said Williamson, was that as I was lead to believe, that
Leak amplifier used a Williamson design. We tended to refer to them as
Williamsons.

** Leak were ahead of Williamson by a fair margin.

https://en.wikipedia.org/wiki/LEAK

Interesting the Harold Leak developed his first hi-fi amp while Germany and Japan were being bombed flat.


.... Phil

[Angus Kerr]

On Sunday, October 11, 2015 at 9:20:08 AM UTC+2, Phil Allison wrote:
Angus Kerr wrote:



https://en.wikipedia.org/wiki/Williamson_amplifier

Because of follow up articles, various maker's transformers being
used and popular modifications like "ultra-linear" connection of
the output valves many, quite different "Williamsons" were built.


You are indeed correct.

What I meant to say, was Leak. They were Leak Point One amps,
he must have bought at least 50 scrapped ones with the transformers intact.

The reason I said Williamson, was that as I was lead to believe, that
Leak amplifier used a Williamson design. We tended to refer to them as
Williamsons.

** Leak were ahead of Williamson by a fair margin.

https://en.wikipedia.org/wiki/LEAK

Interesting the Harold Leak developed his first hi-fi amp while Germany and Japan were being bombed flat.


... Phil

Nothing can keep a good geek down (Geek to me is a compliment)

Amazing to me that by the 40's and 50's, amplifiers could perform to specs that even by today's standards are impressive. I don't think the transducers were up to it, but similarly, in microphone technology, mics like the U47, U67 C12 etc, are sought after today because they kicked butt..

As a boy who grew up in the eighties with synthesisers, boom boxes, CD's and consumer electronics, and the arrogance of the day that IC's, transistors and 'digital' were better than what went before, I am in awe of the valve stuff, that has stood the test of time, and imv, still blows away modern stuff. I mean, most people today use mp3 as their standard of 'high' quality.

The other day, I was listening to an mp3 I did of one of my songs, and I thought 'what is wrong, am I playing two tracks simultaneously?' The cymbals sounded like they had been recorded underwater. Nothing wrong, the raw audio track sounded fine. Just the mp3 encoding....

-Angus.

[Phil Allison[_4_]]

Angus Kerr wrote:


** Leak were ahead of Williamson by a fair margin.

https://en.wikipedia.org/wiki/LEAK

Interesting the Harold Leak developed his first hi-fi amp while
Germany and Japan were being bombed flat.



Nothing can keep a good geek down (Geek to me is a compliment)

Amazing to me that by the 40's and 50's, amplifiers could perform to
specs that even by today's standards are impressive.


** By the end of the 1940s we had FM & TV, microwave radar and ovens, electronic computers, supersonic jets, rockets that could reach orbit and nuclear weapons.

Nothing too strange about audio amplifiers with a negligible THD percentages.



.... Phil

[geoff]

On 11/10/2015 8:45 p.m., Angus Kerr wrote:

As a boy who grew up in the eighties with synthesisers, boom boxes,
CD's and consumer electronics, and the arrogance of the day that
IC's, transistors and 'digital' were better than what went before, I
am in awe of the valve stuff, that has stood the test of time, and
imv, still blows away modern stuff. I mean, most people today use mp3
as their standard of 'high' quality.

Ah, how marvellous things look (sound) through the mists of affectionate
memories.


The other day, I was listening to an mp3 I did of one of my songs,
and I thought 'what is wrong, am I playing two tracks
simultaneously?' The cymbals sounded like they had been recorded
underwater. Nothing wrong, the raw audio track sounded fine. Just the
mp3 encoding....

Yeah, so don't do that to your music - you don't have to these days
especially now that drives/flash memory/etc is huge and cheap. I have
(mu ONLY Apple product) and iPod Touch 64GB with zillions of lossless
songs on it from CD. *No* mp3 or whatever.

Also Signal Suite Pro and a bunch of other great tech apps. And an
incredible guitar toolkit.

geoff

[Scott Dorsey]

geoff wrote:
On 11/10/2015 8:45 p.m., Angus Kerr wrote:

As a boy who grew up in the eighties with synthesisers, boom boxes,
CD's and consumer electronics, and the arrogance of the day that
IC's, transistors and 'digital' were better than what went before, I
am in awe of the valve stuff, that has stood the test of time, and
imv, still blows away modern stuff. I mean, most people today use mp3
as their standard of 'high' quality.

Ah, how marvellous things look (sound) through the mists of affectionate
memories.

It's not just memories. I have a Citation II as my main monitor amp, I
am listening to it right now. It sounds great, and it measures well too.

Occasionally I will swap it out with a different amplifier, and sometimes
the different amplifier sounds different and sometimes it doesn't, but
it never sounds so much better that I want to pay money to change.

I check the bias every once in a while and sometimes I change final tubes.
Believe it or not, I had a pair of David Manley's KT90 tubes running for
20 years without a problem, until a spotweld went bad on one of them. The
other three in the set still look fine on the curve tracer.

I'm not going to say it sounds better than anything else, but it doesn't
sound any worse, and it's paid for and I know how to maintain it.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[PStamler]

On Sunday, October 11, 2015 at 1:30:31 AM UTC-5, Phil Allison wrote:
Angus Kerr wrote:


I'd kill for a pair of those Williamson Point One Monoblocks,
with KT66 power tubes. God they sounded amazing.



** The Williamson amplifier is certainly famous, but not a manufactured product - like Quad, Leak etc.

It was instead a DIY design, published in the UK magazine Wireless World in April and May of 1947. The designer was employed by the MOV valve company, makers of the KT66.

https://en.wikipedia.org/wiki/Williamson_amplifier

Because of follow up articles, various maker's transformers being used and popular modifications like "ultra-linear" connection of the output valves many, quite different "Williamsons" were built.

I believe Heathkit marketed an amp kit that used the original Williamson circuit.

Peace,
Paul

[Phil Allison[_4_]]

PStamler wrote:

Phil Allison wrote:


** The Williamson amplifier is certainly famous, but not a manufactured product - like Quad, Leak etc.

It was instead a DIY design, published in the UK magazine Wireless World in April and May of 1947. The designer was employed by the MOV valve company, makers of the KT66.

https://en.wikipedia.org/wiki/Williamson_amplifier

Because of follow up articles, various maker's transformers being used and popular modifications like "ultra-linear" connection of the output valves many, quite different "Williamsons" were built.

I believe Heathkit marketed an amp kit that used the original Williamson circuit.



** Heathkit produced a number of Williamson based amplifiers in the 1950s - like this one:

http://www.heathkit-museum.com/hifi/hvmw4-am.shtml

Earlier versions had two chassis, one for the PSU and different valve line ups.

As you can see from the specs, achieving the remarkable 0.1% THD figure of the original was not a major concern.



.... Phil

[[email protected]]

As you can see from the specs, achieving the remarkable 0.1% THD figure of the original was not a major concern.



Yes, negative feedback is a very powerful design feature.

Mark

[JackA]

On Sunday, October 11, 2015 at 8:17:58 PM UTC-4, PStamler wrote:
On Sunday, October 11, 2015 at 1:30:31 AM UTC-5, Phil Allison wrote:
Angus Kerr wrote:


I'd kill for a pair of those Williamson Point One Monoblocks,
with KT66 power tubes. God they sounded amazing.



** The Williamson amplifier is certainly famous, but not a manufactured product - like Quad, Leak etc.

It was instead a DIY design, published in the UK magazine Wireless World in April and May of 1947. The designer was employed by the MOV valve company, makers of the KT66.

https://en.wikipedia.org/wiki/Williamson_amplifier

Because of follow up articles, various maker's transformers being used and popular modifications like "ultra-linear" connection of the output valves many, quite different "Williamsons" were built.

I believe Heathkit marketed an amp kit that used the original Williamson circuit.

Heathkit? My goodness, you peeps are old! :-)

Went to Heath for RF linear amplifier, could use 10 meter one on 11 meter (CB).
Too expensive! Settled for one that used a few Horizontal Output tubes for TV!
Cheap is my middle name!

Jack



Peace,
Paul

[Trevor]

On 13/10/2015 12:20 AM, wrote:

As you can see from the specs, achieving the remarkable 0.1% THD
figure of the original was not a major concern.

Yes, negative feedback is a very powerful design feature.



And if 0.1% THD is "remarkable", what do you call the 0.001% that is
now readily available I wonder? :-)
And unlike early solid state amps that only achieved that at full power,
many can do that at less than 1 watt level and up now.

Trevor.

[Phil Allison[_4_]]

Trevor wrote:


As you can see from the specs, achieving the remarkable 0.1% THD
figure of the original was not a major concern.

Yes, negative feedback is a very powerful design feature.



And if 0.1% THD is "remarkable",



** It is remarkable for amplifiers using valves.

Pre WW2, amplifiers had THD figures of 2% to 10%.

what do you call the 0.001% that is
now readily available I wonder? :-)


** Was also remarkable back in the early 1970s, reflecting what could be achieved with complementary silicon transistors and careful design.

More remarkable has been the reduction in size and cost of a good 10 or 20W amplifier, compared to the 1940s.


And unlike early solid state amps that only achieved that at full power,
many can do that at less than 1 watt level and up now.

** The problem at low power is that inaudible amounts of hum and noise increase the THD figure to non spectacular numbers.


.... Phil

[Trevor]

On 13/10/2015 12:23 PM, Phil Allison wrote:
Trevor wrote:
As you can see from the specs, achieving the remarkable 0.1%
THD figure of the original was not a major concern.

Yes, negative feedback is a very powerful design feature.

And if 0.1% THD is "remarkable",

** It is remarkable for amplifiers using valves.
Pre WW2, amplifiers had THD figures of 2% to 10%.

Yes I realise that, and yet so many pine after valve amps but never
admit it is really just an effects box these days.
(Just the effect many electric guitarists want of course.:-)


what do you call the 0.001% that is now readily available I
wonder? :-)


** Was also remarkable back in the early 1970s, reflecting what could
be achieved with complementary silicon transistors and careful
design.

More remarkable has been the reduction in size and cost of a good 10
or 20W amplifier, compared to the 1940s.

No argument, but some people happily pay 10 or even 100 times the price
for a valve amp to give them the sort of extra aural distortion they
enjoy. :-)


And unlike early solid state amps that only achieved that at full
power, many can do that at less than 1 watt level and up now.

** The problem at low power is that inaudible amounts of hum and
noise increase the THD figure to non spectacular numbers.

Right, far more of a problem for valve amps though. For any given
maximum power rating, I doubt even the cheapest solid state amps these
days cannot beat even the dearest valve amps. Or use a SS amp with
double the rating so you can soft clip it and not argue the valve amp
wins on that count if nothing else.

Trevor.

[[email protected]]

some interesting reading here

especially parts 5 and 6

http://altor1.narod.ru/Books_Docs/Baxandall.pdf

Mark

[Scott Dorsey]

wrote:
some interesting reading here

especially parts 5 and 6

http://altor1.narod.ru/Books_Docs/Baxandall.pdf

If you like this series, you may want to read Doug Self's book on power
amplifier design which has a slightly more modern update to this same
stuff, including a very fine discussion on transfer functions and negative
feedback.


For the most part, the high THD from tube amplifiers is the result of the
output transformers and not the transfer functions of the tubes themselves.
But, the group delay of the output transformer makes it difficult to fix
those problems with negative feedback because there's only so much you can
add. (The Williamson Ultralinear circuit is what it is because it adds
additional screen feedback from the primary, which is one hell of an ingenious
trick and works very well.)
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Phil Allison[_4_]]

Trevor wrote:




** The problem at low power is that inaudible amounts of hum and
noise increase the THD figure to non spectacular numbers.


Right, far more of a problem for valve amps though.


** Hum can be almost eliminated with careful layout and using filtered DC for the heaters of the input valves - as is often done with guitar amps these days.

Valves are not very noisy, especially triodes, it is quite easy to get well over 100db s/n relative to a 1 volt input.

Microphony is still a problem, especially with double triodes made in China and Russia.


.... Phil

[Phil Allison[_4_]]

Scott Dorsey wrote:



For the most part, the high THD from tube amplifiers is the result of the
output transformers and not the transfer functions of the tubes themselves.


** The THD figures published for a pair of beam pentodes ( like KT66s ) in UL mode are around 2% near full output. This is much higher than a decent output transformer using grain oriented steel, except at the very low end of the frequency range.

http://www.sowter.co.uk/specs/ua23.htm

Applying 20dB or so negative feedback brings the THD figure down to 0.2% or maybe 0.1% over most of the audio band.


..... Phil

[Trevor]

On 14/10/2015 12:10 PM, Phil Allison wrote:
** The problem at low power is that inaudible amounts of hum and
noise increase the THD figure to non spectacular numbers.


Right, far more of a problem for valve amps though.


** Hum can be almost eliminated with careful layout and using
filtered DC for the heaters of the input valves - as is often done
with guitar amps these days.

Valves are not very noisy, especially triodes, it is quite easy to
get well over 100db s/n relative to a 1 volt input.

Yep, using solid state rectifiers :-)
But 100dB is the norm for solid state amps now anyway.

Trevor.

[Scott Dorsey]

Phil Allison wrote:

** The THD figures published for a pair of beam pentodes ( like KT66s ) in UL mode are around 2% near full output. This is much higher than a decent output transformer using grain oriented steel, except at the very low end of the frequency range.

Yes, but that is distortion that can almost completely be controlled with
negative feedback, until you get to the last edge of the envelope.

http://www.sowter.co.uk/specs/ua23.htm

Applying 20dB or so negative feedback brings the THD figure down to 0.2% or maybe 0.1% over most of the audio band.

If you can get 20dB of negative feedback, which you might with those
transformers.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

On Tuesday, October 13, 2015 at 11:07:34 AM UTC-4, Scott Dorsey wrote:
wrote:
some interesting reading here

especially parts 5 and 6

http://altor1.narod.ru/Books_Docs/Baxandall.pdf

If you like this series, you may want to read Doug Self's book on power
amplifier design which has a slightly more modern update to this same
stuff, including a very fine discussion on transfer functions and negative
feedback.


thanks

Mark

[Phil Allison[_4_]]

Scott Dorsey wrote:

Phil Allison

** The THD figures published for a pair of beam pentodes
( like KT66s ) in UL mode are around 2% near full output.
This is much higher than a decent output transformer using
grain oriented steel, except at the very low end of the
frequency range.


Yes, but that is distortion that can almost completely be controlled with
negative feedback, until you get to the last edge of the envelope.



** In order to get a signal usable for NFB, a transformer must first combine the outputs of each tube in a push-pull pair.

When new tube types are tested in the lab, conditions are optimised by using a driver transformer to split the phase for each grid and an oversize output transformer with many primary and secondary tapings. The lab's B+ supply has plenty of capacity, very low hum and adjustable voltages.

DC bias voltage, if needed, is applied to the CT of the secondary of the driver tranny. Plus the test need only be done at 400Hz or 1kHz.

Doing all this eliminates extra distortion or mismatch coming from driver tubes, voltage sag in the PSU or power loss in the output tranny, allowing the best load impedance and bias setting to be found - consistent with the tube's current and dissipation limitations. These numbers are then published..

A tube amp designer has the more difficult task of producing a marketable product using practical size transformers, multiple driver and input tubes plus performs equally well across the whole audio band.



.... Phil