The quietest audio op-amp with ultra-low THD

[Martin Griffith]

On Mon, 22 Sep 2008 20:01:50 +0100, in sci.electronics.design Les
Matthew <lesmcdm@clara.co.uk> wrote:

Eeyore wrote:

Les Matthew wrote:

Eeyore wrote:
Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !
At Midas Audio in the 80's we used 12k.

Yes, but you were going downhill them. KT group bought out Midas in 88 when I was
there.

Dave Dearden and I were dumbstruck (and not in a good way) just with the mic input
stage.

Graham


Dave Dearden, that name rings a bell. I jumped ship to Brit Row around
87. It was mental at Midas then, bank holding the purse strings, full
order book but no cash flow. Pro40 was crazy, so much more electronics
crammed into the same old Pro4 frame, Geoff just wouldn't contemplate
having a larger frame. They got seriously hot.

les...
Dave Dearden... Many Confused Individuals (MCI consoles). them where

the days, when SMPTE timecode was new

martin

 

[Joerg]

Martin Griffith wrote:

On Mon, 22 Sep 2008 10:18:51 -0700, in sci.electronics.design Joerg
notthisjoergsch@removethispacbell.net> wrote:

Martin Griffith wrote:
snip
Not got round to using it yet but the ADA4899 looks tasty. 1nV, 0.7ppm,
600MHz.

Open the window, more shit flies in.
600MHz is not required for audio, only audiophools

Yeah but: Think what that can do in advertising: Gold plated super
electrons that are made extra agile and can turn themselves around in
under 2nsec. Electrons spend less time in the muddier regions in the
device, therefore get less dirty and don't wear out so fast. Much less
electron fatigue. Makes for extremely crisp crescendos that could never,
ever be heard with an amp that is anywhere less than 500MHz

I've just done a deal with the LHC at Cern, I'm buying the stripped
off electrons from the ultra fast protons that they use in round
thing.

How should I package them?

Those need to be transported in a humidor

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

On Sep 22, 10:18 am, Joerg <notthisjoerg...@removethispacbell.net>
wrote:

Martin Griffith wrote:
On Sun, 21 Sep 2008 21:51:38 +0100, in sci.electronics.design "john
jardine" <john.jard...@idnet.co.uk> wrote:

"Eeyore" <rabbitsfriendsandrelati...@hotmail.com> wrote in message
news:48D6A215.52D62814@hotmail.com...
National's LME49710/20/40 amd LM4562 seem to have the best figures at
2.5nV/sqrt Hz but in a practical circuit I found the venerable NE5534
with its 3.5 nV/sqrt Hz was quieter, presumably due to lower input noise
current in that particular configuration.

The LMEs also have insanely low THD
RL = 600ohms 0.00003% (typ)

http://www.national.com/pf/LM/LME49710.html
http://www.national.com/pf/LM/LM4562.html

Does anyone know of anything better without sacrificing unity gain
stability or THD ?

Graham

Not got round to using it yet but the ADA4899 looks tasty. 1nV, 0.7ppm,
600MHz.

Open the window, more shit flies in.
600MHz is not required for audio, only audiophools

Yeah but: Think what that can do in advertising: Gold plated super
electrons that are made extra agile and can turn themselves around in
under 2nsec. Electrons spend less time in the muddier regions in the
device, therefore get less dirty and don't wear out so fast.

Speaking of dirty... I'm waiting for the marketing types to sell some
super-expensive cans of compressed air to clean out heat sink dust.

Improve heat transfer! Make your heat sinks sparkling clean with
AudioPhool(tm) Compressed Air! Crisper highs! Tighter Bass! Make
your power transistors happy! Give your electrons a bath! We blow
away the competition! (in cubic feet per minute that is)

Michael

 

[Martin Griffith]

On Mon, 22 Sep 2008 13:02:48 -0700, in sci.electronics.design Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Martin Griffith wrote:
On Mon, 22 Sep 2008 10:18:51 -0700, in sci.electronics.design Joerg
notthisjoergsch@removethispacbell.net> wrote:

Martin Griffith wrote:
snip
Not got round to using it yet but the ADA4899 looks tasty. 1nV, 0.7ppm,
600MHz.

Open the window, more shit flies in.
600MHz is not required for audio, only audiophools

Yeah but: Think what that can do in advertising: Gold plated super
electrons that are made extra agile and can turn themselves around in
under 2nsec. Electrons spend less time in the muddier regions in the
device, therefore get less dirty and don't wear out so fast. Much less
electron fatigue. Makes for extremely crisp crescendos that could never,
ever be heard with an amp that is anywhere less than 500MHz

I've just done a deal with the LHC at Cern, I'm buying the stripped
off electrons from the ultra fast protons that they use in round
thing.

How should I package them?


Those need to be transported in a humidor

Ever time I hear the word "Humidor" I think of a Belgium dude,
Hercules Parrot, and over-acting, and an authoress who had a hangover
and went missing for a couple of days, and made the UK "Daily Mail"
headlines( maybe)

martin

 

[Eeyore]

mrdarrett@gmail.com wrote:

Speaking of dirty... I'm waiting for the marketing types to sell some
super-expensive cans of compressed air to clean out heat sink dust.

Improve heat transfer! Make your heat sinks sparkling clean with
AudioPhool(tm) Compressed Air! Crisper highs! Tighter Bass! Make
your power transistors happy! Give your electrons a bath! We blow
away the competition! (in cubic feet per minute that is)

When we did a re-furbishment at my local venue last year we blew them out with
compressed CO2 that they normally use for pressure delivery of the beers. Did a
fantastic job. Make a few people quite dusty though.

Graham

 

[Eeyore]

John Larkin wrote:

Eeyore wrote:
Phil Hobbs wrote:
Eeyore wrote:
National's LME49710/20/40 amd LM4562 seem to have the best figures at
2.5nV/sqrt Hz but in a practical circuit I found the venerable NE5534
with its 3.5 nV/sqrt Hz was quieter, presumably due to lower input noise
current in that particular configuration.

The LMEs also have insanely low THD
RL = 600ohms 0.00003% (typ)

http://www.national.com/pf/LM/LME49710.html
http://www.national.com/pf/LM/LM4562.html

Does anyone know of anything better without sacrificing unity gain
stability or THD ?


What resistance values are you assuming? Not one month ago, in this
very boutique, I posted a link to a new part with some really cute
specs--the ADA4898-1.

http://www.analog.com/static/imported-files/Data_Sheets/ADA4898-1.pdf

I gather it's probably intended for lower source resistances than yours,
but its combination of low eN and low Cin is amazing.

Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !

It's certainly amazingly quiet though.

I'm not familiar with the THD being quoted in dBc though. Can you assist there ?

15K? Sounds like jfet turf.

That's the feedback resistor value in an inverting summing amp thay may be fed from
up to 32 sources simultaneously, giving an Rin of 400 ohms approx.

Just done the sums. Does anyone want to slap me round the face with a wet fish ?

I make 400 ohms 2.6nV/sqrt Hz ! I wasn't expecting it to be that noisy. I didn't
mess up did I ?

Graham

 

[Eeyore]

Les Matthew wrote:

Eeyore wrote:
Les Matthew wrote:
Eeyore wrote:
Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !
At Midas Audio in the 80's we used 12k.

Yes, but you were going downhill them. KT group bought out Midas in 88 when I was
there.

Dave Dearden and I were dumbstruck (and not in a good way) just with the mic input
stage.

Dave Dearden, that name rings a bell.

Tech Director then of DDA that had just merged with Klark Teknik. Now in the same
poition at Audient. He was with Soundcraft previously. I worked alongside him for a
while in design.

I jumped ship to Brit Row around
87. It was mental at Midas then, bank holding the purse strings, full
order book but no cash flow. Pro40 was crazy, so much more electronics
crammed into the same old Pro4 frame, Geoff just wouldn't contemplate
having a larger frame. They got seriously hot.

Weren't XL's being shipped then ? That's where it seems it all went wrong.

I can recall seeing a heatsink drawn on one schematic of theirs !

Graham

 

[Eeyore]

Les Matthew wrote:

Eeyore wrote:

Dave Dearden, that name rings a bell. I jumped ship to Brit Row around
87. It was mental at Midas then, bank holding the purse strings, full
order book but no cash flow. Pro40 was crazy, so much more electronics
crammed into the same old Pro4 frame, Geoff just wouldn't contemplate
having a larger frame. They got seriously hot.

You know I interviewed for a post at Midas once. Would have been around 1980.

I don't recall the names now but would Geoff have been the tech bod ?

I took down some of my work to show him including a pcb layout and an actual pcb IIRC.
Do you know what he said ? He said I should start up my own business !

I simply wasn't financially in that position, having lost my parents at age 14 and 18
and gained a truly evil (wanted to be a black witch) stepmother. Had my father still
been around I have no doubt he would have backed me. He was that kind of guy. It's so
sad both my parents had to die so young, both from cancer.

So there you go. Maybe if Geoff had taken me on. I'd be running Midas (at least as tech
Dir) now !

Graham

 

[Eeyore]

Martin Griffith wrote:.

Dave Dearden... Many Confused Individuals (MCI consoles). them where
the days, when SMPTE timecode was new

Maybe Dave was with MCI before Soundcraft ?

Taling of SMPTE etc, do you remember Audio Kinetics and their synchroniser / locators ? I
worked for them for a while too as a summer holiday job when I was at college.

Graham

 

[Martin Griffith]

On Tue, 23 Sep 2008 00:10:18 +0100, in sci.electronics.design Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

Martin Griffith wrote:.

Dave Dearden... Many Confused Individuals (MCI consoles). them where
the days, when SMPTE timecode was new

Maybe Dave was with MCI before Soundcraft ?

Taling of SMPTE etc, do you remember Audio Kinetics and their synchroniser / locators ? I
worked for them for a while too as a summer holiday job when I was at college.

Graham
Yep DD was with MCI with another guy called bernie.

Qlock , strange company, badly organised. Lot of systems, walked out
of the backdoor, as spares. Opposite side of the road from FWO Bauch
in Boringwood, where I did some time, a year and a day I think, fixing
Studers.
Do you remember Werner?

martin

 

[Phil Hobbs]

Eeyore wrote:

Phil Hobbs wrote:


I'm not familiar with the THD being quoted in dBc though. Can you assist there
?
dBc = 'decibels with respect to the carrier', i.e. the undistorted output.

Unfortunately that doesn't specify a specific voltage or power level AFAICS.

Graham

No, but it's a comparison between two components at the same circuit

point, so the power ratio is the square of the voltage ratio.

Cheers,

Phil Hobbs

 

[Eeyore]

ggherold@gmail.com wrote:

Eeyore wrote:
ggherold@gmail.com wrote:
John Larkin wrote:
Eeyore wrote:
Phil Hobbs wrote:
Eeyore wrote:
National's LME49710/20/40 amd LM4562 seem to have the best figures at
2.5nV/sqrt Hz but in a practical circuit I found the venerable NE5534
with its 3.5 nV/sqrt Hz was quieter, presumably due to lower input noise
current in that particular configuration.

The LMEs also have insanely low THD
RL = 600ohms 0.00003% (typ)

http://www.national.com/pf/LM/LME49710.html
http://www.national.com/pf/LM/LM4562.html

Does anyone know of anything better without sacrificing unity gain
stability or THD ?

What resistance values are you assuming? Not one month ago, in this
very boutique, I posted a link to a new part with some really cute
specs--the ADA4898-1.

http://www.analog.com/static/imported-files/Data_Sheets/ADA4898-1.pdf

I gather it's probably intended for lower source resistances than yours,
but its combination of low eN and low Cin is amazing.

Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !

It's certainly amazingly quiet though.

I'm not familiar with the THD being quoted in dBc though. Can you assist there
?

Graham

15K? Sounds like jfet turf.

John-

15K? Sounds like jfet turf.

Yes, Aren't you going to be dominated by the current noise? Speaking
of jfet opamps, Do you have a low noise favorite? I like the OPA134
from Burr-Brown (TI). But am always looking for something better.
George

That depends how many inputs are assigned. As these are going only to be monitoring
desks, the number of inputs will be 24 or 36 typically.

"That depends how many inputs are assigned. As these are going only
to be monitoring
desks, the number of inputs will be 24 or 36 typically.
So the suming node will see ~ 400-600 ohms. Current noise shouldn't be
a problem
here,"

Ahh I see it's one big summing junction. But what is the feedback
resistor? (I know nothing about high end audio stuff.)

Its value, correcting for the gain structure mess-up of the original design will be 7k5,
i.e a voltage gain of around -18x , but must be stable with nothing routed which equates
to a stable gain of -0.5x. I don't see a problem with the stability issues, I thought it
out on the walk back from the supermarket.

Graham

 

[Eeyore]

Martin Griffith wrote:

Eeyore wrote:
Martin Griffith wrote:.

Dave Dearden... Many Confused Individuals (MCI consoles). them where
the days, when SMPTE timecode was new

Maybe Dave was with MCI before Soundcraft ?

Taling of SMPTE etc, do you remember Audio Kinetics and their synchroniser / locators ? I
worked for them for a while too as a summer holiday job when I was at college.

Yep DD was with MCI with another guy called bernie.
Qlock , strange company, badly organised. Lot of systems, walked out
of the backdoor, as spares. Opposite side of the road from FWO Bauch
in Boringwood, where I did some time, a year and a day I think, fixing
Studers.
Do you remember Werner?

That's after my time. Audio Kinetics was in beautiful converted church in St Albans when I
worked for them. Must have been 77 ish.

I personally wire-wrapped some of the very first Q-locks. We used Ampex ATR 100 series as test
machines. Woo-hoo - were they something else !

Graham

 

[John Larkin]

On Mon, 22 Sep 2008 21:46:19 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

John Larkin wrote:

Eeyore wrote:
Phil Hobbs wrote:
Eeyore wrote:
National's LME49710/20/40 amd LM4562 seem to have the best figures at
2.5nV/sqrt Hz but in a practical circuit I found the venerable NE5534
with its 3.5 nV/sqrt Hz was quieter, presumably due to lower input noise
current in that particular configuration.

The LMEs also have insanely low THD
RL = 600ohms 0.00003% (typ)

http://www.national.com/pf/LM/LME49710.html
http://www.national.com/pf/LM/LM4562.html

Does anyone know of anything better without sacrificing unity gain
stability or THD ?


What resistance values are you assuming? Not one month ago, in this
very boutique, I posted a link to a new part with some really cute
specs--the ADA4898-1.

http://www.analog.com/static/imported-files/Data_Sheets/ADA4898-1.pdf

I gather it's probably intended for lower source resistances than yours,
but its combination of low eN and low Cin is amazing.

Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !

It's certainly amazingly quiet though.

I'm not familiar with the THD being quoted in dBc though. Can you assist there ?

15K? Sounds like jfet turf.

That's the feedback resistor value in an inverting summing amp thay may be fed from
up to 32 sources simultaneously, giving an Rin of 400 ohms approx.

Just done the sums. Does anyone want to slap me round the face with a wet fish ?

I make 400 ohms 2.6nV/sqrt Hz ! I wasn't expecting it to be that noisy. I didn't
mess up did I ?

Graham

That's about right. So the summing resistors are about 400*32 = 12.8K
each. Each input has a gain to the output of a bit over 1. Noise gain
is close to 40.

I wonder if multi-group summing would be any better.

John

 

Eeyore wrote:

ggherold@gmail.com wrote:

John Larkin wrote:
Eeyore wrote:
Phil Hobbs wrote:
Eeyore wrote:
National's LME49710/20/40 amd LM4562 seem to have the best figures at
2.5nV/sqrt Hz but in a practical circuit I found the venerable NE5534
with its 3.5 nV/sqrt Hz was quieter, presumably due to lower input noise
current in that particular configuration.

The LMEs also have insanely low THD
RL = 600ohms 0.00003% (typ)

http://www.national.com/pf/LM/LME49710.html
http://www.national.com/pf/LM/LM4562.html

Does anyone know of anything better without sacrificing unity gain
stability or THD ?

What resistance values are you assuming? Not one month ago, in this
very boutique, I posted a link to a new part with some really cute
specs--the ADA4898-1.

http://www.analog.com/static/imported-files/Data_Sheets/ADA4898-1.pdf

I gather it's probably intended for lower source resistances than yours,
but its combination of low eN and low Cin is amazing.

Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !

It's certainly amazingly quiet though.

I'm not familiar with the THD being quoted in dBc though. Can you assist there
?

Graham

15K? Sounds like jfet turf.

John-

15K? Sounds like jfet turf.

Yes, Aren't you going to be dominated by the current noise? Speaking
of jfet opamps, Do you have a low noise favorite? I like the OPA134
from Burr-Brown (TI). But am always looking for something better.
George

That depends how many inputs are assigned. As these are going only to be monitoring
desks, the number of inputs will be 24 or 36 typically.

"That depends how many inputs are assigned. As these are going only
to be monitoring
desks, the number of inputs will be 24 or 36 typically.
So the suming node will see ~ 400-600 ohms. Current noise shouldn't be
a problem
here,"

Ahh I see it's one big summing junction. But what is the feedback
resistor? (I know nothing about high end audio stuff.)

Georgw

 

[Eeyore]

John Larkin wrote:

Eeyore wrote:
John Larkin wrote:
Eeyore wrote:
Phil Hobbs wrote:
Eeyore wrote:
National's LME49710/20/40 amd LM4562 seem to have the best figures at
2.5nV/sqrt Hz but in a practical circuit I found the venerable NE5534
with its 3.5 nV/sqrt Hz was quieter, presumably due to lower input noise
current in that particular configuration.

The LMEs also have insanely low THD
RL = 600ohms 0.00003% (typ)

http://www.national.com/pf/LM/LME49710.html
http://www.national.com/pf/LM/LM4562.html

Does anyone know of anything better without sacrificing unity gain
stability or THD ?

What resistance values are you assuming? Not one month ago, in this
very boutique, I posted a link to a new part with some really cute
specs--the ADA4898-1.

http://www.analog.com/static/imported-files/Data_Sheets/ADA4898-1.pdf

I gather it's probably intended for lower source resistances than yours,
but its combination of low eN and low Cin is amazing.

Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !

It's certainly amazingly quiet though.

I'm not familiar with the THD being quoted in dBc though. Can you assist there ?

15K? Sounds like jfet turf.

That's the feedback resistor value in an inverting summing amp thay may be fed from
up to 32 sources simultaneously, giving an Rin of 400 ohms approx.

Just done the sums. Does anyone want to slap me round the face with a wet fish ?

I make 400 ohms 2.6nV/sqrt Hz ! I wasn't expecting it to be that noisy. I didn't
mess up did I ?


That's about right. So the summing resistors are about 400*32 = 12.8K
each. Each input has a gain to the output of a bit over 1. Noise gain
is close to 40.

I wonder if multi-group summing would be any better.

That would be ideal and is a method implemented in some more modern products. In this
case we're stuck with what we have i.e. a single mix bus.

Graham

 

[Les Matthew]

Eeyore wrote:

Martin Griffith wrote:.

Dave Dearden... Many Confused Individuals (MCI consoles). them where
the days, when SMPTE timecode was new

Maybe Dave was with MCI before Soundcraft ?

Taling of SMPTE etc, do you remember Audio Kinetics and their synchroniser / locators ? I
worked for them for a while too as a summer holiday job when I was at college.

Graham

That must be it as I was with Soundcraft before Midas.


les...

 

[Les Matthew]

Martin Griffith wrote:

On Tue, 23 Sep 2008 00:10:18 +0100, in sci.electronics.design Eeyore
rabbitsfriendsandrelations@hotmail.com> wrote:


Martin Griffith wrote:.

Dave Dearden... Many Confused Individuals (MCI consoles). them where
the days, when SMPTE timecode was new
Maybe Dave was with MCI before Soundcraft ?

Taling of SMPTE etc, do you remember Audio Kinetics and their synchroniser / locators ? I
worked for them for a while too as a summer holiday job when I was at college.

Graham
Yep DD was with MCI with another guy called bernie.
Qlock , strange company, badly organised. Lot of systems, walked out
of the backdoor, as spares. Opposite side of the road from FWO Bauch
in Boringwood, where I did some time, a year and a day I think, fixing
Studers.
Do you remember Werner?

martin

Didn't MCI end up in Stanhope St? Midas and Martin Audio were in the
yard and MCI had the building at the front and over the top of the
entrance to the yard.


les...

 

[Les Matthew]

Eeyore wrote:

Les Matthew wrote:

Eeyore wrote:
Les Matthew wrote:
Eeyore wrote:
Yes, my source resistance may dominate. It's a new module for SSL 4000E/G
professional sound mixing desks to convert the 'channel buckets' into a
monitor desk for Digital Audio Workstations. I was shocked at how high their
mix resistor values were (15k). Crikey, even at Studiomaster in the latter
days I was using 4k7 !
At Midas Audio in the 80's we used 12k.
Yes, but you were going downhill them. KT group bought out Midas in 88 when I was
there.

Dave Dearden and I were dumbstruck (and not in a good way) just with the mic input
stage.
Dave Dearden, that name rings a bell.

Tech Director then of DDA that had just merged with Klark Teknik. Now in the same
poition at Audient. He was with Soundcraft previously. I worked alongside him for a
while in design.


I jumped ship to Brit Row around
87. It was mental at Midas then, bank holding the purse strings, full
order book but no cash flow. Pro40 was crazy, so much more electronics
crammed into the same old Pro4 frame, Geoff just wouldn't contemplate
having a larger frame. They got seriously hot.

Weren't XL's being shipped then ? That's where it seems it all went wrong.

I can recall seeing a heatsink drawn on one schematic of theirs !

Graham

XL's were after my time, so maybe I left earlier. It's all a bit hazy now.

les...


les...

 

[Les Matthew]

Eeyore wrote:

Les Matthew wrote:

Eeyore wrote:

Dave Dearden, that name rings a bell. I jumped ship to Brit Row around
87. It was mental at Midas then, bank holding the purse strings, full
order book but no cash flow. Pro40 was crazy, so much more electronics
crammed into the same old Pro4 frame, Geoff just wouldn't contemplate
having a larger frame. They got seriously hot.

You know I interviewed for a post at Midas once. Would have been around 1980.

I don't recall the names now but would Geoff have been the tech bod ?

I took down some of my work to show him including a pcb layout and an actual pcb IIRC.
Do you know what he said ? He said I should start up my own business !

I simply wasn't financially in that position, having lost my parents at age 14 and 18
and gained a truly evil (wanted to be a black witch) stepmother. Had my father still
been around I have no doubt he would have backed me. He was that kind of guy. It's so
sad both my parents had to die so young, both from cancer.

So there you go. Maybe if Geoff had taken me on. I'd be running Midas (at least as tech
Dir) now !

Graham

Geoff was the owner, iirc it was Jim Cousins doing most of the design
work and some other guy who I cant remember at this time. This was after
Chas Brookes had left.


les...