G
Guest
Guest
Firstly may I point out that Cyril Jones is a total gentleman and he and his wife made me extremely welcome and the coffee and cohcolate bscuits were a most welcome addition.
I went there just to buy some old Sifam meters - I stayed for hours.. (I got there just after lunch and left at 5 o'clock in the evening)
So I popped up the road to visit Cyril at his home - the first thing that strikes you is the very English house he lives in with attached very old dairy - which had been converted into a number of rooms for metalwork, office etc..
Cyril seems to do an awful lot of the metalwork himself - there are ancient massive drill presses everywhere
As you open the doors there is a massive old Raindirk desk with all the modules pulled and the VU meters still up - with ribbon cable everywhere.
Now as you all know I am not the brightest electronics guy on the block (and then some) so take what I say as how I understood it - I may have totally mis-interpretted what is said - if there are mistakes - it's my fault and not Cyrils.
Now here are the rambling notes:
Q - What do you want out of the gear you design?
A - To satisfy the engineers requirements - we then went of on a lovely rambling talk about designing for what the user asked for and then what they didn't ask for but may ask for in a few months time (I do the same in my line of work)
Q - How do you go about picking input transformers
A - By reputation, listening to the market and building test boxes (as on cue I looked down at the bench to see two Lundahls hooked up to a scope).
Nowadays he uses Stevens and Billington transformers - naturally all these guys know each others for years (then Cyril talks about Per Lundahl and his dad - how they have known each other for years and are really really nice guys)
The guy behind S&B is an hifi buff and checks all his transformers on his hifi gear first
Q - Which stage buffering, gain make up, summing should be where you put quality opamps
A - Gain is always where the quality should be. I don't use TL072 /FET types.
The main main problem with quality chips in consoles is that the require more current - more current, lots of chips - huge power supply needed.
(fact check alert) I use a pot around a chip - 1K2 feedback, 2K2 to ground
Q - What is the involvement of ADR
A - I didn't have time to make the compressors so we were in partnership with the Dutch.
They were designed and prototyped in Holland - designed was a base around Urei.
Built in the UK
I then have a couple of notes - wich may or may not be related to the above
.25 amp because lots of LEDs
2 VCAs - 2151
The next few notes are just random jottings which some people may be more aware than me
Prefer 600ohm fader - due to lack of noise but P&G will only supply non 10Kohm faders unless you buy thousands
Cyril was another one of the Sound Techniques technicians (under Geoff Frost - see my previous ramblings on the subject of Geoff Frost and Sound Techniques)
And ever since those days the main thing he has always worried about in Audio design is leakage and a very very wide frequency repsonse.
It seems an awful lot of his consoles ended up in Broadcast stations
Capacitors:
He didn't care about caps until one day a circuit was oscillating then he put a Suflex/Poly cap in - and since them in mixing amps he has always put poly/caps in parallel
As with other console designers he has alwayas massively over spec'd the farad rating of the caps
So if a 2uf was required - a 47uf was subsituted in build
Tend to simplify designs in build and modularise them - and along with the overspeccing of caps - this is due to ham fisted maintenance engineers
who if they cock up the maintenance its the consoles name that is on the line
Fader amp - always put a big cap - so low noise as the fader goes down
And then Cyril pulls out schamtic after schamtic - of some of the stuff he did with Barry Porter
Using a SB737 chip as a low base bulk resistance before a NE5532 - result - low noise
(I then made some notes about a HPF buffer chip before the caps)
Then a fader amp circuit - 100R with the resitors going from the chip of 2K2 - 470R - 2K2
I really should have been paying attention but to be quite honest - I was like a kid in a sweety shop
Cyril then starts pulling out old modules
A module from the FIRST Helios desk ever made
I spotted - Colvin Pots - the turret board with BIG mustard caps
Then - Veroboard/Stripboard
Lustraphone transformers and the inductor
Then he pulls out the module from the SECOND ever Helios desk
Now this one is quite different inside - two little RadioSpares (RS Components) Interstage transformer right behind the panel
The whole place has got a load of racked up units for Canada being tinkered with
His new DI box is down there on the desk
We then go upstairs to more metalworking units - and his spares
Naturally he has to go lead free so there is a stack of stuff up there - and I mean LOADS
I purchased 3 Sifam PPM 22AFs, 3 Sifam VU 22AFs and a Sifam Phase Meter with all the bezels etc for £150.
He also bunged in a bag load of freebies.. loads of jack sockets, and a stack of old Decca multi pole switches
(4 clicks - 2, 3 and 4 ganged multi poles) (I must have about 15 of them)
There are loads of EAO switch covers, series 31 lens caps (thats for my next visit - hopefully)
I can't stress how much stuff is actually there - old transformers, everything, amphenol connectors, old EDACs
He actually said if I wanted any of those 2151 VCA to get in touch as he has loads
And then he said - oh - do you use them for this circuit - then he pulls out a folder with Jakobs VCA circuit in it
Some guy came in saying he couldn't finish it - so I did it for him
A very very pleasant afternoon talking about everything and anything - Deep Purples desk, design of broadcast desks, fixing stuff down in Chris Diffords Studio etc..
Each time - dragging out a folder with puitures and circuits in them
Or reaching down and dragging out a old module from a desk
To be quite honest I was dumb struck and my mouth was catching flies most of the time
Next time - I promise I will take more notes
A true gentleman - and he took a transformer I had to do some testing and would stick it in the post later in the week with some info for me
I went there just to buy some old Sifam meters - I stayed for hours.. (I got there just after lunch and left at 5 o'clock in the evening)
So I popped up the road to visit Cyril at his home - the first thing that strikes you is the very English house he lives in with attached very old dairy - which had been converted into a number of rooms for metalwork, office etc..
Cyril seems to do an awful lot of the metalwork himself - there are ancient massive drill presses everywhere
As you open the doors there is a massive old Raindirk desk with all the modules pulled and the VU meters still up - with ribbon cable everywhere.
Now as you all know I am not the brightest electronics guy on the block (and then some) so take what I say as how I understood it - I may have totally mis-interpretted what is said - if there are mistakes - it's my fault and not Cyrils.
Now here are the rambling notes:
Q - What do you want out of the gear you design?
A - To satisfy the engineers requirements - we then went of on a lovely rambling talk about designing for what the user asked for and then what they didn't ask for but may ask for in a few months time (I do the same in my line of work)
Q - How do you go about picking input transformers
A - By reputation, listening to the market and building test boxes (as on cue I looked down at the bench to see two Lundahls hooked up to a scope).
Nowadays he uses Stevens and Billington transformers - naturally all these guys know each others for years (then Cyril talks about Per Lundahl and his dad - how they have known each other for years and are really really nice guys)
The guy behind S&B is an hifi buff and checks all his transformers on his hifi gear first
Q - Which stage buffering, gain make up, summing should be where you put quality opamps
A - Gain is always where the quality should be. I don't use TL072 /FET types.
The main main problem with quality chips in consoles is that the require more current - more current, lots of chips - huge power supply needed.
(fact check alert) I use a pot around a chip - 1K2 feedback, 2K2 to ground
Q - What is the involvement of ADR
A - I didn't have time to make the compressors so we were in partnership with the Dutch.
They were designed and prototyped in Holland - designed was a base around Urei.
Built in the UK
I then have a couple of notes - wich may or may not be related to the above
.25 amp because lots of LEDs
2 VCAs - 2151
The next few notes are just random jottings which some people may be more aware than me
Prefer 600ohm fader - due to lack of noise but P&G will only supply non 10Kohm faders unless you buy thousands
Cyril was another one of the Sound Techniques technicians (under Geoff Frost - see my previous ramblings on the subject of Geoff Frost and Sound Techniques)
And ever since those days the main thing he has always worried about in Audio design is leakage and a very very wide frequency repsonse.
It seems an awful lot of his consoles ended up in Broadcast stations
Capacitors:
He didn't care about caps until one day a circuit was oscillating then he put a Suflex/Poly cap in - and since them in mixing amps he has always put poly/caps in parallel
As with other console designers he has alwayas massively over spec'd the farad rating of the caps
So if a 2uf was required - a 47uf was subsituted in build
Tend to simplify designs in build and modularise them - and along with the overspeccing of caps - this is due to ham fisted maintenance engineers
who if they cock up the maintenance its the consoles name that is on the line
Fader amp - always put a big cap - so low noise as the fader goes down
And then Cyril pulls out schamtic after schamtic - of some of the stuff he did with Barry Porter
Using a SB737 chip as a low base bulk resistance before a NE5532 - result - low noise
(I then made some notes about a HPF buffer chip before the caps)
Then a fader amp circuit - 100R with the resitors going from the chip of 2K2 - 470R - 2K2
I really should have been paying attention but to be quite honest - I was like a kid in a sweety shop
Cyril then starts pulling out old modules
A module from the FIRST Helios desk ever made
I spotted - Colvin Pots - the turret board with BIG mustard caps
Then - Veroboard/Stripboard
Lustraphone transformers and the inductor
Then he pulls out the module from the SECOND ever Helios desk
Now this one is quite different inside - two little RadioSpares (RS Components) Interstage transformer right behind the panel
The whole place has got a load of racked up units for Canada being tinkered with
His new DI box is down there on the desk
We then go upstairs to more metalworking units - and his spares
Naturally he has to go lead free so there is a stack of stuff up there - and I mean LOADS
I purchased 3 Sifam PPM 22AFs, 3 Sifam VU 22AFs and a Sifam Phase Meter with all the bezels etc for £150.
He also bunged in a bag load of freebies.. loads of jack sockets, and a stack of old Decca multi pole switches
(4 clicks - 2, 3 and 4 ganged multi poles) (I must have about 15 of them)
There are loads of EAO switch covers, series 31 lens caps (thats for my next visit - hopefully)
I can't stress how much stuff is actually there - old transformers, everything, amphenol connectors, old EDACs
He actually said if I wanted any of those 2151 VCA to get in touch as he has loads
And then he said - oh - do you use them for this circuit - then he pulls out a folder with Jakobs VCA circuit in it
Some guy came in saying he couldn't finish it - so I did it for him
A very very pleasant afternoon talking about everything and anything - Deep Purples desk, design of broadcast desks, fixing stuff down in Chris Diffords Studio etc..
Each time - dragging out a folder with puitures and circuits in them
Or reaching down and dragging out a old module from a desk
To be quite honest I was dumb struck and my mouth was catching flies most of the time
Next time - I promise I will take more notes
A true gentleman - and he took a transformer I had to do some testing and would stick it in the post later in the week with some info for me
