Whoops

Re: Neve 80 series Console Build
« Reply #240 on: February 20, 2021, 09:34:47 AM »
You can average 100ma per module, so around 6 amps for the whole console. What I meant is that it doesn't get hot. Which has the biggest impact on the bill: no need for AC!!

Even if you don't need HVAC system for PSU's or console, and even if you don't leave it on all the time what I wanted to say is that any new PSU will be more efficient than 50 years old Coutant PSU (late 60s/ early 70s), as we are in 2021 and you are building a new console at the present it makes sense to not go back in time and using a Coutant but using something better.

Best regards


Whoops

Re: Neve 80 series Console Build
« Reply #241 on: February 20, 2021, 09:50:10 AM »
Some good info from Geoff Tanner about Neve PSU's:

"Hi

If we take the 1073 as a classic example, one of the biggest flaws in its design is that it takes the negative feedback for the output stage from the collector of the 2N3055 which puts it the primary winding impedance and a 12 ohm resistor away from the dc supply.

So, if you don't have gobs of capacitance after that 12 ohm resistor, then the noise and crud on the power supply can get into audio via the feedback. If you don't recap the modules in their lifetime and the electrolytics lose their efficiency you can get a situation where the signal in the output stages modulates the power rails, which is picked up in the feedback, and leads to "motor-boating" instability/oscillations.

So the power supply needs two thing...

1. Gobs of current headroom to accommodate the switch on surge of all those electrolytics charging up.

2. Absolutely damn all ripple and noise... if it measures -60dB (1mV) that's too much. It should be measured in microvolts.

So there's not really an audiophile power supply per ce, just very good ones with adequate current capabilities and minimal noise or ripple.

I'm amazed at how tiny some power supplies are for racks of modules. I'd allow at least 1 amp for two modules (1073's draw 122mA each) and at least 5 amps for a rack of 8."



https://www.gearslutz.com/board/high-end/185613-neve-10-series-psu-how-much-does-affect-sound.html

Re: Neve 80 series Console Build
« Reply #242 on: February 20, 2021, 10:02:43 AM »
"Some typical values would be: 4048 - 1700 Watts, a 4040 – 1500 Watts, a 4056 – 1900 Watts. "

Is that DC post regulation ? that's over 40A for +/-18 rail  ;D

My 70' studer have 3x 3A regulator, single rail 22V that's less than 200W max, and reg don't draw that many amp in use.

Remy should be around 150W regarding data he just give.

For sure "modern" big desk have lot of function/routing options but man what a fail in energy saving...

Regarding amount of time and money involved in this build, I'm with Whoops, it deserve to try a modern hiend SMPS, like industrial Vero PK series etc ...

Best
Zam

Whoops

Re: Neve 80 series Console Build
« Reply #243 on: February 20, 2021, 11:02:39 AM »
Is that DC post regulation ? that's over 40A for +/-18 rail  ;D

That's Power consumption of the power line

1700watts x 230VAC = 7.39 Amps

Re: Neve 80 series Console Build
« Reply #244 on: February 20, 2021, 03:41:02 PM »
About 165mA for each router too if I understood the topology you went with correctly (2 X 283 output stages)

Plus the 1272's at about 90mA each.

Not efficient but, it's the price ya pay for class A with headroom  :)
 
 
D. J. H.

The standard way to reduce much of the noise and distortion in audio gear in 1955 was to have a couple of beers.
 Anything else was too fiddlesome and too expensive.

ruffrecords

Re: Neve 80 series Console Build
« Reply #245 on: February 20, 2021, 05:34:23 PM »
About 165mA for each router too if I understood the topology you went with correctly (2 X 283 output stages)

Plus the 1272's at about 90mA each.

Not efficient but, it's the price ya pay for class A with headroom  :)
I think Rupert's transformer stage is a bit better than 'classic' Class A. Everyone is taught that class A is at best 25% efficient, which is true for a a resistive collector load. But for an inductor collector load the collector can swing up to twice the supply voltage which gives this class A stage a maximum efficiency of 50% which is not that far behind the 70% you get with a typical class B stage. Probably exactly the same reason why the V72 et al use the same technique.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: Neve 80 series Console Build
« Reply #246 on: February 20, 2021, 06:11:28 PM »
I think Rupert's transformer stage is a bit better than 'classic' Class A. Everyone is taught that class A is at best 25% efficient, which is true for a a resistive collector load. But for an inductor collector load the collector can swing up to twice the supply voltage which gives this class A stage a maximum efficiency of 50% which is not that far behind the 70% you get with a typical class B stage. Probably exactly the same reason why the V72 et al use the same technique.

Cheers

Ian

Yes of course.  I was allowing for this.    It's about the best we'll do with a 24V single rail.
Not all of the RMS signal swing comes from the stored energy in the choke/transformer too, we have 4dB step up from the 200:600 transformer.  Of course, this means the output transistor has to be biased for full RMS signal into a potential 200 ohms but, with just a +24V rail them's the choices. 
D. J. H.

The standard way to reduce much of the noise and distortion in audio gear in 1955 was to have a couple of beers.
 Anything else was too fiddlesome and too expensive.

Re: Neve 80 series Console Build
« Reply #247 on: February 20, 2021, 06:25:42 PM »
For reference by others, what Ian means is that a single 24V rail would only be capable of max +18dBu in class A by itself. 
 
(24V/2)/1.414 = RMS voltage.

The inductor adds almost twice that so another 6dB.  And the transformer step-up adds another 4dB.

This is +28dBu max.

In practicality, the 1272 doesn't quite get double swing out of the choke load and there's a little loss from the step-up, so the max output signal is somewhere around +26dBu which isn't too shabby really. 
 
D. J. H.

The standard way to reduce much of the noise and distortion in audio gear in 1955 was to have a couple of beers.
 Anything else was too fiddlesome and too expensive.

Nickos

Re: Neve 80 series Console Build
« Reply #248 on: February 24, 2021, 08:24:53 AM »
Hi guys!
First of all... I think this project is the greatest thing I've seen on the internet so far! Thank you, it's so inspiring! :)

I don't understand the purpose of the T1310 inductor... If it's just to keep the load of the missing transformer, why it can't be replaced with a resistor?

ruffrecords

Re: Neve 80 series Console Build
« Reply #249 on: February 24, 2021, 04:45:44 PM »
Hi guys!
First of all... I think this project is the greatest thing I've seen on the internet so far! Thank you, it's so inspiring! :)

I don't understand the purpose of the T1310 inductor... If it's just to keep the load of the missing transformer, why it can't be replaced with a resistor?
Because using an inductor (or transformer) allows the output transistor collector to swing up the twice the B+ rail. A class A amp with a resistive collector load it at most only 25% efficient. With an inductive load it can be up to 50% efficient. Rupert knew what he was doing. It is the same reason the old German preamps have inductor plate loads.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


Nickos

Re: Neve 80 series Console Build
« Reply #250 on: February 25, 2021, 03:35:10 AM »
Thanks  Ian!
So, if i understand correctly, it will cause a lack of headroom, right?
It will affect the sound as well?

Nick

ruffrecords

Re: Neve 80 series Console Build
« Reply #251 on: February 25, 2021, 04:05:34 AM »
Thanks  Ian!
So, if i understand correctly, it will cause a lack of headroom, right?
It will affect the sound as well?

Nick
Exactly, about 6dB less.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

lotus

Re: Neve 80 series Console Build
« Reply #252 on: February 25, 2021, 11:36:54 AM »
Hi Ian, how are you?  I was wondering how the new tube console for Taylor Swift, for our place in Los Angeles is coming along?  And Winston O Boogie behave! And I might just give you a raise.

Whoops

Re: Neve 80 series Console Build
« Reply #253 on: February 25, 2021, 11:41:00 AM »
how the new tube console for Taylor Swift, for our place in Los Angeles is coming along?

tell us more about that please

ruffrecords

Re: Neve 80 series Console Build
« Reply #254 on: February 25, 2021, 12:41:54 PM »
Hi Ian, how are you?  I was wondering how the new tube console for Taylor Swift, for our place in Los Angeles is coming along?
I am not in a position to talk publicly about that right now.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: Neve 80 series Console Build
« Reply #255 on: March 03, 2021, 01:50:28 PM »
Hey guys,
This is of no academic interest, but i just wanted to share with you a song that I recorded with the console yesterday.
https://we.tl/t-q2S2meJ9LG
Beware, this is me deliberately trying to not make a big sound ;D This is a 60's style band, so I wanted to keep it era correct and have more focus on tones, midrange and spontaneity than lo-end and mixing trickery.
But I think the console really sings for that kind of stuff, I'm loving it more everyday...
I can elaborate more on the recording process if anyone's interested, and though there is lots of very vibey gear involved, I very much hear the console on that one, so there you go!

Re: Neve 80 series Console Build
« Reply #256 on: March 03, 2021, 02:04:45 PM »
Hey guys,
This is of no academic interest, but i just wanted to share with you a song that I recorded with the console yesterday.
https://we.tl/t-q2S2meJ9LG
Beware, this is me deliberately trying to not make a big sound ;D This is a 60's style band, so I wanted to keep it era correct and have more focus on tones, midrange and spontaneity than lo-end and mixing trickery.
But I think the console really sings for that kind of stuff, I'm loving it more everyday...
I can elaborate more on the recording process if anyone's interested, and though there is lots of very vibey gear involved, I very much hear the console on that one, so there you go!

Incredible Remi!!  You are a first class engineer in my book.  When I first heard your samples in earlier posts I mentioned the desk having a thinner tone than I was expecting and like you say it really suits this 60s kind of style.  I'm sure you have no problem achieving a big sound too.  Your console and your engineering chops is something to use as inspiration to improve what I do.

Keep rocking bro!


 

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