Mr Neve's portico...some thoughts.

[ianb79]

i gotta get some new pres to go with my distressor. i'm just thinking out loud here - and i'd like to hear some other thoughts.
Everybody complains about pres for some reason or another unless its a neve 1073...i know there are some lovely boutique pres like the redd 47 and d.w. fearns and APIs are great on drums and the GRs are great and the Manleys are tops and the Chandlers make my records sound like Abbey Road......BUT lets be honest here...everybody uses 1073s: from ziggy marley to Muse to Slayer...the 1073s just do it all and all these albums sound incredible and they are all so different BUT the 1073 is the common string. Sure they have great rooms and mics and compressors and converters +/- 2 inch tape etc. And occasionally they will use a telefunken on direct bass BUT the 1073 pretty much has its fingerprints on everything and what lovely fingerprints they are!

Now, to buy a 1073 you really have to shell out and if you are doing this music thing as a V.E.H.* like me then it's hard to get clearence from the boss (wife!) - So what do you do? do you buy a 'clone' - maybe a vintech or a chandler LTD-1??? But you know what - the makers of these rehash models have supposedly hunted down original St Ives T'formers and original resistors, switches etc etc BUT people STILL say : "oh the vintech sounds fuzzy compared to a real 1073" or Chandler say: "our high frequencies are even sweeter than the neve".....what does this mean - that even when 1073s are pain-stakingly ripped off then the resultant preamp dosn't sound like a 1073???? I don't think Muse sat down at mix-down time and said: 'gee i wish our album had a 'sweeter' top end'...i reckon they were pretty pleased.

Now i come to the Portico - Mr Neve's new preamp design. Who ISN'T interested?!...the thought of having 2 'Neve' channels for ~$700 each sounds pretty good hey?! All the characters who have purchased the Portico so far are stoked when you read their comments on the net...BUT - I WANT TO KNOW HOW THESE PREAMPS CAN SOUND ANTHING LIKE A "VINTAGE" NEVE PREAMP??!!

I know Mr Neve has laid hands on them BUT they are FAR from being a lovingly ripped off copy. A big Neve console with 1073 preamps uses HUGE power supply with HUGE transformers which generally equates to HUGE head-room, sound, and plenty of power reserve for powering many-a-48v mic. The Portico has a tiny power supply (similar to that used to power a Boss guitar pedal - correct me if i'm wrong) - it has small do-nut style Transformers (not that there is anything wrong with do-nuts!) - I probably sound like i am trying to compensate for something here but i believe that when it comes to head room, size does matter!!!
Sure it has a "silk' button that dials in more lovely euphonic harmonic distortion BUT this does not = an 'instant 1073'. My distressor has the same functional button and it sounds lovely, putting a lovely warm sexy jacket on anything that passes by it BUT you get my point.

So anyway - i have been thinking a lot about Mr Neve and his Portico and i am just so curious and sceptical and curious and sceptical and excited and sceptical and....damn - i think i just have to get 1...just think: 2 channels of hallowed 1073 magic for ~$700 each...that's a bargain!

*V.E.H. = very expensive hobby

 

[AudioGaff]

I would fully expect that the Portico will sound NOTHING like any of Mr. Neve's legacy pre amps of the past. He has said many times that none of that old stuff he designed was his best work. Only the best that he was able to achieve at the time. He is long past that now. What I believe he has done is to provide a high quality, clean, smooth pre amp at a fair price for those low and restriced budget folks just like he said was going to do 3-years ago. The man is not capable of making anything but a product of greatness in one form or another.

 

[vividsonics]

This is purely an academic comment and I in NO WAY consider myself an expert on preamps or their circuit topology, but...

In regards to the portico and vintage Neve preamps transformers, aren't the transformers of the vintage 1073's regular "cube shaped" transformers. If the Portico's transformers are do-nut shaped they would be toroidal transformers. Isn't there more surface are for windings on a toroidal transformer than a regular transformer?

 

[AudioGaff]

Assuming that there is more surface for windings, so? The core size, percentage of iron and steel, wire type and how many windings, ect all have an affect of the way they will sound.

 

[vividsonics]

I was just curious. I really have little knowledge in these matters.
Thanks!

 

[overlookfran]

so...eh......




.......how do they SOUND? lol

 

[Davedog]

There is a couple of giant threads as well as some personal reviews at gearslutz.From what I gather they sound like....uh....well just like a Neve.Amazing huh.....but then, what did you expect.?

 

[MistaG]

There was one guy over there at Gearslutz who thought they were pretty similar to the 1073 with the Silk switch in the "ON" position.

 

[Kurt Foster]

http://www.rupertneve.com/index.html


Here's the hundred thousand dollar question .... what about the line lump power supply?

A lot of people who have good ears and good monitoring systems are saying the Portico sounds very good and has a lot of depth and dimension in one of those threads at GS. I have to hear what they are saying but ....

I have a hard time swallowing this, it goes against everything that I have heard, seen, learned and been told in the past but I have to say if anyone could pull this off, Rupert Neve would be the one to do it.

I haven't heard it yet so I can't say ... but when I look at the specs for the power supply, it seems a bit under powered. For example both Averil and JLM use external line lump type supplies ... and they sound great but these supplies provide a ton of volts and amps while the Portico supply specs out at:

Main Power Required: (From External Power Unit) Voltage Range, 9 to 18 Volts DC.
Current consumption:
@ 9VDC = 1.3 A typical
@12VDC = 1A typical
@15VDC= 800 mA typical
@18VDC= 650 mA typical

The specs say that Portico runs on DC voltages from 9 volts to 18 volts. It draws 1.3 amps at 8 volts and 650 milliamps at 18 volts (less amps, the higher the voltage).

At any of the voltages mentioned, that's not a lot of amps to run the pre amp alone (never mind how much juice a condenser mic might need).

A JLM TMP8 power supply puts out 54 volts @ 3 amps! (not milliamps like the Portico)That will power even the hungriest phantom powered mic! I would bet that anyone who has a BA 1272 could look at the power supply and see similar figures.

I know I'm out on a branch all alone here ... and I am not saying the Portico sucks, but I am still skeptical regarding the power supply issue. I think I will wait on making the call at least until someone like Fletcher who is well known to support the concept that large power supplies are a good thing, weighs in and says it rocks.

It really doesn't add up when you look at how much energy the thing consumes and the task it is supposed to perform, taking a very low level mic signal and amplifying it to line level, and supply 48 v phantom power for condenser mics, it seems to me, these numbers just don't crunch.

This has been the issue with wall wart and line lump power supplies all along.

 

[Davedog]

It would seem to be a foolish exercise to second guess an electronics engineer with the credentials of a Rupert Neve.The proof is, of course, in the actual hearing.And while there are several 'schools of thought' on power supply design and it has been an issue in past years for the very reasons mentioned, I'm sure that technology hasnt stopped in the middle of the road on the development of power supplies and their ability to develop the power to correctly reproduce their intended sounds.NOT being an engineer, it is beyond me to question those that obviously have the abilities to do this and as an interested consumer, to simply enjoy the spoils and benefits of their genius.To sit from afar and question or even condem something without personal experience seems to me to be a huge waste of time.

 

[BlackSoul]

Kurt,

I bought a pair of Yamaha MSP5 monitors based on your review and I am so happy with them!

I get the impression that you have great ears for great sound.

Please let me kindly point out that you fall short when you approach the subject of power supplies and circuit design in general.

Your grip on the theory behind electronics design is far to loose to even raise an eyebrow about the PSU design on the Portico.

It's a real pattern. You provide great feedback and advice about the practical aspects of gear, but your comments and presumptions about the technical side of audio gear comes off really half- baked. It's hard to take. It concerns me that the less technically inclined folks here who respect your opinion about gear functionality and sound(count me in on the latter!) might continue to follow your opinions about general circuit design. You don't know enough about electronics to make the off hand comments you make. Simple as that.

You just can't make sweeping genaralizations about external transformer/psu's. It all comes down to the design as a whole. We're talking about preamp level signals here. Yes, a solid, clean supply is almost always a good thing; a compact supply such as the one in question goes way beyond what is needed for a pair of mic amps...even pure class A ones running hot as hell-which these Porticos do! The whole idea is to have the circuit running at full bore regardless of signal level.

The Portico has another power supply inside the chassis that further refines/steps up what is provided by the external supply.

To my ear, this thing (Portico) reproduces a very wide spectrum with no sign of struggling at any frequency.

I really like your reviews on the sound and functionality of gear Kurt, but you should stick to that side of things unless you learn more about audio electronics design.

 

[Kev]

You just can't make sweeping genaralizations about external transformer/psu's.

true
and we shouldn't make comments too specific with out having a unit to get inside and fully check out
even so ....
there are some interesting ways that the specs have been presented

Maximum Output Level:
Balanced and Floating Transformer Output from 20 Hz to 40 kHz: +25 dBu. (Clips at just over +26 dBu)

it does say dBu

but then comes

Total Harmonic Distortion and Noise:
Main Output
@ 1kHz, +20 dBu output
level, no load: Better than 0.001%.
(No high order Harmonics)

NO LOAD ... ?
the other output specs also say no load
but still refer to dBu ...
these levels and a 600 ohm load would suggest a little more current is need at the PS

as for the input

Balanced, using “Transformer-Like-Amplifier” (T.L.A.) with toroidal Common Mode Rejection Low Pass Filter that excludes frequencies above 150 kHz.

The T.L.A. is followed by an actual input transformer permitting a full +26 dBu input signal to be handled at unity gain without an input pad over the whole audio spectrum.

!!!!
fascinating
I'd love to see more on this...
a Millennia style circuit follower by a transformer ???
... interesting

 

[Kurt Foster]

I am surprised how everyone latches on to some remarks and ignores anything else I had to say on the Portico.

I did not pass any kind of judgment. So please don't misunderstand my remarks. I am not questioning or condemning, or making any kind of judgment Dave. I am skeptical about the line lump, that's all ... I always have been and I will remain so. Several other people questioned it as well in this thread.

I fully admit (and always have said ) that I am not an electrical engineer and that I do not have a full grasp on design BlackSoul, but as you point out, I do know what sounds good to me t .... and so far it hasn't been anything with a wall wart or line lump.

I base my opinions on my own personal experience rather than what some person who I have never heard of or don't even know has to say on the internet. Things can change and as I said before, if anyone can design a decent pre that uses a low volt and lo amp power supply, I would imagine that Mr Neve would be the one to do so. The question remains if it works so well, why didn't he do it sooner? I don't think there's anything new here.

Kev makes the argument regarding the power supply better that I can,

... there are some interesting ways that the specs have been presented

Maximum Output Level:
Balanced and Floating Transformer Output from 20 Hz to 40 kHz: +25 dBu. (Clips at just over +26 dBu)

it does say dBu

but then comes

Total Harmonic Distortion and Noise:
Main Output
@ 1kHz, +20 dBu output
level, no load: Better than 0.001%.
(No high order Harmonics)

NO LOAD ... ?
the other output specs also say no load
but still refer to dBu ...
these levels and a 600 ohm load would suggest a little more current is need at the PS

So I am waiting to hear some more on this from guys like Kev who know the skinny. Then and only then will I make a judgment on whether or not this is a Neve I would be interested in. I'm just not so willing as others it seems to embrace it simply on the basis of its pedigree.

BlackSoul you seem to have a handle on this kind of thing so please tell me, how you can take 9 volt power supply that provides @ 1.3 milliamps and drive a mic pre and a mic that draws 0.8 milliamps@48 volts?

 

[BlackSoul]

Kurt,

BlackSoul you seem to have a handle on this kind of thing so please tell me, how you can take 9 volt power supply that provides @ 1.3 milliamps and drive a mic pre and a mic that draws 0.8 milliamps@48 volts?

OK, I'll tell you:

First of all, you quote a 9V power supply that provides 1.3 milliamps of current. That should read 9V @ 1.3 Amps You have your amperage units off by a factor of 1,000.

1.3 amps = 1,300 milliamps

Your quote of 0.8 milliamps @ 48V for the mic's current consumption actually sounds about right. The standard is 2 miilliamps, and some mics draw as much as 4 milliamps.

Now, 1.3 Amps is what a typical box will draw @ 9V. The actual supply that comes with the unit is rated to deliver 1.6A @ 15V.

Up to a point, you can deliver more voltage(up to 18 volts) with proportionally less current draw.

Inside the box a circuit changes/regulates the input voltage to a bipolar +/-17Vdc and +48Vdc. You don't ever get something for nothing; anytime you step the voltage up for a given current, you increase the current draw proportionally at the wall lump. So, going to +48Vdc is going to pull more current. BUT, in the case you present here, we only need 0.8 milliamps @ 48V for the mic. That translates to about 5 milliamps at the wall lump if you go with 9V.

1,295 milliamps to spare for the rest of the circuit.

Even a pair of power hungry condensers, drawing 4 milliamps each, will only eat up around 50 milliamps at the wall lump.

1,250 milliamps to spare for the rest of the circuit. Hell, let's double the worst case and call it an even 1,200 milliamps left to run the preamp(remember, the actual supply is rated to deliver 1,600 milliamps!).

So, we have two channels running +/-17Vdc each. That's a total swing of 34Vdc. Well, 9V @ 1,200 milliamps translates to 600 milliamps per channel, but with the voltage stepped up to 34V, that drops us down to a very conservative number of about 150 milliamps per channel at the actual preamplifier circuit.

These are class A circuits, so each channel is dissapating at least 150 milliamps whether the circuit is amplifying or not; that is running really f@#king HOT. I can verify this somewhat by feeling the heat coming off chassis of this thing after about an hour of power on. The supplied wall lump, on the other hand, is barely warm.

Kurt, I hope that clarifies how you can take a 9 volt power supply that provides 1.3 AMPS and drive a mic pre and a mic that draws 0.8 milliamps @ 48 volts.

Kev makes a good point about the output being spec'd at no load. But, in all fairness, that is at +20dbu...way higher than one will be driving any input, unless you WANT some distortion. How well will it drive a 600 ohm load, I dunno. It does drive the sh*t out of 10K and sounds fine doing so. Actually, the spec just says the output is not loaded. It may still very well be terminated(loaded) internally to provide a stable output into a variety of inputs.

I'm just not buying the hypothesis of a weak power supply on this product. No way. Imagine what the proportionate PSU would look like to run a 24 channel mixing console using these as mic pres. It would be a monster and the console a deluxe space heater.

I'm curious to hear some Neve folk here thrash about on the sound quality of the Portico.

But if it's got a weak point, it ain't the PSU.

 

[Kev]

So I am waiting to hear some more on this from guys like Kev who know the skinny. Then and only then will I make a judgment on whether or not this is a Neve I would be interested in. I'm just not so willing as others it seems to embrace it simply on the basis of its pedigree.

... not that I'm such an expert and yes I do give some cred to Mr Rupert Neve
BUT
like Kurt
I just can't make any big comments until I get to see inside and touch one of these things
... just too much we don't know yet.

Kev makes a good point about the output being spec'd at no load. But, in all fairness, that is at +20dBu...way higher than one will be driving any input, unless you WANT some distortion.

not sure I totally agree about this being high and wanting distortion
If this pre were to feed a typical modern interface that went to 0dBFS at 20 dBu ... 20dBV for the 20k to 40k stuff
then we would have no headroom in the mic-pre as the interface pegged out.
Some would say OK and some might say they do want a little headroom ... 3 to 6dB perhaps

especially when tracking a drum where these short transients do get up there
often this is the big difference in tone between the mic pres do handle drums well.

then the BIG problem may occur when you then follow the mic-pre with an 1176 or LA2 and you not only do you have the higher level BUT also the 600 ohm termination

.... :shock:

what was the question ... why am I here ?
I'll shut up now

 

[Kurt Foster]

BlackSoul,

Thanks for you explination but I have heard a lot of that before and I just don't buy it. Ferd Berffel (Mark McQuilken) said exactly the same thing about his RNP but when I finally heard it, my ears told me different.

To have adaquate headroom and acceptable phase response, power supplies need to deliver enough current on demand to be capable of forming a proper bass wave and pass transients. That's from Fletcher ... and yes large format consoles do have huge power supplies and they do generate a lot of heat which is why they require so much maintenance.
I suppose one could argue that what I think is acceptable may be excessive ... but I don't think so.

Many high end manufacturers use up to 60 volt rails in their pres ... waaaaay more than what the Portico or any wall wart powered device will have. If this is not necessary, why do they do it?

And "that's what I'm talkin' about Willis".

 

[BlackSoul]

Kurt,

I was pretty sure this is where we would end up after I made my initial response. You talk in circles by pulling out arbitrary facts from a variety of sources to build an argument on a specific issue because you lack the knowledge to discuss a technical topic on level ground.

Surely you'll get to hear a Portico sometime. Whether you like it or not who knows. I'll be interested in your comments.

On the technical side of things, you're still incapable of substantiating anything. Stick to the listening tests.

Kev,

FWIW, I pulled out the scope and signal generator and took a few measurements at the Portico's output with two different loads:

250Hz sine wave. Reference: 0.775Vrms=0dbu

Maximum output before clipping into a 560 ohm load: +15dbu

Maximum output before clipping into a 10K load: +25dbu

Signal attenuation going from no load to a 560 ohm load: -0.65db

Full scale on my 2408MKII: +14dbu

One would probably be driving the 600 ohm LA2A or 1176 at around +4dbu before reaching the interface anyway, so thiis output/headroom should be plenty...what do you think?

Going straight to a modern interface with a +20dbfs limit, one would still probably have at least 5db or so of headroom above clipping the converter(that +25dbu output limit is also published in the user guide).

Thoughts? Should I make other measurements to satisfy any curiosity?

 

[Kev]

without getting picky .. most of those figures look typical for gear today

you have plenty of headroom for your 2408MKII and fair headroom for a D-96 or D-192 so on that level things look fair.

the fact that the power supply is running cool is a good sign
but
not convinced everyone would be truely happy when using it into the 600 ohm stuff and hot.

note

+20dbfs limit, one would still probably have at least 5db or so of headroom above clipping the converter

not sure that came out right ... ?
are we talking about your converter ?
0dbFS is the max

 

[BlackSoul]

Thanks Kev,

note
Quote:
+20dbfs limit, one would still probably have at least 5db or so of headroom above clipping the converter
not sure that came out right ... ?
are we talking about your converter ?
0dbFS is the max

No, we're talking about a hypothetical converter with a +20dbFS limit with the Portico driving it. It has +25db of headroom, so it would appear that one would have 5db of reserve at the preamp, assuming it is driving a modern line input of 10K or so.

fair headroom for a D-96 or D-192 so on that level things look fair.

not convinced everyone would be truely happy when using it into the 600 ohm stuff and hot.

Kev could you submit an example of a mic preamp on the market today that you would consider excellent in these areas as well as sounding superb?

 

[Kurt Foster]

I was pretty sure this is where we would end up after I made my initial response .... On the technical side of things, you're still incapable of substantiating anything. Stick to the listening tests.

:lol:... and I was pretty sure you would be dismissive of my opinion and try to make it look as if I don't know what I hear. I think I have been here before.

I agree .. I am not well grounded in electrical engineering. I say this all the time. But I do know what I hear, and I know what kind of devices sound good to me. I have never heard any mic pre that used a low voltage DC power supply that sounded really good ... and I doubt that I ever will. This knowledge of my experiences, is all I have to go by. You are asking me to take everything I have learned in the past and throw it out the window. I don't think I am ready to do that.

I'll ask again, if large high volt power supplies are unnecessary, why do manufacturers like Great River, Pendulum, Millennia, Manley, D.W. Fern and in the past R. Neve himself, employ them? It would be a cost savings which they could pass on to the customer making them more competitive.

I believe the truth lies within the answer to this question and that is why, despite my inability "to discuss a technical topic on level ground", I don't believe it when people try to blind me with science. You aren't the first to try.

I do not mean to sound hostile, I only want to have a conversation on the topic. If I can learn something from you Black Soul, I will be content. You obviously have an understanding of the facts ... Please try to explain in terms I can understand, the answers to my questions.