Mr Neve's portico...some thoughts.

[BlackSoul]

Kurt,

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.

It comes down to a designer that knows how to create a circuit that does exaclty what he or she wants it to. Some obviously know what sounds very good to the end users and themselves; they are able to translate that into a given audio device.

These brands you mention(and I'm assuming you like them) use the power supplies they do because they work for the particular circuit. The ones you don't care for use the power supplies they do for the same reason, but the design as a whole has failed your listening test. The power supply may be part of the reason, all of the reason or none of the reason why a particular circuit sounds better or worse than another.

Using a 15V outboard DC supply as part of the PSU does not condemn a mic preamp. It's as dumb as saying that a high voltage supply is going to make any given circuit sound great.


The Portico with its' power supply sounds good to me.
The mic preamp I designed and built for myself with an enourmous high voltage outboard power supply also sounds good to me(finally).

RND took a circuit that sounded good to RND and built a PSU to make it work to their specifications. I'm not sure what they did was all that cheap, either. It does make the unit flexible for feild work and overall compactness...if that saved some costs in the process, then good for them and us.

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.

The presence of an outboard line lump in and of itself does not indicate an underpowered and/or bad sounding circuit. The entire design makes or breaks the product. Talented individuals are responsible for great, cost effective products. Some are more talented than others for a given task, like designing a good sounding mic preamp.

 

[Kev]

... No, we're talking about a hypothetical converter with a +20dbFS limit with the Portico driving it.

sorry
... even hypothetically I just can't think in that way

0dBFS is full scale and that's all there is
.... no +1 or +2 ... no +20dBFS

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?

Any of the units Kurt suggested above probably have the go required

I guess I have to start with a fellow Australian
JLM Audio - TMP8
http://www.jlmaudio.com/8packoftrans.htm

Maximum output into 10k load = +30dBM (limiter disabled)
Maximum output into 600 load = +24dBM (limiter disabled)

even this one only just gets to +24dBM and but is in line with many 600 ohm units
and Joe can set the limiter to suit some of the popular interfaces

+22dBM for Protools HD \ Protools 888 \ Yamaha 02R input \ Mackie HD System \ Mackie DXB-200
+20dBM for Aark24 \ ESI Juli@
+19dBM for RME Multiface and Fireface
+18dBM for Protools 882 \ Digi001 \ Digi002 \ Paris \ MOTU896HD
+10.8dBM for Creamware A16 \ MOTU 2408 mk II \ Alesis A13

For a unit that goes above and beyond the call of duty is the Pendulum range
I have not had a chance to audition any of these as they are a little out of my reach
http://www.pendulumaudio.com/MDP-1.html

Pure class A, high voltage circuitry
Transformerless tube output stage capable of delivering +35dBu

+35dBu is BIG by anyone's standards and should get almost any unit past it's sweet spot.

I guess the question might be ... where is the sweet spot for the average 1176 or LA2 ?

 

[kats]

A microphone is a voltage generator, not a power amplifier. Most microphones give their most accurate performance when they're not loaded by the input impedance of a traditional preamplifier.

Years ago Transformer inputs with tubes were used for microphone preamps. It was convenient to design the input for impedance of 1000 or 1200 ohms. Some microphones are still designed to work well into a low load impedance. If the microphone has an inductive source (such as would be the case if it has a Transformer output) a low input impedance would cause the high frequencies to roll off. This can be an advantage with some microphones!

If the microphone has an electronic circuit output, loading this with a low impedance will stress the mic amplifier, causing slew rate and compression. A high input impedance allows the microphone to "breathe" and give of its best, particularly advantageous with a very high level percussive sounds.

If it is desired, nevertheless, to present a lower input impedance to the microphone, we suggest that an XLRF and XLRM assembly be made up with the desired resistor value connected between pins 2 and 3."

^^^^^That blurb from the manual


The Portico input impedance is 10k ohms - got this over at GS

 

[Kurt Foster]

Until I hear the Portico for myself which will most likely be never unless someone asks me to review it (doubtful given this and other threads regarding power supplies), I will remain skeptical. I would ask for a Portico to review but I hate to petition for review pieces I don't think I will like. Perhaps someone in town will get one and let me borrow it for a week so I can run it through the paces. We will see. I would love to say it's the cats meow but my past experience doesn't make me very optimistic.

RND took a circuit that sounded good to RND and built a PSU to make it work to their specifications. I'm not sure what they did was all that cheap, either. It does make the unit flexible for feild work and overall compactness...if that saved some costs in the process, then good for them and us .... The presence of an outboard line lump in and of itself does not indicate an underpowered and/or bad sounding circuit. The entire design makes or breaks the product. Talented individuals are responsible for great, cost effective products. Some are more talented than others for a given task, like designing a good sounding mic preamp.

Did you mean "R&D" :?:

"Sticking to the listening tests" I can say unequivocally that I have never heard a pre amp with a wall wart that offered dimension, depth or handled bass and phase correctly.

Some insist I need to continue taking bites of the "sh*t sandwich" every time new products with wall warts or line lumps hit the market, in order to be qualified to comment on the subject. I don't agree. I do not need to step in sh*t to know it's gonna be a big stinky mess if I do.

I know on paper, your arguments make sense. The numbers crunch. But having a deep understanding of electronics and math doesn't insure that anyone can hear. In the real world there is something else going on no one seems to have put their finger on. I believe, headroom and bandwidth are what it's about. The more there is, the better it sounds. It takes a lot of energy to boost a mic level signal to line level while retaining full headroom, forming a proper bass wave and correct phase. That's why Neves designs up to this point, have massive over engineered power supplies. The power supply is the foundation upon which the rest of the device sits upon! 60 volt rails rule!

I have a ton of respect for the accomplishments of Rupert Neve. He has made his mark on the industry but the man lives in the real world. He has to deal with reality. In this case, the reality is that there is a huge market for mic pres and audio gear in the "affordable" category. I think Neve is responding to demand, more than trying to create yet another masterpiece. He has come to the conclusion, "If you can't lick 'em, join 'em". My impression is the Portico will sound as good or better than any other pre powered by wall warts or line lumps. It will most likely beat the snot out of any other pre in it's price range, which is an accomplishment in itself. But I do not think for one nanosecond that it will compare to his earlier designs.

The Portico very well may be a breakthrough product. As I said before, if anyone can do it, Rupert Neve would be the one. I will reserve final judgment until I can hear one myself as you suggest. I am also very interested in what some others who think the same way as I do about power supplies, have to offer on the subject. Is it possible to make a good pre amp using 9 to 18 volt power supplies?

 

[BlackSoul]

Kurt,

Did you mean "R&D"

No, I meant "RND", as in Rupert Neve Designs.

Your pal,
BlackSoul