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Author Topic: Bernie G's modified DB's  (Read 8280 times)

danlavry

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Re: Bernie G's modified DB's
« Reply #15 on: January 12, 2005, 07:57:36 PM »

I spoke with  Beno May, Chief Technician at Bernie Grundman Mastering. He said that using external supplies is something they have been doing for a long time. That practice is not restricted to my converters specifically, nor is it restricted to converters only. He said they have been doing it to much of the gear that comes to their facility because they decided, over many years, that it improved the sound.
   
Clearly, doing such modifications will take at some care, and can be done well or poorly.
I recall the first time Beno told me they are taking the supplies out.  I immediately got concerned about the issues of voltage drops. Say your gear requires a 5V supply at 3A current, and the supply is to be placed at say 10 feet away (20 feet of wire when you count the return path). A 20 gauge wire will introduce about 200 mili Ohm
resistance which will lead to a loss of .6V! That can “kill” your digital logic.

Clearly, shorter distance and more copper is a good thing for many reasons. Beno told me that I need not worry about voltage drops because they KEPT the power supply REGULATOR SECTION INSIDE. They moved out the section responsible for RAW DC (the DC to be fed to the regulators). Therefore, the concern regarding DC voltage loss on the wires is not much of an issue.

I can only guess that one of the reasons they moved a PART of the power supply out is to keep the transformer and the rectifying diodes away. Why use a higher current raw supply? I do not have a clue, because  using the original regulators would limit  the amount of current available to the circuit at the same level.

It is not surprising that an external supply (or much of it) works better than internal in some cases. I can think of a couple of mechanisms that may yield advantages. One such  mechanism is less heat – which does decrease semiconductor and resistor noise by a little bit. The decrease is not very large because it is not a linear function, but a slight improvement is still an improvement. The second advantage is less coupling of AC fields and diode switching noise into sensitive circuits. A third advantage is increased part reliability, assuming use of a good power connector. A poor connector may decrease reliability (spoken by a guy that hates connectors).

However, I do not think that external power supplies automatically guarantee better gear performance. External supply increases cost, and it may improve some units (subjectively?). It may make no difference to some units.  

Best Regards
Dan Lavry
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Level

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Re: Bernie G's modified DB's
« Reply #16 on: January 12, 2005, 08:13:21 PM »

Mr. Nakamichi has been involved with the eletromagnetic domain and how electromagnitism (from large transformers) can affect the signal level flow. I am not much into it and no where near his level but he certainly considers the possibility that strong electromagnetic fields can certainly affect the signal path in ways not yet thouroughly documented.

His line of amplifiers from 2001 are controlled field devices. He is hard core about it actually.
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ammitsboel

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Re: Bernie G's modified DB's
« Reply #17 on: January 12, 2005, 09:40:47 PM »

Thanks Dan,

I'm glad you talked to Beno May so we could get this cleared up! Smile

Best Regards
Henrik
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danlavry

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Re: Bernie G's modified DB's
« Reply #18 on: January 13, 2005, 01:28:23 AM »

Level wrote on Thu, 13 January 2005 01:13

Mr. Nakamichi has been involved with the eletromagnetic domain and how electromagnitism (from large transformers) can affect the signal level flow. I am not much into it and no where near his level but he certainly considers the possibility that strong electromagnetic fields can certainly affect the signal path in ways not yet thouroughly documented.

His line of amplifiers from 2001 are controlled field devices. He is hard core about it actually.


There were some early pioneers in a branch of Physics called Electricity and Magnetism. They lived about  2 centuries ago and they discovered the principles of the electric and magnetic field. The terms used today to measure electricity - Volt Ampere and Ohm are the named after the researchers that discovered and studied the electric field. The magnetic field is measured in Gauss, and Webber, again in honor of the discoverers. The 5 physical laws of nature dealing with electricity and magnetism where “combined” into 5 “equations” called the Maxwell Equations. You guessed it, it was Maxwell that put it all into a one complete and unified picture.

Now, when I say “equations” I mean much more than a few letters with an equal sign. Each one of the “equations” is a three dimensional picture of “imaginary curves” with arrows to show direction, and with varying density to show intensity. There is the electric field, there is the magnetic field, and they also interact to make the electromagnetic field… when the 3 are all perpendicular to each other, the electromagnetic field carries energy with it… There is a need to study some math to be able to compute it all…

OK I will stop. Yes there are a lot of EE’s that do not go beyond some basic Ohms law, but take my word for it, the good EE’s live in that world where we do not see things yet we have “imagine them” with some “model” of what one calls electrical signals. In fact we rely on the Maxwell’s equations. It does take some years to get comfortable with being able to “see it in your head” – I mean those electric and magnetic fields, and their interaction with each other and with electrons. It gets complicated when the “pictures are time varying”. And man, are they interactive! (the electric field, the magnetic field and the electrons). You do one thing and another happens. You move a bunch of electrons through a magnetic field, and they start moving in the same direction – current flow. You take a wire and run current through it, and you generated a magnetic field… That was the tiniest of examples…

So to get to the point: a good designer is aware of all the fields generated and or picked up by each and every wire or trace. A good designer knows the capacitive interaction between metals we call capacitance. We know where it does not matter and when it is important to calculate matters to great accuracy. We are trained to see things others do not see. It is a big part of analog and hardware.

I always look at electronics through my “Maxwells Equation” glasses. I am very pleased to know that Mr. Nakamichi is also a student of the Maxwell Equations, as a good engineer should be.

Back to internal vs. external supplies, the suggestion to "just move the power supply out because it may be better" is what you may expect from someone incapable or unwilling to understand what is taking place. An EE can and should be able to QUANTIFY, to calculate or at least measure what takes place, how much of it takes place, what is the impact on the expected outcome.

Best Regards
Dan Lavry
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danlavry

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Re: Bernie G's modified DB's
« Reply #19 on: January 13, 2005, 01:20:24 PM »

Below are comments from Beno May (Chief Technician at Bernie GrundmanMastering). I have Beno's permission to post it here.

Hello Dan,

I enjoyed our visit yesterday. I was a little amused looking at the forum. Here is what I have to say on the whole matter. Lavry Engineering manufactures what we at Grundman Mastering feel are the best A/D and D/A converters on the market. That said, in a fixed facility and not out in the hostile world one can take liberties that manufactures cannot. Modifications that we do on equipment in many cases come down to ones that are subjective in nature and not always measurable with test equipment. In our facility, we build or own consoles form the attenuators up. We also build or own power supplies to supply the dc to all the electronics. We have found subjectively
that our equipment and other manufactures equipment sounds better with our power supplies. We did not build external supplies for our Lavry converters because they were blowing up. We did it because we thought they would sound a little better, and they do. Our well regulated dc supply brings an overvoltage to the converter, and the on board regulators fix the voltages to the proper level. The A/D converters do run a little cooler because of this. I've found that through the years, just about anything is open for debate. We are not an equipment manufacturer. What we do in our facility is to try and get the best transfer possible for our clients. Our decisions are based on listening tests that we do with all the components we use and equipment that we build or buy. We do not purchase gear because a "Golden Ear" engineer or specifications says that it is great. This may not be a scientific approach, but it has always been the path taken by Bernie Grundman and his almost 40 years in the mastering business.

Best Regards,

Beno
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ammitsboel

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Re: Bernie G's modified DB's
« Reply #20 on: January 13, 2005, 04:11:44 PM »

Thanks for the info Dan.
So is Beno considering getting a member of this forum?

I find the "Bernie Grundman facility" very interesting.
In my facility I'm the practical technician and work together with highly respected engineers on developing the best mastering equipment for my studio. My approach is of course focused on tweaking devices but i feel that the real work for me lies in participating in the designing of the absolute best equipment in the world from the ground(with all it takes), only on that basis a mastering studio can be considered as truly uncompromised IMO.

Best Regards,
Henrik
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danlavry

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Re: Bernie G's modified DB's
« Reply #21 on: January 18, 2005, 09:23:10 PM »

This internal vs external power supply issue is one of those cases that can drives people nuts, and audio is “full of it”. We heard that some gear sounds better with a supply outside. We also heard two suggested explanations.

One explanation is electromagnetic interference “getting into” the sensitive analog circuitry. There are numerous ways to combat the problem, and reduce it to an acceptable level (with a margin). The electromagnetic coupling is MEASURABLE. Note that we are talking about linear supplies, where the supply interference is predictable (AC line frequency and its harmonics). The point is –measurements will show you the impact on the audio. There is no magic here, with standard engineering techniques. If and when a designer can make the internal supply works as well as the external, why go external?

The other “explanation” has something to do with having a supply capable of supplying more current than is needed by the circuit itself. To my understanding, this “explanation” is reached by “ear”. Such a claim is at best very fuzzy.

First, the explanation breaks down when one is keeping the internal voltage regulators part of the supply inside, and moving the transformer and rectifiers outside. With such a setup, the internal regulators set the maximum current capability, not the external supply. If it still sounds better it can not be due to access current.

Second, when one keeps the regulators outside, the long wire self inductance, interacting with the bypass capacitors may be more of a problem than a solution, for sudden current surge requirement. That also puts the access current explanation into question.

Third, while extra current capability calls for a bigger supply, it does not always explain the need for external supply. Bigger does not always call for external. It depends on the power requirements and box size. How much more current is enough? 100% margin? 200% margin? 10000%? Is it really an internal vs external question? One needs to be clear about it.

That internal vs. external supply issue seems to me to be one of those “audio generalizations”. I am sure it began when people heard the difference, and possibly even measured the difference. But as often in audio, it was not well explained and certainly not well quantified. Instead it became one of those “I can hear it and I do not know why” statements.  I can see opting for an extra heavy duty bumper on a light passenger car, but not on a military tank. With so many years of audio, I would hope for more insight than such generalization. Engineering is about dealing with physics, not “vague guidelines that may or may not hold true”.

I am not against having a designer decide they get better results on specific gear with external supply. It may be a wise strategy for some designs. My problem is with the “explanations”, and the “associated marketing” that leads a whole bunch of people to make generalizations.

Regards
Dan Lavry
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ammitsboel

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Re: Bernie G's modified DB's
« Reply #22 on: January 19, 2005, 11:03:02 AM »

I also think that there are so many factors involved that you can't make "audio generalizations".

Best Regards
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Bob Olhsson

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Re: Bernie G's modified DB's
« Reply #23 on: January 19, 2005, 02:40:24 PM »

There's a big difference between assembling a system from various manufacturers' products and building a system from scratch that incorporates a few manufacturer's products. Grundman's is a case of the latter.

A commercial product needs to be able to interface with other products on a one size fits all basis. Grundman has total control over what everything will be interfacing with and most of it is home brew. It's a very different situation from most people.

danlavry

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Re: Bernie G's modified DB's
« Reply #24 on: January 20, 2005, 02:31:54 PM »

Bob Olhsson wrote on Wed, 19 January 2005 19:40

There's a big difference between assembling a system from various manufacturers' products and building a system from scratch that incorporates a few manufacturer's products. Grundman's is a case of the latter.

A commercial product needs to be able to interface with other products on a one size fits all basis. Grundman has total control over what everything will be interfacing with and most of it is home brew. It's a very different situation from most people.


Yes it is a very fine facility, and they do many things their own special way. They do pay attention to details, and they do build electronics for their own use.

Regards
Dan Lavry
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