John Curl's Blowtorch preamplifier part III

Status
Not open for further replies.
There you go - see attachment.
A file player (Amarra) by the same company that created mastering software that up until recently was used in production of about 90% of all digital releases on the market (CD and High Res) since 1989. Player uses the same playback "engine" as the mastering software. Modified (encrypted) version of this player is produced on the fly by the mastering software and is sent to client for playback of final DDP file to get their approval.
Now go and call Sonicstudio and tell them that you know better.
Ignorance is indeed a bliss. :(

It's not ignorance at all. The only ignorance is the statement you quoted. The fact is, as far as I am aware, Pro Tools, Logic Pro X, Ableton, Sony Vegas etc. (serious pro software) are disk-based editors because you have no idea how large a file can be. They do have large buffers, but they don't force load an entire file into RAM. A max of 2.8 Gb is sad... this is not professional software. The software is 32-bit obviously based on this limit and the author may or may not know the difference between Gb and GB (or GiB). This is sad.

Just because one person claims sound quality is better, does not make it true.

Writing software in 1989 isn't going to get you any award. Sure, there are parts of stdlibc and other ubiquitous libraries that exist from that era, but not much else - and they have been refactored. Most software written in 1989 would get rejected in a pull request before it ever made it out the door today.

I can find no evidence Amarra was used in 90% of releases and the website and product page looks like amateur hour. I highly doubt 90% of Redbook releases were made with this software. I re-read and noticed you meant the company (Sonic Studio) made the software responsible for 90% of releases. Well, even if that were true, it does not make them right.

Loading files into RAM for playback does not improve sound quality. It might make you feel better. My workstation has 128 GB of RAM, their instructions are ridiculous even if you had 8 GB of RAM.
 
Last edited:
Chris, afaik ESS recommends the use of high end opamps such as the AD797 to generated a stable and noiseless reference voltage. I am not aware of AKM recommending a cheap bit like a 7805 for their reference voltage, so if you have a link, I am interested. What I am aware of is for example the voltage regulator for the AK4497 https://www.akm.com/content/dam/doc...dac/ak4497eq/ak4497eq-en-evaluationmanual.pdf. At the end of the document, it shows quite an elaborate schematic for a voltage regulator based on an AD817.

This discussion came over from another thread on an AK4499 DAC design. AKM does recommend a Jung/Sulzer style regulator with AD817 for the VREFH. They are using NJM 7805 for AVDD on the evaluation board. I mistakenly said Rohm... although I swear I saw an Rohm 7805 somwhere - might have been the previous revision or I am confusing it with something else.

The idea of using the 7805 for the VREF (ESS equivalent AVCC) was just hypothetical. :)
 
Last edited:
Perhaps you are correct, I haven't followed the matter closely for far too long. However digital playback are not only PC based, it is going into smaller or embedded platforms like the Raspberry Pi with multi channel filtering, equalization and crossover function.

You're right that mobile and embedded platforms are important, but I would argue that RAM is even more scarce on these platforms, so I would aim to use as small of a buffer as is practical for latency purposes. An average desktop PC could have anywhere from 8 to 32 GB of RAM. The top Raspberry Pi 4 has 4GB. A lot of RPi 3s have 1GB of RAM. All plenty to load a 6 minute WAV file, but who knows what the user might open. Might be Rush 2112 hi-res uncompressed at 20 minutes long and could be annoying if you are using the device for anything else.

I promise, no reasonable media player tries to load the entire file when you click Open.
 
Last edited:
Is not it obvious to everyone? (As long the speaker is an electrodynamic one and not an electrostatic one.)

It should be obvious indeed and a kind of lip service is paid to it and then sort of ignored. For example, Jneutron tells me he is the real expert and not me (as if I had made such a claim... not) and then proceeds to tell me it does not matter. Earl Geddes told me the same thing, he said I was wasting my time because it was not important whether it was one or the other. I disagree!

I had a discussion a while back with Roger Sanders (Sanders Sound Systems) and he pretty much confirmed this: An electrostatic speaker ignores the current of the amplifier, particularly when it is a voltage source and the current can go anywhere. So it 'tracks' the voltage - all of this is clear and I believe accepted by all sides.

So this is because the electrostatic speaker is a voltage device and the amplifier is a voltage source.

But the converse must also be true, as inconvenient as it sounds: That the dynamic driver only 'tracks' the current of the amplifier, even if the potential for current is voltage.

Many find this hard to fully grasp and understand. Not everybody, thankfully. I have found a way to confirm that this 'tracking' of current can both be measured and confirmed by numbers, yes maths. This is where the 0.1dB challenger comes in. The examples I posted were rounded to 1dB, now I need to make it very much more precise and hence further confirm the mechanism. This will also further support my notion of a "back-EMF impedance" because that value is used in the maths. It then becomes pretty conclusive.

So, the solution to reduce distortion should be to add the RLC+RC networks I use with all my speakers in order to linearize their impedances curves down to their DC value (amp side). And to drive them in current (high impedance source) that I never tried for bass speakers because we are looking for max damping at the resonance frequency. Happily, I use horns for medium treeble, that are > 10dB more efficient and are powered across a serial resistance.
To tell the truth, across an attenuator. You gave-me the idea to use the B

What you are really describing and what we both are doing, is equalising the current of the amplifier. This has benefits for both voltage and current drives, since efffectively you are cancelling out the output impedance of the amplifier. With current drive, you keep the response flat. With voltage drive, the benefit is not just a flat impedance, but more importantly, a flat current phase angle.

What is a reactive load? Any deviance from that of a resistive load. Under voltage drive, the current becomes reactive, but under current drive the voltage becomes reactive. Under current drive, the voltage can go over all the place; with voltage drive, the current can go where it likes. It is because we have to decide which to control. The world has chosen to control voltage, but have for some reason decided not to look carefully where the current goes - seemingly ignoring that with dynamic drivers we are actually listening to the current. The voltage only creates a potential for current to flow, but it is the actual current we listen to.

A funny video in topic with Jean Hiraga about "paramagnetism": YouTube (He explain that the phenomena is the same with a magnet inside a copper tube (shorted coil ?)

Wish somebody could transcribe into English. BTW, the slim guy I recognise from ETF meetings.

I never tried for bass speakers because we are looking for max damping at the resonance frequency...

Do attempt to EQ the impedance of your speakers at LF when you can try it. It is a challenge, but when done, the idea for "max damping" disappears. If you get the current right, damping is not a problem. The response locks in, the source impedance gets cancelled out. Try it sometime and you will see that it works, beautifully.
 
Last edited:
Member
Joined 2014
Paid Member
QUAD ESL impedance. Doesn't look that much different from any other speaker to me. Why do people think it's somehow special?
 

Attachments

  • esl impedance.JPG
    esl impedance.JPG
    56.5 KB · Views: 206
Member
Joined 2014
Paid Member
Doesn't have to be dsp, but that's the best option imho
In my case, it's optical not wifi to the speakers, though you could use wifi.


I would agree but I would not tell someone who likes the simplicity of poorly matched passive components with no way of adjusting for driver mismatches that they were wrong. Everyone has their preferences and if those make them happy and able to kick back and enjoy the choons all good. If they tell me its better, that's a different issue :D
 
I had a discussion a while back with Roger Sanders (Sanders Sound Systems) and he pretty much confirmed this: An electrostatic speaker ignores the current of the amplifier, particularly when it is a voltage source and the current can go anywhere. So it 'tracks' the voltage - all of this is clear and I believe accepted by all sides.

So this is because the electrostatic speaker is a voltage device and the amplifier is a voltage source.

But the converse must also be true, as inconvenient as it sounds: That the dynamic driver only 'tracks' the current of the amplifier, even if the potential for current is voltage.

Many find this hard to fully grasp and understand.

I don't know Mr. Sanders and I am sure that, being an expert, he was able to tell you that, as in any capacitor, it requires current to charge up to a certain voltage. The amplifier is the current source that enables this voltage to develop.

And dear Joe, many understand and grasp this fully, have done so for years, at high degrees of theoretical and practical sophistication, but still think many of your conclusions just don't cut wood and are phrased in incomprehensible terms to boot.
 
It’s worse than BS quality wise, it’s proprietary, locking in the user. I would make any attempt to move the business focus from content to encoding a crime against humanity. Like moving the focus from the writer to the printing shop.
This is a subject I do know, Tidal (hi fi) gives several versions of the same music in flac format, granted it isn’t labeled very well but it is there in cd (16/44.1) if available ‘master’ (24/48 - 24/96) or MQA (up to 192 ?) a MQA file can still be played at whatever it’s standard rate by any equipment. To fully unfold MQA you must have a dac with the ‘proprietary’ ability.
I do not have one that does MQA but would like to see what the fuss is about some day.
Tidal (and/or Qobuz) is a great way to bring new music into your life with hq sound in most cases better than cd. Hardly a crime against humanity.

It was at least in part a question. Is there a player that reads the file from disk entirely before starting playback? It's something I can imagine an extremely paranoid person would do. I thought I've heard of some player that did this, but I don't want to misstate the facts.
.
Many of the high end streamers buffer

Doesn't have to be dsp, but that's the best option imho
In my case, it's optical not wifi to the speakers, though you could use wifi.
How do you sync and control your setup?

I would agree but I would not tell someone who likes the simplicity of poorly matched passive components with no way of adjusting for driver mismatches that they were wrong. Everyone has their preferences and if those make them happy and able to kick back and enjoy the choons all good. If they tell me its better, that's a different issue :D

Bill, Not quite sure if your referencing me (gpauks comment was to me) but I assure you great amounts of time/care goes into matching components in my system. It is also a hybrid of passive/active......fully active has always been on the back burner. Fully active digital is peaking my interest also, but one thing at a time!
 
I think he can't hear me. Maybe it's selective deafness cuz he thinks my question is a trap of some kind, I assure him it isn't, I am genuinely interested in how he measures accuracy (sound betterness), it's the bigger picture of what people look for that I find interesting, it helps put things in perspective, something that is easily distorted here.
 
The way behaves, in this thread, a handful of people, always the same and ubiquitous, is incomprehensible and unbearable. Educated adults? I can not believe it.

Attacks on the person, insults, ad hominem, harassments, everything goes. And all this on a subject as derisory as technology of high fidelity material ?
 
Last edited:
Status
Not open for further replies.