diyAudio - View Profile: rjm
Go Back   Home > Forums > Members List

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

rjm rjm is offline

Richard Murdey

diyAudio Member

About Me

  • About rjm
    Biography
    Canadian citizen, Japanese resident.
    Location
    Kyoto
    Interests
    Audio Circuitry
    Occupation
    Research Scientist
    Country
    Japan
    Real Name
    Richard Murdey
  • Signature
    RJM Audio (phonoclone.com / G+)

Statistics

Total Posts
Blog
Wiki
General Information
  • Last Activity: Today 02:28 PM
  • Join Date: 2nd May 2004

Friends

Showing Friends 1 to 1 of 1

Blog

View rjm's BlogRecent Entries
Latest Blog Entry

Posted 14th October 2014 at 01:55 PM by rjm Comments 0
Posted in Uncategorized
Eye candy.

My fourth. Each one comes packaged the same, with a serial number and individual calibration sheet.

This little guy is no. 2096, .39/.40 mV. Signed off by Mr. Nemoto (根本さん、ご苦労様!)

Posted 3rd October 2014 at 01:40 AM by rjm Comments 0
What we are looking at here is the Fast Fourrier Transform (FFT) of the line output from my b-board buffer recorded at 24 bit, 96 kHz by an Onkyo SE-200PCI sound card. Upstream from the b-board is the Phonoclone 3 MC phono stage, connected to a Denon DL-103. The tonearm is Denon DA-307, and the deck is a Denon DP-2000.

Four recordings, taken 1) with music playing, 2) with the tonearm raised 3) with the phonoclone powered off and 4) with the b-board and all upstream components powered off.

True 24/96 data was obtained, measurements out to 48 kHz are possible, with -130 dB noise floor. (I was using Digionsound 6 to do the recording as Audacity truncates 24 bit recordings to 16 bit in Windows due to licensing issues. The FFT was generated in Audacity however.)

The soundcard's line input may have an impressive-looking low noise floor, but it's still useless for measuring line level audio devices like the b-board because the noise of the preamp/ADC...

Posted 23rd August 2014 at 12:33 PM by rjm Comments 1
I suppose everyone has at one point or another adjusted the volume sliders in Windows. The ones that go from 0-100, and you are never quite sure what whether its a boost, or an attenuation, or what.

Some years ago I measured the outputs and inputs using a fixed amplitude .wav file created in audacity and played back through the Onkyo SE-200PCI. I've taken another look at the worksheet I made and I've noticed that the volume settings correspond to very logical, even steps, namely:

100 0 dB
90 -1 dB
80 -2 dB
70 -3 dB
60 -4.5 dB
50 -6 dB
40 -8 dB
30 -10 dB
20 -14 dB
10 -20 dB

or for the mathematically inclined: 20*log(volume/100)

This scale is the same for both the output master volume and the line input, so its probably maintained throughout the operating system.

So now you know.

Posted 20th August 2014 at 03:18 PM by rjm Comments 0
Part I is here.

Setup notes are in part I. Listening system downstream is the Sapphire headphone amplifier and Sennheiser HD-600 headphones. As the SE-300's line output routes though the Windows sound mixer, while the SE-200's bypasses it, it was not possible to keep the headphone amplifier volume at a constant setting between cards. Since I found the built-in headphone amplifier of the SE-300 to be good but not at the level of the Sapphire, only the stereo RCA output is being reviewed here.

Let me begin by saying that Windows is fundamentally an anti-audiophile proverbial dog's breakfast of setting and driver layers (quick, what's the difference between the DirectX and WaveOut sound modules?), and most soundcards are also anti-audiophile in that they cater to gamers and casual listening with a full barrel of virtualization, equalization, and reverb features enabled by default.* No surprise then that both cards require careful setup to sound their best, or,...

Posted 11th August 2014 at 01:39 AM by rjm Comments 0
When I upgraded my computer recently I accidentally bought a motherboard with no PCI slots which meant I could no longer use my SE-200PCI card, my main reference source now for some years. Rather than switch motherboards again I figured I'd try Onkyo's latest version which has been out for a while now, the SE-300PCIe. I picked up a used "R2" model for $200.

I mention the price up front because the cost of this thing outside of Japan is astronomical. I've seen asking prices of $450 US! In Japan the retail price is about $300 in most stores. That's still very expensive. Despite the good things I have to say about it, the cost/performance must be taken into account based on the particular price you are looking at paying.

This is a Japan-only product, so the web site is Japanese:

main page (gallery)

The basic specs for the stereo line output is 120 dB S/N A weighted, 24/192 capable, 0.3-88kHz -3dB for the 2 channel stereo...
Recent Comments
Quote:
Originally Posted by dimkasta
I recently modified
...
Posted 25th October 2014 at 10:59 PM by hallom hallom is offline
Good point, it seems...
Posted 3rd October 2014 at 01:17 PM by rjm rjm is offline
The performance of this...
Posted 19th September 2014 at 07:46 PM by Chris4 Chris4 is offline
Thanks for putting that...
Posted 24th August 2014 at 02:40 AM by fas42 fas42 is offline
I recently modified...
Posted 17th July 2014 at 11:17 AM by dimkasta dimkasta is offline
Hide this!Advertise here!

New To Site? Need Help?

All times are GMT. The time now is 03:05 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2