|
|
|
Comparison Tests
of some AMPEX ATR-100 key components
MDI PrecisionMotorWorks vs. ATR Service Co.
|
|
|
|
1. Pictures and Prices
2. 1/3 Octave Swept Response - Record/Play - Flux Magnetics heads vs. EMC-Electromag (1/2“)
3. THD @ 1 kHz - Record/Play - Flux Magnetics heads vs. EMC-Electromag (1/2“)
4. 1/3 Octave Swept Response - Input-to-Output - ATR Service Co.‘s Transformerless I/O vs. MDI Precision’s __Xiron™ Transformerless I/O
5. THD @ 100 Hz - Input-to-Output - ATR Service Co.‘s Transformerless I/O vs. MDI Precision’s Xiron™ __Transformerless I/O
6. THD @ 1 kHz - Input-to-Output - ATR Service Co.‘s Transformerless I/O vs. MDI Precision’s Xiron™ __Transformerless I/O
7. Noise Floor - I/O - ATR Service Co.‘s Transformerless I/O vs. MDI Precision’s Xiron™ Transformerless I/O __(broadband unweighted)
8. I/O square wave response - 100 Hz (Xiron vs. Ampex OEM I/O) and 20 Hz (ATR Service (SSI) vs. Ampex OEM __I/O)
9. THD+Noise vs. Frequency and THD+Noise vs. Amplitude - Input-to-Output Xiron vs. Ampex OEM I/O - by Ap __System One dual domain
10. Some early customer Feedback |
|
|
|
|
|
The data collected by way of our SpectraPLUS System from PHS Software is not represented as absolute. Our SpectraPLUS system is PC based and is bandwidth limited (96 kHz sampling) with slight self distortion as a result of the ADC/DAC in use at the time. Although close, we do not represent distortion or swept response values as absolute. It is true, however, that given identical tests, if Product A exhibits .006% THD and Product B, .011% THD, the obvious is conclusive. Furthermore, since the reponse of the test system is "flat" unto itself, deviations from flat response are, infact, the result of the equipment under test.
This comparative data was initially gathered for our own reference and so, for the record, all testing was performed numerous times and conducted in a fair, accurate and scientific manner with the intention of demonstrating the best case performance of each and every tested component. For control, the same set-up was used for all similar tests. i.e. magnetic heads were compared on the same machine using the same electronics. Electrical adjustments, such as bias and EQ, were made so as to optimize the performance of the recorder in each and every case. We find the SpectraPLUS system particularly useful for the very detailed results it produces and it is this very same system which we use daily in our work. From time to time, we rent an Ap system to validate the accuracy of our own hardware and software; hence, the inclusion herein of some Ap data.
This presentation is for comparison sake and since all tested components were given identical treatment - the included data is absolutely valid to that end. These tests do by no means represent the entire picture and we make no claims here as to “the sound” of a component or a piece of equipment. The reader/listener is left to make that determination. All that said, the time has come to set the record straight! The following is what our competition fears most -- Some undeniable proof that he has no lead in the race to build the best ATR-100 recorder! |
|
|
|
|
|
Copyright 2001. MDI PrecisionMotorWorks 241 White Pond Rd. Hudson MA 01749 USA
Contents may not be reproduced for distribution or used in any publication
without the express written consent of MDI PrecisionMotorWorks.
|
|
|
|
|
|
|
|
|
|
|
|
|
