MICHAEL A KOULOPOULOS
Broker in Andover, MA
License number
Massachusetts 57913
Issued Date
Jan 1, 1985
Expiration Date
Apr 16, 1995
Type
Salesperson
Address
Address
Andover, MA 01810
Professional information
Multiple Clock Signal Generator Apparatus
US Patent:
5266908, Nov 30, 1993
Filed:
Jan 26, 1993
Appl. No.:
8/009293
Inventors:
Michael A. Koulopoulos - Andover MA
Russell A. Siggelkoe - Natick MA
Thomas R. Hegg - Chestnut Hill MA
Russell A. Siggelkoe - Natick MA
Thomas R. Hegg - Chestnut Hill MA
Assignee:
Vimak Corporation - Woburn MA
International Classification:
H03L 7099
US Classification:
331 2
Abstract:
A digital-to-analog converter--preamplifier apparatus serving as an interface between a source of digital audio signal data and an amplifier is disclosed. A digital stage receives multiple digital audio signal inputs, a selected one of which is analyzed by a digital audio interface receiver, processed by a digital signal processing device and a delta-sigma modulator prior to passing to the analog stage for conversion from the digital domain into left and right channel analog audio output signals. Volume control is performed on the audio signal in both the digital domain and the analog domain in order to optimize performance and minimize noise. The present invention automatically adjust for input word lengths of greater than 18-bits.
Digital-To-Analog Converter--Preamplifier Apparatus
US Patent:
5243344, Sep 7, 1993
Filed:
May 30, 1991
Appl. No.:
7/708061
Inventors:
Michael A. Koulopoulos - Andover MA
Russell A. Siggelkoe - Natick MA
Thomas R. Hegg - Chestnut Hill MA
Russell A. Siggelkoe - Natick MA
Thomas R. Hegg - Chestnut Hill MA
International Classification:
H03M 166
US Classification:
341143
Abstract:
A digital-to-analog converter--preamplifier apparatus serving as an interface between a source of digital audio signal data and an amplifier is disclosed. A digital stage receives multiple digital audio signal inputs, a selected one of which is analyzed by a digital audio interface receiver, processed by a digital signal processing device and a delta-sigma modulator prior to passing to the analog stage for conversion from the digital domain into left and right channel analog audio output signals. Volume control is performed on the audio signal in both the digital domain and the analog domain in order to optimize performance and minimize noise. The present invention automatically adjust for input word lengths of greater than 18-bits.
Housing For A Digital-To-Analog Converter-Preamplifier
US Patent:
D355654, Feb 21, 1995
Filed:
Jan 6, 1992
Appl. No.:
7/820941
Inventors:
Michael A. Koulopoulos - Andover MA
Assignee:
Vimak Corporation - Woburn MA
US Classification:
D14188
Cd Transport Apparatus
US Patent:
5289439, Feb 22, 1994
Filed:
May 27, 1992
Appl. No.:
7/889609
Inventors:
Michael A. Koulopoulos - Andover MA
Ronald P. Rappel - Peterborough NH
Thomas R. Hegg - Chestnut Hill MA
Ronald P. Rappel - Peterborough NH
Thomas R. Hegg - Chestnut Hill MA
Assignee:
Vimak Corporation - Woburn MA
International Classification:
G11B 1722
US Classification:
369 32
Abstract:
An improved CD transport apparatus wherein said apparatus incorporates a digital signal processor for processing digital audio signals read from a compact disc. The digital signal processor additionally serves to alter the gain of the digital audio signal when various control operations are commanded by the user so as to minimize audibility of extraneous noises which accompany such control operations and the potential damage which may be caused to audio components. The improved CD transport apparatus further includes a cueing switch for causing movement of the CD pickup only during movement of the cueing switch and a shuttle switch for causing movement of the CD pickup only when the shuttle switch is in an active position.
Method For Correcting Errors In Digital Audio Data
US Patent:
5412638, May 2, 1995
Filed:
Jun 2, 1993
Appl. No.:
8/071505
Inventors:
Michael A. Koulopoulos - Andover MA
Praduman Jain - Lowell MA
Sriram Jayasimha - Hyberabad, IN
Praduman Jain - Lowell MA
Sriram Jayasimha - Hyberabad, IN
Assignee:
Vimak Corporation - Woburn MA
International Classification:
G11B 5035
US Classification:
369 59
Abstract:
An improved method for correcting errors in a sequence of digital audio data for use in a system having a compact disc player device and a digital signal processor. A compact disc player device reads a compact disc and outputs digital audio data as a series of digitized samples and detects erroneous samples. An error correction apparatus implements a finite impulse response filter. The method achieves a low level of interpolation error within the corrected output of the finite impulse response filter by assigning zero-valued filter coefficients to digital audio samples that are likely to be erroneous due to their proximity to a known erroneous digital audio sample.
Digital-To-Analog Converter Housing
US Patent:
D349500, Aug 9, 1994
Filed:
May 30, 1991
Appl. No.:
7/713442
Inventors:
Michael A. Koulopoulos - Andover MA
Assignee:
Vimak Corporation - Woburn MA
US Classification:
D14217