CassetteMaster | Sony TCM-5000EV Professional Cassette Tape Recorder @CassetteMaster | Uploaded 5 years ago | Updated 4 hours ago
This long-winded, chinwagging-filled video is on a very nice cassette tape recorder, a battery-operated unit, intended for high quality professional voice recording by reporters, interviewers, and investigators.
The unit boasts features such as:
Pitch control
Auto/manual level control
Voice activation mode (VOR, Voice Operated Recording)
Dual mike inputs, whose levels can be set to get a good recording of conversations and interviews
Internal condenser microphone
Mechanical pause, counter, and cue/review
Remote jack
Line-in
3-head design so you can monitor recording as it is performed for proof of recording
DC 6V in or 4 C cells
Freq Response: 90-9kHz
Frequency Response for VOR mode: 300 to 5kHz (I believe the typical use of VOR mode would've been for telephone call recordings, hence the narrowed frequency response).
Music shown on recorder by ROBERT LAWRENCE!!!
From Cassette Tape 27, called "The Last Tune?"
Link:
soundcloud.com/5xod/tape29-audio?in=5xod/sets/robs-cassette-tape-corner-1980
EDIT:
I have found out a very interesting thing regarding the design of this recorder. With voice activation mode, you may have noticed that it captured the first word of me speaking, and did not have that characteristic sound of pitch changing associated with the motor starting up. How is this possible?!
Also, why limit the frequency response so much in VOR mode (my thoughts about it being limited for "telephone recording" were just a hypothesis. You may have also noticed (maybe) that the recordings made in VOR mode seem to sometimes clip (not tape-saturate). Why clip in that mode, but be fine in auto and manual?
The answer has been found:
Enter the MN3205 BBD (Bucket-Brigade Delay) chip!
This is a 4096 "bit" ANALOG delay MEMORY chip! It is similar to a shift register, and uses a series of capacitors (in the silicon, of course!), 4096 if them, to store analog values. It is a clocked IC (similar to a shift-register) that sends the analog value down along the "row" of capacitors. That way, you can store very short samples of sound on this chip, which last less than a second long. These chips are common for echo and reverb devices. But in this recorder, the audio passes through it (with a sampling rate I believe of 10kHz, giving a Nyquist frequency of 5kHz, the maximum frequency that can be passed through it, and low-pass-filtered to prevent aliasing) before getting recorded. That way, when speaking to activate the recorder in VOR mode, the motor will (most of the time) already be up to speed and the first word that activated it will be recorded! But because the BBD has a maximum amplitude, there is the tendency for occasional clipping and the frequency response is narrowed because of the sampling rate required to get enough delay time.
Fascinating, eh?
This long-winded, chinwagging-filled video is on a very nice cassette tape recorder, a battery-operated unit, intended for high quality professional voice recording by reporters, interviewers, and investigators.
The unit boasts features such as:
Pitch control
Auto/manual level control
Voice activation mode (VOR, Voice Operated Recording)
Dual mike inputs, whose levels can be set to get a good recording of conversations and interviews
Internal condenser microphone
Mechanical pause, counter, and cue/review
Remote jack
Line-in
3-head design so you can monitor recording as it is performed for proof of recording
DC 6V in or 4 C cells
Freq Response: 90-9kHz
Frequency Response for VOR mode: 300 to 5kHz (I believe the typical use of VOR mode would've been for telephone call recordings, hence the narrowed frequency response).
Music shown on recorder by ROBERT LAWRENCE!!!
From Cassette Tape 27, called "The Last Tune?"
Link:
soundcloud.com/5xod/tape29-audio?in=5xod/sets/robs-cassette-tape-corner-1980
EDIT:
I have found out a very interesting thing regarding the design of this recorder. With voice activation mode, you may have noticed that it captured the first word of me speaking, and did not have that characteristic sound of pitch changing associated with the motor starting up. How is this possible?!
Also, why limit the frequency response so much in VOR mode (my thoughts about it being limited for "telephone recording" were just a hypothesis. You may have also noticed (maybe) that the recordings made in VOR mode seem to sometimes clip (not tape-saturate). Why clip in that mode, but be fine in auto and manual?
The answer has been found:
Enter the MN3205 BBD (Bucket-Brigade Delay) chip!
This is a 4096 "bit" ANALOG delay MEMORY chip! It is similar to a shift register, and uses a series of capacitors (in the silicon, of course!), 4096 if them, to store analog values. It is a clocked IC (similar to a shift-register) that sends the analog value down along the "row" of capacitors. That way, you can store very short samples of sound on this chip, which last less than a second long. These chips are common for echo and reverb devices. But in this recorder, the audio passes through it (with a sampling rate I believe of 10kHz, giving a Nyquist frequency of 5kHz, the maximum frequency that can be passed through it, and low-pass-filtered to prevent aliasing) before getting recorded. That way, when speaking to activate the recorder in VOR mode, the motor will (most of the time) already be up to speed and the first word that activated it will be recorded! But because the BBD has a maximum amplitude, there is the tendency for occasional clipping and the frequency response is narrowed because of the sampling rate required to get enough delay time.
Fascinating, eh?
