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thank u so much for this manual that was so cheap that i thought it was a scam but i gambled anyway because it was too good of a deal to pass up and behold,the manual has everything and details of everything even the screws and im still amazed and very happy with my manual .so take my word and jump on it before they realize how cheap they selling thier manuals..thank you so much for taking time to read my thoughts
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I do not have very much to say.
The price is quite covenient, delivery was better as promised (about 12 ours, against the specified 24 hours if I remember well), and the quality of the PDF is more than acceptable.
The Service Manual of Sansui R30 itself is also satisfactory: good graphic for schematics and layouts, simple and well structured.
Giovanni Bianchi
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Happy to find finally a schematic for this amplifier. The schematic is of good quality, the pcb layout is useless: all is black. Never the less, it is very easy to find the components on the board using the schematics.
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Hard to find manual was ready the next day. Scans were very legible (including schematics). All the essential parts of the service manual were present (adjustment procedure, schematics, and parts list). It would have been nice if the rest of the manual was included (disassembly procedure, theory of operation, etc.).
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The Service Manual for the Kenwood KR-V55R provided by owner-manuals.com was as described/advertised. The contents provided the necessary information to effect a diagnosis of the unit. The schematics above all else was instrumental in tracing the the signal flow from component to component.
TKR-851
CIRCUIT DESCRIPTION
5-6. DSP
The DSP circuit filters transmit/receive audio signal and encode/decodes signaling (QT, DQT). This circuit consists of IC618, IC612, IC613, IC614, IC603, IC606, IC608, IC610, IC616, and IC619. The receive signal DET is converted from analog to digital by IC614 with a sampling frequency of 16.128kHz. The digitized audio signal is sent to DSP IC618 to process the signaling signal and audio signal. The processed digital audio signal is fed to CODEC IC613, converted from digital to analog, and the analog signal is output from pin 16 (AOUTR). Then, the audio signal is amplified by IC619 (B/2), passes through the IC619 (A/2) low-pass filter, and goes to an electronic volume IC615. The transmit audio signal coming from IC605 is amplified by IC610, fed to pin 3 (AINL) of CODEC IC614, and converted from analog to digital at a sampling frequency of 16.128kHz. The digitized transmit audio signal is AGC-processed, preemphasized and filtered at 300Hz to 3kHz by DSP IC618, and the resulting signal is fed back to CODEC IC614, and converted from digital to analog, and the analog signal is output from pin 15 (AOUTL). The transmit signal from AOUTL is amplified by IC616 (B/2), passes through the IC616 (A/2) lowpass filter, and goes to the IC611 (A/2) summing amplifier. IC613 is a counter IC and the clock required for the CODEC and DSP is generated by dividing the 16.515MHz clock signal produced by DSP IC618. IC603 and IC606 are interface IC between the CPU operated at 5.0V and the DSP operated at 3.3V.
5-7. Base-Band Circuit
The base-band circuit switches between the modulation signal to the transmitter circuit, and remote audio and adjusts their levels. This circuit consists of IC605, IC607, IC611, IC615, and IC617. Modulation inputs include local microphone input, lowspeed data (LSD), high-speed data (HSD), external audio input (TA), and external data input (TD), and demodulation outputs include receive audio output (RA), and receive data output (RD). The multiplexer (IC605) changes signals, the electronic volume (IC615) adjusts the level, and the operational amplifier (IC607, IC611, IC617) amplifiers and sums signals.
5-8. RS-232C Circuit
The RS-232C circuit connects the RS-232C serial port of a personal computer directly to this model to perform FPU operation. The FPU operation can also be performed by connecting a programming cable (KPG-46) to the local microphone on the front panel. But, if the D-sub connector on the rear panel is used, the programming cable is not required. The 232C driver IC (IC620) changes the TTL-232C level. The firmware can only be rewritten with the local microphone on the front panel.
5-9. Power Supply Circuit
The power supply circuit generates power to operate the CPU, DSP, flash ROM, bi-directional buffer, and base-band circuit. This circuit consists of IC624, IC625, IC626, IC627, IC628, and IC630.
CODEC IC IC614 : AK4550VT RX detected signal RD TX modulation signal 3 Local Mic (AINL) TA [Frequency response] RX 15 TX 300Hz 3kHz (De-emphasis) (AOUTL) TD 2 RX 16 (AINR) REPEAT (AOUTR)
RA RX audio amp. TX VCO (Modulation circuit)
TX
(Pre-emphaisi)
REPEAT
(300Hz~3kHz Flat)
Fig. 10 An audio signal course and the frequency characteristic
16
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