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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.).
 ;
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.
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This manual was the factory original. Excellent value and contained all the details I needed. Easy dowwnload provided the information when I needed it.
Section III Paragraphs 3-8 to 3-14 50 volts (dc o r rms): for the Model 350D (input impedance, 600 ohms), 5 watts corresponds to approximately 55 volts (dc o r rms). CAUTION The Model 350C/D may be damaged by applying power to the OUTPUT terminals or by applying more than 5 watts to the INPUT terminals. 3-12. USE OF IMPEDANCE-MATCHING NETWORK. 3-13. NEED FOR INPUT MATCH. An impedancematching network is necessary between source and Model 350C/D attenuator under the following conditions: a. Source frequency is 100 kc o r above. b. Model 350C/D is set for l e s s than 20-db attenuation. c. Source output frequency response is affected by mismatched impedance. d. Source output is monitored by meter which is accurate only when source operates into matched load. 3-14. MATCHING AT THE INPUT.
3-8. O P E R A T I N G PROCEDURES.
3-9. MATCHED IMPEDANCE. 3-10. When the Model 350C/D INPUT and OUTPUT terminals are terminated properly, attenuation is the sum of the 10 DB and the 100 DB control settings. The voltage a t the output of the Model 350C/D may be determined if input voltage (or input db level) and the amount of attenuation inserted by the Model 350C/D a r e known. Table 3-1 shows the attenuation factor (Af) over the attenuation range of the Model 350C/D. The method for finding the input level in dbm, is explained in section IV. To find the voltage a t the output terminals proceed as follows: a. Determine the input voltage to the Model 350C/D and the amount of attenuation s e t on the Model 350C/D. b. Locate the amount of attenuation in the db column of table 3-1 and read the corresponding attenuation factor. c. To calculate the output voltage, multiply the input voltage by the attenuation factor. See paragraph 3-11 for an example.
3-11. In figure 3-1 A and B the Model 350D is shown connected to a matching source and load. In both cases the Model 350D is s e t to attenuate the signal by 24 db. The attenuation factor for 24 db from table 3-1 is 0.0631 and the output voltage, for the conditions shown in figure 3-1A, is then:
Vout = ( 5 5 ~ (0.0631) = 3.47 volts )
a. When the source is not affected by mismatchand source impedance is lower than that of Model 350C/D, a s e r i e s resistor may be used between source and attenuator. The resistor value should be the difference between Model 350C/D impedance and source impedance. For example, to match the Model 350C to a 200ohm source requires a s e r i e s resistance of 300 ohms.
b. Except for the condition stated in a., a resistive impedance-matching network should be used. Resistors should be deposited film o r carbon type. Also, better accuracy is obtained if the network is enclosed in a shielded container and connecting leads a r e kept short. Data on impedance-matching networks for the Model 350C a r e given in figure 3-2 and table 3-2; data for the Model 350D a r e given in figure 3-3 and table 3-3. The amount of insertion loss is included in tables 3-2 and 3-3.
1.
IMPEDANCE OF = MODEL 350C IMPEYNCE OF = SOURCE OR LOAD
ID-3-163
For figure 3-1B the attenuation factor is the same a s for figure 3-1A and the output voltage is:
Vout = ( 5 0 ~ (0.0631) = 3.155 volts )
Figure 3-2.
Model 350C Matching Network
Table 3-2. Model 350C Matching Network Values
Z
l
u
(ohms) 474.3 387.3 13.22 31.3 11.66 1.166 .8843 245.2 1733.0 4743.0
W
I Insertion
I
(ohms)
(ohms) 50 200 600 2000
(ohms) 51.40 256.7 1148.0 536.2 514.1
Loss
16 db
9 db 4 db
1 2 db
500 01307-1
5000
16 db 3-3
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