8 . 4 FL INDICATORCIRCUIT

FrequencyDisplayCircuit

oThe counter IC (PD5009) has been designedto match FM ceramic filter IF offset (caused by displacementof the central frequency) by com- bination of the inputs (of H or L level) applied to pin nos.3 & 4. The matching IF offset in the SX-3800 is determined according to the com- binations of connections and disconnections between the R 28 and R 28 resistors in the equalizer assembly(AWM-22?). Check that the combinations shown in the table below have

followed for the conesponding grades of FM ceramicfilters F1 - F3 (3 ranks- color coded).

FM ceramicfilter

PD5009

AVtM-227

{ F 1 - F 3

}

Pin no . 3

Pin no . 4

R 2 8 ( 2 . 2 n 1 8 2 9 ( 2 . 2 n )

 

 

R e d

 

L

H

Cut

Connect

Blue

 

H

H

Cut

Cut

Orange

 

H

L

Connect

Cut

H = 5 . 5 V , L : O V

If the SX-3800 frequency display reads 97.95MH2 or 98.05MH2 when a 9B.00MHz signal is applied to the receivet, adjust TCl so that the display reads98.00MH2 correctly.

If an accurate 9B.00MHz input signal source is not available, tune the receiver to the nearest known broadcasting station in the 98MHz re' gion, and check that the station'sfrequency is correctly displayed,adjustingTCl if necessary.

Output PowerIndicatorCalibration

1.Apply a l"kHz signal to the POWER AMP IN terminals.

2.Adjusi the level of this input signalso that the voltage on the output terminals(SPEAKERS)

read8.95V (AC).

3. Adjust VR1(L) and VR2(R) so that the out- put power indicator read L0 watts.

FL indicatorassembly

vR2*€) @_vnr

Fig .8 - 5

I

I

I

Page 34
Image 34
Pioneer SX-3800 manual VR2*€ @vnr, FL indicatorassembly, Fig .8, PD5009, Blue Cut

SX-3800 specifications

The Pioneer SX-3800 is a classic stereo receiver that emerged in the late 1970s, embodying the high-fidelity audio aspirations of its time. As part of Pioneer’s widely respected SX series, the SX-3800 is hailed for its exceptional sound quality, robust construction, and an array of features that cater to both audiophiles and casual listeners alike.

One of the SX-3800's standout characteristics is its power output. It delivers a solid 80 watts per channel into 8 ohms, making it capable of driving a variety of speaker systems with ease. This ensures a dynamic audio experience, with clear highs, rich midrange, and deep bass. The receiver also exhibits low total harmonic distortion (THD) ratings, which means the sound produced is clean and faithful to the original recording.

The SX-3800 is equipped with a high-quality AM/FM tuner, which is known for its excellent sensitivity and selectivity. Featuring a large analog dial, it allows users to effortlessly dial into their favorite stations while the signal strength meter helps in fine-tuning the reception. This tuner is complemented by Pioneer’s proprietary Auto-Seek tuning function, making it easier for users to find and lock onto stations.

In terms of connectivity, the SX-3800 comes with several inputs and outputs, including phono, tape, aux, and multiple speaker outputs, offering flexibility for various audio setups. Additionally, the built-in phono preamp ensures that vinyl lovers can connect their turntables with ease, preserving the rich detail and warmth that analog sources are known for.

Another technological highlight of the SX-3800 is its inclusion of a loudness control feature, which allows users to enhance the low and high frequencies at lower volume levels. This feature is particularly useful for late-night listening or in quieter environments where detail is essential but loudness is not an option.

With its solid construction, vintage aesthetics, and a beautiful wood finish, the Pioneer SX-3800 not only performs well but also adds a classic touch to any audio setup. Its blend of features, performance, and timeless design continues to make it a desirable component in the world of vintage audio equipment. Collectors and enthusiasts appreciate the SX-3800 not just for its sound quality but also for its enduring legacy in the rich history of audio technology.