hifi engine

Manual Library / Sansui

Sansui 500A

Stereophonic Tuner Amplifier

add a review (1 review)

Sansui 500A

Specifications

Tuning range: FM, MW

Power output: 20 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 20kHz

Total harmonic distortion: 1%

Damping factor: 10

Input sensitivity: 2.5mV (MM), 180mV (DIN), 180mV (line)

Signal to noise ratio: 70dB (MM), 75dB (line)

Channel separation: 50dB (MM), 45dB (line)

Speaker load impedance: 8Ω to 16Ω

Valve complement: 3 x 6AQ8, 1 x 6BE6, 2 x 6BA6, 4 x 6BL8, 2 x 12AU7, 1 x 6AU6, 4 x 7189A

Dimensions: 18-3/10 x 5-9/10 x 15 inches

Weight: 39.7lbs

Downloads

Reviews

 Login or register to post reviews

rating
Reviewed Oct 17th, 2018 by AMCHornet

I love my 500a. It was one of the last tube receivers and the technology was nearly perfected. It is large, heavy, and made of glass and steel. The only solid state components are a few diodes and transistors in the power supply, phono preamp, tuner detector, and stereo indicator.

The 500a has a lot of features for a tube receiver of it's age. The FM multiplex tuner works extremely well. It pulls in stations as well as later solid state tuners with good clarity and channel separation.

This is a beautiful sounding receiver. I don't believe in the tube sound that people talk about, because I A/B compare the output of the 500a to the source and I hear little to no difference. All the crispness, clarity, and detail is there from the deepest bass to the highest treble. It just reproduces the music, it doesn't change the music. That's what an amplifier should do and the 500a does it.

Be warned: it's no powerhouse. The 20w RMS per channel rating is optimistic. If you push it too hard it will clip, distort, and sound awful. Don't treat a beautiful old amp that way. You can achieve painfully loud volume levels without distortion IF you use sensitive speakers: at least 93db. You will hit your discomfort level before the receiver starts to distort. However, if you use less sensitive speakers (like most modern speakers) you will find yourself at that distortion point pretty easily. I strongly suggest using speakers about the same age as the 500a itself. They tend to be very sensitive to make the most of it's power and sound great. They are a great match together. Sansui made some great speakers like the SP-100 or SP-200 to match the 500a. My 500a sounds better on 50 year old speakers than on modern ones.

The four 7189A output tubes are nearly extinct and extremely expensive. You can rewire the tube sockets and reduce the bias for the cheaper and more common 7189's and it sounds just as good. You can even run it on robust EL84's if you bias it accordingly. It's a pretty tolerant amp. The coupling capacitors to the output tubes tend to short and cause the output tubes to red-plate (overheat). FIX THAT if it happens. I'd replace those capacitors anyway just in case. You do not want to fry expensive output tubes or worse: the output transformers. The 6AQ8 preamp tubes tend to develop microphonics as they get old. I suggest replacing them with the most robust ones you can find. The Russian mil-spec ones work nice.

The 1000A is more common and is what everyone wants...and their price reflects it. The 500a is nearly as good and sells for less money. It's an excellent buy for a vintage tube stereo receiver.

 

Comments

vinylkid1's picture

re: 500A

i just bought one of these ,nice receiver but it only has sound in the left channel on all inputs??

re: 500A

As an audio technician with 40+ years experience, my guess you have a bad pre-amp transistor , a bad vacuum tube or a bad coupling capacitor.
This model is a hybrid, it uses both transistors and vacuum tubes.
If you are LUCKY...it will be a dirty switch or volume control.

re: 500A

Have you given the controls a good cleaning with deoxit contact cleaner?

This website is not affiliated with or sponsored by Sansui. To purchase 500A spares or accessories, please contact the company via their website or visit an authorised retailer.