• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Would upgrading my sansui amp give noticeable sound difference?

J

justinjtim

Member
morning. I recently purchase a new pair of KEF Q300s to go with my kenwood kd650 tt and vintage Sansui Au555a amp. It's a system strictly for 2ch audio listening in the dining room. I love the sound of these new speakers very much improvement in my opinion over my old Bose 901 in sound clarity. My question is how much more could I get from these speakers bu upgrading my current amp? I don't want to spend much more that what I could get for this online plus a couple hundred bucks. Would they benefit from more power, keeping in mind I am not listening at real high volume. Just like clear great sounding music. Here are the specs for my circa 1970 Sansui amp. As someone new to this any ideas would be appreciated.

Form Stereo Integrated Amplifier
<Main-amplifier part>
Output power
Music power (IHF) : 85W (4ohm)
60W (8ohm)
Effective output : 33/33W (4ohm)
25/25W (8ohm)
THD 0.5% or less (Output power)
Cross modulation distortion (SMPTE, 60Hz:7000Hz=4:1) 0.5% or less (Output power)
Power Band Width (IHF) 20Hz - 40000Hz (8ohm)
Frequency characteristic 20Hz - 40000Hz, ±1dB
Channel separation 60dB or more (1kHz, Output power)
A hum and a noise (IHF) 100dB or more
Input sensitivity/impedance 1V (Output power) / 100 kohms or more
Load impedance 4ohm-16ohm
Dumping factor 50 (8-ohm load intensity)
<Preamplifier part>
Output voltage Maximum output: 5V
Output power: 1V
THD 0.1 (Output-power voltage) or less
Frequency characteristic 20Hz - 30000Hz, ±1dB
Channel separation (1kHz, Output power) Phono1, 2:45dB or more
Tuner, AUX: 50dB or more
A hum and a noise (IHF) Phono1, 2:70dB or more
Tuner, AUX: 80dB or more
Input sensitivity/impedance (1kHz, Output-power voltage) Phono1, 2:2mV / 50kohm
Tuner: 180mV / 50kohm
AUX: 180mV / 50kohm
Tape Play(Pin): 180mV / 50kohm
Tape Recorder(Din): 180mV / 50kohm
Sound-recording output (1kHz, input voltage) Tape Rec(Pin):180mV
Tape Recorder(Din):30mV
Equalizer Phono:RIAA NF type
Control Bass: 30Hz, ±12dB
Midrange: 1.5kHz, ±5dB
Treble: 15kHz, ±10dB
Loudness: +3dB (10kHz), +8dB (50Hz)
Switchpoint A low filter: 50Hz-8dB
A high filter: 10kHz-7dB
<Synthesis>
Power source 100V, 50Hz/60Hz
Power consumption 130W
Dimensions Width 395x height 127x depth of 278mm
Weight 8kg
 
Register to hide this ad
Hi,

At nearly 50 years old your amplifier has probably seen better days. Some would recap. Some
would just sell as is if it still works just fine and move on to something used but much more recent.

FWIW you can get a good new remote controlled amplifier with phono stage for around $200.
Correction you can in various parts of the world but they don't seem to be US sold models.

If they knock the 20% VAT off its price and shipping, it would be about $175.

rgds, sreten.
 
Last edited:
The amp I own was recapped before I purchased it. It works and sounds good however, I have never listened through a more powerful amp so not sure if I'm missing out. That amp does look nice however. Thanks for the recommendation.
 
What is your music source? Whether the input could be improved (?). You've got a good amp it takes a lot of power to make a difference that way.
I would spend the money on more music.
 
If you do not listen very loudly, and if your Sansui sounds good at that volume, more power will likely not benefit you on the Kefs. Different amp circuitry may sound better, or not. For an inexpensive test, get a Lepai 2020 or other reputable chip amp for about $20, and give it a listen. If you can hear more than you are used to, then you have your answer.
 
Big thing to consider, many B&W speakers are less than efficient. Your Sansui, while excellent and sweet sounding is underpowered for most B&W speakers.
 
As a listener I went from vintage Sansui to early 2000 upper tier Yamahas as my main amp source with great success.The Sansui were very listenable but the Yamahas took me to another level of cleanliness,detail and separation.
 
If you use this system for critical listening I'd investigate other amplification options. If, however, it's primary function is to provide background music I'd stick with the Sansui.
 
If your Sansui AU-555A has been recapped as you say, you are very unlikely IMO to get anything better for your budget of hundred bucks. In fact, I sold a $10k amp after getting a recapped 555A! The 555A is a superb amp and if it's loud enough for you on those speakers I would stick with it. Read around on the Exclusively Sansui sub-forum and you will find the 555A is very well liked.
 
If SQ is paramount, Far more important than power is getting the first watt right. No amount of power can compensate for a compromised first watt. Sansui is well known for making some of the better mass produced amps. I don't know if yours is one of them, Or if it is, what condition it is in, other than a recap. If by chance it is one of their better models, and up to par, There are many more powerful amps out their that you could probably trade down too with extra $200, I say down because the only time many of them will sound better is when you have run the Sansui well into clipping. While Headroom is a factor, Hence more power, for 90% of us it is WAY over rated.
 
Last edited:
Great amp - however if it has the original round "flying saucer" ceramic small signal transistors on the main board (that's not the large metal output transistors) then replacing these would also help. They will fail with time if they haven't already been replaced plus doing this in my sansui amps created immediate sonic benefits. If you hear any intermittent or steady crackling from a speaker then that is likely to be them dying.....
 
On efficient speakers, that model Sansui integrated amp is very excellent. It is a very sweet sounding amplifier, especially that midrange and the sweet treble. In good order, serviced well as necessary, it is worth keeping. Sansui in that era made excellent sounding gear. And it's worth if need be finding efficient speakers to pair with it. And as a secondary option, getting something to drive your B&W's better with. Both approaches are worth having.
 
My local audio store has a sale in Rotel RA12 new for $499 think this would be worth the investment. Seems to have great reviews. Thinking about it
 
Is there any chance you could bring the new amp home for a night? I would probably test it side by side with the Sansui.
 
Try this: Say to the store owner, "Can I take the Rotel for the weekend (take a cc imprint) and if I don't like it, I'll buy you a carton of beer for letting me audition it, and if I buy it, you buy me a carton of beer!, fair enough?"

Everyone gets beer and everyone is happy.
 
You must log in or register to reply here.
Back
Top Bottom