My SONY TA-AX44 Integrated Stereo Amplifier - Minor Modifications

[Hari Iyer]

I am using this rugged Sony Integrated Stereo Amplifier since 1986 and am so impressed by its sound signature that never thought of an upgrade. May be i am used to its SQ. I am planning a very minor upgrade after reviewing the amps circuit diagram. Will be replacing all the electrolytic capacitors in the signal path 2 no.s 1 microfarad an 1 nbr 47 microfarad each channel in the signal path to a polyester capacitors & non-polar capacitors of the same value.

I have read that some of the high-end amplifiers do not use any by-pass capacitors in the signal path to prevent any phase shift in the audio signal. I am not sure if this amplifier will support completely removing these capacitors as it can cause some DC voltage to creep into the signal path causing probable noise an DC hum. First let me try replacing the capacitor types. This is planned for this month an will post the improvement report (if any).

Cheers,
Hari.

 

[avidyarthy]

I have the same one ..... its lying around now, and only recently retired it from active duty since 1988. The push-buttons run pretty rough, seemingly due to dust accumulation on the button edges.

The SSS 440 speakers and the cassette deck still work flawlessly.

 

[Hari Iyer]

I have the same one ..... its lying around now, and only recently retired it from active duty since 1988. The push-buttons run pretty rough, seemingly due to dust accumulation on the button edges.

The SSS 440 speakers and the cassette deck still work flawlessly.

You can get the switches serviced, it might be just carbon deposit over the years. You can spray CRC spray on the PCB and it will start working like new. I had done this 5 years ago and till now no problem.

 

[kapvin]

Oh, I remember this amp!

I was in school at that time and used to lust after this system. At 2 x 45w (afaik) it was way more powerful than anything else. (I remember akai bush had a rack system which was around the same price about 23k which at that time was a king's ransom) which many preferred because it had a rack and a separate 2 x 9 band equalizer. But for sq. this was the benchmark among what was available in Indian retail, partly because of the speakers, which had really decent bass and clarity versus anything else in the showroom.

I remember it having something called "legato linear" circuitry - never figured out what that meant. Also it had some innovative cooling that allowed it such a slim shape. Do shed more light on this. It is a nostalgia trip...



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[Hari Iyer]

Oh, I remember this amp!

I was in school at that time and used to lust after this system. At 2 x 45w (afaik) it was way more powerful than anything else. (I remember akai bush had a rack system which was around the same price about 23k which at that time was a king's ransom) which many preferred because it had a rack and a separate 2 x 9 band equalizer. But for sq. this was the benchmark among what was available in Indian retail, partly because of the speakers, which had really decent bass and clarity versus anything else in the showroom.

I remember it having something called "legato linear" circuitry - never figured out what that meant. Also it had some innovative cooling that allowed it such a slim shape. Do shed more light on this. It is a nostalgia trip...



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This amp uses a hybrid IC pack which consist of Single ended Push-pull darlington transistors for the main power amp drive. The output stage is also capacitorless. Sony called the amplifier legato linear because of its very low distortion characteristics < 0.008% THD & IM and very low switching distortion due to some kind of class A operation. The amp does not use any traditional alunimum extruded heatsink, but instead uses a novel heat pipe with a cooling liquid in it. The heat pipe is then connected to alinimum finned heat sinks. The heat is exchanged to the ambinent by thermodynamic property and the liquid is vapourised and is sucked back by capillary wick action and the cycle is repeated again. Due to this novel heat pipe technology the heat transfer is excellent and one of the reasons for the amplifiers high performance as per Sony. This also allows the darlignton transistor IC pack to be mounted and connected effeciently with minimum losses. This amp uses the STK2240 Hybrid IC from SANYO.

 

[Prasad Karpe]

Hi,
I also have the same amplifier with speakers ss-s440 however a tweeter & super tweeter of one of the speaker is not functionning. When i opened it surprisingly i found that both the woofer & super tweeter has got a tag of made in Japan but the tweeter is indegeniously manufactured.Further the tweeter depicts that it is having an impedance of 4 ohms. Can somebody shed light over it as i am littlebit confused regrading the different values of impedance of those speakers

 

[greenhorn]

have you swapped the power supply caps? Usually the caps last only 30 years or so, and if you can replace them with equally high quality caps, it would be good, though some folks have said that it changes to sound signature (though most of them agree it was for the better)

 

[reubensm]

Amazing thread! Just saw it though it is from last year.

 

[Hari Iyer]

Hi,
I also have the same amplifier with speakers ss-s440 however a tweeter & super tweeter of one of the speaker is not functionning. When i opened it surprisingly i found that both the woofer & super tweeter has got a tag of made in Japan but the tweeter is indegeniously manufactured.Further the tweeter depicts that it is having an impedance of 4 ohms. Can somebody shed light over it as i am littlebit confused regrading the different values of impedance of those speakers

The SSS-440 uses a solid state tweeter which is pezio electric type which has its inbuilt capacitance. The woofer does not have any cross-over and it rolls-off naturally at 3000Hz, the mid-range operates between 3KHz till around 10KHz and the super tweeter takes over beyond 10KHz. This speaker has a frequency response of 40Hz to 20KHz (-10dB) and has a inbuilt overload protector. The impedance of individual drivers are Woofer - 8 ohms (RMS 45 Watts), Mid-range - 10 ohms (RMS 30 Watts), Super Tweeter - 16 ohms (RMS 10 Watts). The sensitivity of this speaker is 90 dB/w/m.
The woofer is connected with the +ve and -ve terminal directly to the +ve and -ve terminal. The mid-range and tweeter is reverse connected for in-phase operations. I have quoted all the above values from the service manual of the speaker SSS-440.

Hope the above information will be of assistance to you.

Cheers,

 

[Prasad Karpe]

Thanks Mr.Iyer for this useful information. However i am still in a dilemma regarding the substitution for the mid range driver as it seems that the previous owner of the speakers had replaced with the Indian ones. Further the super tweeter of one of the speakers is also not working which will also need replacement with an indian counterpart. Pls. guide me.

 

[Hari Iyer]

Thanks Mr.Iyer for this useful information. However i am still in a dilemma regarding the substitution for the mid range driver as it seems that the previous owner of the speakers had replaced with the Indian ones. Further the super tweeter of one of the speakers is also not working which will also need replacement with an indian counterpart. Pls. guide me.

If you suspect the mid-range to be modified and the super tweeter to be not working, the best solution is to salvage the speaker completely. You can still use the woofer and get a separate box made with the required cross-over networks. Please PM me if you require assistance in this.

Cheers,

 

[Prasad Karpe]

I do require an assistance but since i do not have the privilege to PM I can not do that. Pls. suggest some alternative

 

[Thad E Ginathom]

Seeing your reference to this amp in another thread, I googled the model number, and google, happily, brought me right back here!

Yes, this was the amplifier that was at the heart of my first self-owned hifi. I'm not sure of the date now, must have been 1980-something.

I had moved to a house where I would be living alone. No more benefit of other peoples' stereo systems, but a need for music. I undertook some additional work from my employers, for which they paid me a freelance fee, and accumulated about UK400. I read hifi magazines and compared meaningless-to-me specifications until my head hurt, and, finally, in despair, went to the original London Richer Sounds shop and told the guy, "I have this much to spend, I want amp, turntable, cassette deck and speakers: can you give me a good system at that price?" His answer was, "I can give you a superb system!" and I pretty-much went with his recommendations without further ado.

No part of that system survives to this day. The amplifier was the longest-lived component, but was only functioning intermittently. I gave away everything that was not fully-functional before coming to India in 2005 --- and now I wish I hadn't, as Mr Sayeed (Chennai) might well have been able to re-rejuvenate that amplifier.

Hari, thanks for the memory of some of my happiest music-listening days

 

[Saket]

...finally, in despair, went to the original London Richer Sounds shop and told the guy, "I have this much to spend, I want amp, turntable, cassette deck and speakers: can you give me a good system at that price?" His answer was, "I can give you a superb system!"

Hari, thanks for the memory of some of my happiest music-listening days

Quite nostalgic.
At exactly half your age now, getting my first turntable, amp and speakers was not too different. Just that I had the luxury of internet and this forum. The equipment is hardly younger than yours; most of the stuff is from the golden era of the 70's. From your post, I can only get to re-affirm my decision of never selling my equipment in future.

Quite ironical, but I was offered the same Sony amp before I sealed the deal in favour of the Pioneer 434 because the Sony amp started throwing some tantrums at the seller's place! Else, I would have finalised the TA-AX44!