Replace STK4332 with more powerful one ? - UK Vintage Radio Repair and Restoration Discussion Forum

pletevl · 14th Feb 2019, 9:44 am

Hi all,

In my man cave I have an old AMSTRAD TS-90 stereo, linear record deck, full logic cassette deck and all controllable via a 32 button remote controle.

As with most AMSTRAD stereos, it is high on features but very low on volume.

Inside, the amp IC is an STK4332 by SANYO, the datasheet says it gives out 5 watts per channel. AMSTRAD says 8 watts per channel.

Can I simply change this IC to a more powerful one, type STK4412 for example ? the datasheet says it's the same, uses the same external components and would only need more power to get more watts.

Any ideas ?

Thanks.

Pete.

Nuvistor · 14th Feb 2019, 9:50 am

5 watts into many speakers would fill most domestic rooms, are the speakers you are using very insensitive, or is there another fault with the unit?

pletevl · 14th Feb 2019, 10:13 am

Everything is fine, I just want more watts.

Nuvistor · 14th Feb 2019, 10:21 am

If you change the IC can the power supply delivery the extra watts to drive the new chip? Sorry I cannot advise if it would be a simple swop of the IC.

The Amstrad is what it is, unless all the fancy features are important and you just want it louder perhaps replace the whole unit with something more suitable.

Radio Wrangler · 14th Feb 2019, 10:25 am

And the more powerful amplifier module will need a more powerful power supply, and more heatsinking. And you may find that the speakers can't handle much more

Amstrad pared everything down to the bare minimum on all the internal stuff.

If you look around you may be able to find something like a Denon/Sony/Technics mini system for less money than you'd pay for STK modules. The modules are known failure points and there is plenty of demand for working ones of all their sizes, so you can guess that they don't come cheap.

David

Crossposted with Nuvistor..... at least we agree!

pletevl · 14th Feb 2019, 10:50 am

I know about the powersupply and the heatsink.

The Ic comes in at around 10 dollars.

I have JM LAB / FOCAL speakers connected to it.

I would just like to know if it can be done.

Lloyd 1985 · 14th Feb 2019, 10:51 am

If the Amstrad has some sort of audio output, then maybe buy an amplifier that has more power and plug the Amstrad into it, then you'll need to see if the speakers can handle the extra power, which if they are also Amstrad then they are probably a bit weedy as well!

Regards,
Lloyd.

snowman_al · 14th Feb 2019, 10:57 am

You will waste your money and time changing from the STK4332 to a 4412.

The STK4332 runs off 24 to 30 volts maximum voltage.
If you fit a 4412 straight in there the output power will be the same.
You have to increase the supply voltage to 45 - 50 volts to get any increase in power out. Not practical or sensible for the rest of the units functions...

Alan

14th Feb 2019, 9:44 am	#1
pletevl Triode Join Date: Nov 2018 Location: Pont Saint Vincent, France. Posts: 37	Replace STK4332 with more powerful one ? Hi all, In my man cave I have an old AMSTRAD TS-90 stereo, linear record deck, full logic cassette deck and all controllable via a 32 button remote controle. As with most AMSTRAD stereos, it is high on features but very low on volume. Inside, the amp IC is an STK4332 by SANYO, the datasheet says it gives out 5 watts per channel. AMSTRAD says 8 watts per channel. Can I simply change this IC to a more powerful one, type STK4412 for example ? the datasheet says it's the same, uses the same external components and would only need more power to get more watts. Any ideas ? Thanks. Pete.

14th Feb 2019, 9:50 am	#2
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Replace STK4332 with more powerful one ? 5 watts into many speakers would fill most domestic rooms, are the speakers you are using very insensitive, or is there another fault with the unit? __________________ Frank

14th Feb 2019, 10:13 am	#3
pletevl Triode Join Date: Nov 2018 Location: Pont Saint Vincent, France. Posts: 37	Re: Replace STK4332 with more powerful one ? Everything is fine, I just want more watts.

14th Feb 2019, 10:21 am	#4
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Replace STK4332 with more powerful one ? If you change the IC can the power supply delivery the extra watts to drive the new chip? Sorry I cannot advise if it would be a simple swop of the IC. The Amstrad is what it is, unless all the fancy features are important and you just want it louder perhaps replace the whole unit with something more suitable. __________________ Frank

14th Feb 2019, 10:25 am	#5
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,874	Re: Replace STK4332 with more powerful one ? And the more powerful amplifier module will need a more powerful power supply, and more heatsinking. And you may find that the speakers can't handle much more Amstrad pared everything down to the bare minimum on all the internal stuff. If you look around you may be able to find something like a Denon/Sony/Technics mini system for less money than you'd pay for STK modules. The modules are known failure points and there is plenty of demand for working ones of all their sizes, so you can guess that they don't come cheap. David Crossposted with Nuvistor..... at least we agree! __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

14th Feb 2019, 10:50 am	#6
pletevl Triode Join Date: Nov 2018 Location: Pont Saint Vincent, France. Posts: 37	Re: Replace STK4332 with more powerful one ? I know about the powersupply and the heatsink. The Ic comes in at around 10 dollars. I have JM LAB / FOCAL speakers connected to it. I would just like to know if it can be done.

14th Feb 2019, 10:51 am	#7
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,819	Re: Replace STK4332 with more powerful one ? If the Amstrad has some sort of audio output, then maybe buy an amplifier that has more power and plug the Amstrad into it, then you'll need to see if the speakers can handle the extra power, which if they are also Amstrad then they are probably a bit weedy as well! Regards, Lloyd.

14th Feb 2019, 10:57 am	#8
snowman_al Octode Join Date: Dec 2018 Location: Llandeilo, West Wales, UK. Posts: 1,092	Re: Replace STK4332 with more powerful one ? You will waste your money and time changing from the STK4332 to a 4412. The STK4332 runs off 24 to 30 volts maximum voltage. If you fit a 4412 straight in there the output power will be the same. You have to increase the supply voltage to 45 - 50 volts to get any increase in power out. Not practical or sensible for the rest of the units functions... Alan __________________ Never Leave Well Enough Alone...