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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 8th Mar 2021, 7:41 pm   #1
Michael Maurice
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Default Replacing TBA800

I need a TBA800 IC and although they are available from a couple of sources, they are not available from Cricklewood Electronics.

Can one fit a TDA1908 in place of the TDA800?
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Old 8th Mar 2021, 8:09 pm   #2
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Default Re: Replacing TBA800

What about using a TBA810?

In times-past I used loads of them [the TBA810AS version for preference. with a proper bolted-on heatsink]. They survived a lot better than the versions where 'heatsinking' was allegedly supplied by an unspecified area of PCB-copper.
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Old 8th Mar 2021, 9:40 pm   #3
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Default Re: Replacing TBA800

The maximum supply voltage for TBA810 is lower at 16V, There is nowhere to bolt a heatsink on to.

The TDA1908 has a max supply voltage of 30V
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Old 8th Mar 2021, 9:47 pm   #4
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Default Re: Replacing TBA800

What exactly do you intend using it for?

The TBA810AS I suggested has the 'wings' sticking-out sideways from the package, with two holes for the heatsink to bolt to.

One version has the 'wings' folded to fit to an inefficient PCB-area heatsink but that's silly.

I used loads of the TBA810AS in times-past. Pye also used the chip in the "Olympic" two-way radios back in the late-70s/early-80s. It's pretty much bomb-proof.
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Old 8th Mar 2021, 9:59 pm   #5
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Default Re: Replacing TBA800

It's in a Stereosound radiogram with a supply voltage of around 22 -24V, that is why I'm not keen on the TBA810
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Old 9th Mar 2021, 9:51 am   #6
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Default Re: Replacing TBA800

Have had a look at my vast amount of ICs everything except TBA800, you could go with these.https://www.ebay.co.uk/itm/TBA800-wi...sAAOSwRvdZZlhs.Do not think TDA1908 has the same pin out as TBA800.
John

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Old 9th Mar 2021, 12:13 pm   #7
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Default Re: Replacing TBA800

I just looked at a Fidelity Stereosound chassis, mine has SN76013, as does the equivalent Music Centre MC2 on Radiomuseum. If the pinouts are the same I can offer several, with or without PCBs
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Old 9th Mar 2021, 12:23 pm   #8
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Default Re: Replacing TBA800

Please excuse my curiosity Michael, given that the radiogram is not by any means in the first flush of youth, and that the TBA800 as fitted lasted this long before (presumably) dying, why not just fit a 1 for 1 replacement if they are available (as they appear to be,) just not from Cricklewood - apparently?
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Old 9th Mar 2021, 7:33 pm   #9
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Default Re: Replacing TBA800

Seller G00fie on ebay has them for under £2 each

https://www.ebay.co.uk/itm/TBA800-wi...sAAOSwRvdZZlhs
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Old 9th Mar 2021, 11:46 pm   #10
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Default Re: Replacing TBA800

The reason I wanted to replace with another type is because I needed it quickly to finish a job, the post is so bad, it can take a week for anything to arrive. That said, Cricklewood Electronics are getting some in stock, so hopefully I'll get one tomorrow.

BTW TDA1908 does not work in place of a TBA800
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Old 10th Mar 2021, 12:34 pm   #11
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Default Re: Replacing TBA800

Be careful the repair does not bounce back with the other channel being faulty. Been there done that! From my experience with any ic outputs that share the same power supply, change both of them. This especially applies to the SN76 series, the supplies are often close to the chips maximum operating voltage and are seldom properly regulated. This can cause a momentary increase of supply that weakens the opposite channel output chip.
Good luck.
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Old 10th Mar 2021, 1:50 pm   #12
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Default Re: Replacing TBA800

Hi!

I should also add the '76 series of audio power ICs has a bias output pin that is often used when two of a pair are used in a stereo unit, and failure of these devices can occur due to either or both going defective within the bias circuits, the recommendation by Uncle Les and others always was to replace both these ICs together as a pair!

The TBA800 to TBA820 are all together much more reliable devices with better internal fault protection, but it is still a very good tip to replace the small electrolytic caps dotted around it as well as the LS coupler – failure of the smaller 47u one used as the bootstrap capacitor can cause a replacement i.c. to have a short life!

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Old 12th Mar 2021, 1:56 pm   #13
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Default Re: Replacing TBA800

Thank you all for your advice, I will be replacing these later today together with a couple of capacitors as suggested.

What I should have told you was that the reason it failed in the first place was that I inadvertently shorted the speaker whilst carrying out some tests!
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Old 14th Mar 2021, 6:52 pm   #14
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Default Re: Replacing TBA800

I knew the SN76013 (etc) ICs as 'flying fins'. Don't know if that was a common name.
Weren't Sinclair's IC12 the same thing?
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Old 20th Mar 2021, 10:48 pm   #15
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Default Re: Replacing TBA800

Rumour has it that they were the Texas rejects.....
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Old 27th Mar 2021, 10:08 pm   #16
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Default Re: Replacing TBA800

Quote:
Originally Posted by stainless View Post
I knew the SN76013 (etc) ICs as 'flying fins'. Don't know if that was a common name.
Weren't Sinclair's IC12 the same thing?

There were replacements with a square heatsink marked AC76013N. If I remember correctly, they were made by RCA. I don't know if reliability of these was any better.
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