Hello can anyone suggest a suitable replacement for IC 401 in the Philips 22GF603
all the IC has on it is SBF 3 & no other identification number
I have no output on the left channel & scops checks in this area suggest a replacement IC would be a good next step
any ideas
Andrew
Looking at the cct for the Philips (see below), the SBF3 is a dual opamp.
Then researching the SBF3 at the Radiomuseum, suggests (A) and (C) versions appear suitable. The link below for where you can get some (A), although not cheap. I suspect if you did a bit more checking perhaps a suitable generic dual opamp would suffice.
SBF3A Integrated Circuit - Buy from Littlediode
I guess and most importantly, you have checked and verified all the expected voltages on the opamp, and the associated transistors as per the diagram below, to be sure before condemning the opamp?
This thread I found over on UKVRRR (link below) is very telling, it might just be worth investigating on yours, as it turned out to be tin whiskers not the ic.
Sbf3bp ic ? - UK Vintage Radio Repair and Restoration Discussion Forum
Caveat; none of this is my area of expertise, but hopefully enough to get you to follow up with your own research/investigations.
Edited to remove my obvious error, hopefully before pedants jumped on it.
I seem to recall that the SBF3 was a bit more than an op-amp. I think it was a complete AF amplifier up to and including the driver stage and all it needed was an output pair. Bit of an oddity and I'm not sure if it was a special since it didn't have a 'standard' type number.
I seem to recall that the SBF3 was a bit more than an op-amp. I think it was a complete AF amplifier up to and including the driver stage and all it needed was an output pair. Bit of an oddity and I'm not sure if it was a special since it didn't have a 'standard' type number.
Now you mention it, I'm sure I've seen devices like this used by other manufacturers and I'm moderately certain Grundig was one of them - that circuit going straight to an output pair rings bells. Certainly very different from the Leak TL/10 and matching "Point One" pre-amp I have in bits before me (which I shall write up).
I don't recognize that pinout as being anything like any general purpose opamp I've seen..
I've been known to replace such setups with an LM1875. It's basically a power opamp. Runs on anything from 12 to 60 volts, can deliver up to 30 watts RMS with low distortion. And it's virtually indestructible.
For a single power supply amp the heatsink can be bolted directly to ground.
Also very useful for vertical output in many SS TVs, replaces lots of parts.
Hello everybody
Thank you very much for taking the time to reply to my question
From what I’ve been told the SBF3 IC was a device manufactured by Philips in their own semiconductor factory & was used in their own brand HiFi equipment only
Sadly there are no equivalents & a replacement seems to be around £27 which is more than I gave for the record player. So it’s salvage unfortunately.
On a positive note at least the dual AC187 & AC188 can be removed & used for other repair projects
The SBF3 IC is apparently a known problem, myself never encountering one of these devices before. All my testing on the good channel & compared to the bad side keep leading back to the IC
Thanks again
Andrew
You can buy 10 pcs of LM1875 online for under 2 pounds....
Just search for "LM1875 buy"
I'd post the link but it's got too much rubbish in it.
Very, very useful part.
And at two quid for ten, I'd expect I'd get five legs and some epoxy for my trouble.
Where's you sense of adventure?
I've actually had good results buying this class of IC this way.
@irob2345 I prefer genuine components that meet the published spec, personally. I remember a former member of this forum buying a certain brand of electrolytic from China and then opening them up randomly to check they were what they said they were - many were not.
Still not expensive
https://uk.farnell.com/texas-instruments/lm1875t/audio-pwr-amp-b-0-to-70deg-c-to/dp/3116855
