RCA CA3100T obsolete 38mHz IC

Anyone who knows where to find this old Harris or RCA CA3100T 38mHz IC?

I try to renovate two very well sounding NAD's. To a reasonable price , the NAD 3080 was one of the first amplifiers that was able to drive a load in 2 Ohm.

The TO-3's in NAD 3080 : NEC 2SD287 /2SB539 delivers in the "A" version 10 A by max. 120 Vceo and 7/8 mHz .....10A is to the limit when the load is 2 Ohm.

The mentioned TO-3 NEC's are obsolete as well.

Any suggestions where to find TO-3 /TO-204 op transistors with 12A or 15A and the above mentioned specs ..120V / 7/8 mHz?

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https://sites.google.com/site/httpstubeamp/home/nad-3080

internet search brought up some results .
https://www.google.co.uk/search?q=R...9i57j69i61&sourceid=chrome&es_sm=122&ie=UTF-8

look up c1458 and see if they are close enough . i have 4 in my hand if any use to you .
also i think there is a conversion socket available to use dip

You may need to root around for this IC. See if any substitutes exist for it. And I would highly not recommend 2 ohm loads on any NAD equipment. Do not use soft clipping either. Use NAD within their limitations as they are not conservative circuit designs. .

Littlediode UK

petehall347 said:

internet search brought up some results .
https://www.google.co.uk/search?q=R...9i57j69i61&sourceid=chrome&es_sm=122&ie=UTF-8

look up c1458 and see if they are close enough . i have 4 in my hand if any use to you .
also i think there is a conversion socket available to use dip

Click to expand...

Thanks for your offer...it's very kind of you. I tried to look for the C1458 DIP-8, and it seems to fit in with a little higher +- supply voltage ... not quite so fast, but it should work in the circuit.

I received a link to "littlediode.uk"....they offer the genuine RCA CA3100T. It's not a cheap offer, but this is the original component.

Kim

KentTeffeteller said:

You may need to root around for this IC. See if any substitutes exist for it. And I would highly not recommend 2 ohm loads on any NAD equipment. Do not use soft clipping either. Use NAD within their limitations as they are not conservative circuit designs. .

Click to expand...

Yes, I have been looking around.... I found the IC by help from some friends, and I have just bought 2 pcs. RCA CA3100T...not cheap.....
As I mentioned....a 10A transistor is to the limit when the load is 2 Ohm.
On the other hand....the NAD 3080 drives the AR3a pretty nicely and it's rather difficult for any amplifier to handle the AR3a impedance curve.

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https://sites.google.com/site/httpstubeamp/home/ar3a/ar3a-rebuilt

When it works. I like NAD. Too often they do not work. Especially when owners don't heed their limitations. Just because they can do it briefly, does not mean they can do it full time either. Especially as NAD is built to a price. I do like NAD sound quality and their controls and simplicity. A critic years ago said NAD was for music lovers who wanted High End sound at Panasonic prices. Which was most apt. Bang for the buck.

I serviced NAD from early to the generation after the 3020 line. I checked to see if I had any RCA CA 3100T IC chips, regrettably I didn't. Otherwise I would have given you replacements. I am happy you found replacements. Do run it conservatively on easy to drive loads. They last longer keeping them within their safe operating limits. Your NAD will thank you. Keep the music flowing.