LM378N Alternative

[thunderfm]

Hi,

I'm restoring a Dynamix 3000 mixing console and I'm struggling to find a replacement IC for the LM378N in the monitor section. Does anyone know of a suitable alternative?

Datasheet is here: https://www.datasheetarchive.com/pdf/download.php?id=69482863dca77b29d6ebbd5cfec86dd9ed701c&type=O&term=LM378N

Thanks!

[Chris56000]

Hi!

Little diode and Nikko Electronics both list small stocks of this device, however if the L.T. supply is less than 22V you can get away with the much more readily available LM380!

Chris Williams

PS!

I don't have the power supply schematic – apparently that never got leaked out of Dynamix's emporium, however, since two ±15V regulator i.c.'s are shown on the monitor board circuit diagram, I would think it's nothing more than a dual–voltage unregulated linear type (transformer, bridge rectifier plus two smoothing electrolytic capacitors) fed from a transformer of something like 18–0–18V at 1.5A!

[thunderfm]

Thanks Chris!

You're right, the PSU is very simple and outputs +-18V. I've already recapped and repaired the PSU.

I'll look into the LM380.

Thanks for your help!

[rayj306]

Holy Canoli,

I cant believe this was posted 3 days ago. I am in the process of restoring a Dynamic 3000 as well.

Ray

[thunderfm]

Regarding the LM380, do you know how one would re-map the pins? I've looked at the datasheets and I'm confused as to what the Output, Bias, and Feedback pins of the LM378 would be mapped to on the LM380?

Thanks,

[ijchan223]

https://www.ti.com/amplifier-circuit/op-amps/audio/overview.html

the 380 seems like a fairly bad choice to me.

to change the pinout you will have to make an adapter board but most likely you will have to change the components that set the gain of the amp and what not.

[fzabkar]

The NTE804 is an equivalent (identical?) part.

https://www.nteinc.com/search.php
https://www.nteinc.com/specs/800to899/pdf/nte804.pdf

Several suppliers have stock:

http://dilp.netcomponents.com/cgi-bin/nteinc.asp?partnumber1=NTE804

If you can believe this ...

https://instrumentalparts.com/ic-ic-lm378n/

[thunderfm]

Thanks, that does look like a good equivalent. I can't seem to find any stockists in the UK sadly, but I'll keep searching!