Project files: An unloved amp?

Well this is really “unloved” in two ways, but I thought I’d share it anyway 🙂

A while ago I ws cleaning up a little and I found the boards for this amplifier based on the LT1210 IC. Despite being from 2016 I never put the design together originally (don’t remember why) so I decided “better late than never” and tried it now. And you know what – it works!

Apart from being “unloved” because it took me nearly four years to put it together and test it, this amp is also “unloved” because the LT1210 doesn’t seem to be used that much for audio applications. It is a a current feedback power opamp with a massive current capability and so it should – albeit with a few caveats – be possible to use for audio as well with good results. Also, like e.g. the AD815 the original applications for the LT1210 (ADSL line drivers and suchlike) have all but disappeared, so – again with a few caveats – it should be possible to pick these ICs up at very good prices.

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Project files: The ACP+ clone…

Well, both my ACP+ clone boards are now fully populated with relays and working as expected so I guess it is appropriate to share the design files 🙂

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ACP+ clone progress…

Just a quick update because my ACP+ clone is now (very nearly) done. It took a bit longer than I had expected because of some delays getting boards and parts, and I do actually still miss one part that will hopefully turn up next week – fingers crossed.

As I did with the “Whammy” headamp I’ve taken the original “all-in-one” board layout of the ACP+ and turned it into a mono amplifier board and a separate PSU (and offboard volume control). Other changes include:

  • New heat sink profile (Fischer SK104 or equivalent).
  • Various footprint-changes for parts on the amplifier board.
  • Larger footprint for the initial filtering resistors in the PSU so it’s possible to use inductors instead.
  • Output switching (pre/headphone) directly on the board with a tiny Omron relay (these are the parts that I am still missing).

Until I get the relays I can’t do the last bit of testing but so far the PSU works and both amplifier channels bias correctly and play clean audio and that is always a good starting point 🙂

More information (and hopefully better pictures…) to follow when everything is done.

Happy New Year!

This year’s new years destination is something a bit closer to home – Berlin! Partly because I haven’t been here for a while, partly because I haven’t been here for New Years but I have heard a lot about it from friends and family.

I don’t expect a lot of diy audio related stuff to happen on this trip, but hopefully that means I’ll come back with the batteries fully recharged and ready for more projects in 2020 🙂

As always, thanks to everyone who reads, follows and comments on what I do here and best wishes for 2020.