2014-03-25 · in Tech Notes · 371 words

While I'm not in general a fan of changing fashions in audio hardware, there is one big advantage: the hardware that I dreamed of owning ten years ago can now be bought, boxed, with all its accessories, for next to nothing on eBay.

Delta 1010LT

This is an M-Audio Delta 1010LT, a PCI soundcard with 8 analogue I/O channels, plus SPDIF, word clock and MIDI — which means I've got enough input channels that I don't need a mixer next to my PC any more. This is the third M-Audio card I've owned, having started with an Audiophile 2496, which I upgraded to a second-hand Delta 44 when I started experimenting with SDR. All these cards use the ICEnsemble ICE1712 PCI audio chip, which has excellent Linux support and works well with JACK; they differ in the number of audio codec chips on the board (the 44 and 1010LT use the AKM AK4524VF, and the 2496 uses the slightly-higher-spec AK4528VF).

But there's a problem here — can you spot it?

Here are some close-ups:

Leaking electrolytics

Leaking electrolytic capacitors — not uncommon in computer hardware of this vintage...

Gunk on the underside of the board

... and the electrolyte's wicked through the nearby vias and started to attack the solder joints on the underside of the board.

Those are reservoir capacitors for the positive and negative rails of the perfectly respectable NE5532 op-amps that act as input and output buffers, fed from the PCI +12V/-12V pins via 100Ω resistors. Noise on those supply rails wouldn't be a good thing — those capacitors need replacing.

I desoldered the existing capacitors, with a bit of fresh solder and a solder sucker, and gave both sides of the board a good scrub with some isopropanol and an old toothbrush to clean off the electrolyte muck. The original capacitors were 470µF 16V, and a quick trawl through my capacitors drawer turned up some 1000µF 16V replacements:

Shiny new capacitors

For this application, there's no harm in the value being a bit larger, but would they physically fit? Time for a test fitting:

Test-fitting the new capacitors

That'll do — although I'll need to be careful if this card's ever sitting next to something with a heatsink on the back! The capacitors fit neatly enough with some careful bending of their leads:

Delta 1010LT with replacement capacitors

That looks better — and the card works nicely.