About a month ago I stumbled across a thread (in German) about improving the sound of DeLonghi ESAM coffee machines. It was said, that with rather few changes the sound profile of the machine can be significantly improved. I’ve used a necessary complete overhaul of our DeLonghi Magnifica ESAM 4500 (Pronto Cappuchino) coffee machine to also add this modification…
…with more or less significant improvements. Only two parts are necessary:

• The ULKA EP5 pump was swapped for an Innensys CP4/SP.
• The DeLonghi pressure relief valve was exchanged by a Saeco membrane filter (sorry, no type/model number available).

The original DeLonghi pump.

The new parts installed in the DeLonghi ESAM 4500.

The membrane filter and the pump (originally intended for Saeco coffee machines).

The new pump and membrane filter both let the coffee machine sound much deeper and calmer. Although the new pump has about 20 W more ‘power’, it runs a bit slower (about five seconds for one cup of coffee, as shown in the figure with the acoustic profiles).

Comparison of the acoustic profile of the DeLonghi ESAM 4500 before and after the modification.

I’ve also made a video which shows (or should I say: plays 🙂 ) the before/after effect. The most significant change can be heard after the coffee was grounded, when it is actually poured into the cup.