I built a new pack of 12V+6V lead-acid batteries to provide +/- 18V for my JFET RIAA MC phono stage. Despite the bad reputation of these being noisy, Geoff tried them with great success. The Haze brand are the recommended and the low capacity ones (i.e. 1.3Ah) are very quiet.
I decided to build and test it. As the proof is in the pudding!
Here is a simple test on my workbench of the 18V battery set with a 20mA load to simulate the RIAA stage consumption. The LC is formed by a 33mH choke in differential mode + 100uF/20V OSCON capacitor.
No twisted cable pair, just banana alligator clips. The noise level is really low and is obvious that 3.3μV 50Hz hum is picked from the workbench. I also listened to it for a while and can hear the difference. I monitor the FFT with no average and lower FFT size and also couldn’t see any spikes due to chemical reactions. They may happen in future though 🙂
The performance of this battery pack is outstanding, so far so good!
I’m interested in the difference between lead acid and for example LiFePo . Intresting stuff this!
Yes, but not planning to buy any LiFePo battery packs shortly given its cost. I’m more than happy with what I have now so problem sorted!
cheers
Ale