First set of piezo preamp boards

Error message

  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Use of undefined constant filter - assumed 'filter' in preg_replace() (line 1 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module(363) : regexp code).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _filter_drutex_process() (line 315 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Use of undefined constant filter - assumed 'filter' in preg_replace() (line 1 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module(363) : regexp code).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _filter_drutex_process() (line 315 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Use of undefined constant filter - assumed 'filter' in preg_replace() (line 1 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module(363) : regexp code).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _filter_drutex_process() (line 315 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Use of undefined constant filter - assumed 'filter' in preg_replace() (line 1 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module(363) : regexp code).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _filter_drutex_process() (line 315 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Use of undefined constant filter - assumed 'filter' in preg_replace() (line 1 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module(363) : regexp code).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _filter_drutex_process() (line 315 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Use of undefined constant filter - assumed 'filter' in preg_replace() (line 1 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module(363) : regexp code).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _filter_drutex_process() (line 315 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Use of undefined constant filter - assumed 'filter' in preg_replace() (line 1 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module(363) : regexp code).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _filter_drutex_process() (line 315 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_create_regex() (line 363 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Deprecated function: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in _drutex_unhide_all() (line 479 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).
  • Notice: Undefined index: en in drutex_node_view() (line 81 of /home/davemr/mo-seph.com/sites/all/modules/drutex/drutex.module).

Got the first set of boards from [http://mattvenn.net Matt Venn] for prototyping piezo preamps, and they're great! I've soldered both boards, after using the JFET matching described [http://www.nrgrecording.de/html/fetmachting.html here] (NOTE: link seems to be dead - I'll copy the circuit diagram from my notebook).

I'm constructing contact mics by gluing a magnet to the white side of a piezo disc, then soldering the preamp on, and gluing it (with some suitable insulation!) to the back of the magnet. Magnets are good for connecting with many metal structures, which often have good noises in. I think having a bit of weight behind the disc also helps to pick up more bass, but I haven't tested rigorously.

Comparative recordings to come.

Clean first-gen piezo board
First-generation piezo board soldered
Closeup of soldered boardPreamp on back of disk

Project Type: