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About Mottlefeeder

  • Birthday January 31

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  1. I think you mean connected in parallel. Cabs in series would increase the impedance and draw less power from the amp. David
  2. Out with Loose Change Buskers on Sunday, playing at a Makers Market - a 5 hour shift with a front line that changed every hour or so. Also the first serious outing with my combo lockdown project, the "Joe Bloggs Briefer Case". About 150W, but smaller and lighter than a PJ Briefcase - build thread here. https://www.basschat.co.uk/topic/445027-combo-lockdown-project/ Our audience was anyone passing, or queuing for food stalls within about 30m of us, and our PA volume was loud enough to be clear, but not so loud that the audience had to raise their voices as they talked. I was pleasantly surprised to find that the "Briefer Case" was plenty loud enough to be heard throughout our catchment area, and the built in battery was still working after nearly 5 hours of playing time, so I now have a viable small rig, and an emergency backup to the larger rig. David
  3. Portable appliance testing is used to ensure that equipment containing dangerous voltages continue to be safe. If your pedal is mains powered, test it: if it is powered from a 9/12/15/24 volt brick, test the brick. David
  4. There may be some confusion here between amplifier ratings, current drawn on start-up and current drawn in use. An amplifier rated as 100W output will deliver much less most of the time - an average power of about 1/8 of the peak power is possible for bass guitar, and the peak power here will be 100W. To deliver that 12W average power, the amplifier may draw 100W if class A, 48W if class AB (25% efficiency at low power), or 13W if class D (90% efficiency most of the time) During switch on, a large transformer can draw *6 of its rated current in the initial fraction of a second, and a switched mode power supply can be worse, or can be designed to have a slow start to limit the inrush. When you connect several bits of kit to a single socket, you should switch them on in sequence so that the switch-on current pulse does not take out the fuse. It is unlikely that your class AB amps and class D amps will draw more than 13 A, but your lights might. David
  5. My cab came in at 7kg I think - I'm away for a couple of days, so I can't weigh it. I'll let others comment on whether you can swap speakers.
  6. Might have been this one? https://www.basschat.co.uk/topic/322103-battery-powered-rig/?tab=comments#comment-3959658 David
  7. I've just looked on the Eminence site for their recommended enclosure designs, and the links don't work. Searching by product type does not bring up B102, and a search for B102 finds it, but when you click on that product, the link takes you elsewhere. I'm not sure if that is a fault on the website, or an indication that the product in no longer available, but either way it doesn't move us forward. David
  8. An RCD at the switchboard/fuseboard will not require an earth to operate correctly, but many plugtop RCDs require an earth before they will switch on. David
  9. Depending on what it is you are trying to adjust out, a neck shim might allow you to back off the truss rod tension David
  10. Odd - it has an electronic crossover, but only one speaker according to the website, and no mention of battery operation, which would help it compete against the likes of the Rolland Bass cube. David
  11. Thanks @basstone, but I've already done my modification - fixed gain of 10dB and a switched passive attenuator of 10 dB between the instrument and the input capacitor. It has the advantage of dropping the input impedance for high gain active basses. The gain switch click is now a lot quieter, as is the power on/off click, so I think I'll stop there. So, what have I achieved? The positives - It's small, battery powered, loud for its size and plays a low B without farting. The amplifier is rated at 90w x 2 into 4 ohms x 2 with a 14.4 volt battery, but it is not clear whether its power supply compensates for lower battery voltages, so it could be down around 100W or worse, but it's still pretty loud. At a recent band rehearsal in someone's garden it was still going after 2 1/2 hrs, but that was at a relatively low volume. The negatives - Twin speakers means two ferrite magnets, and a lead acid battery, so it weighs 9.7kg, which is a little heavier than I had hoped. Secondly, small speakers are less efficient, so it uses four times the power to generate the same volume as my neo Eminence Basslite 1 x 10 cab. Having said that, where I need a small loud combo, this will do the job. A few pictures and a couple of sound clips to finish off. For the sound clips, instrument EQ was flat, HPF was at 30Hz, and for the Yamaha, pickup blend was 75% neck, 25% bridge. The recorder is a Tascam guitar trainer which I assume has reasonable microphones on it. Ibanez acoustic.mp3 Yamaha solid body.mp3
  12. I think the main advantage to a manufacturer is that all their fretboards are cut the same so they save on a bulk order. They can then put in frets or lines. David
  13. Finally built the new circuit with the switched gain on veroboard. I didn't finish working out the layout before a trip to see family in the North, and I didn't finish the build before a trip to see family in the South. Add in some self isolation between visits, just to be on the safe side, and that's a month gone. The circuit has enough gain, which was the reason for the redesign, but the gain switch causes a loud 'crack' when operated, so I'm not out of the woods yet. I'm now looking at a fixed gain preamp, with a passive attenuator on the input. More rework... Definitely reached the point where I wish I had not started this. David
  14. Back in the 70's, Barkley James Harvest had a hit with 'Mocking bird'. When I saw them at the Hammersmith Odeon, they had a neon tube prop that they only used once, for that song, on their 5th encore - they planned 5 encores? David
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