Mottlefeeder

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+1 for Leathergraft. I have the 100mm wide strap and I can busk a 5 hour set without shoulder pain (but my brain is totally knackered) David

Something to be aware of is that the original rack specification was for 19" by 1.75" modules, but as a result of standardisation in Europe it is now a close metric equivalent. Although the new standard allows compatibility with older gear, building your sleeve around an unknown panel may mean that not all panels will fit. David

Just to add my thanks to Rob for the organisation and pizza, and to say that it was great to meet other bass players and listen to their playing style, and talk about bass gear. Also, thanks to our drummer for the day, whose name I didn't catch. David

Planning to arrive about 10 - satnav tels me it's about 90 minutes from home. David

I replied to James' wanted advert for a Zoom B1-4. The resulting sale was smooth, quick and stress-free. I'd be happy to buy from/sell to James again. David

Great, count me in please. I'm vegetarian too. David

Have you got room for one more body? I can bring - 5-string acoustic Ibanez EW205WNE 5-string fanned fret headless Ibanez EHB1265MS 5-string Hohner active cricket bat Home brew Eminence neo 10" in cab *2 Home brew briefcase combo Battery powered amps (and batteries) Vong variable HPF,LPF & DI David

Yes, that's the plan. Most of my busking is done on 240v from street furniture or battery power packs provided by the event organisers. For those I would use the Meanwell power supply. Where there is no 240v supply I would need a little under 2 × 7AHr batteries to run for the 5 hour set. For open mic nights, and / or Victorian pubs where the only power socket is on the wrong side of a gangway, I can play for a couple of hours on one battery. For 'acoustic' rehearsals and the like, the smaller amp and battery will reduce the weight by about a third. David

And finally, fully assembled, the slightly briefer briefcase:

If your band has a drummer, then your target is to be loud enough to be heard alongside him/her. If they can play quieter for rehearsals then one of the Elf/Gnome etc heads should be enough. If not, then you probably need the same wattage as your performance rig, and wear earplugs. David

Two more pictures: The back of the cab, with the amp connectors in the recess and the power connectors besides the battery compartment access. Amp and battery options - Top left: 90w per speaker Kenwood car amplifier Top right: 7AHr battery with fuse and one way only plug Middle right: Meanwell 12v 5A mains power supply. Bottom left: 15w per speaker ebay amplifier for home practice or 'jamming with a friend' - work in progress. Bottom right: 2.3AHr battery to power the smaller amp, giving a reduced weight rig for travelling - also a work in progress. David

Getting there... The preamp layout The preamp circuit The capacitor bank and acoustic foam on the back wall. David

I understand that some switching power supplies conserve energy by going into a burst fire mode on low loads, and the power-up / power-down is audible as noise on analogue circuits. David

Filling in some of the background, when I started the revamp I considered the electronics recess on the back of the Mk 1&2 and whether I could fit in 'Treble, middle and bass' on one row and 'variable HPF, swept mid-frequency & variable LPF' in a row below. But when I thought about it, I already have EQ on my basses, and I tend to leave the HPF set to suit the speaker, so I was able to curb my enthusiasm and go for a simpler option. - one hi-Z input stage with switched gain, followed by an 18dB/octave fixed HPF to suit the speaker, with a volume control between that and the amp. The only frills were a tuner out and a live/tune switch. Having made that decision, I then realised that the recess I built in for the electronics would be a tight fit for two jack sockets and the circuit crammed in between them, especially since I could not use the space under the overhanging control panel supports. To minimise the number of items on the control panel, I had to ditch the live/tune switch. The tuning jack socket is now always on, and can be used as an emergency 'DI', and you turn down the volume for silent tuning. I also opted for a combined power switch and volume control - a bit retro but it also solved another problem: the switch-off transient that blasted out from the Mk 2 is effectively muted by turning the volume down before switching off - simples. Another problem with the Mk 1 & 2 was that the peak current drawn by the amp was enough to pull down the voltage of the battery to the point where the amp momentarily tripped out on low voltage. Fitting a bank of 10 x 1000mfd capacitors in parallel with the battery seems to cure that problem. David