Mottlefeeder

My Ashdown MyBass was fried by a faulty generator at an out-door event. Ashdown talked me through the diagnostic checks I had done/needed to do and then sent me a new amplifier/PSU circcuit board with the agreement that if it worked I would send them the faulty one and £80 and if it didn't work I would send the amp back and they would check it out. No complaints here. David

An alternative might be to get an inverter and a cheaper (but heavier) lead acid battery. Cheap 'modified sine wave' inverters will cause a buzz on some sound systems, but a 300W 'true sine wave' inverter starts at about £80 and gives you the benefit of using the amp you already know and love(?) David

Something you might like to consider - WD40 is designed to repel water, so it may help as a cleaner in the short term, but it will leave a residue that will cause problems later. A proper switch cleaner is mainly solvent, and leaves no residue. David

If you have two tweeters pointing in different directions are you not going to get a hole in the middle at higher frequencies? David

An outfit called Buzzard basses or something similar offers advice and kits for converting 1/2 and 3/4 size guitars into U-basses, and said that the standard (20-inch) Thundergut strings will fit up to 23 inches without risk of snapping. Also, Kala make solid bodied U-basses with a 23 inch scale, including a 5-string with a low B. Aquila also make a short necked bass (https://aquilacorde.com/en/shop/strumenti-en/shortbassone-60/) and rubbery strings to suit - they are doped with copper to make them lower pitched without being thicker. The scale length is 60 cm / 23.5 inches If you want something longer, it may be feasible to pick A-D-G strings for a 20 inch U-bass and a C or similar from a baritone ukulele (also 20 inch scale), and tune them to work as E-A-D-G on a longer scale. David

In theory, yes all test equipment should be regularly checked to ensure that it is still within its specification. In practice, the chances that the test equipment still works, but fails to detect gear that is just bad enough to fail is pretty remote. Given that one of HSE's surveys of electrical equipment found that over 90% of faults were visible and needed no test equipment (failed cable clamps, damaged cables etc) if I'm visually checking my gear every time I use it, and testing it to a schedule, I can live with that residual risk. David

The legal requirement is that the equipment is maintained in a safe state, so far as is reasonably practicable. If you are paid for the gig, you are at work, and it is your responsibility. If you are not 'at work', the organizer is, and it will be his/her responsibility. The easiest way to discharge that responsibility is to ensure that all mains powered equipment has been checked by a competent person, and looking for 'PAT tested' labels on everything is one option. However, there is no legal requirement to put a sticker on each item, and that option can be abused. Asking for a certificate itemizing the tested items is a more professional approach. Carrying that itemized list on your phone, so you can show it/email it to an organizer, is your easiest option. Basic equipment to carry out portable appliance testing (pass/fail of equipment and mains leads) start at £150 [https://www.tester.co.uk/testsafe-minipat-appliance-tester], so it will pay for itself in 2-3 years, or sooner if you start charging for checking other local bands' gear. David

£456,000 in the summer to £500,000 between Christmas and new year - that's why we have January off! I'm not sure we've ever shared the stage, so that's something to rectify in 2019. David

Assuming it is a class D amplifier and a switch-mode power supply, there is not much you can do without a circuit diagram, test gear and the skills to use them. You could take the lid off and check for connectors not seated correctly on printed circuit boards, but I would only recommend that after letting the unit sit unused for several days. The power supply capacitors may be charged to 200-300 Volts and that will take time to leak away. Ashdown charged £80 for a replacement Amp+Power supply board after I blew mine up connecting to a faulty generator, so it may be that is the going rate for swapping out the faulty unit.

Loose Change Buskers, based in South Manchester, are a group of about 30 musicians and collectors (bucketeers) whose sole aim is to raise money for Cancer Research UK. From small beginnings about eight years ago, we reached £100,000 after a few years but in the last 2-3 years, we have averaged about £100,000 per year. For busking, we field a team of 10-16 people per day, changing the front line every couple of hours to keep it fresh. For functions, we have a 5-6 piece band drawn from the same pool of musicians. For me, it started out as a retirement hobby - 'a gig every so often would be nice' - fast forward four years and I'm playing 2-3 times a week: 9 gigs in one week is probably our record. If anyone is interested in starting their own busking band to raise money for Cancer Research UK, please let me know and I will see whether the charity can put together an information pack like the one that got us started. David http://www.loosechangebuskers.org.uk/

No idea where to get one from, but the 'fast food delivery' backpacks used by cyclists look to be about that size. David

If you don't want to go for leather, you could try spraying the underside of your existing strap with the rubbery gunk designed to stop carpets moving around. Alternatively: (a) reduce the neck weight by fitting lighter tuners, (b) make the body heavier by hanging an old phone case full of washers from the bridge-end strap button, or (c) make the upper horn longer to shift the balance point (I gained 50mm by using a 100mm bolt instead of the strap-button mounting screw OR there is a thread on here about adding a carbon fibre 'horn' to a steinberger/hohner type body) I ended up selling my problem bass, so I hope you find a solution that works for you. David

My starting point would be to check the drive units, and how they are wired. If each speaker is 8 ohms, they you have several options, but if they are all 32 ohms, then your options are more limited. Personally, since I don't have a dedicated roadie, I'd be thinking in terms of 2-speaker boxes, and take 1-4 depending on the volume that you want. David

I've just been on the Pascal website and checked out the module specified - it claims 1000w RMS into 8 ohms or 4 ohms ( the latter limited by the power supply capability) at 1% distortion. http://www.pascal-audio.com/product/s-pro2/ On paper that looks good, but if testers cannot get that power out of it that suggests that the gain structure may be wrong. David

Less likely to be the value of the pot, and more likely to be the gains of the circuit blocks before and after the pot. Also, the law of the pot may also be defined by its place in the circuit, e.g. within a feedback loop in designs where there in no separate input gain control. David

I agree with the comments about load and distortion, but most users will never use continous high power, so the larger an amp, the less relevant RMS power becomes. If the ratio of bass peaks to bass average signal is about eight to one [citation needed here], then specifying RMS power will cover you if you want to play a continuous synth or organ bass note, but for any other meaningful bass line you will be paying a lot of money for a high-powered, RMS, 24/7 rated system whose capabilities you will never use. Surely what we need is a measurement that covers both continuous power and higher powers for a defined proportion of the time. For example, 300W RMS 24/7 and 500W RMS for 10 seconds in every minute and 250 W RMS for the remaining 50 seconds. If we specify the right proportions of intermittent and continuous power right then we should be able to ensure that bass amplifiers have enough reserves in their power supplies to provide the heft we crave while not being priced out of our reach. David

It's missing the electrics, but sold as 'missing mechanicals' so it is not clear whether you are getting the bass as pictured, or just two bits of wood. David

It's an area in which I'm weak, so I was interested to watch it. Unfortunately, especially on your second example, I really struggled to hear the undelying bar structure as you played. Can I suggest that after you have demonstrated the note sequence, you play with a metronome or backing track to make it more obvious? David

You can convert a linear pot to a lower value log pot by ptting a resistor between the wiper and one end of the track. A fixed resistor value somewhere between 1/4 and 1/6 of the value of the track will get you fairly close. That suggests that a 100K twin pot could give you a 100K linear and a 20K log pot. Not sure if that helps. David

+1 for Steve Robinson David

Dirty contacts may be the cause of your switch-on click, or alternatively, a faulty output relay could cause that, and the distortion that you are hearing. I've only used Ashdown to repair one of their amps (fried by a faulty generator), so I cannot comment on amp techs in general, but there have been threads on that topic. David

if you don't know its history, it's possible that whatever ambient crap the fan pulled through it has tarnished the Fx socket contacts, and also some of the other switches, so yes you probably need an amp tech, but it may be no worse than cleaning the various contacts in the signal path. This is the type of jack socket fitted to the FX circuit of a Hartke HA4000 This is the state that the contacts were in This is what they looked like after cleaning David

Having seen the block diagram, I suggest starting with a mic cable from the DI out to your mixer. That will check out the whole preamp (post EQ) or just the input stage (pre-EQ) while bypassing the Fx sockets (which might be the problem). David