Mottlefeeder

I can see both sides of the argument when pub A has no bands due to Covid, and during that period, punter B buys a property close to the pub. When the pub music restarts, punter B complains that it spoils his peace and quiet and pub A appeals because they were there first.

As an older musician with hearing aids, I stopped going to a local open mic night because everyone played at the level the house band had used to keep up with heir drummer. Playing three songs and spending the rest of the evening shouting at people beside you is not my idea of fun.

The point I'm getting to is: why does the music have to be that loud? - if the drummer cannot play quieter, get him/her on an electronic kit through the pa, and control the sound level. If the guitarist has an overdrive-based signature sound, get it from a pedal and put it through the pa.

It's not rocket science,  it just needs people to push hard enough, and it sounds like that is what they are starting to do.

David

Another downside to the 'modified sine wave' invertor is that the harmonics it produces will kill small transformers - they run so hot that the thermal fuse melts.  Not a problem if your FX power supply is modern and switched mode, but it is a problem if you have an older transformer based wallwart, or want to run a small mixer where the power supply is something like 15-0-15 AC. I lost several transformers before I worked out what was going on.

David

As an alternative to converting battery power to mains and back down to amplifier supply rail voltage, you could consider a car booster amp.  These are designed to work from a 10-15V supply, contain a dedicated voltage converter, are built to withstand harsh treatment, and have a sensitivity that allows you to connect an active bass to them and get something approaching full power without needing a preamp.

£70-80 will get you 75W into 8 ohms or 150W bridged into 4 ohms. All you have to do is bolt it to a piece of plywood, connect speakers, power and input jack socket, and you are good to go. The amp even has its own fuse so you don't have to provide one.

The amp on the left is Class AB as described above. The amp on the right is Class D, giving 35+35W into 8+8ohms or 90+90W into 4+4Ohms - it's 4 amplifiers wired as two bridged pairs.

David

30 minutes ago, Sonic_Groove said:

Reggaebass do you run double-ball flats on that? The only ones I've ever found cost a bomb. I do think part of the of the original Steinberger sound is the Carbon-Fiber in my experience Flats sound great on Carbon basses

I bought a convertor block to clamp normal strings, and it gives me a much wider choice of strings. It might be worth investigating. I'm using D'Addario Chromes on a Hohner 5 string headless. 

David

Why it is 440Hz - a bit long winded, but fascinating.

David

On 15/10/2021 at 17:29, Woodwind said:

Car amplifier is a great idea.

Several 12v mixers around to run all the OP's inputs from this as well

The picture below shows:

On the left, a Class AB stereo car amp bolted to a piece of plywood, and connected in bridge mode to give 75W RMS into 8 ohms or 150W RMS into 4 ohms. With the 7 AHr battery shown, it gives about 2 hours of playing time.

On the right, a Class D 4-channel amp which I use as 2 bridged pairs, each giving 35W into 8 ohms, or 80 W into 4 ohms. Using the 7AHr battery, I busked for nearly 5 hours and it was still going.

The mixer I use is the Behringer 1002B, which runs on mains, or two 9 volt batteries.

https://www.andertons.co.uk/behringer-1002b-battery-powered-analog-mixer-000-a0401-00010?utm_source=google&utm_medium=organic&utm_campaign=surfaces&gclid=Cj0KCQjwtrSLBhCLARIsACh6RmgidspbWPV-o7EHRGp4bv5UzMbTzEJSkdUOqxtAMiEnW3izZmrxuAMaAgUrEALw_wcB

Not a combo, but less than half of the price of a street cube if you use an existing smallish speaker cab.

David

1 hour ago, Woodwind said:

Will you be busking in resonant spaces (eg railway arches) or completely outdoors?

 

I ask as I used my phil jones double4 running off a battery as a two channel system for my Contrabassoon effects and samples.

In railway arches it is the perfect volume.

 

In unsupported areas - footpath etc it completely dissappears. It's like I'm making no sound at all.

 

I have seen people running multi instrument sets ups in outdoor spaces using the new 240v powerblock systems and using a mixer into a single powered pa speaker.

 

If I was starting from scratch tomorrow this is the route I would go. The battery for my double4 was 100quid right off the bat which makes this thing pretty good value -

https://www.amazon.co.uk/Jackery-Portable-Explorer-Generator-Outdoors/dp/B08RNPYLQW/

 

It says it will provide 200w (400w peak) so that would do a mixer and 100watt+ PA speaker

The problem with inverter + mains systems is the standing current drawn by the amplifier. It may only be 12 watts which is insignificant on mains, but that alone is 1 amp continuously from the battery, and that assumes that your inverter is 100% efficient. My amplifier plus inverter takes 1.5 amps before it produces any sound.

A better route is to use a car audio amplifier connected directly to a 12 volt power pack - less voltage conversion eating up your battery power.

On 11/10/2021 at 16:03, DaytonaRik said:

Does anyone else carry a spare mixer?

I carry the bands spare mixer. We mainly plug into mains or generator supplies, so I went for a small mixer that could also run on batteries. We've needed it twice in the last couple of gigging years, both times because of generator problems.

The string clamps sold by a US independent have a bowl ended screw pushing the string into a bowl shaped recess. This clamping mechanism pinches the string windings against the core so that the string will not unravel when the tension is increased, nor when the tension is released and the clamp is removed.

That works for my steel flatwound strings, but may not work for nylon.

David

The three kits are different.

The diamond shape of the 4 pots rotates from kit to kit.

David

In my defence your honour, I was just following orders.

The supplied instructions referred to fixing the module using the supplied screws or cable ties, and made no mention of the need to earth the case, which has no discernable earth terminal. 

Having avoided cheap far-eastern modules because they have a reputation for being noisy, I assumed that a major brand would have incorporated whatever was necessary into the module. Having said that, to be fair to them, a bass pickup is a lot more sensitive than anything likely to be fitted in a car, so it is probably fit for purpose in their eyes.

One learns (or is reminded of things one has forgotten).

David

A quick update - 

Checking out mains power supply options, I noticed that I was getting a high-pitched buzz through the speaker. I rejigged the earth connections to get as close to a single earth point as I could, but then noticed that the noise varied as I moved the bass around, so it was probably radiated interference. With a bit more testing I discovered that the amplifier case isn't connected to earth. 

Connecting it to the earth star point cured the problem completely.

David

34 minutes ago, SteveXFR said:

Have you got your cabs connected in series? ...

 

I think you mean connected in parallel.  Cabs in series would increase the impedance and draw less power from the amp.

David

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

PM'd

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

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

47 minutes ago, fleabag said:

That might be it

What did that extension cab weigh in the end ?  The Beymas i have are only 3.1 kg each

 

I dont do WinISD, too  thick, so do you think a cab for the Beyma would be equally small as your little cab ?

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. 

3 minutes ago, fleabag said:

That build is bigger than i wanted, probably because it features a tweeter and crossover.  I thought i'd seen  a plain 10"  build without tweeter on the forums, but i could  be imagining this

Might have been this one?

https://www.basschat.co.uk/topic/322103-battery-powered-rig/?tab=comments#comment-3959658

David

1 hour ago, Stub Mandrel said:

 

 

I'd have ago at a design but WinISD keeps coming up with strange results, like a cabinet of over  a million litres!

 

That's what it suggests for an Eminenece 102 for a vented enclosure and default chebeshev design.

 

... ah just tried again and It's come up with a 16.5 litre box, but the curve -3dB point is about 110Hz - this is a speaker with a resonance of 35Hz claimed to work down to 40Hz.

 

What is going on?

 

Edit - I was choosing B102 instead of Legend BP102. Now the -3dB point is at 42Hz and the volume is 106 litres which looks a little big but potentially doable.

 

10cm x 10cm x10cm is a litre =  1 cubic decimetre. 5^3 is 125. so a 50cm cube would be 125litres, so if using thos external dimensions and 13mm ply...

 

Internal volume would be 4.74^3 =  106.4 litres A 50cm cube with the front inset 1cm would be about 105 litres. WinISD suggests a vent 10cm x 9.03cm long.

 

Any skilled WinISD joockeys want to check these figures or suggest a better driver*?

 

*Particularly one happy in a smaller box.

 

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

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

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

1 hour ago, pineweasel said:

Half a Double 4 by the look of it, and “Asia Market Only”

https://pjbworld.com/cms/index.php/p-x-4-combo-amp-asia-only/

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

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

3 hours ago, Soledad said:

Very good indeed (IMHO) to see a maker doing UNLINED necks. Personally I don't see the point at all, from a normal playing position I can't see the lines... and they do look a bit naff anyway...

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