Mottlefeeder

I haven't used one, but I checked out the website information - the input is 15 volts at up to 1 Amp, and the outputs are almost all 9 V up to a total load of 1 Amp. When it is lightly loaded I would expect it to work well, but if you take it up to the current limit, the electronics inside will have to dissipate (15-9)V * 1Amp, which is 6 Watts. To do that you would need to leave space around it for air circulation, so its footprint would be considerably bigger. David

Thank you both - very useful information. David

[quote name='Andyjr1515' timestamp='1498855653' post='3327640'] ... you need to have the strings slackened off before you adjust the truss rod in any event. [/quote] When I tighten the truss rod, I tend to straighten the neck with hand pressure to make the operation easier. Loosening the truss-rod reduces the pressure anyway, so I did not think it was a problem. I only remove one string at a time, because I'm working on the basis that a truss-rod force with no counter-acting string tension is as bad as string tension with no counter-acting truss-rod force. You have much more experience, and you do it differently, so what is the rational behind your advice? David

Looking at your truss rod cover, is it shallow enough to allow it to be removed while the strings are on? It looks quite thick in the picture. David

I take one bass to play, one amp, two speaker cabs, and cables to suit that equipment. Locked out of sight in the car, I keep a back-up bass, spare amp, and spare cables. I work on the basis that I should be able to deal with any failure anywhere from instrument to speaker. On two occasions in the last month I have had to fall back on my back-up U-bass (space-saver spare?) because the stage volume was giving me feedback problems with my jumbo acoustic bass. David

[quote name='cheddatom' timestamp='1498638922' post='3325989'] In my experience you get less feedback on an acoustic guitar when you go with the magnetic pickup as opposed to the peizo pickup. I'm not 100% sure on the science behind that but it's my experience. [/quote] I have acoustic basses with peizo pick-ups and solid-bodied basses with magnetic pick-ups, but none have both, so I have no comparable experience to yours. Possibly the magnetic pick-up majors on string vibration, while the peizo pick-up majors on body vibration if it is under the bridge and transmits string vibration to the body? David

[quote name='cheddatom' timestamp='1498568245' post='3325568'] has anyone ever had the peizo go straight to the PA and had a separate magnetic pickup for just the stage monitors? I wonder if that'd be much better? [/quote] A peizo on its own would need a high impedance which the PA input would not provide. If you had a buffer preamp, then you could feed into the PA, but the problem is the instrument's area of wood which picks up the local vibrations, and I don't see how having separate feeds to the PA and stage monitors would reduce that - am I misunderstanding your comment? David

[quote name='Maude' timestamp='1498547786' post='3325331'] Yep, used it for a couple of rehearsals and a couple of gigs. I did away with the volume control as I've got one of them on my amp already, the HPF control seems to work backwards in that fully clockwise seems to be the least affected, and I leave it there, fullest sound and my speakers have stopped leaping around. If I turn the HPF control fully anti-clockwise the sound is very thin so I assume that's the most affected. It has really cleaned up the subsonic rumbles and made the whole band sound clearer although it seems to add almost a compressed sound to my bass, like a very sharp attack to the front of a note but that could be the sound of my playing but was disguised by all the low frequencies that are now gone. [/quote] The control pot fitted to the FDeck is logarithmic to give an even sweep of frequencies as you turn the control - it's cheap because lots of circuits use them, but in this design it works backwards so fully to the right is 30Hz cut-off and fully to the left is 140 Hz cut-off. A reversed logarithmic pot would give you 30 Hz to the left and 140Hz to the right but cost you a lot more money. In addition to cutting out the subsonics,you can also use it to make your sound more punchy - as you increase the frequency, you will hear the bass becoming clearer, before you reach the point where it becomes too thin. Also, if you are on a hollow stage, increasing the frequency of the cut-off can remove a lot of the boominess. It's a lot more versatile than a 'set and forget' device. Finally, the 'compressed sound' that you are hearing is more likely to be soft clipping. One of the design feature of the HF-Pre is that if you overload the front end, it does not sound ragged like an overloaded transistor preamp. You could check this out by playing quieter to see if the sound changes, and if so, then consider whether you can get a reduced output from your instrument. David

Another option that has not been mentioned is to turn down the bass. Using a graphic EQ or a high pass filter (on the PA desk?) you can take out the bottom octave and probably not notice it has gone, except that your bass will be clearer and have more punch. If you use a variable high pass filter e.g. the FDeck design, you can take out more lows, and your sound will become more 'low-mids' focussed, but will be less likely to feed back and will still cut through. Finally, if the stage volume is still too much for you to cope with, go for a smaller-bodied instrument - my Countryman bass uke works long after I have given up with my jumbo-bodied Ibanez. David

[quote name='deepbass5' timestamp='1498375458' post='3324094']... Use an RCD socket outlet on your extension to be safe [/quote] Sorry but I disagree with this - domestic 'plugtop' RCDs are intended to be used on electrical systems where there is a connection between the neutral conductor and earth at the distribution board. On small generator powered system, if the generator is connected to the earth by a metal stake, and not electrically connected to the generator neutral, many RCDs of that type will not allow you to power up. David

My experience is that class D amplifiers have better filtering than old school amps, so you are less likely to get a whine from your bass.Wost case scenario, your bass will pick up generator brush noises and whine, most of which can be reduced by EQ settings, and by keeping one hand on your strings - at all times. With regard to power ratings, my Ashdown 500 Watt amp takes 24 watts on standby, and about 35 watts when I play through it. This is a major advantage of class D amplifiers - my class AB amplifier has the same standby power, but takes about three times the power in use. In general, a bass amplifier's average power (what the generator must deliver) is about an eighth of the peak power (which your amplifier is designed to deliver). David

[quote name='Andyjr1515' timestamp='1492167792' post='3278406'] And out comes the hacksaw again : And we have two strings strung up! I would have been 4 but my pretend fretboard was too narrow Here's the tuner block: ...and here's the double clamp at the pseudo headstock: ...and here's the whole thing: ... [/quote] I've only recently found this thread, so apologies for revisiting an earlier part of the design. I'm using the same bridge and nut arrangement on a headless bass kit, and I have a problem with it - where the string is bent at 90 degrees to be clamped, you need to ensure that there is no outer winding on the E string, otherwise it breaks when you bend it. On the headless bass kit, the strings just happen to be have the correct length of overwinding, but when I tried to upgrade, I ended up unwinding overwindings to get the string to fit - flatwould strings are not an option. Inevitably, manufacturers do not specify ball-end to end-of-overwinding lengths, so you may find that your design limits the choice of string you can use. A string clamp that will cope with the full string diameter would be more versatile. David

The badge may be authentic, but the grill is not and the bass speakers are not... David

I'm in a band that busks to raise money for Cancer Research UK. In the run up to Christmas we regularly play outdoors in temperature below 10 degrees. On one day, the car thermometer read 3 degrees an the way there, and also on my way home, so we probably played for 5 hours at about 4 or 5 degrees. As others have said, wear fingerless gloves, wooly hat and lots of layers. David

Anf other point that may help Keep the verse, chorus and bridge separate in your head. If one of them has a keychange, it can throw you off what you thought you had nailed down. Taking this example from our set list, I could not identify the key, but another musician pointed out that it was two keys (it's Tom Jones - Delilah) Verse: Dm /A7 /Dm /A7 /D7 /Gm /Dm /A7 /Dm /C7 / Chorus: F /C7 /F /F7 /Bb /Gm /F /C7 /F /A7 / There is more information in this thread - http://basschat.co.uk/topic/288025-here-are-the-chords-but-im-on-capo-4/ David

If you are playing rockabily on an acoustic instrument, you are probably not playing at pub-rock sound levels. Your gear is not in the budget bracket, so it ought to be working better than it is. When you say that the source is not the problem, you may be equating a 34 inch scale low-action instrument with a 41 inch scale high-action instrument based on them both having magnetic pickups. But the subsonics generated by the longer string, being plucked harder, will be substantially higher and this is where I think your problem lies. If you have access to a mixer with a high pass filter on it, try playing through that and into your existing setup. Those filters are typically set at about 75-80 Hz, and will give you the punchy sound you want while taking out the fundamental that is (probably) distressing your speaker. An MP3 will have bass that has probably been compressed or limited, so this can also be used to identify the problem. Yes is is possible that your amp just doesn't go loud enough, but in my experience, not amplifying stuff you don't want leaves much more power to amplify the stuff you do want. To put that in context, I'm using 150 Watts through a pair of 10 inch speakers and I'm playing a 5-string (low B) on outdoor gigs. It works because I have a high-pass filter. David

Third time lucky? So for you have discussed the amplifier and the speaker. Just supposing that it is your instrument that is generating the problem - you could spend quite a lot of money on an amplifier whose power you can not use, and a speaker that farts even more because you have put it a box that was not designed for it. May I suggest that before you spend any money, you do some more testing with other signal sources - conventional bass guitar, MP3s that have a bass solo on them - anything other that a DB with a Piezo pickup - and find out if they fart too, or can be played at the higher volumes that you want. David

[quote name='Wayne Firefly' timestamp='1488551348' post='3249947'] So the existing pre amp / tone controls would not work then ? Looks like a combo search then !! [/quote] A cheaper interim solution might be to turn down the bass a lot, turn up the volume to find out how loud it gets, then start bringing the bass back in. If you can get enough volume, but with not quite enough bass, then a high pass filter may be all you need. David

A common problem with amplified uprights is that the sub-bass as you pluck the string is lower than the speaker can cope with, so it farts. Once you have got rid of that problem, you may find that your existing gear can be turned up to be loud enough. If you search on 'Thumpinator' or 'FDeck' or 'high pass filter' you will find several options to filter out that low frequency content without strangling your sound (FDeck is the designer of one of them). Alternatively, I am based in Warrington, and would be happy to meet up so you can try my high pass filters (based on the FDeck design). David

[quote name='fleabag' timestamp='1488537839' post='3249737'] How did you get varnish to stay on a waxy finish like boot polish ? [/quote] From what I remember, I was using black and a couple of shades of brown, and white spirit to take off the excess, so by the time I had finished the surface was clean and did not feel waxy. I assume that the solvents in the varnish would disolve and blend with any sub-surface wax. David

I use a Snark clip-on, and it is sensitive to position. At the end of the headstock, it loses the B and the E, unless you press the transducer hard against the headstock, then it picks it up. Alternatiely, moving it closer to the nut works, but may get in the way when you need to get to a tuning head. I also have a headless bass tuned BEAD, and the Snark works fine clipped onto the volume control knob. David

Many years ago I stripped the varnish off an old chair leg as I repaired it, then tinted it with a mix of brown and black shoe polish to bring it close to the original colour, and then I revarnished it with a clear varnish. Yes it works, providing the wood surface is not sealed, and provided that you seal it afterwards. David

Just to echo all the comments above, I had a great day, and I'm very grateful to Chris and Kevin for setting it up. It was interesting to try / hear things I had only read about, but nice that I came away without feeling that anything there would make a significant difference to my bass playing. When first I arrived, I walked into the main bar area, and the bar-person and security person conferred and told me that there was no bass-players' event on that day. Fortunately, I stuck around and eventually found another entrance with a B/chat notice on it. For anyone who sets up another bass bash, may I suggest that a contact mobile number is PM'd to all delegates for use in emergencies. David

[quote name='i81b4u-ou812' timestamp='1486672132' post='3233775'] Hi guys, is this still going ahead? [/quote] As far as I know. There was one planned for March that has just been cancelled - that may be what you heard about. David

[quote name='BassApprentice' timestamp='1486569517' post='3232878'] Side note. What are peoples experience with steel strings on U basses? Is it worth just sticking with the rubber(y) ones? [/quote] As far as I am aware, the only metal strings that fit a 20-22 inch scale are the Pyramid ones mentioned above. David