jimbartlett Posted June 12, 2008 Share Posted June 12, 2008 Hello, I always use two Basses when gigging and there is always a noticable volume drop due to one being active and the other passive. I know you can buy a pedal to allow to different inputs but I was wondering if anyone had built one? I was hoping to make a rack-mount version with two switchable inputs with seperate volume controls and one output. I would also like to put a couple of LED's in it to show me which input is selected. Any help, ideas or telling me that it is not something a wally like me can do would be helpful! Thanks, Jim. Quote Link to comment Share on other sites More sharing options...
cheddatom Posted June 12, 2008 Share Posted June 12, 2008 I think it should be as simple as 3 jack sockets, 2 pots, 2 LEDs and 2 resistors, and a switch. You can find info on the net on how to make a pot into a volume control, the rest is simple. Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 12, 2008 Share Posted June 12, 2008 There are two ways you can equalise the volumes - 1. Reduce the volume of the louder bass 2. Increase the volume of the quieter bass (yeh - stating the obvious, I know !) If you choose (1) then you could do this passively, simply by putting the bass signal through a "volume pot" and adjusting this pot to reduce the output. If you choose (2) then you need a powered active circuit (effectively a simple preamp) to boost the volume. Building a rackmount version could get pricey - the rack box components themselves tend to add up. Another option would be to use a small mixer. Plug both basses into the mixer, use the mixer to equalise the volume levels, then use the "Mute" switches on each mixer channel to select or deselect each bass. Behringer do a cheap rackmount mixer [url="http://behringer.com/RX1602/index.cfm?lang=ENG"]Behringer RX1602[/url] for about £70 new. On the plus side it has lots of knobs and LEDS !! It's worth examining all the options first. Quote Link to comment Share on other sites More sharing options...
cheddatom Posted June 12, 2008 Share Posted June 12, 2008 You could surely build it for less than £70? 3 jacks, 2 pots, 1 switch, some leds resistors, wires and a battery clip - £25 at the most? And a case wouldn't cost more than £20 surely? To be fair, I haven't bought any of these things in a long time so I wouldn't really know. Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 12, 2008 Share Posted June 12, 2008 [quote name='cheddatom' post='217406' date='Jun 12 2008, 09:36 AM']You could surely build it for less than £70? 3 jacks, 2 pots, 1 switch, some leds resistors, wires and a battery clip - £25 at the most? And a case wouldn't cost more than £20 surely? To be fair, I haven't bought any of these things in a long time so I wouldn't really know.[/quote] You could probably build a footswitch-type of box for about that. To make a rack-mount version would cost a bit more as the actual rack-mount hardware isn't cheap (unless you can get something second hand and modify it). It wouldn't have as many knobs and LEDs though..... Quote Link to comment Share on other sites More sharing options...
cheddatom Posted June 12, 2008 Share Posted June 12, 2008 When you're saying "rackmount hardware" isn't cheap, you're just talking about a metal box the right size and some rack ears right? Quote Link to comment Share on other sites More sharing options...
BassBod Posted June 12, 2008 Share Posted June 12, 2008 Talk to John at Orchid electronics - he can make all sorts of passive switching/active DI boxes and is happy to do custom work. I'd recommend a two input DI (that can run from phantom) with a tuner output/mute switch. Even our banjo player can work it...on a good day. BB Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 12, 2008 Share Posted June 12, 2008 [quote name='cheddatom' post='217433' date='Jun 12 2008, 10:01 AM']When you're saying "rackmount hardware" isn't cheap, you're just talking about a metal box the right size and some rack ears right?[/quote] Yes. You'd need a front panel (that includes the reack ears) and the metal box behind to hold everything. If you buy a 1U enclosed empty rack box it costs about £30 ! There is a kit system that allows you to build you own rack bits that might be cheaper. Better still, look for something second hand. Quote Link to comment Share on other sites More sharing options...
cheddatom Posted June 12, 2008 Share Posted June 12, 2008 £30?!?!?! FS I would buy a couple of baking trays and bend them. Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 12, 2008 Share Posted June 12, 2008 [quote name='cheddatom' post='217483' date='Jun 12 2008, 10:57 AM']£30?!?!?! FS I would buy a couple of baking trays and bend them.[/quote] And that's just for an empty box ! Don't forget the "sticky backed plastic" to hold it all together.... Quote Link to comment Share on other sites More sharing options...
jimbartlett Posted June 12, 2008 Author Share Posted June 12, 2008 Thanks for the replies guys, all that is really helpful. I am quite keen on building one myself so I will probably go down that route. I really like the volume pot idea, simple but effective! Quote Link to comment Share on other sites More sharing options...
Mottlefeeder Posted June 12, 2008 Share Posted June 12, 2008 [quote name='jimbartlett' post='217506' date='Jun 12 2008, 11:41 AM']Thanks for the replies guys, all that is really helpful. I am quite keen on building one myself so I will probably go down that route. I really like the volume pot idea, simple but effective! [/quote] Using a sensitivity pot is fairly easy when you have an active bass, since it has a higher current drive capability. With a passive bass, you may find that another pot in the circuit makes a noticable difference to your tone. Also, building on Cheddatom's comments, your switches will need to be two pole to switch both your signal and an LED, and you will need to add in a power supply or a battery to power the LEDs. A format that might be worth considering is to use one switch to select the bass, and a second switch to provide a mute/tune facility. This would be easier than having one on/off switch per bass, and no easy way of connecting one or the other to a tuner. Quote Link to comment Share on other sites More sharing options...
mike257 Posted June 13, 2008 Share Posted June 13, 2008 Just out of interest, because the thought of building fancy switchy lighty boxes often occurs to me when I'm mucking about with my rig.... how simple is it to build one of these to sit in your rack, but make it footswitched, so it can be controlled from my board? Quote Link to comment Share on other sites More sharing options...
cheddatom Posted June 13, 2008 Share Posted June 13, 2008 I think for remote control you might have to add a relay circuit to switch at the rack when the footswitch switches. Not sure though! Quote Link to comment Share on other sites More sharing options...
BOD2 Posted June 13, 2008 Share Posted June 13, 2008 [quote name='mike257' post='218069' date='Jun 13 2008, 02:59 AM']Just out of interest, because the thought of building fancy switchy lighty boxes often occurs to me when I'm mucking about with my rig.... how simple is it to build one of these to sit in your rack, but make it footswitched, so it can be controlled from my board?[/quote] +1 to cheddatom's suggestion. You would need to use a powered relay (sounds more complex than it actually is). You would house a switch in a box on the pedal board which connects to the rack unit via a jack cable. Inside the rack unit is a powered relay switch. When you press the footswitch it flips the relay. The good thing about relays is that they can have lots of contacts (or you can daisy chain several together). This means your one simple footswitch can actually switch loads of things simulataneously. It needs a bit more planning but technically it's no more complex than a normal footswitch. Although you will need a power supply for the relay (probably 12 V dc) but that can also power any LEDs in the unit. Quote Link to comment Share on other sites More sharing options...
mike257 Posted June 13, 2008 Share Posted June 13, 2008 Blimey, that was quick! You lot are flippin' ace, you know that? Quote Link to comment Share on other sites More sharing options...
tauzero Posted June 13, 2008 Share Posted June 13, 2008 [quote name='mike257' post='218069' date='Jun 13 2008, 02:59 AM']Just out of interest, because the thought of building fancy switchy lighty boxes often occurs to me when I'm mucking about with my rig.... how simple is it to build one of these to sit in your rack, but make it footswitched, so it can be controlled from my board?[/quote] Get a Behringer AB-100, take it out of the box, get a blank 1U panel and find a way of bracketing the PCB onto the back, remove the microswitch and replace it with connections to a jack socket for a momentary action footswitch. Stick a pot in each of the input channels to do the relative volume thing, and that's it sorted. I'm assuming you'll be able to get a 9V feed to it too. It only has two LEDs, I hope that will be enough. Quote Link to comment Share on other sites More sharing options...
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