obbm

It'll be worth the wait.

I think he's got a screw loose. (I'll get my coat)

[quote name='niceguyhomer' post='403909' date='Feb 8 2009, 11:09 PM']Thanks Dave - are you up to anything at the moment?[/quote] No nothing apart from house band at a local jam once every 5-weeks and maybe an occasional dep. I was rehearsing with a rock band but the drummer and I had serious musical differences so I walked. His attitude from the outset was "I don't need to rehearse" and then proceeded to play certain iconic rock classics in his own style and not as original which basically wrecked the rythmn and made it impossible to lock in with. I'm all for creating ones own arrangements but there are some numbers that you don't mess with. I could see that it would just end in arguments so I got out quickly. A shame because the two guitarists were very good. I'm sure something will pop up soon but I'm too old to panic about not having a gig.

Well done Al. That's an interesting list and should be fun.

[quote name='Linus27' post='401106' date='Feb 5 2009, 03:14 PM']Am I also thinking that the fan is on top of the unit and so this would be covered if you rack mounted it????[/quote] Not necessarily. It's not a full 2U high so if it was fitted at the bottom of some 2U brackets there would be sufficient space above. I've written to Ashdown. I'm pretty certain that the bracketes conform to the EIAJ (USA and Japan) specs which is different to BSI/IEC.

I'm using my LG1000 for the first time in the house band rig at the local Jam tonight. just to tidy things up I thought I'd rack mount it in a flight case. bad idea. Firstly it is neither 1U or 2U high and the holes in the supplied brackets don't line up with the rack strip cage nuts. Basically the rack brackets do not conform to BS5954 or IEC297 which is the "Specification for Dimensions of panels and racks for electronic equipment". Really bad design.

[quote name='jim_bass' post='400435' date='Feb 4 2009, 09:25 PM']What about the other way around... Would it damage your bass/amp using speaker cable instead of a guitar cable to plug in your bass?[/quote] Speaker cables are designed to volts and amps. the levels are high and as there is little chance of induced in interfernce they are not shielded to keep out the unwanted. Instrument cables are designed and required to carry miilivolts and milliamps. Because the levels are so low the cable is co-axial with a shield around the outside of the signal conductor to protect it from interference. It would not damage your amp using a speaker cable as an instrument cable, however it might well damage your hearing. I guarantee you would only do it for about 30-seconds as your beautiful bass tone gets lost in the induced interference, microphony, etc. Speaker cables are for speakers, instrument cables are for instruments. Don't let anyone tell you otherwise.

I've been down this road with my lakland Duck Dunn. The pick-ups are [url="http://cgi.ebay.co.uk/Lindy-Fralin-Precision-Split-Coil-Jazz-Bass-Pickups_W0QQitemZ270339480049"]Lindy Fralin Split Coil[/url] They come as a matched pair. No problems with imbalance or hum/noise when using bridge only. have stack-knob controls V/T + V/T so I can tweak the tone from each pick-up independently. Routing was done by the Gallery. Sent them the body and they routed out for the pick-up, plus a battery box and side jack just in case I want to make it active in the future.

[quote name='owen968' post='399335' date='Feb 3 2009, 07:50 PM']been doing a bit more research on the power conditioner subject, dont they also manage the electric input which can reduce the electric hum you get when you have a lot of electrical goods?[/quote] Nope. Mains is 50Hz. Hum is 50hz, usually the result of poor earthing or mains crosstalk into poor signal cables. Get really good cables and check your earth continuity. Can be the result of running a wallwart or pedal PSU beyond its capacity causing the volts to be dragged down. Can be induced by inferior design equipment power supplies. A Power Conditioner will do nothing to eliminate these problems. [quote name='owen968' post='399335' date='Feb 3 2009, 07:50 PM']Also i wanted to reduce the amount of wires in my stack for ease of use.[/quote] As already mentioned, get a power distribution strip.

I would have thought that an Alesis SR16 would do what you want. You can programme your own patterns and use the patterns to make complete songs. They go quite cheaply now. In fact I have one I don't use any more.

Power conditioners are a waste of money if you live and play in the UK. Our power system is much more stable and better regulated than in the USA. If you want it for the myriad of IEC outlet sockets there are other, probably cheaper, alternatives. In all my years of playing I've never used one or felt the slightest need for one.

[quote name='hatori' post='395998' date='Jan 31 2009, 10:31 AM']Is the power output of an all valve amp (Marshall JCM800) proportional to the impedance selected i.e. 100watts @4ohms 50watts@ 8ohms as is the case with SS amps?[/quote] No. The impedance selector is there to match the cab to the output stage, ensuring the output valves have the correct load so they will always deliver the full output.

This might help explain, otherwise there is a very good book by Morgan Jones which covers vale amp theory in depth. [code]Q:Will it hurt my amp/output transformer/tubes to use a mismatched speaker load? Simple A: Within reason, no. Say for example you have two eight ohm speakers, and you want to hook them up to an amp with 4, 8, and 16 ohm taps. How do you hook them up? For most power out, put them in series and tie them to the 16 ohm tap, or parallel them and tie the pair to the 4 ohm load. For tone? Try it several different ways and see which you like best. "Tone" is not a single valued quantity, either, and in fact depends hugely on the person listening. That variation in impedance versus frequency and the variation in output power versus impedance and the variation in impedance with loading conspire to make the audio response curves a broad hump with ragged, humped ends, and those humps and dips are what makes for the "tone" you hear and interpret. Will you hurt the transformer if you parallel them to four ohms and hook them to the 8 ohm tap? Almost certainly not. If you parallel them and hook them to the 16 ohm tap? Extremely unlikely. In fact, you probably won't hurt the transformer if you short the outputs. If you series them and hook them to the 8 ohm or 4 ohm tap? Unlikely - however... the thing you CAN do to hurt a tube output transformer is to put too high an ohmage load on it. If you open the outputs, the energy that gets stored in the magnetic core has nowhere to go if there is a sudden discontinuity in the drive, and acts like a discharging inductor. This can generate voltage spikes that can punch through the insulation inside the transformer and short the windings. I would not go above double the rated load on any tap. And NEVER open circuit the output of a tube amp - it can fry the transformer in a couple of ways. Extended A: It's almost never low impedance that kills an OT, it's too high an impedance. The power tubes simply refuse to put out all that much more current with a lower-impedance load, so death by overheating with a too-low load is all but impossible - not totally out of the question but extremely unlikely. The power tubes simply get into a loading range where their output power goes down from the mismatched load. At 2:1 lower-than-matched load is not unreasonable at all. If you do too high a load, the power tubes still limit what they put out, but a second order effect becomes important. There is magnetic leakage from primary to secondary and between both half-primaries to each other. When the current in the primary is driven to be discontinuous, you get inductive kickback from the leakage inductances in the form of a voltage spike. This voltage spike can punch through insulation or flash over sockets, and the spike is sitting on top of B+, so it's got a head start for a flashover to ground. If the punchthrough was one time, it wouldn't be a problem, but the burning residues inside the transformer make punchthrough easier at the same point on the next cycle, and eventually erode the insulation to make a conductive path between layers. The sound goes south, and with an intermittent short you can get a permanent short, or the wire can burn though to give you an open there, and now you have a dead transformer. So how much loading is too high? For a well designed (equals interleaved, tightly coupled, low leakage inductances, like a fine, high quality hifi) OT, you can easily withstand a 2:1 mismatch high. For a poorly designed (high leakage, poor coupling, not well insulated or potted) transformer, 2:1 may well be marginal. Worse, if you have an intermittent contact in the path to the speaker, you will introduce transients that are sharper and hence cause higher voltages. In that light, the speaker impedance selector switch could kill OT's if two ways - if it's a break befor make, the transients cause punch through; if it's a make before break, the OT is intermittently shorted and the higher currents cause burns on the switch that eventually make it into a break before make. Turning the speaker impedance selector with an amp running is something I would not chance, not once. For why Marshalls are extra sensitive, could be the transformer design, could be that selector switch. I personally would not worry too much about a 2:1 mismatch too low, but I might not do a mismatch high on Marshalls with the observed data that they are not all that sturdy under that load. In that light, pulling two tubes and leaving the impedance switch alone might not be too bad, as the remaining tubes are running into a too-low rather than too-high load.[/code]

[quote name='martinbass7750' post='394316' date='Jan 29 2009, 08:14 AM']Hi Tony, AN amplifier is designed to run into a minimum load of say 4 ohms. If you take the load below this you will draw excessive current from the output stage and cause damage. (current = voltage / resistance in ohms) As you add a speaker cab in parallel the value of the load resistance is reduced. e.g. 2 x 16 ohm cabs = 8 ohm load ohm load, 4 x 16 ohm cabs = 4 ohm load. Hope that helps. Cheers Martin[/quote] Please note that the above only applies to solid state amplifiers. Valve amplifiers should ideally always use the output transformer tap matched to the speaker cabinet impedance, so if using an 8-ohm cab then set the speaker impedance to 8-ohms.

[quote name='ashevans09' post='394228' date='Jan 28 2009, 11:56 PM']Hey there, Being the sad and dozy sod that I am I've been wandering around various forums and came across the info that an all valve head puts out the same wattage at any ohmage. So, that considered, were you to run a cab with an all valve head, is there any particular benefit in going for an 8ohm cab over a 4 ohm cab? Ta! Ash[/quote] The most important thing is that you select the output transformer tap to match the cabinet impedance.

[quote name='Beedster' post='393570' date='Jan 28 2009, 12:14 PM'][attachment=19308:CIMG0437.JPG] Volume pots are original and the tone pot seems to be the same age and condition. Is this a standard volume pot for the era, I've seen a few like it in pics elsewhere? Why is it so bloody big! Chris[/quote] It looks like a double ganged pot. Are both sections wired?

Welcome aboard. Second drummer in a fortnight. You could be starting a trend. Aldershot Eh? Hmmm. Just around the corner. Good luck with your search for a singing bass. If I were 40 years younger then I might jump at it.

Have a browse through [url="http://www.hearingprotection.co.uk/index.php"]ACS's Site[/url]. They have several options and they make pretty much all of the in-ear monitors for people such as Handheld, etc.