Chienmortbb

Those can be quite hard to use PhilIf you are not at 90o to the work they can snatch, almost spraining your wrist. In addition you need a heavy duty drill and the weight of that, plus the hole cutter, is hard on the wrist.

I would echo what is said above about the SW Bass Bash. It is a greta way to check out all kinds of gear but you would have to be patient.

You are right that you should never connect or disconnect a jack speaker cable with the power on. Yoy are wrong in that very few Plug/Jack combinations can happily work with a 500W amp safely. Many Jack uockets and plugs are made for signals and are good for only 0.5 amps. Using the power law, that is only 2 watts into 8 ohms and 1 watt intio 4 ohms. The best jack socket for speakers is the one in the Neutrik combo speakons (the green ones) these are good for 10 amps or 800 watts with an 8 ohm speaker and 400 watts with a 4 ohm speaker. But why use a jack cable when you have a speakon socket capable of 20 amps, that is 3200 watts into 8 ohms and 1600 watts into 4 ohms.

You are correct except about the choice of cable. For a bass rig no one really needs more that 1.5mm2 cable. 2.5mm2 and 4mm2 are for high power PA rigs with long cable runs.

I was joking.

Too much amp overhang for my liking lol.

You are right the with all controls at half pot travel, many amps are not flat, my point was that the two main amps I use are both ruller flat to the extremes of their frequency responses, although both exhibit low end roll off (An HPF). I agree that sound changes as an amp is pushed but we have several things in play then. Apart form the amp, the speakers change chariteristics when pushed harder and our own ears react differently to different SPLs as identified in the Fletcher-Munson Curves.

I recently did a frequency response sweep on both my Bugera Veyron and Ashdown Mibass 2.0 and both were flat with all EQ set to 12 o'clock. The only difference was that (from memory) the built in HPFs were quite different.

Profanity filters are usually built into forum software. Must be hard if you are running a porn forum.

A 2 pole plug will go into a 4 pole socket but not the other way round. A 4 pole plug will NOT fit a 2 pole socket.

I have been in electronics since I left School and have done a smaall amount of coding/programming professionally, The thing I should always remember is that a good knight's sleep often gives you the answer. I forgot that the outputs of the opamps in the circuit above have 100 ohm resistors in line. With my headphones being connected in parallel and having a combined impedance of 16* ohms, the output will be attenuated by 15-16dB (* the exact amount depends on the impedance of the heaphones at a particulat frequency). So by taking the output directly from the opamp output, the headphones will recieve more power. Unfortunately this means soldering a wire directly onto the PCB but as much of the preamp is hardwired, it is not a massive problem.

Dave (@obbm) has retired and I have now got much of his stock so drop me a PM if you need anything.

I hope you are sorted however I bought much of OBBM's stock, including speakon connectors so it you need a specific cable, please let me know.

So I have finally finished the amp section of the After Eighty. I have connected the headphones only when the mute/standby switch is activated. The headphone side needs more gain as if you disconnect the headphones, the speaker output is so much louder. However the sound of the amp (through my 8" PA Cab) is really nice, I can't wait to try it with its own cabinet. Now it is time to sort out the cosmetics. The side of the cab where the port is needs sanding and repainting and I need to try to make some decals to reflect the new functions I have added.

After thinking about it for a while I have had a rethink. The headphone PCB is not easy to mount and I was.having second thoughts about using it. I went back to the blog post by NwAvGuy and looked at his measurements of the NJR4556 and it gave excellent results into 15 ohms. My headphones are rated at 32 ohms but my idea is to parallel the L and R earpieces from one side of the NJR4556. This would give an impedance of 16 ohms so that looks feasible. So I will be replacing the NE5532 in the balanced transmitter with an NJR4556 to drive either the amp or headphones. while the 4556 is not that well regarded as an audio device, the measurements show it is well suited to driving headphones and is more that good enough to use to both drive the amp/headphones and the DI out. I recently used a head that (to my surprise) did not mute the speaker output when the headphones were plugged in. I queried it with the manufacturer and was told that they considered that a small lightweight amp would be used without a cabinet with headphones so it was no necessary. Although I originally disagreed, I have to admit there is some merit to the argument. Disconnecting the speaker in a combo is not an option so the speakers must be muted. Luckily I can use a double pole double throw switch to both ground the enable pin on the icepower module (muting the power amp) and divert the signal from the amp input to the headphone jack.

I have laser sheets but ly laser is momo only. I will buy some inkjet ones and see wht they turn out like.

Sometimes I surprise myself how stupid I am. The original idea was that the D sized hole on the back would be the DI out and the one on the top would be for the external cabinet output. The reason for this was that the original speaker output jack was on the top and the legend was still visible with the Speakon fitted. That skewed my thinking and it was this morning that thought to reverse that. So now the XLR is on the top and the extension AB output is on the back. The wiring is complete although I still have to spray over the legend and find some way of printing gold on black. It should be dry tomorrow so hope to Sam’s the port and get a cost of tuffcab on. The it’s joust a case of sorting the headphone circuit.

Funny that, I have the same feelings about the two skinny pups on. a Jazz. I do agree about mulyi stringed, wide necked monsters though.

I am shocked to realise that it is over 3 months since I posted. I did fit the port properly after Stevie had checked the performance. Of course that ruined the finish. It needs some sanding around the port as well as a new coat of Tuffcab. The amp is being a bit of a B. Although the rear mounted speakon looks good, it does take up a lot of space, in addition to which, I cut the speaker cable from the power amp a little short. So I am struggling to get the speakon and internal speaker connected. I do have a faston speakon connector somewhere and that might be the answer. The headphone amp is also a bit of a problem as there is no way of mechanically mounting it. If there was no headphone hole in the chassis I may have just left it off, although that severely limits its use as a practice amp. My other dilemma is that the preamp power supply is a mess. I used it to try a number of things and it just looks ugly. However it does work, so I am considering whether to replace it with some PCB power regulators (originally bought for a different project) or leave it as it is. There was a very small amount of hum (i really mean small) that was just audible with boty Volume controls at max, Changing the power suppy regulators would also make it easier to rework the cable routing in an attempt to reduce the hum. As it is raining here, I won't be finishing the cabinet any time soon so on with the amp section.

My main amp is a Bugera Veyron (the MOSFET one) and iy has every input output available including an FX loop. My Ashdown MiBass 2 has nothing but an input, speaker output and Aux in. This got me wondering if anyone used the FX loop on their amp, and if so, what for? I have only evet used the EFX Return as power amp input bypassint]y the preamp but of course AUX in also usually does this.

Well done. I am sure you hae learnt a lot from the build and would do some things better next time. However it looks a lot better than my first cabinet.

I have one of those too.

I was lookimg at one of those but a Picoscope 2006 came up on ebay and that includes an Arbitrary Waveform Generator that can be automated. I have not had it long but I have used a plug in to check the frequency response of my amps. I will be doing a response of the Zoom B1 Four tomorrow.

I would love an ABM600 if it was a little narrower. I suspect they were designed with 19" rack mounting in mind, but something 350mm ish wise would suit today's smaller cabs. Please Mr Ashdown,

Not wishing to sound like a killjoy but should this thread be moved to theEffects forum?