Subthumper

Thanks Bill for your input. I was under the impression that it was it bit more mathematical than seat of the pants. I shall pursue another avenue. Shame though cos it looks wicked.

So does this mean they're no good for bass guitar? From what I've read they were used for hifi, pa and studio monitors and apparently were pretty efficient. It's just that I'm on the charge to build a cab and wanted something weird and different to conflict all those boring square boxes that all.look alike and sound average.

Hi all, I was trawling the net and came across these speakers designed in the 50's. They have a front cavity and a tapered slot. I've seen pics of Stanley Clark using them in a rig by acoustic, looks like it was the seventies. Anyone got any knowledge on these? If they were as good as claimed how come you never hear of them? I'm suspecting it's down to cost of build like most superior designs plus some pooh pooing from those who are locked into conventional ideas. I'll see if I can put up a link once I've worked out how to on this new tablet I got. Be interested to hear of anyone's experience of these. Cheers Just

Look for a peaveyl alpha or TB Raxx. Always regretted getting rid of mine. Dead simple to use and better built than most of today's offerings. The ampeg sounds good but does tend to be a bit fragile and is a total pain if you need to change a valve. Worth getting it serviced if you get one second hand. I,'ve always thought this is a superior way to put a rig together despite the draw back of size and weight as it allows you power amp of superior quality to most power sections in a lot of amp heads. Don't skimp on your interconnection leads.

Or it could be a broken pot. If the amps had a whack on the front panel its possible the shaft of the pot has pushed the wiper through the track. Best pop it out and check it. Tech job if you dont know what your doing. Its got to come to bits anyway even to resolder it so it may as well be done while its apart. Also take the opportunity to check over all the other solder joints especially the ones on pots. Good luck cheers Just

Yeah those are guitar speakers, too low a power, too high a resonance, too low an excurtion, and the cab is too small for bass. You'll fry them in an instant with either amp. Go for the 3500, flog the guitar cab and get a proper 4x10. As has been said there's loads of great second hand gear at the mo. Recently saw a Peavey 410tx for £80...thats less than the cost of a peavey replacement driver.

Was that too technical an answer?

The Ad200 does seem to be a pretty robust amp though. I know of one that gets thrashed stupid several times a week with few problems over the last couple of years that I've known the owner of it. If you like the sound of it I'd say go for it. They are bloody heavy though no worse than any other 200w valve head I can think of, and certainly less heavy than an SVT.

When buying second hand valve amps always factor in that you may have to replace some or all of the valves immediately or in the near future. Not being a downer, I use valve amps myself, love em to bits, but I also service and repair gear and its a common issue with guitar and bass amps when people buy second hand and there is no warranty. Maybe worth asking the seller to have the amp serviced and checked out by a tech before you buy, kind of an MOT. Also if the amp is old or "vintage" ask if its been re capped at any point, its not a major expense but it all adds to the initial outlay. Good luck , cheers Just

I think these amps should be fitted with an anti thump relay. Basically there's a relay that connects and disconnects the speaker outputs during switch on/ off that is powered by a time delay circuit so that the power supply and amp powering up/down doesent make the speaker thump with the switch on transient. Its usually a delay of about 3-5 seconds. It sounds like the relay in your amp has fused shut or the circuit that operates it is faulty and allowing the speaker to thump when you switch on or off. I'll have a look at the schematic to see if it should have one. If this is the case you need to get it to a tech. Cheers Justin Just looked, I've only got diagrams for the ABM but I think its probably very similar or maybe the same power amp and psu for both amp and it should have a delay circuit....sounds like yours is faulty. FWIW some amps dont have this feature...usually smaller ones, but the thump can become more exagerated as the amp gets older and the components especially the smoothing caps age with use and time. Hope this is usefull.

Has anyone who PM'd the OP had a reply from this yet?

Hi all, I've been asked to replace some blown drivers in a markbass 4x10. Does anyone know who or where sells them? Cant seem to find much other than the markbass website which doesent seem to deal with customer support. Any help much appreciated. Cheers Just

Singers..........................we became a three piece for this very reason.

[quote name='apa' timestamp='1355935306' post='1904747'] The question still remains do I need an MM Pre to get close to an MM sound? Subthumper seems to suggest so. Anyone else? A [/quote] No, what I said was I did'nt think you needed a mm preamp. On my bass the pickup sounds the same with or without the active eq. I think the mm eq is +- 15dB at 100hz and 5 or 10khz (someone please correct me). Its the humbucking/out of phase and the pickups design and construction that makes its noise. If your so keen on that sound why not just get a MM pickup and save all the grief of trying to make something that isnt a mm be something its not?

I like building my own gear too but why not just get a small 4 channel mixer? It will probably work out cheaper and more effective than your own. I think some of the B**********r ones start at about thirty quid. There's quite a good selection in the CPC catalogue too. Cheers Just

I think the Ray sound is more to do with the actual pickup and the out of phase created by the two coils so you should get pretty close using two single coils as a humbucker. Its certainly the case with my five string, got a seymour basslines MM5 replacement pup and a John East U retro deluxe and it sounds like a Ray in active or passive mode. Personally not a fan of onboard eq so might ditch the u retro. There are some sounds you just cant eq its got to be created by the pickup. Good luck cheers Just

PM'd. Cheers Just

Where are you based?

Hi, sorry to hear your news. You might get the same story from most techs, but as an amp tech myself I've made a point of not doing Behringer stuff at all...any of it. As has been said already its not designed to be fixed and even if it could be Behringer do not give out schematics. Alot of their pcb's are suface mount which makes it virtually impossible for the amp tech to do anything with it. I usually get these donated to me and strip them for what spares I can find that are removable. The rest is consigned to the bin. Although I must add that Behringer are not the only company doing this. Good luck in your quest to get it fixed. Cheers Just

Did they test the pre amp valves too? The driver/phase inverter valves need to be in good order to drive 4xKT88's. The phase inverter is the middle one and the driver is the second. The first is the pre amp. Also was it biased properly?

Hi all, as the title suggests I'm trying to find out the response of this cab as I have to build a crossover for it to run with a 2X10. I know that manufacturers are usually a little optimistic and somewhat vague with their figures so was wondering if anyone might know. Or if anyone can tell me what speaker is used so I can look up the spec somewhere. Cheers Just

Sounds like it might be a smoothing cap issue. I've seen quite a few Traces and Ashdowns(very similar power amp pcb) with failed solder joints on the main smoothing caps.This will cause horrible hum and buzz as the amp will be running on an unsmoothed supply. Its a very easy job to fix as removing the pcb is just 4 screws and then resolder the joints. Be careful removing the screws at the back as the heatsink may well be carrying some stored charge from the caps and will short out to the screwdriver. Whilst its out check the whole board for bad joints plus all the wire connections. Good luck cheers Just

The only tones its making at the moment is me swearing at it. Think I might actually have found the problem...some seem to thinks its because its an Ampeg...cue for furious debate.

As it says really, anyone got a copy? I've got the rest of it but the PSU eludes me. Pig of an amp to fix. Cheers Just