Alien

Gave the little fella a 'real world' test tonight. Ran it at a band rehearsal, using my Hartke HA7000 as a preamp. It's amazingly powerful - you'd never believe something that small could deliver that much wallop. I ran it pretty well flat out, so the clip indicator lit occasionally. After the dummy load testing, I thought it might run hot with music, but I needn't have worried. It barely got warm - possibly a little cooler than my Hartke gets after the same sort of run. I also mentioned the fan noise in an earlier post, but that too proved to be (marginally) quieter than the one in the HA7000, which has never been a problem, so I'm happy with that. [attachment=10896:PICT0421.JPG] This pic shows the extra heatsinks I fitted. Probably unnecessarily as it turns out, but it never hurts. As I said before, the load testing I did was a pretty severe test, as tonight proved. Just need to put a couple of labels on it (ratings and the like) and stick it on the PAT tester at work and it'll be good to go. Andy

[quote name='Marky L' post='240890' date='Jul 16 2008, 02:28 PM']Anyone used a Behringer BASS V-AMP?? I've just been lent one with the option of buying it for £30.[/quote] Unless it's totally knackered I'd buy it at that price. The manual can be downloaded [url="http://www.behringer.com/LX1-B/index.cfm?lang=ENG"]here[/url]. Andy

[quote name='ste_m3' post='239690' date='Jul 15 2008, 12:41 AM']Aguilar do a little cab id like very much to hear, i think its 2 8" speakers and a 5" one or something like that? Edit:- Here we are! [url="http://www.aguilaramp.com/products_cabinets_db285jc.htm"]Little Aggie[/url][/quote] It's pretty big for a 2x8 though - there are 2x10s smaller than that. Andy

I'll be first:- Talk to OBBM Andy

I tried one of the combos many moons ago, I believe it was a 2x8 but I may be misremembering. The thing that most stuck in my mind was the compressor. It had a separate attack control that went from a 'slow attack' sound at one extreme to a peaking thump at the other, almost like a drum hit. The whole combo was built like a flightcase, with a removable front covering the controls and speakers. Andy

[quote name='Rich' post='237248' date='Jul 11 2008, 12:48 PM']Stug, do you own the Challenger in your avatar pic? If so, I'm about to call you a very rude name, preceded by the words "you lucky" [/quote] Even luckier *#$% if he can afford to fill its tank these days! Andy

Just picked up an Ibanez Musician for an absolute song! Needs a bit of work, but even as it is it's a nice player. [attachment=10669:PICT0425.JPG] Lovely looking grain pattern [attachment=10671:PICT0427.JPG] Hardware's a bit corroded [attachment=10672:PICT0428.JPG] Buckle rash? Looks more like a shotgun to me! Even came with the original fitted hard case, all for the bargain price of £130. 4-string, neck through construction. 2 passive pickups, Vol, Tone Blend controls. Machines are Schaller semi-enclosed type, which look like replacements as there's a little hole near each one. The Serial no. is H825862 - dunno if that'll help with dating. If any of you knowledgeable types can tell me anything more about it that'd be brilliant - I really have no idea. Andy

Well, it's been nearly a month since I last posted an update. This weekend, however, sees an uncharacteristic burst of energy and enthusiasm from me, so some progress is being made at last. As I mentioned in my last post, a lot of the noise was coming in via the volume pot. I've replaced the twisted cables with a short length of screened twin core, which helped a lot. I also found that driving the Power LED from the +12V auxillary supply brought a noisy supply line into close proximity with the volume control. I decided to run the LED from the Fan supply instead and this, along with swapping the twisted pairs for coaxial cable and re-routing the LED cable so it's further from the volume pot, has quietened this amp down a lot. OK, time for some pics. [attachment=10459:PICT0415.JPG] Initial load testing with the fan fitted. The holes at the front are to try and force air across the amp module. I've since added more to the other end of the amp to try and improve air flow. I'm not too happy about the holes being so open - I shall have to do something about that later. The fan is held in place with 2-part plastic rivets. [attachment=10460:PICT0406.JPG] My signal generator, built from a Maplins kit years ago, still going strong. I used a triangle wave set at about 200Hz for the load test - no real scientific reason why, it just seemed right. [attachment=10461:PICT0403.JPG] This is the dummy load I used for testing the amp. A dozen 25 Watt resistors and a 100 Watter give about 370 Watts of load at about 5 Ohms. The amp ran quite hot after 20 minutes on this load. [attachment=10462:PICT0407.JPG] The amp under load, with the clip LED lit. The more observant among you may have noticed that the blue Power LED has moved to the bottom position. This happened as part of the cable re-routing. [attachment=10463:PICT0418.JPG] I've stuck some coarse weave speaker cloth across the vent holes. Should keep most things out, but not reduce the airflow too much. It'll also act as a dust filter, but that's definitely not its main purpose. [attachment=10465:PICT0419.JPG] Here's the same thing from the other side - not quite as pretty, but no-one's going to see it but you lot. The cloth is glued to the case with epoxy. [attachment=10467:PICT0420.JPG] Before re-assembly. I deliberately left enough room for the fan as I had a suspicion it would be needed. Still a tight fit though. Also, I've coloured the amp and PSU black in the hope it improves heat sinking. I performed a second load test, again using triangle wave set to approx 200Hz, at the very onset of clipping. (The LED indicator 'fades up' as clipping is approached, making this easier to set) The amp still ran pretty hot after 30 minutes of this, although not as hot as previously. This is a pretty severe test for an amp, as real music has dynamic peaks and troughs, and would not normally be run flat out for 30 minutes like this. However, I would like to try and improve the cooling a little further, so I'm going to try to fit a small vaned heatsink inside the amp, where it will intercept some of the airflow through the case. That's for tomorrow though. The last thing I've noticed is the fan noise. The fan runs fairly quiet, not noticeably louder than a PC fan in reality, but it seems hugely loud in a quiet room with a dummy load on the anp. I don't think it'll be a problem in the real world of a gig though. Watch this space... Andy

I did one for Higgie using a dual output DC/DC converter (Traco) with filter caps and regulators, but I believe he had a lot of noise problems from it. BTW, C&D are no longer C&D, they're MuRata Power Solutions now - They offered me a job a couple of weeks back. Andy

The 7000 can handle two 4 Ohm cabs, or four 8 Ohm. To be quite honest, unless you want the biamp facility or the ability to drive a wall of cabs, then the 7000 will be overkill. Have you given any thought to the HA3500? They have the same front end as the 7000, can be picked up pretty cheaply these days, and the difference between 350 and 400 Watts is less than 1dB (ie you'll never notice it) Andy

They're very different animals. The 4000 has a single 400W amp, whereas the 7000 has a pair of 350W amps. The 7000 can be run in Biamp or mono mode, so if you run a 2x10 and a sub (for example) that's the one to go for. I pretty much use 1 channel on mine most of the time - more than enough for most situations. As to whether they're better than Ashdowns, that's pretty subjective - one mans meat and all that. I personally prefer Hartke to Ashdown, but don't take my word for it - use your ears. Andy

I'd have thought it's best to use the 2 Ohm setting. Mixing a 4 and an 8 will send 2/3 of the power to the 4 Ohm, 1/3 to the 8 Ohm . With 2 cabs of the same impedance, the split is 50/50. Andy

Almost certainly Rick Anderson. Other than Re Styles leaving, and a few session/tour guys, the Tubes had a pretty stable lineup. Andy

[quote name='OldGit' post='220628' date='Jun 17 2008, 02:45 PM']Whatever you do learn the [b]gaps[/b] and where they come or you'll end up doing a an unscheduled solo ...[/quote] There's a version out there somewhere with accordion solos in those gaps - the lengths of the gaps makes more sense with the accordion in. Andy

Best bet would be to use a Speakon-Speakon cable to the first cab, then a jack-jack to daisy chain the second. Andy

It seems that most of the noise was coming in on the connections to the volume pot. Bypassing it with a jumper quieted things down a hell of a lot. Since it's actually audio going through the pot (rather than a control voltage), I'm going to rewire it with some screened cable, which should help things along nicely! Andy

Time for the next episode boys and girls. Are you sitting comfortably? I've closed up the case, and done a bit of testing. Before all that though, I decided to weigh the amp. [attachment=9464:PICT0389.JPG] 1.6 kilos (thats about 3 1/2 lb in old money). Strange thing is, it feels heavier - probably because of the size of it. If any of you are having difficulty picturing the size of this amp, have a look at this next pic. [attachment=9465:PICT0391.JPG] And then I fired it up for the first time... [attachment=9466:PICT0396.JPG] Christ that LED's bright, despite only running at 12 mA. It's like a spotlight. Well, Froilan reckons he likes blue LEDs. Initial testing was done (not very scientifically) by plugging into a pair of PA cabs, and plugging a bass straight into the input. Houston, we have a problem. There's a high pitched whistle coming through at about 15kHz (I'm guessing here, but I know my hearing tops out about 15k, and it's right at the top of my range). It's not loud, but it is audible and would be very annoying, so I'll have a poke about in there with a 'scope later and try to find the source (my bet is that it's the power supply). Other than the whistle, it seems very quiet in operation, no buzzing or humming came through. The other issue is heat. I had hoped that the case would be enough to act as a heat sink, but sadly that is not to be. I've sourced a tiny fan (40x40x10mm) and I'm going to fit it into the side of the case. I'd cunningly left enough room for this eventuality, so not a big problem. Looks like I'm going to be drilling some holes this afternoon! Andy