dincz

[quote name='XPAULUSX' post='1131687' date='Feb 18 2011, 12:14 AM']How much power will I lose? Is that possible to work out? Will it be that noticeable or not? Thanks [/quote] According to the figures, you'll be missing out on only about 1dB. That's barely noticable and it will help you keep clear of clipping the power amp.

[quote name='XPAULUSX' post='1131485' date='Feb 17 2011, 09:09 PM']I have a link to the QSC manual here but the only thing i can find in it is input impedence, not sensitivity, if somebody could help me out that would be great.[/quote] It's listed in the specifications as 1.16 volts, which is about +1.3dBv. So you won't be able to get full power out of the amp with that pedal.

Is it desirable? If you're sure, then yes you can do it but you'll need a current limiting resistor in series with the LEDs. Calculator here: [url="http://ledcalc.com/"]http://ledcalc.com/[/url]

All very interesting. Thanks for the responses. What would be the easiest and cheapest way to increase the horizontal dispersion of a Compact? Stack another Compact on top? I'm rather hazy about all of this. I realise that vertical stacking reduces the vertical dispersion, but does it also widen horizontal dispersion? That may be a stupid question in that if there's less vertical spread then it has to go somewhere else. Would it be feasible to add a separate 6" or 8" in its own small enclosure with a suitable Xover network? A Barefaced Broad Baby perhaps?

[quote name='alexclaber' post='1123020' date='Feb 10 2011, 07:56 PM']The size of the cab affects two things - the low frequency sensitivity and the dispersion[/quote] Is there any way to widen the high frequency dispersion of large drivers by adding some kind of magic reflector (effectively a kind of "audio lens") in front of the cone?

[quote name='fatgoogle' post='1119052' date='Feb 7 2011, 05:28 PM']Does anyone by any chance have a layout for a woolly mammoth at all?[/quote] There's info and a kit available here: [url="http://www.madbeanpedals.com/projects/Sabertooth/docs/Sabertooth_ver.4.pdf"]http://www.madbeanpedals.com/projects/Sabe...tooth_ver.4.pdf[/url]

... under the "Affiliates" section?

Thanks for all the tips. To be honest, I'm unlikely to be playing below A anyway on the songs where I use the octaver. Admission - I'm using a Behringer V-Amp - one of several bits of Behringer kit I've acquired in recent months. No complaints whatsoever with any of them.

Is using a suboctave effect likely to strain the relationship with my Compact? I play EADG 4 string.

[quote name='BOD2' post='1113860' date='Feb 3 2011, 02:51 PM']I don't know how helpful the block diagrams will be, but here you go....[/quote] Cheers for those! A bit basic but they give some idea what goes on inside and in what order. Just what I wanted.

I've just bought a Bass V-Amp (in Ken and Barbie form rather than the rackmount Pro). So far very impressed, but to make the best use of it I need to understand a little more about its internal architecture. The manual is next to useless - just a random unstructured mess of information. Someone on TalkBass mentioned that the Pro version has a block diagram printed on its top cover. If anyone out there has easy access to the top of their V-Amp Pro, I'd be very grateful if you'd take a photo or feed it into the photocopier and post the pic here.

The 2 channels of your amp are actually 2 separate amplifiers sharing only the power supply - and the case. You can run whatever you like through each side and adjust their volume independently to compensate for any difference in volume. As long as each channel is loaded with a cab of the minimum required impedance, there's no problem.

[quote name='Protium' post='1110018' date='Jan 31 2011, 09:19 PM']Anyone can carry a 25kg cab[/quote] With a head and a bass and a bag of effects and cables up 3 flights of stairs in one trip?

[quote name='Mr. Foxen' post='1104666' date='Jan 27 2011, 02:51 AM']Probably worth noting that class D and switch mode power supplies aren't necessarily 'digital', and 'being made with pcbs and surface mount components' is just construction and not to do with amplifier class. You could handwire a solid state amp, but it is even more effort than having to pick up a box with transformers in it. My solid state amp is handwired and it is lovely, and I should be able to solder bits in as necessary. Class D amps just suffer from the age in which the came into use, rather than an actual issue with the technology.[/quote] Yes. My point was that gear in general is going surface mount (for me that means unrepairable) so I may as well go for lightweight class D/SMPS.

[quote name='Mr. Foxen' post='979550' date='Oct 6 2010, 04:15 PM']And increasing windings will result in a darker tone as the [b]capacitance[/b] increases.[/quote] Well yeah but the opposite in fact - inductance

[quote name='Maverick' post='1102033' date='Jan 25 2011, 02:06 PM']over-exaggerating[/quote] That's going a bit far!

[quote name='waldemar' post='1104329' date='Jan 26 2011, 09:28 PM'][/quote] Looks good. Just make sure the brown wire is connected to the bridge.

Thanks for the responses. All food for thought, although I guess component-level repair is, or at least is becoming, a thing of the past whether we're talking class D or linear, analogue or digital, so maybe it's time to bite the bullet.

A bit quiet round here. Does this mean they don't break down?

Could be this: [url="http://www.talkbass.com/forum/showthread.php?t=326622&referrerid=176830"]http://www.talkbass.com/forum/showthread.p...ferrerid=176830[/url]

I'm considering a lightweight class D power amp and wondered if any of you have experience with faultfinding and repair. I've repaired class A/B (bipolar and mosfet) amps and have found repair to be fairly straightforward - especially with mosfet output stages as they tend to take out only the output devices. I'd imagine that the low thermal dissipation of switching transistors in class D amps would make them more reliable. Does your experience confirm this? And when they do fail, what are the more common causes?

Not so massive in this case but it illustrates the point. [attachment=69486:01.JPG]

[quote name='tauzero' post='1096546' date='Jan 20 2011, 05:49 PM']No, the voltage is split between the load resistance and the amp's internal resistance in the output stage. As the load drops, the potential divider between the internal and external resistance puts proportionally less voltage across the load. Plus the amp will blow up in the limiting case.[/quote] The voltage divider idea is correct, but in practice the output impedance of a solid state class A/B amp is in the order of milliohms - not enough to make a scrap of difference. The power supply is where the serious drop happens. Note I said power "supply" not "supplies" as a common supply for both channels is the norm.

[quote name='Faithless' post='1096403' date='Jan 20 2011, 03:42 PM']Oh, and I've found an interesting quote in Genz Benz manual: "Don't plug anything but Headphones into Headphone socket"...[/quote] The headphone output on the Shuttle is not the usual hot/earth configuration - both sides are hot. If you aren't already using it for something else, the FX send jack (which is earthed) might just do the trick.

There's actually no such thing as RMS power. RMS values of voltage and current can be used to calculate power in watts - and there's only one kind of watt. What manufacturers call "RMS" power is normally the continuous power rating rather than the peak, or short burst capability.