Chienmortbb

Power conditioners c[size=4]ame from the USA and were useful there because the [/size]internal[size=4] mains wiring was often aluminium rather [/size]than[size=4] the copper we use in the UK. This led to a lot of poor mains connections and really noisy mains. The copper over here did not have that [/size]problem[size=4] and even switch mode power supply noise is easily handled by most pieces of kit.[/size] [size=4]Most noise comes as RFI through the air and a power conditioner will not solve that.[/size]

I seem to remember reading about a Fender research project that aimed to remove the dead spot. The result was that a headless bass with a though neck was the best and second best was a 2L2R headstock with a through neck. Neither of these were acceptable for aesthetic reasons at Fender so we live with the dead spot. I gave real credence to Ned Steinberger's work though.

One of the things that has changed over the years is the drivers in loudspeakers. Fane, Goodmans, Celestial, Jensen all made high efficiency speakers and a 50 watt head would create a lot of noise but little bottom end. A 15" Bass Guitar speaker would have a rated efficiency of over 100dB. Most of the drivers we use now are 96dB at best. I know some of the Eminence drivers claim 100dB or more but that is marketing peaks. Today many drivers are around 94dB and that old 50 watt baseman would need to be 200W to get the same perceived old skool volume. Add marketing watts and you can see why we now need 900 or 1000. The truth is that a true 200W amp will do most gigs a unless its a Bugera. 300W will more than you need. If you use an Acme cab however you may need a lot more By the way my spell checker replaces Bugera with Bugbear #justsaying

[quote name='bassman7755' timestamp='1447950312' post='2911777'] The master vol needs sufficient boost headroom to account for widely differing preamp signal levels that result from the different drive and eq settings available. It should be borne in mind that a master volume is a power amp [b]input[/b] gain control not an output limiting control (I'm hoping most BC regulars know that by now ). [/quote]Most are an input attenuators not gain controls.

[quote name='alexclaber' timestamp='1447251798' post='2906144'] No but I bet a lot of them have hearing damage! [/quote]Most of mine comes from a 100W Sound City stack in the 70s when I was a Guitard. Seriously surely a Retro 210 would be a monster wit a 200W amp?

[quote name='FlatEric' timestamp='1371632358' post='2116318'] Pic for EMG456. [/quote] They look very like Matsumoku basses.

The original MAG series heads and combos were made in the UK I believe. The Mag 200s I think. The 300 watt MAGS were from China.

AS far as I know the picture almost explains it. If you have stacked cabinets you get more output from mutual coupling. If you have one speaker on the floor then a "mirror image speaker is created that acts s a second driver so again you get higher low frequency output. I am not sure how far away the drivers need to be apart for these effects to diminish.

[quote name='Phil Starr' timestamp='1447518180' post='2908286'] I use one of these [url="http://www.toolstation.com/shop/p45494?table=no"]http://www.toolstati...p45494?table=no[/url] either look good for the job. Building the slot port design was slightly trickier than building the tube ported design so I'd agree with the decision to go that way. I'll offer notes on how to build the slot ported design as others may prefer to build that. It does look very nice IMO but I'd rather go the trouble free route. [/quote]Any thoughts on whether to port forward or backwards also do you think that the round ports break up the standing waves. What I mean is that the four round ports in the original prototype would cause waves to be reflected in a quasi-random fashion?

[quote name='SwamiRob' timestamp='1447169586' post='2905476'] If sound guys put enough bottom end through the PA instead of the low end all being kick drum at the vast majority of heavy gigs then I'd happily let the PA do the very bottom of things and enjoy a little more clarity on stage. When it does happen it's a very nice thing cos I prefer to be sitting in a mix as much as possible with a reasonabley audible about of woody lows and a subtle amount of percussive clankyness going on. Makes everything alot cleaner then the gigs where there's no depth to the bass and I have to crank it up on my amp which only has a 3 band EQ and isn't the most accurate for doing stuff like that. [/quote] Why do they do that? Are the recruited with sub standard hearing? Almost ruined the recent Glenn Hughes gig in Southampton for me.

[quote name='Bill Fitzmaurice' timestamp='1447096337' post='2904854'] By 4dB to be precise, which isn't worth the bother. As equally valid a question is what is the point of 500w amps? If I manufactured amps I'd make the size differential between models at four times the power rating, say 50w, 200w, 800w. [/quote]Surely a Jack cabinet with a 200W amp and you are good to go Bill.

I have to be honest, having once re-designed a protection circuit for a class A/B power amp, I would not recommend you rely on one at 2 ohms. it is too close to a short and at some frequencies the speaker will go below 2 ohms. In fact we found that if you don't use jack plugs, amps rarely short. The, and the current limit of most jacks, is why I prefer speakons.

A power amplifier has two main circuits, the power amplifier and the power supply. Either can be we working close to their limit on either current or voltage and that will determine the power output. In the case of the F1 et al, the user manual quotes 300 watts into 8 Ohms should give 600 watts into 4 ohms i[b]f there is enough in the power supply and the output devices in the power amp. [/b]Clearly the F! has limitations in one or both areas. Of course if the F1 and the other amps really output the powers they say, the only real difference will be the sound the preamps impart.

So Mesa offer a 2 ohm switch but the ASC70 minimum load is 2.5 ohms? it looks a good amp but there does not seem to be enough room for smoke and mirrors in that box. Maybe a 2 ohm loading will allow the smoke to come out? Passinwind, you must have the designer manual for the ASC700. Is 2 ohms possible?

I hope I will do. Inrush current is the extremely high instantaneous current that happens at switch on. It is determined by the power supply design and/or technology. It wan't make a jot of difference to your sound but, if not controlled may affect the reliability. Slew rate is the speed at which an amplifier can change over time. Usually measured in volts/uS (micro seconds).. As far as I know, most modern amps have an adequate slew rate for bass. Early op amps like the 741 used in many early SS amps had a slew rate typically of 0.5V/uS. Generally considered too low for audio. Industry standard Audio opamps like NE5532 have a slew rate of 9V/uS. Of course the slew rate of a complete bass amp is more important than an individual component, and is rarely quoted.

Can't say about the round wounds bu I put Fender Flats on my peavey as the shop was out of Picatos. The low E went "soggy" in a week.

[quote name='dincz' timestamp='1446486503' post='2899773'] Their rated powers are measured differently. [/quote]No it is not that simple. Lets take say a 400W SS and a 200W Valve amp. If we measure them both at 200W into an 8 ohm resistor,* they may well both have a distortion of under 1%. There is no standard for distortion for MI use but 1% is the figure I used when I decided on the power unit for my amp. If they are well designed the output will be almost identical. Push them harder and the SS amp will start to sound nasty and the valve amp will "compress and distort" in a more musical way. TC electronics add this effect to their amps to claim much higher perceived power than the real power of their amps. So you will get a little more usable power from the valve amp and it sounds louder. Louder in the same way the adverts sound louder than the programmes on TV. Assuming the valve amp has 4 ohm tap on the output transformer, we connect both to a 4 ohm speaker. Now the Valve amp will again output something over 200W but the Solid State amp will be outputting 400W, This would be almost 3dB in power terms and as as 1 db is a just noticeable change in level, 3 dB is obvious but not earth shattering. Of course what is earth shattering is the weight of the 200W valve amp. * a resistor is used because loudspeakers are coils of indeterminate values and the impedance (ac resistance) at each frequency differs from driver to driver, cabinet to cabinet.

Bill is right 600W solid state is usually quoted into 4 Ohms and the will give you 300W into * Ohms providing the watts are not "marketing watts". Add the increased power due too compression in he valve amp and there will be little difference. If it is a Behringer or Bugera, the Valve head will be louder. However set the valve head to 4 ohms and the 600W SS into 4 ohms will be louder but not by much. Of course the issue here is that compression is distortion and any amp will be louder with distortion. So if you want a loud SS head add a little fuzz an pitch of compassion and your there (don't forget the lead weights top if you want a "vintage" valve sound).

Well I have the chance to buy many small practice amps from reputable makes and they were with tosh, expensive or both. The was cheap and a bit tosh

Has any one got any service info on these? It works but has horrid pop on switch on.

On many digital systems there is a reset button or sequence of buttons to reboot/reset the processors. You might find it in you user manual.

After my eye op I have had trouble as my new lens is quite different to my other eye.That is due to be operated on next month. So no need e work has been done. I have been running the power amp on its own using my Korg AX3000B as a preamp. Although the AX3000B has a reletively low output but the amp iseems to have so much in reserve. I was a little concerned earlier when the amp got a little warm. However I realised it was in the sun all day. One thing I have confirmed is that the Powercon for the mains. That is the blue plug in the pictures. It locks really well and fils you with a confidence that the IEC does not. You can also see the speaker cable (Orange) connected via the speakon/Jack combo connector. The Orange cable is 2 metres of 2 core mains cable. Over the distance from amp to cab there is no need for a monster cable.

[quote name='xgsjx' timestamp='1446341314' post='2898722'] Now that's not quite true... It's just spelt differently & means something completely different. [spoiler]Homage[/spoiler] [/quote]I give homage to you. Are you Wictionary in disguise?

I get all my screws from TR Fastenings you have to buy 100 min but when I bought 100 M3 x 6MM machine screws they charged me £1. The same as many places charge for 10 screws. Of course they are about a mile from my house but they have branches all over. If not them look for Fastener Suppliers in your locale.

On a passive bass the pickups are "loaded" by the pots, cap, your lead and the amplifier input stage. The tone control affects the top end and the volume control affects both volume and tone and the lower you have the bass volume, the more the treble is cut. [size=4]A good preamp takes out some, or all,of these and lets the pickup sound come [/size]through unaltered.[size=4] Of course the passive sound is what most of us are used to and so the natural sound of [/size]the[size=4] pickup sounds too bright or [/size]zings[size=4]. The biggest load on the pickup on a passive bass is the volume pot and the 250K resistor that is added is the same as having a 250K pot set to max volume. In other words it gives you back (most of) your passive sound.[/size] [size=4]I understand that some of John East's [/size]preamps also have a preset mid scooped sound pre set. It may be worth chatting with John re your options as few know as much as him about preamps and sound.