Question about pedal power and supply

[agedhorse]

Actually, since phantom rides the center tap to ground, it never sees the actual device impedance. And since a passive instrument, by definition, does not need power (no preamp), with a preamp, the pickup impedance isn't really relevant, since only the preamp balanced out would be on the line. (If you are talking about trying to float power down an ubalanced line, your comments make more sense . . )

That's not how phantom power works. (48V) Phantom power is delivered via 6.8k resistors in series with the + and - lines, these resistors are what define the input impedance that ANYTHING connected to the input sees (13.6k actually). There is no center tap involved, and in fact there is likely not even a transformer.

 

[tadawson]

Well,, yes and no . . .In the older days, when everything was transformer based, the original design was power on the center taps, which put the same voltage on both signal legs, and was taken off the center tap to ground on the other end (mic or whatever). Since no potential difference between legs, no flow in between, just to ground. The transformers coupled the signal on top of the DC transparently. As time ran forward, and solid state front ends (IE non transformer) came into being, yes, they do what you describe, but I think if you check, a lot of mics still use a transformer to drive the balanced line, and pull power from the cener tap. Even in the older stuff, there was a current limiting resistor, but only one . . . and not sure it was 6.8K. Tthe po9jt I was mak9ng is that while that is what may be seen as the input impedance (at least to DC), it's via the common pair to ground, and as such, does not necessarily exist in the remote device using the power, where it's souce impedance is more based on the output stage of the device driving the line that the circuitry extracting power.

And in a bass, you would need something to get between the high impedance of the pickups, and the 600 ohm line, *or* use a different line impedance for the MI version more suitable to instruments and shorter runs.

I've found numerous circuit images showing exactly this, but my tablet is refusing to cut and paste them, and I'm not up formtyping the long strings of gibberish that arebthe links.mThe one thing I am certain of,however, it that Imdamn well know how phantom works, and the various implementations . . .

 

[PhatBasstard]

Well, being one n among many, I can't remember the last time I used a pedal powered by battery, and I wouldn't buy a pedal if it were battery powered only.

I barely put up with having a battery in my bass.

No comment. I simply couldn't improve on this. ;-)

 

[agedhorse]

Well,, yes and no . . .In the older days, when everything was transformer based, the original design was power on the center taps, which put the same voltage on both signal legs, and was taken off the center tap to ground on the other end (mic or whatever). Since no potential difference between legs, no flow in between, just to ground. The transformers coupled the signal on top of the DC transparently. As time ran forward, and solid state front ends (IE non transformer) came into being, yes, they do what you describe, but I think if you check, a lot of mics still use a transformer to drive the balanced line, and pull power from the cener tap. Even in the older stuff, there was a current limiting resistor, but only one . . . and not sure it was 6.8K. Tthe po9jt I was mak9ng is that while that is what may be seen as the input impedance (at least to DC), it's via the common pair to ground, and as such, does not necessarily exist in the remote device using the power, where it's souce impedance is more based on the output stage of the device driving the line that the circuitry extracting power.

And in a bass, you would need something to get between the high impedance of the pickups, and the 600 ohm line, *or* use a different line impedance for the MI version more suitable to instruments and shorter runs.

I've found numerous circuit images showing exactly this, but my tablet is refusing to cut and paste them, and I'm not up formtyping the long strings of gibberish that arebthe links.mThe one thing I am certain of,however, it that Imdamn well know how phantom works, and the various implementations . . .

Respectfully, before being so damn sure, you might look at some real industry standard circuits.

The reason very few (I can't think of any off hand) don't use the center tap to inject phantom power is because the D.C. current flowing tends to magnetize and saturate the core which then requires a much bigger core which reduce high frequency performance.

The phantom power is generally applied through the appropriate resistors directly to pins 2 & 3 of the input connector.

As promised, this is the industry standard way, as supported by the industry standard transformer manufacturer:

Typical standard transformer input circuit:

http://www.jensen-transformers.com/wp-content/uploads/2014/08/as016.pdf

Follow-up transformer input circuit with amplifier:

http://www.jensen-transformers.com/wp-content/uploads/2014/08/as018.pdf

 

[handofdumb]

Just my two cents - I ALWAYS plop fresh 2-for-a-dollar 9 volt batteries in each of my pedals before a gig, and run exclusively off of battery power.

I'd really rather not trust my power supply with everything during crunch time. Plus, I can't always expect that there will be one more free outlet for me (though that's never actually been an issue). On top of that, set up and tear down is slightly faster and I have one less thing to forget at a venue.

Batteries for life!

 

[Stevorebob]

Just my two cents - I ALWAYS plop fresh 2-for-a-dollar 9 volt batteries in each of my pedals before a gig, and run exclusively off of battery power.

I'd really rather not trust my power supply with everything during crunch time. Plus, I can't always expect that there will be one more free outlet for me (though that's never actually been an issue). On top of that, set up and tear down is slightly faster and I have one less thing to forget at a venue.

Batteries for life!

Using Boss or similar pedals with easy-access batteries and no board? I think it’s a time-consuming pain to rip off a Velcroed pedal and unscrew the box to access the battery.

 

[s_wood]

I suspect there may be a self selection bias in the TB effects forum. People on here really like effects and tend to own and use a lot of them

I think that’s right. Talkbass is full of gearheads. We use pedalsboards with power supplies. I would say that, in the real world, at least half of the guitar players and bass players I see in bars are not using power supplies, even if they have pedal boards.

 

[PDGood]

I prefer to have the battery option. I didn't realize how important it was until I was in a session and the pedals were just making too much noise plugged in. Switched to battery and it got quiet. I admit I don't know enough about electronics to sort out the problem if there was another way to do it, but batteries saved the day then, so I continue to want that option.
The issue of available outlets live is another real concern. I run a very small pedal board and there is no power supply that I have found that fits under the small Pedaltrain board. (I'm open to suggestion if you know of one!). So I wind up with a tangle of three 1-spots to plug in.

 

[beans-on-toast]

Many condenser microphones used remote power supplies often placed on the floor to deliver a DC voltage to the mic.

When Neumann, Schoeps, and others developed a new mic powering standard, the power was there but the supply was invisible, they called it phantom. The term phantom translated well between German and English.

 

[BurningSkies]

Maximum useable current for phantom power is 6-8mA, not enough to do much with low noise circuitry.

Seems underpowered for my board.

Also, fussing with XLR or other connectors always feels like a lose to me when it comes to applying them for other purposes than either intended or as generally used in the industry. While most of us are pretty good about knowing before we plug, lots of XLRs on stage for people to get in trouble if they're not careful.

ATR Magnetics is a big player. A 2500’ roll of 2” tape for a 24 track machine costs about $345. At 30 inches per second, that gives you 16.7 minutes, at 15ips, that’s 33.3 minutes. Media costs add up quickly.

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¼” tape is much more reasonable at $68 for 3600 feet.

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Yeah, there's still some tape out there. But you need to be REALLY picky for Space Echoes. The tape is always spinning when it's powered on. It never disengages. That 12' loop is in constant contact with those 5 heads, so if the tape is rough at all, you've sanded off your record/playback/erase heads. Luckily there's still a repair industry for these but it's small, expensive and fairly specific...so if you can keep your machines in good shape. Also it's aboutt he rubber on the wheels and the tank remaining clean and a handful of other things like the tension of the felt pads.

I still have a handful of 2" reels from past bands...although I haven't stored them nearly as nicely.

That's got to be NOS. Who makes magnetic tape anymore?

It was. I've had it for a few years. It sits triple bagged in my fairly well climate controlled basement, so roughly 65 degrees F and somewhere 40 percent humidity. It's also where my basses sit.

I bought it from someone in Greece, as NOS. It's really the best space echo tape there is. Production ran from 1981 to 1998 for BASF LGR-50. So for those who are paying attention, it's start of production post-dates the RE-201 which was in production from 1974 until 1990. 1990...holy crap, did anyone know they made Space Echoes until 1990? I would have though they killed 'em off by the mid 80's. I'd love to find a 501 someday but I'm not willing to spend what people want now.

Accent on vintage. I am pretty sure BASF "even the bad times sound good'' tape is out of production.

I'm guessing that this reel is less than vintage. Which is a good place to be when it comes to tape, although it is on the cusp at 20 years out.

The good news is that this tape will probably outlive my Space Echo and me. It's a 1000m pancake. The unit uses a 12' loop (Many say 4m loops, but I find that much can cause problems in a tank), so if you do the math, that's 273 loops. Although I do make them up for friends in the sound/dub/band side of things...because having a friend who can splice up loops and give them to you and not charge 20$ and you know it's the right tape is an excellent karmic thing.

 

[ad9000]

As a self-confessed pedal junkie, I have several scenarios going on depending on the gig:

Pedaltrain pedalboard with 9 pedals: Voodoo Labs Pedal Power 2 mounted underneath powering all pedals.

I may grab 2 or 3 pedals only for certain gigs (typically a Sans Amp original, octave pedal and envelope filter or distortion pedal). Currently I go with battery power or AC adapters for those, but I am in the process of weaning myself off batteries and going with a One Spot instead. I find that the One Spot, not being a regulated power supply, can be noisy if you have too many pedals in the chain or ones demanding a lot of voltage (like some of the Strymon pedals).

If I use my Noble Preamp/DI, I will use its capability to power pedals also (usually same selection of pedals as above, but sometimes only the Sans Amp).

One notable bugaboo with all of this are some of the less basic Electro Harmonix pedals that either don't run on pedalboard power or have odd size barrels (the Frequency Analyzer is one of the latter). I use their supplied adapters since I haven't really figured out a better solution.

I'm noticing, as I'm sure others have, that it's a lot more common for pedals to not have 9v battery power. I hope to wean myself off batteries completely except for my tuner, which I don't have in the signal chain.

 

[beans-on-toast]

Accent on vintage. I am pretty sure BASF "even the bad times sound good'' tape is out of production.

BASF got out of the magnetic tape business in late 1996, spinning off the tape company to what became EMTEC. Eventually the reel magnetic tape business was sold to Recording Media Group, RMG. That company was sold to Pyral 2012, they eventually declared bankruptcy. In 2015 Mulann took over the assets, it took that long to sort out the legal issues with Pyral. Mulann currently produces magnetic tape under the brand, Recording the Masters. The tape is made to the BASF spec. So BASF tape is still being produced as SM900.

RecordingTheMasters – Professional Analog Audio Tapes

As a company BASF are still around selling chemicals to enrich our lives.

 

[ahtimsir]

These days, how important is it that a pedal operate from a 9V battery (acknowledging that some simply can not) and is it worth paying more for a pedal that can support battery operation (even if it means <20 hours of battery life)?

When I gigged in some 3rd world countries and rural places, I had to use batteries for my pedals. The AC power was not reliable in those places, to the point where the sound would fluctuate in and out when I'm playing if I try to use the AC power. So the ability to use batteries to drive my gear with DC power was very beneficial.

 

[BurningSkies]

BASF got out of the magnetic tape business in late 1996, spinning off the tape company to what became EMTEC. Eventually the reel magnetic tape business was sold to Recording Media Group, RMG. That company was sold to Pyral 2012, they eventually declared bankruptcy. In 2015 Mulann took over the assets, it took that long to sort out the legal issues with Pyral. Mulann currently produces magnetic tape under the brand, Recording the Masters. The tape is made to the BASF spec. So BASF tape is still being produced as SM900.

RecordingTheMasters – Professional Analog Audio Tapes

As a company BASF are still around selling chemical to enrich our lives.

A quick look at their catalog, yeah, they sell a few formulations, but the LGR's are gone. But then, I could have told you that because if there was a modern equiv., I'd have heard about it from about a dozen people.

 

[BurningSkies]

When I gigged in some 3rd world countries and rural places, I had to use batteries for my pedals. The AC power was not reliable in those places, to the point where the sound would fluctuate in and out when I'm playing if I try to use the AC power. So the ability to use batteries to drive my gear with DC power was very beneficial.

Yeah, I flew to the Caribbean a few weeks back for a gig and wasn't sure if the outlets, voltage, etc. would be the same...I only took a tuner with a new battery rather than my whole board. But I figure that had I needed my board I could have specified some amount of control over what they provided.

 

[Wfrance3]

Personally I think batteries are something that will let me down when it’s most inconvenient. I play passive basses and have my small pedal board hooked up to a cioks power supply.
My fear is that I would have a pedal I take out of rotation, forget about the battery inside and ruin the pedal when it corrodes.

 

[Loring]

Could always sell an external battery adapter to the luddites and those looking for a preamp to powered speaker for cocktail / teahouse gigs. Make it rechargeable li Ion or 9v plug and extra revenue stream...

 

[MattZilla]

I like going battery power when I'm only using one pedal for the night and want as clean a stage as I can have without antennae. Sometimes that one pedal is dirt, sometimes it's my old Crybaby.

Modulation and time pedals don't come out without a board and power adapters.

 

[beans-on-toast]

A quick look at their catalog, yeah, they sell a few formulations, but the LGR's are gone. But then, I could have told you that because if there was a modern equiv., I'd have heard about it from about a dozen people.

They are just starting out, you never know what they are working on.

Might be worth contacting them.

 

[BurningSkies]

They are just starting out, you never know what they are working on.

Might be worth contacting them.

I'll hit 'em up the moment I run out of LGR50. Or maybe sooner.

Also, tape echo guys are funny. The don't like the tape too 'new' and not too too 'worn' there's a sweetspot that also coincides with the machines...you have to be able to hit it just right to send the unit into self oscillation. It's really an instrument in it's own right.