Reddit mentions: The best recording signal direct boxes

I'd recommend working your way up to 7 mics. If you try to buy all seven at once, you'll end up getting cheap ones, and it'll sound worse than buying four good ones. Monoprice has a decent matched pair of condensors for $100. For the snare, you can go with an SM57. They're $100 new, but you can get them more cheaply used, and they last forever. I have the same ones I used in highschool, and they still work just as well as the day I got them. You can use it on your guitar cab, as well (or just buy two for live tracking). I also use a Beta 52 for the kick drum. That runs for a bit under $200.

As for stands, if you're not using them live, Guitar Centre sells a 10 pack for about $90. They aren't perfect, but they'll work.

So, for good equipment, you're looking at almost $600 in mics alone. You can get cheaper kits, but the sound quality won't be as good and they'll break more easily. You get what you pay for.

For bass, I just DI. You can buy a proper DI box or just plug into the interface. But, for $40, having a few DI boxes around comes in handy, especially if you want to record live. You can also mic the bass cab with something like the aforementioned Beta 52.

As I said before, you'll want an SM57 for the guitar cab. It gets the job done, and is pretty much the industry standard. You can spend more on fancier mics, but that money is best spent elsewhere.

As for vocals, you can buy a decent condenser mic from Monoprice, but to start off, just use the same 57 you've used for the guitar and drums, and just put a $14 pop filter on it.

Finally, you'll need an interface. If you really want to track seven drum mics, I'd go with a Tascam 1800 or a Focusrite 18i20. The latter is better quality, but also double the price.

Sadly, there is no good cheap method of doing things. But here in the digital age, things are a whole lot easier than going through to a 4-track cassette Portastudio when I was your age. If I was in your place, and had $1,000 to spend, I'd buy the following:

Tascam US-1800 ($250)
Two Behringer DI-100s ($80)
The Monoprice Small-Dia Matched Condensers ($100)
Shure Beta 52 ($200)
Two SM57s (or 58s) ($200)
The Guitar Centre 10 Mic Stand pack ($90)

And spend the rest on XLR and 1/4" cables from Monoprice.

After working on recording and mixing for a while, see if you want to expand your drum tracking, or if you want to invest in additional gear as needed. Nothing sucks more than blowing your budget, never using a certain thing, but having to do without something you discover you need.

And most importantly of all, have fun with it. It's a great experience.

That would work, but a couple notes:

1. The mixer: Keep in mind a cheap mixer will introduce more hiss/noise into the system, but proper gain-staging will help minimise this. It can also convert the stereo signal of the turntable to mono if the turntable won't do that itself.
   
2. If your cables to the mixer and/or amplifier will be very long or run along power cables then it would be better to use balanced signals (typically XLR, sometimes TRS when used correctly) to avoid buzz being introduced. You would want a mixer that has balanced outputs and inputs, and possibly a direct box to convert the unbalanced signal from the turnable to balanced if the mixer isn't close to it. With the right direct box and an adapter you technically wouldn't need a mixer as the direct box can convert to mono, but you might want a mixer anyway as the signal level from the turntable may be too low without it, plus then you can plug in other devices.
   
3. The speakers are 4 Ohm @ 500W continuous and the amplifier is rated for either 4 x 1600 Watts @ 2 Ohms or 2 x 3000 Watts @ 4 Ohms. It's okay that it doesn't match perfectly if the amp ohms are lower than the speaker ohms - it just means the amp won't be able to drive as much power through the speakers, which is probably good in this case since 1600W is too much. So running each speaker to 1 output on the amplifier is probably the best bet.
   
4. I don't know how the speakers are set up in the venue, and this might be the venue's responsibility unless they're your own speakers, but there are a couple extras that could help audio quality:
   
   1. A graphic equalizer would be a welcome addition to adjust the sound so that it sounds best for the room - ideally you'd also use a calibration microphone and software to take measurements and see where the peaks and valleys are in the frequency response, but it can also be done manually if you have a decent ear and listen closely - don't just make it V-shaped or some other nice pattern because it looks nice.
      
   2. It might be useful to use a signal processor that can independently add delay to the signal for each speaker so that they can be time-aligned. Sound travels pretty slow through air - about 1 millisecond per foot. This is getting a little advanced for just a DJ setup, but a professional system would consider this IF the speaker placement demands/allows it and the venue is large enough. This can be done using a combination of measuring tape and ear, or ideally a calibration microphone and software.

Warning: this should work, but these things can always be a crapshoot.

I work in pro/live audio, and there's a special piece of kit we tend to use to get rid of the kind of ground hum you're talking about. Typically they're called isolators/isolated transformers/isolated splitters/etc.

One of the most cost effective yet also most impressive variants is this one: https://www.amazon.com/ART-DTI-Transformer-Isolator-Interface/dp/B0009GUOQA

You could just get one 1/8" to 1/4" adapter, or a 1/8" to RCA cable or something, and try running it through this. It's a very versatile little thing. Any input 1 is matched to any output 1. Any output 2 is matched to any output 2. No need to configure or learn anything to use it. Plug and play, as we call it.

Someone will probably have a better solution, but that's how I would go about it. Best of luck!

Focusrite Scarlett Solo and Scarlett 2i2 (Link 1). On amazon for around a benjamen. I would also get a DI box like link 2 to be in front of the Scarlett. This setup is pretty cheap but more than capable of recording, or playing through a laptop at Church. THe scarlet has output on back. hope that helps. I have both of these, great value.

Link 1: https://www.amazon.com/Focusrite-Scarlett-Audio-Interface-Tools/dp/B01E6T56CM/ref=sr_1_3?s=musical-instruments&ie=UTF8&qid=1472744892&sr=1-3&keywords=scarlett+2i2

Link 2 : https://www.amazon.com/Behringer-DI400P-BEHRINGER-ULTRA-DI/dp/B000KUA8G6/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1472744729&sr=1-1&keywords=di+box

Thanks for this. I just ordered a whole pile of stuff on Amazon with Prime. Came out to be a good bit cheaper than your estimate. I traded down on a couple of things like the vocal mics (Behringers for 1/3 the price) and direct boxes (half the price). The big thing I skimped on to make my budget was the mixer - I got a Behringer 12-channel mixer with great reviews for about $90. Hopefully it will get the job done.

Definitely couldn't have figured out what to buy without you. Hopefully this is everything we need for a great summer and beyond!

Like you said, it's not strictly necessary. I do think there are benefits for tone, however - and I didn't become a believer until I got a better one. This is the one that I am using now ($99). It's definitely a purchase I wish I had made earlier.

There are some other benefits with DIs - having a thruput is really helpful, both sonically and in terms of workflow. Personally I like to record amp and DI simultaneously, especially for bass. When recording guitar, even if you don't want to record an amp because you are in a small space or whatever, running the thruput to a little tiny practice amp is great for monitoring without latency.

Edit:

To try to quantity the improvement in tone with the Radial compared to a cheap DI or running direct into an interface: the bass DI has more low end, and the guitar DI sounds like a clean and dry electric guitar instead of a buzzy cigar box with rubber bands. If your interface has a Hi-Z input the difference will be less drastic (because there is no impedance mismatch), but even taking that into consideration the improvement has been really worthwhile for me.

An inexpensive solution that I have in one of my ukes is
this Artec piezo mounted under the saddle paired with this endpin jack. As you can see the components simply plug into each other. This is a passive pickup so it will benefit greatly/require an external preamp. I use the Behringer ADI21.

I've also installed the JOYO JE-62 in three different ukes for friends. It can be found on eBay from various Chinese vendors. It comes with a flexible wire piezo for under the saddle but I replaced it with the Artec piezo. This is an active unit with a built in tuner.

On the higher end I've installed MiSi Acoustic Trio pickups in two of my ukes.
All are good solutions for different budgets.

Use it last, but I'd recommend copping this to put right after. You may need a DI at a show, might as well get one with a cab sim in it. Note, this needs power.

Together playing it sounds great in my headphones, just waiting for a time to try it in the sound system of my practice space.

Would typically go Glove -> DS-1 -> Phase 90 -> Obscura -> Oceans 11

OD into distortion is pretty much non-negotiable, the other way around won’t really do anything. However, phase into distortion is a great sound that I like a lot, and reverb into distortion is great for shoegaze. Delay into phase is fun, I run delay into chorus and then into reverb on one of my pedalboards for some huge dreamy modulated sounds.

You might have to turn the minibrute down on volume a lot if the non-distortion pedals start to distort, I sometimes use one of these as a passive attenuator to drop the sound levels if I’m having clipping issues.

I can't speak to your insturment specifically. I did however, do a lot of research into acoustic amplification trying to make a nylon strung acoustic guitar work with Rocksmith.

You can get a stick-on Piezo pickup relatively inexpensively from Amazon.com. My experience has been that an expensive pickup won't significantly out-perform a cheaper pickup. Start inexpensive and see if the pickup is going to work before throwing a lot of money at it.

As you already know, you'll need a pre-amp to bring the volume up to a reasonable level. I bought this Behringer external pre-amp from Amazon relatively inexpensively.. This setup is enough to bring the stick-on pickup within an order of magnitude of any other instrument at your gig. You can then run it through an amp or a PA.

Be aware that a Piezo pickup will not produce the deep full sound you are used to with your upright bass. Piezo pickups will tend to produce really wonky response curves with a bit more of a synthetic tone than your instrument produces naturally. They work by detecting the vibrations of the body, not of the tone actually coming out of the bass. They usually pickup string vibration more than acoustic vibration.

If you want to capture the natural tone of your bass, consider using a Microphone pickup. A mic pointed at the sound-hole of your bass can produce very good sound, and is a very common way to amplify acoustic instruments. In fact, this seems to be the most common way to amp an acoustic bass.

A clip-on mic like the one I just linked will help produce the most consistent sound levels as your instrument moves around. But you can use a conventional stand-up mic as well.

A mic will be sensitive to feedback, so properly testing your environment and ensuring that there's no feedback is critical. This will still be an issue with Piezo pickups as well, though it won't be as much of an issue.

TL;DR: Mic your bass.

Before you buy anything (and don't pidgeonhole yourself into spending $100+ on a new dac as /u/Diablo-D3 says - he may as well be a Schiit shill with how much he's pressuring you to spend money with them) try adjusting the current setup first. Spend $300 on new equipment to fix a little buzz? Please.

You are using a USB dac/mixer as your dac stage. You're connecting through balanced 1/4" outputs - presumably these are line-level. The buzz only comes when when your GPU is under load.

From that we can extrapolate it's due to power problems. Go to the power management menu, advanced settings. There should be something there for USB power selective sleeping - make sure that's disabled.

The problem persists with a powered hub, but the headphone amp section of the 2i4 is fine. The amp circuit is removing the power problem.

I'd do a couple things:

Use a microphone to record the hum and see what frequency it is. If it's 60Hz (US) or 50Hz (elsewhere) then it's a grounding problem and a guaranteed way to solve it is to put a DI box like this in the signal path to the speakers to ground it. That whirlwind is the type of box we use at work for very long XLR runs and they work great. Your 1/4" outs would work fine, an XLR -> 1/4" cable would work on the output side.

You could also try the unbalanced RCA output. It could be a flaw in the circuit for the balanced output, or something is just barely touching inside.

A more 'severe' option would be to buy a power conditioner, but there is no guarantee that could fix it. Or you could get a new motherboard, that could fix it too but would be silly. A USB power isolator would work as well, such as this which is unpowered. It limits the output to ~200mA though, and the 2i4 probably needs more juice than that.

Really I'd look into the unbalanced RCA out first, since that's like a $8 potential fix for a cable. If that doesn't work a DI box should fix it.

I've already got Logic, which as I understand is a great option/competitor to Reaper, though some of my windows-using friends swear by it too!

I also already have an input/DI for sound box, sorry if I made that unclear in what I called it. I have the Focusrite Scarlett 2i2, which connects via USB. What I was wondering was if per my concerns about a clean signal through that from my guitar, I could help things by buying a product like this one to change my guitar signal to a mic-level XLR connection before routing it to the Scarlett box.

Get a passive DI box and run the XLR master out to that then RCA from the DI to the tube amp.

You need to bring the +4dBu output of the mixer's XLR down to -10dBu of consumer line level audio. And a passive stereo DI is the best way to do that. That particular one linked above also gives you another ground lift and some gain flexibility with the volume pots. But there's a ton of different options.

Sounds like a ground loop to me. I had some trouble with a ground loop a couple of months ago and this comment ended up helping out a lot to understand what exactly might be the source of the sound: https://www.reddit.com/r/edmproduction/comments/502u0x/i_cant_get_this_hum_out_of_my_audio_recordings/d71kmiz/

Biggest take away (and my best guess) is that it's an electrical issue. If you can't find it and are looking for an equipment solution, this helped me and is relatively inexpensive: https://www.amazon.com/gp/product/B000CCSWPQ/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

Hope this helps!

Mark the best place for a 57 on your cab with tape and permanently install one of these: http://www.amazon.com/Palmer-PDI-Passive-Box-Guitars/dp/B001QUL9OY. You're good to go in seconds. :)

> Hum X Eliminator

https://www.guitarcenter.com/Ebtech/Hum-X-Hum-Exterminator-1274115046356.gc

https://www.sweetwater.com/store/detail/HumX--ebtech-hum-by-ground-loop-hum-exterminator

Though I many not hear it properly, what I hear does not sound like Hum, it sounds more like hiss or Amplifier noise. But again, I can't hear it very well.

This is what 60hz sounds like -

60hz Test Tone -

https://www.youtube.com/watch?v=GqwFimG3X3w

If that is what you are hearing then it could be eliminated with the Hum X Eliminator.

Also, given that your house/apt has 2-wire circuits with no earth ground, it could be the connections are dirty on the outlets. Though this is dangerous, do not mess with them if you don't know what you are doing, and definitely shut the power off to that outlet.

Again, not clear what options are really available to you. It this a large apartment building, a duplex, a 4-plex? What are the water pipes made out of Copper or Plastic? Where is the nearest COLD water pipe relative to the outlet you are using?

The make special clamps that can be used to add an earth ground to existing circuits.

https://www.homedepot.com/p/1-2-in-to-1-in-Ground-Clamp-for-Bare-Wire-25-Pack-16011B/202361719

Actually that is for a pack of 25, so they are about $1 each.

That would allow you to add an earth ground to the outlet assuming you can get from the outlet to a METAL cold water pipe. It has to be a Cold Water Pipe because the Water Heater electrically isolated the Hot Water Pipe from Ground.

There are also Unbalanced to Balanced converters at a very reasonable price. If that is a conversion your speakers allow, this could be an option -

https://www.amazon.com/Passive-direct-instrument-balanced-unbalanced/dp/B009AARY2I/

The above is MONO. Here is one that is Stereo -

https://www.amazon.com/Premium-Direct-Injection-Audio-Box/dp/B00356J8KE/

This Stereo Device uses Transformers to lift the signal from reference to ground for floating balanced XLR out.

You would have to get adapters to convert RCA to 1/4" Phone, but that is easy enough.

https://www.amazon.com/VCE-6-PACK-6-35mm-Female-Adapter/dp/B0727VZXP5/

https://www.amazon.com/Tisino-Adapter-Copper-Quarter-Connector/dp/B0782LPDZG/

https://www.amazon.com/Tisino-Adapter-Quarter-Coupler-Connector/dp/B078DSKHSB/

And so on...

You might consider investing in a Radial JPC DI. (Also the manufacturer's website. )

They're a pretty great investment, sort of a swiss army knife of audio ins and outs. It saves my butt on many a corporate presentation. If you shop around, you should be able to get it cheaper than whats listed on Amazon here. I find that most music stores that stock radial products have bought two or three of these units and don't shift them as much as the guitar or keyboard centric products.

We've been using these DI boxes. Could you tell me what the difference might be if we had nicer ones? In the past we've used a dynamic mic for solos, but that's it. Oh yeah, I play rhythm guitar in the OP's band.

Basically you will need a couple of things:

• Some way to get sound from your bass to your computer. I'd recommend a DI. Some amps include them, or you can purchase one for not too much money (e.g. Behringer has a $20 one).
  
• Some way to get the audio into your computer. There are relatively cheap USB or Firewire audio interfaces out there. I have a Focusrite Saffire 6 that was under $200 and works well.
  
• Some software to record and process the audio. There are many options; Reaper is relatively cheap and free to try.
  
  All told you can probably spend less than $300 and have a solid setup for most things you would do.

A standard instrument cable is a quarter inch Tip-Sleeve Connection. It is an unbalanced cable. Which is fine for use with instruments obviously, but can lead to electrical interference, ground loops, and loss of signal over long lengths.
When you use a DI you want to use a balanced cable, basically a cable that is has a ground connection. The two most common kinds of balanced cables are XLR, and quarter inch TRS (Tip-Ring-Sleeve). TRS cables look almost identical to instrument cables.

This explains the difference: http://www.sweetwater.com/sweetcare/articles/whats-the-difference-between-ts-and-trs-cables/

This is probably way more in depth than you'll ever need, but it is a good reference: http://www.sweetwater.com/insync/cable-buying-guide/

Edit: To Clarify, when I say DI I mean using a DI box like this http://www.amazon.com/Behringer-DI400P-BEHRINGER-ULTRA-DI/dp/B000KUA8G6/ref=sr_1_2?ie=UTF8&qid=1417904828&sr=8-2&keywords=DI+box

If you are talking about just plugging your directly into an interface, an instrument cable will work just fine.

Well this interface is really highly rated, exceptional quality for the price and this DI box was standard use back in uni. Hope that helps get you started anyways.

What do you think of a direct input like the Behringer? It's got great reviews.

The professional way to do this, is with a DI box. I think these are the best:

Radial Pro DI Passive Direct Box https://www.amazon.com/dp/B000A8J3N2/ref=cm_sw_r_cp_api_i_gNYlDbW95JSWJ


But in a budget, an impedance marching transformer will do the trick:

Shure A85F Transformer; Low Z, Female XLR to High Z 1/4-Inch Phone Plug https://www.amazon.com/dp/B0006NMUHW/ref=cm_sw_r_cp_api_i_GJYlDb4PE0T99

Edit: didn’t want to leave out the a solution.

Lots of things you can do with $25 on Amazon:

Behringer Ultra Vibrato UV300 pedal ($25)

Behringer Ultra Chorus UC200 pedal ($25)

Rock Band 25-key MIDI keytar ($24)

M-Audio SP-2 sustain pedal ($14)

Behringer Ultravoice XM8500 dynamic vocal mic ($20)

Auphonix 6" double mesh pop filter ($19)

Behringer Ultra-DI DI400P passive DI box ($20)

On-Stage single X keyboard stand ($22)

Andoer melodica ($20)

Andoer kalimba/mbira thumb piano ($12)

Big Thunder Tube ($30)

Small Thunder Tube ($8)

Angled Thunder Tube ($28)

Meinl Percussion 8" claves ($6)

Stylophone ($24)

Cables

Cable adapters

Hey man, sorry it's been a while. Let me ask you if this is a good deal? I'm running a Scarlet solo, so would it be good to run that through the Cloudlifter and into the SM7B?

Thanks, though some are pricey. Since saving money is paramount for me, which one would you recommend?

This one, perhaps? https://www.amazon.com/Behringer-Ultra-High-Performance-Passive-Injection/dp/B000KUA8G6

Thank you so much! I ended up getting a Rolls DB24 Stereo Direct Interface because it has two outputs, and a lot of good input options.

If the venue has a mic jack like this, you want a DI box, and a dual 1/4" to TRS mini cable, and a short XLR cable. Venues often can supply these things since this is an extremely common request from clients renting spaces. Is it a community hall or a hotel ballroom or what kind of space is it? In community centres there is often only one or two people who even know the parts exists in inventory and the rest of the staff has no idea and might say they don't have it. Dig deeper. Also if you have musician friends like guitar or bass players, they may have the items you require to borrow.

Thanks for the insight, I have a couple additional questions because I'm so green on this haha. Would something like this do the trick? And then what cables/how would I connect the two.

Here's the one I bought. It works perfectly with my focusrite. http://www.amazon.com/gp/aw/d/B00172EAD8/ref=mp_s_a_1_1?qid=1459387764&sr=8-1&pi=SY200_QL40&keywords=livewire+direct+box&dpPl=1&dpID=51dgaUClCyL&ref=plSrch

I think some of the parts need to be re recorded, since the performances might be a bit sloppy, but it also kind of works for the style.

The main thing I’m questioning is if the bass is too loud as well as how to get the guitars to sound more natural. They’re running through amp sims (Kuassa Matchlock and a ProCo Rat modeller), so I’m not sure how feasible that is. But they have this tone to them that I can’t get to go away no matter which amp sim I use. Is this just something I can’t avoid doing direct in? I’m only plugging into my Presonus Studio 24-C; would I benefit from adding a direct box?

If you’re just going to have one DI for your studio at least get one with an active transformer. Radial makes this one with Jensen a transformer It will do for your high end and what your passive box did for your bass, only better...like lifting a blanket. You’ll be able to hear the harmonics you probably don’t even know you’ve been missing.

Try an ISOBLOX somewhere inline.

These will fix a lot of ground hums and RF pickup.

The ultimate solution is to have a separate breaker panel for EVERYTHING audio separate from everything else (mixer, guitar amps, keyboards, preamps, amplifiers, DSP, everything). It can have the same hot legs come in, but the ground rod must be at least 20 ft away from any another ground rod.

If the above is already in place and you are still having issues it will most likely be caused by an audio line (balanced or unbalanced) crossing paths or running parallel with a dimmed lighting circuit.

Another possible solution is to convert your analog snake to a digital snake if the interference is in the snake.

Source: I have been in Pro Audio Concerts for over 15 years

Edit: word Everything

If If you look into purchasing what is called a DI (Direct Input) it turns the sound from your Digital Piano (through the headphones or output jack) and inputs the unedited sound into the software you use.

MIDI wouldn't ever record what you HEAR on your piano, DI would!

EDIT: I found some good ones on these links (they do cost a bit)

LINK 1

LINK 2

> ARTClean Box Pro

Looking at the reviews, it states that you'll probably still end up with an unbalanced XLR signal possibly so maybe this other box may be your better choice
http://www.amazon.com/Whirlwind-Direct-Interfacing-Outputs-Players/dp/B0002OKGNK/ref=pd_sim_267_1?ie=UTF8&dpID=417gEuUJh2L&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&refRID=1F3VNDNKG0FCHZ5ZFMSP

But the video shows female for input and male for output?

A DI box converts unbalanced, high-impedance signals into balanced low-impedance ones, physically it will take the 1/4" output of your DM5 and convert it into an XLR input to the front-of-house mixer. Basically it's there so there isn't volume problems when connecting electronic instruments into a mixer. In terms of relatively cheap DIs I have experience using the Whirlwind IMP 2 which are relatively basic in terms of features, but should work well enough for your setup.

I would start with the Cheap Dean Markley if you are experimenting. Piezo pickups like to see a very high (~10Ω) impedance, the difference in response when using a proper DI is profound. Links below.

Dean Markley: https://www.amazon.com/Dean-Markley-DM3000-Transducer-Acoustic/dp/B00542YQSQ/ref=sr_1_1?s=musical-instruments&ie=UTF8&qid=1497045344&sr=1-1&keywords=dean+markley+piezo

Cheapest ultra-high-z DI I'm aware of: https://www.amazon.com/Behringer-V-Tone-Acoustic-Modeler-Recording/dp/B000KITQK2/ref=pd_sim_267_2?_encoding=UTF8&pd_rd_i=B000KITQK2&pd_rd_r=CF0BQGFFMPZTJ0TVM3W4&pd_rd_w=jRvQb&pd_rd_wg=tR8Rv&psc=1&refRID=CF0BQGFFMPZTJ0TVM3W4

[Something like this ?] (https://www.amazon.de/dp/B000KUA8G6/ref=cm_sw_r_other_apa_i_Gzb9AbC80P234)

Is this the only thing that you use for you setup, or do you also have an audio interface/DAC ?

My amp doesn't have a DI output unfortunately... would something like this be good?

https://www.amazon.com/gp/aw/d/B000KUA8G6/ref=mp_s_a_1_3?ie=UTF8&qid=1479535732&sr=8-3&pi=SX200_QL40&keywords=active+di+box&dpPl=1&dpID=414veu%2B2FtL&ref=plSrch

There are ones that cost way more than this. My bass doesn't have active pickups so I probably shouldn't get an active di box rather than a passive one, right?

The "right" way to go from an unbalanced 1/4" instrument cable -> balanced XLR is to use a direct box. You can also get an impedance matching cable.

As for the cable you have, whether you bridge pins 1-2 or 1-3 is a matter of convention. Some systems consider #2 the "hot" pin and others treat it as the "cold" pin. See Wikipedia for more info

Yes. This is the one I am using.

https://www.amazon.com/Whirlwind-1-channel-Passive-Instrument-Direct/dp/B0002DUQ72

Get a cheap DI box

Something like this should work

https://www.amazon.com/Behringer-DI400P-BEHRINGER-ULTRA-DI/dp/B000KUA8G6/

Sounds like you aren't using one of these.

You could try something like this:

https://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/

or

https://www.amazon.com/ART-DTI-Transformer-Isolator-Eliminator/dp/B0009GUOQA/

But, if that doesn't work, you're probably gonna need an electrician to install a grounded outlet.

$500?!?! At that point go and get yourself an S2, it has balanced and unbalanced outputs so all you would need is an adapter to get to either XLR or RCA or TS.
If you want a DI, get this one
There's really a small probability that you'll need one, though.

What kind of sound system at the other end? PA system with a mixer (live sound) or home stereo equipment?

A regular stereo AUX cord is unbalanced, which is not ideal for running long distances. Technically you should use a DI box like this one (http://www.amazon.com/rolls-DB24-Stereo-Direct-Interface/dp/B001032GK8) to convert to a balanced signal over XLR cables. If you have a mixer on the other end you can go right into 2 channels on the board.

Bluetooth is not idea for sound quality (due to compression of the audio signal), and the general rule of thumb is that Bluetooth range is ~30ft, so 50ft may or may not work.

This one: https://www.amazon.com/Whirlwind-1-channel-Passive-Instrument-Direct/dp/B0002DUQ72/

​

However, it's also worth noting that the monitors pick up the radio signal to some degree even with no audio cable plugged in. So not sure if balancing the audio would even help that.

Passive DI into the first input?
https://www.amazon.com/Livewire-SPDI-Passive-Direct-Attenuation/dp/B00172EAD8/
Or for about the same cost you could get a Rocksmith cable...

Is this a good option for a cheap 'preamp' from an under soundboard passive pickup to a small amp, just for insode use, not gigging or anything?
https://www.amazon.com/dp/B000KITQK2/ref=cm_sw_r_cp_apa_5QHHzbWJH1P7Q

You'd need to put something between the Theremin and the amplifier in the powered speaker to isolate them, and match the impedance of a line-level input. I'd suggest something like a DI, or Direct Inject, Box which is a piece of professional audio equipment meant to do just that.

$20 D.I. Box powered from the speaker:

https://www.amazon.com/Behringer-DI400P-BEHRINGER-ULTRA-DI/dp/B000KUA8G6/ref=pd_lpo_vtph_267_bs_lp_t_1?_encoding=UTF8&psc=1&refRID=E60VVX77Y170MGHQRTSW

An inexpensive option: https://www.amazon.com/Behringer-DI100-BEHRINGER-ULTRA-DI/dp/B000CCSWPQ

https://www.amazon.co.uk/Behringer-Ultra-DI-DI100-DI-Box/dp/B000CCSWPQ

Looking at this, it might work as an interface between the mixer and the guitar.. right?

Get a Cloudlifter.

Hello, sorry to pick your brain again but I'm still having some issue here. My current set up is as follows: Roland Fantom X8 keyboard -> 1/4 inch cable (3ft) -> Behringer Passive DI Box -> XLR to TRRS Smartphone Adapter -> HTC Desire Eye . I confirmed that the XLR to TRRS adapter follows the CTIA standard which I understand should work with the HTC (Android) phone. I tried simply recording video with the phone's built in camera app, however the phone is only picking up ambient noise using its built in mic. I tried recording audio only using the phone's "voice recorder" tool, with the same result. When I test record my voice using a headset with in-line mic, I have no problems. So my guess is that there is still some issue with the XLR to TRRS adapter. Is there something that I'm missing?

Whirlwind Director has been an industry standard for as long as I can remember. Either that or the Imp 2.

Never tried the Direct 2, myself, but it sounds like you could kill two birds with one DI.