Premium Direct Injection Audio Box – Passive DI Unit Hum Eliminator w/ Input Attenuator to Connect Guitar & Bass – 1/4 Inch

(10 customer reviews)


  • DEVICE CONNECTOR: Provides a variety of DI solutions with its ¼ inch device connector and detachable AC power cord for live sound recording applications. It allows you to easily connect keyboards, guitars & outboard signal processors
  • PROVIDES CLEAN AUDIO: Useful for connecting unbalanced signals from sources submixers, effects processors & keyboards to a main PA or recording mixer. This impedance transformer also has buzz & hum cancellation ability
  • EASILY CONNECTS INSTRUMENTS: Getting the signal of a musical instrument to the PA system is easier with this direct box. Just connect the electric bass, guitar, keyboard or other processors to the ground lift adapter & enjoy pure & clean audio
  • VERSATILE DIRECT BOX: Aside from music instruments, the DI unit can also be connected to the line output of a boom box or consumer stereo system if you want to sample old records. The hum eliminator is used for connecting unbalanced devices as well
SKU: B00356J8KE Categories: ,


PylePro Model : PDC22 1/4” XLR Direct Box Dual 1/4” Instrument To Balanced & Unbalanced (1/4” XLR) Direct Box Construction: All Steel Chassis Ground Lift: Switch-Able Ground Lift Balanced Output: 600 Balanced XLR Jack Instrument Input: 50K Unbalanced TS Jack Parallel (Link) Out: 50K Unbalanced TS Jack Input Attenuation: Switch-Able (0db,-20db,-40db) Two High-Quality Direct Boxes In One Convenient Enclosure Dimension: 5.5” x 4.72 x 1.57 ” Pyle PDC22 is a necessity if you are looking for the higest quality of sound, with low distortion, noise, and eliminate ground loops. A DI unit, DI box, Direct Box, Direct Input, Direct Injection or simply DI is an electronic device that connects a high impedance, line level, unbalanced output signal to a low impedance mic level balanced input, usually via XLR connector. DIs are frequently used to connect an electric guitar or electric bass to a mixing console’s microphone input. The DI performs level matching, balancing, and either active buffering or passive impedance bridging to minimise noise, distortion, and ground loops. DIs do not perform impedance matching. Pyle has been in business for over 35 years, and their manufacturing experience and expertise is easy to see – and hear.

From the manufacturer






Easily Connects Instruments

Getting the signal of a musical instrument to the PA system is easier with this direct box. Just connect the electric bass, guitar, keyboard or other processors to the ground lift adapter & enjoy pure & clean audio

Great Sound, Exceptional Value

PDC22 is ultra-compact and housed in a tough, road-ready metal case. This means the PDC22 box will give you great sound gig after gig, session after session. And thanks to its low price, you can afford to outfit the entire band. See for yourself what it can do for your sound.

Direct and Clear Sound

With its parallel ¼ ” In and Out jacks, the PDC22 allows you to plug in your instrument and send the same signal to your onstage amplifier, while the XLR Output sends a balanced signal to your mixer. You can even plug your guitar, bass or keyboard amp’s speaker output into the PDC22, which can handle ratings and still deliver a perfect signal. The superior ground-lift switch eliminates hum associated with ground loops.

Truly Trans-formative

The secret to the PDC22 ruler-flat frequency response is its balanced-line transformer. Praised by audio engineers the world over, the OT-2 provides superior signal isolation from local AC and RF hum, and the ultimate in impedance matching. The resulting output signal is entirely true to the original source – in all its pristine glory.



Additional information

Weight 1.25 kg
Dimensions 1.78 × 5.33 × 6.67 cm
Item Weight

1.25 pounds

Product Dimensions

1.78 x 5.33 x 6.67 inches

Domestic Shipping

Item can be shipped within U.S.

International Shipping

This item can be shipped to select countries outside of the U.S. Learn More

Country of Origin




Item model number


Date First Available

December 19, 2005

Color Name


Speaker Amplification Type




10 reviews for Premium Direct Injection Audio Box – Passive DI Unit Hum Eliminator w/ Input Attenuator to Connect Guitar & Bass – 1/4 Inch

  1. Sizzlinfiddlin

    General observation at unpackingProduct seems sturdy for the price. Metal housing. Switches seem a little loose. Haven’t used it yet.

  2. Amazon Customer

    Easy setupGreat product for the money

  3. By_Rant_Or_Ruin – truth.

    It works but I don’t know how it could be.I used my PC for recording and playing back music I created. I had a ridiculous amount of USB/electrical noise coming through my audio system to and from my PC audio and my Behringer XENYX-1204USB mixer. That was making any attempt to produce a solid recording impossible. I decided to start isolating and replacing gear.QUICK AND DIRTY RESULT = I NO LONGER USE USB AUDIO OF ANY KIND. I now limit how many USB items I use with my main editing PC. I will be buying a stand alone digital recorder with XLR and Line inputs. I will only use my PC for Post Audio file editing and software music creation.I have found that USB 3.0 and 2.0 are angry at each other so be wary of using both, use either or. I think that the power requirements of USB 3.0 make the system more susceptible to noise and interference with USB 2.0 wireless devices.BELOW IS WHAT I WENT THROUGH TO MAKE MY FINAL DECISION ABOUT DISCONTINUING USE OF USB AND/OR ON-BOARD AUDIO RECORDING.PROBLEM: I had huge, ugly, noise coming through my mixer from my PC in the form of system/USB noise and general scittery power noise related to my PC (unrelated to buffering, ASIO, midi, or audio hiss).1) I bought a highly rated PC power supply (SeaSonic 650 GOLD plus) – That made things much more visible (worse).2) I bought a Monster Power PRO 3500 power conditioner from guitar center – that did not help with PC audio noise at all, but did help with some buzzing of new JBL monitors.(My guitar amp is bad and-needs to be replaced.)3) I bought a PYLE PDC22 lift BOX and ran my PC analog audio card out through the PYLE PDC22 to my mixer. That worked well, but not 100%. I still had migrant, but low level bursts, of electronic chatter. Thank you for a good effort PYLE.4) I isolated every power cord and audio cord from each other and from my PC. I kept my PYLE box isolated – even from its own audio cables. That killed a great deal of my audio-through issues pertaining to PC system noise.UPDATE: I found HUGE pieces of the USB and audio electronic noise puzzle.5) I replaced my standard magnetic hard drive with a Kingston v300 240 GB SSD drive. POOF, Noticeably less USB scrittle. It turned out that the reading and writing was causing noise in the whole system as well.6) Through trial and error, I found that the USB connection of the Behringer XENYX 1204USB is just plain crap. No matter which computer I plugged it into (three different laptops and my main PC), HUGE USB noise was generated. Once the USB was disconnected and the drivers removed, the audible noise was noticeably reduced.*Tertiary Note: I found, through trial and error, that the Monster Power supply “broadcasts” a huge amount of interference which wreaks havoc on my gear if placed anywhere near the supply. Now I keep anything related to power generation, away from all of my gear by a meter or so, and all of my audio cables separated as well as I can.PLEASE SEE MY DECISION ABOUT USB AUDIO AT TOP OF THIS POST.Thank you so much for reading this. I hope it helps would be private musicians.

  4. rich l

    great valuegreat construction

  5. C

    Good DI, quick and easy attenuate switch fix.Works very nicely as a passive DI. We use both single and double models. My most recent purchase exhibited the flaky attenuator switch reported by others. I disassembled the DI (4 screws) and soldered the contacts in the 0dB position as that is all I have ever needed. That works perfectly and took about 5 minutes.I was puzzled that older boxes I had worked perfectly but seemed identical. After soldering the contacts I looked at the DI construction. What I found was that the end of the circuit board with the attenuation switch is held by the 1/4″ jacks that are also soldered to it. The nuts holding the jacks to the case appear to have been abruptly and excessively tightened. That twisted the circuit board and stressed the legs of the attenuation switch that are soldered to it. That in turn likely distorted the contacts in the switch making the switch erratic. Loosening the nuts allowed the circuit boards to straighten out and relieved stress on the switch legs. Gently re-tightening the nuts held the circuit board in place without twisting.I had already soldered the 0dB connection so cannot be sure that straightening the circuit board to relieve stress on the switch solved the erratic attenuation switch problem. But, if you get a box with a flaky switch it is easy to do from the outside and only takes a few seconds. When loosening the nuts watch the switch, if the circuit board is twisted the position of the switch in the hole in the case will change as the circuit board straightens. Re-tighten the nuts gently until both are firm then add enough torque to lock them up so they do not loosen. Watch the switch position in the hole in the case to be sure it does not shift when you re-tighten the nuts. If it moves that would indicate the circuit board has again twisted.These inexpensive DI Boxes have worked perfectly for us over more than 100 gigs on guitar, bass and pedal steel. Getting instruments simply and inexpensively into an XLR snake reduces stage clutter, noise and signal loss from long instrument cable runs. It would be a 5 star if I had not had to fiddle with the attenuate switch.

  6. Death Metal

    Confused so forget my review but…Okay man what happend was like all my guitar amps with my death metal distortion settings when hooked together with all the pedals and cords to any of my guitars(sounds fine) but i have the static in the background when not playing and it’s so loud sometimes, it becomes frustrating or i get a headache but i know there are static and grain sound silencers or dampeners or whatever so i got on AMAZON 🤘😈 to look for it to play my death metal from my soul bro. So i find this thing one here the inject box or whatever and i could have sworn that i saw it cancels out static and plus i can hook up more of my instruments to it like i could plug in like 3 guitars and a bass and a electronic drumset and a keyboard at once or something wild of the sort. But i gotta have some giant robot thing called a PA system for it to work cause directions for guitar were all like “oh blah blah gotta connect it to PA SYSTEM to the amplifier then the guitar to the amp sound system or something stupid like ugh now i have to get more cords everywhere like usual i feel like a lost Vietnam veteran in the jungle stuck in vines. So many vines. Anyway from the physically held point of view and overall appearance it looks like it can do what it says and it has a lot of directions so if i think I understand it then everyone can understand it. Satisfying weight to it, not too light which is good cause light typically feels weaker. Not too heavy cause thank god lol. Two different panels in one small portable system at avery good deal. Keeping it even though itll be couple years til i get the pa system crap. That is what happened. I wanted no static on my guitars. (Sad hold F to pay respect rip george bush did titanic)

  7. Rob Taylor

    Great PASSIVE Direct Box – Know what that means before you get it.So this is a good product for a decent price if you know what it is you’re getting. What this is, is a passive direct box with nothing but a transformer to match impiedance between XLR balanced and 1/4″ unbalanced. As such a few things to keep in mind are that this is not an amplifier, it has no active powered electronics inside. Also there is some inherent loss in any transformer, so the signal coming out may not be quite as strong as the signal going in. If you’re looking for a lossless direct box with low impiedance, then you will want an active direct box with operational amplifiers and powered circuits. This is not on of those. But having said that, it does a fairly good job and is built like a brick ####-house. It has some serious weight to it, and if it fails as a proper direct box for you it can certainly be used as a theft deterrent device. Seriously though, good little unit. Since there is no active electronics there is little to no chance of inducing extra noise or hum. It does have some attenuation resistors (meaning it can make loud things quieter) for if you are feeding something with higher volume like a speaker output into something that’s expecting lower volume like a microphone input. It also has the ability to do ground lift, if you’re getting ground loop hum. (And if you don’t know what that is, simply nod and act impressed.)All in all I rated it with 4 stars because as long as you know what you’re getting, its a great little unit. But just be sure you do some reading on the differences between active and passive direct boxes. Happy Hunting!

  8. Friendly Neighborhood Nitpicker

    Buy them, but handle with careI really like these. I took a star off only because of the bad switch design. The switches should be recessed/inset so they do not get accidentally moved, and I have this fear that if I don’t keep them in their boxes at all times when not in use, and do not keep them under something hard while in use, someone’s going to step on them, knock them, or look at them funny, and the switches are going to get snapped off as others have described here. Forget throwing them naked in a gig bag. When I got mine, one of the ground-lift buttons had come off in the box. It’s really just a pusher for the button which is internal, but in pushing it back on, it is now more recessed than the other one on that box. Not a big deal, but again these should probably be recessed switches, although at least in that case the XLR plugs protect the buttons, so not as big an issue as the pad switches.All that said, I am happy with the units themselves, used in 0-pad or -40-pad mode (someone here with a scope said not to use them in -20, and I am taking that advice).But I do recommend these boxes, provided that you can take care of them physically. I used a set of them to provide an audio signal from my board, to a front of house camera, using our regular ~100 foot snake, and it worked perfectly. (tip: if you’re doing that, buy a set of F-F XLR gender changers at the same time, not the night before the gig because you forgot you would need them to attach a di-box to the male side of your snake, LOL).

  9. David Roehr

    Good performance,especially for the priceThis is a good unit for the price, although it has one serious idiosyncrasy to be aware of: The “-20 dB ATT” setting is garbage.I have access to lab grade test equipment, so I measured this units performance on an Audio Precision Cascade 2.Measurement-wise, it looks good in general. It has a wide and flat frequency response and good resistance to overload.The THD is ok over most of the frequency spectrum, above 50Hz it’s less than .1%.Below that, THD smoothly rises to 1% @ 50Hz and hitting 3% at 20Hz.Separation (ie isolation between the two channels) is an OK -60dB at 3 kHz.I haven’t used this at a gig yet, so I can’t comment on how well it fixes real world ground loop issuesThe attenuator switch is this units weak point.- The switch is really cheezy mechanically; it won’t last long with normal use and will get broken when tossed in with your other DI’s.- The -20dB setting is just bad, don’t use it. First off, it’s really a -10 dB pad, so it’s either an incorrect design or incorrect labeling. Second, the frequency response and THD go all to hell when it’s engaged. Note: the -40dB and unity settings are fine, and work as expected.–Summary–Pluses:- Great value for a stereo/2 channel DI.- Nice metal box.Minuses:- Attenuator switch is really flimsy, baby it.- The “-20 dB” setting is really ugly, don’t use it.- I wouldn’t use this as a bass DI, the THD at the low end is a little too high for my taste.

  10. Navi

    PriceWe needed these to be able to connect instruments to our console. Cheaper than other similar products and a similar price. Worth it.

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