Double Bass Dumb question about DI

[Mark_T]

I'm primarily an orchestral bassist so I'm posting here on the double bass side, but my question would apply to either double bass or electric bass. My orchestra is playing a piece next year that requires an electric bass. I have a tiny PJB Double 4 amp and I was hoping to use that. However, it doesn't have a DI out, just a regular line out.

What I'm trying to figure out is, should I buy a DI box to run from the amp to the mixing console, or between my bass (active EQ) and the amp, or none of the above (rely on the venue to have some idea what to do with my signal)? If so, what kind would I want?

I have some use for having a DI box because I have an analog to digital converter that I could use to run my bass in to my computer but it only has XLR inputs (I use it to record miced double bass). But I'm also happy not to own gear.

 

[CatOnTheBass]

Your PJB's Line Out is a DI, and you can connect it to the mixing board's Line In, using a balanced 1/4" TRS cable.

11. Line output jack
The pre amp in the DOUBLE FOUR is recording studio quality so the line out is a
very pure signal for recording or driving another amplifier.

Sometimes the sound guy doesn't have a 1/4" input for you; sometimes there are only XLR jacks on stage. If you ever find yourself in that situation, a balanced 1/4" TRS male to XLR male adapter cable will save the day.

 

[Ric Vice]

I'm primarily an orchestral bassist so I'm posting here on the double bass side, but my question would apply to either double bass or electric bass. My orchestra is playing a piece next year that requires an electric bass. I have a tiny PJB Double 4 amp and I was hoping to use that. However, it doesn't have a DI out, just a regular line out.

What I'm trying to figure out is, should I buy a DI box to run from the amp to the mixing console, or between my bass (active EQ) and the amp, or none of the above (rely on the venue to have some idea what to do with my signal)? If so, what kind would I want?

I have some use for having a DI box because I have an analog to digital converter that I could use to run my bass in to my computer but it only has XLR inputs (I use it to record miced double bass). But I'm also happy not to own gear.

Most line outs from amplifiers even ones as good as a Phil Jones Bass have a much higher noise level than a DI, so sound guys generally have a DI of some sort. Most decent DI boxes have a 1/4" in and out to pass your signal from the bass back to the amp, but not all of them. The Countryman 85 is a very common one that will work and most (not all) sound techs use them. I'd contact the sound tech that the orchestra will be using and figure out what's up. If I were playing Electric with a full orchestra I'd want something a little more present than the PJB Double 4, unless I was surrounded by some kind of sound isolation, and the monitor system was absolutely great. My Walter Woods Electroacoustic Ultra only has a 1/4 line out, so with me it's always DI dejour. In most cases it works out just fine, occasionally it doesn't, because the sound company has crappy DI's that don't accept a 1/4" instrument input, or they are just crappy DI's.

 

[Ravenblack67]

I'm primarily an orchestral bassist so I'm posting here on the double bass side, but my question would apply to either double bass or electric bass. My orchestra is playing a piece next year that requires an electric bass. I have a tiny PJB Double 4 amp and I was hoping to use that. However, it doesn't have a DI out, just a regular line out.

What I'm trying to figure out is, should I buy a DI box to run from the amp to the mixing console, or between my bass (active EQ) and the amp, or none of the above (rely on the venue to have some idea what to do with my signal)? If so, what kind would I want?

I have some use for having a DI box because I have an analog to digital converter that I could use to run my bass in to my computer but it only has XLR inputs (I use it to record miced double bass). But I'm also happy not to own gear.

 

[Greg Clinkingbeard]

The Countryman 85 was a great DI when it was first introduced many years ago and it’s still great. I occasionally have sound guys wanting to put me through a passive DI and I always use my Countryman. I always put it before the amp. Buy it and keep it for life.

 

[Keyser Soze]

You or the orchestra Production Manager should contact the house Production Manager with your question. They will likely put you in touch with the sound company or house sound tech to resolve your issue.

As stated above, by two stalwart veteran bassists, you can't go wrong having a Countryman 85 and an a couple of cables in your gig bag wherever you go.

 

[crd]

Just because I am pedantic and maybe sometime it will be useful to you: line out is not the same as a di. Line outs send out line level which is hotter than a di. You can plug directly into a sound card line in with it but not into a mic preamp or most mixing desks. It's good to know this because a surprising amount of sound men don't know this... Most amps now have a DI on them. My Walter Woods doesn't (or your PJB) so I always have a radial JDI in my bag just incase I need it.

 

[Ric Vice]

... Most amps now have a DI on them. My Walter Woods doesn't....... so I always have a radial JDI in my bag just incase I need it.

That was a strange idiosyncrasy of Walter's. He placed a DI on the second revision of the MI series amplifiers. When he started building the Electroacoustic series he removed it. He claimed that "folks
would just prefer to use their own DI's" anyway and he was partially correct, because many do. Personally, I think he ran out of "real estate" when he expanded the EQ section with the "Vari" and "Balance"
controls so there wasn't enough room to add one. Just my take of course.

 

[DoubleMIDI]

DIs are mic level typically.

Some can be switched to line level for better S/N-ratio, but not every console might be able to accept that. Also the switchables are often part of an amp because they need power.

DIs use a balanced signal to the console. That way a hum loop could be opened by using the ground lift. This is not possible with an unbalanced line level signal.

If you want to use a DI box in front of your amp always use an active one with a high input impedance, ideally 10 MegOhms as it is in parallel with your amp impedance, or one with a buffered piezo input.

You can use your line out, if it is clean, and put that into any (active or passive) DI box. To be able to get the line signal level roughly down to mic level, it should have a switchable attenuator for the input signal.

I would check once with the orchestra if the DoubleFour gets loud enough to be heard by the other musicians when playing. You might need some more power for the BG and maybe even for the DB.

 

[brianrost]

Just because I am pedantic and maybe sometime it will be useful to you: line out is not the same as a di. Line outs send out line level which is hotter than a di.

It's true that most DI boxes drop instrument or line level (and sometimes speaker level) down to mike level. The Countryman 85 mentioned above is a 10dB gain reduction for instrument inputs and 26dB gain reduction for speaker inputs.

There are some active DIs that output line level or mike level. Some might consider these to be preamps.

Avalon U5

Radial HDI

 

[Zbysek]

It is likely that the sound company will provide you with di box which be placed between your Bass and the combo.

On the other hand, it is useful to own a di box.

In case you decide to buy one, I recommend getting one with 1. High input impedance, and 2. buffered “through” output, such as Radial Sb4 or Radial PZ DI…

 

[Wasnex]

1. It's not clear if the line out of the Double 4 is balanced. Ideally it should be. Use a 1/4" TRS to XLR and it could serve the role of a DI. If it's not balanced, you generally use a 1/4" TS to XLR, but these can be wired different ways. Also an unbalanced connection will be more prone to noise problems.
2. The manual says the preamp output level is 1.2V. There is no preamp out AFAIK, so perhaps this is the level of the line out. 1.2V RMS = 3.8dBu which is line level. Most mixers can handle this level, although I have sometimes needed to use an adapter to go from the XLR on the snake to the mixer's 1/4" TRS line input. Most quality modern mixers can handle line level on the XLR input. You simply engage a pad and adjust the gain/trim.
3. Most DIs have a ground lift. You won't have this feature if you use the line output. However the audio tech may have an adapter to lift the ground if necessary.

I would contact whoever will be providing sound for the event. Usually the sound company provides DIs and prefers to use them. Also most audio techs prefer for you to plug your bass into their DI and then run the Thru from the DI to your amp. This idea here is to have an unprocessed signal that is easy to work with. Also with this setup you can fiddle with the volume and tone controls on your amp without impacting the DI signal.

The CountryMan Type 85 is still a respected DI. I would not buy one if you don't typically have a need for a DI and the audio tech can provide one. Most bass guitars work fine with a passive DI, and there are cheaper/more compact options. Consider a Whirlwind IMP 2 or one of the Radial Stage Bugs. The IMP 2 is passive. The SB1 is active and the SB2 is passive. Either of these should work fine with most bass guitars.

The Radial SB4 is active and designed to work with piezo pickups. If you will ever need a DI for your upright, I would consider the SB4. It will work fine for bass guitar. Advantages for piezo: 1. Input impedance is 5 Meg and the Thru is buffered.

In comparison the input impedance of the Countryman Type 85 is 10 Meg, which used to be considered the gold standard for piezo pickups. However, the Thru is parallel rather than buffered. So if you run the Type 85 to an amp, the pickup will see the input impedance of the amp in parallel with the input impedance of the DI. In other words the amp may load the pickup through the DI.

If you are going to use an amp, I would suggest just a regular DI. This setup allows you to adjust your stage sound without having an impact on the signal going to the PA.

If you will ever go ampless, consider a Preamp/DI such as the Tech 21 Q/Strip or MXR M81. The idea with these is for you to have some tone shaping controls at your fingers so you can dial-in your sound in your monitor.

 

[Greg Clinkingbeard]

I don’t doubt the other recommended DI’s are top quality but I’d rather carry a Countryman with me than one of those. I’m not lazy; maybe just trying to be efficient in how I burn calories.

 

[Ric Vice]

You or the orchestra Production Manager should contact the house Production Manager with your question. They will likely put you in touch with the sound company or house sound tech to resolve your issue.

As stated above, by two stalwart veteran bassists, you can't go wrong having a Countryman 85 and an a couple of cables in your gig bag wherever you go.

Good words! I would posit that it’s not economically sensible to purchase a expensive DI for a single performance, so perhaps for the OP
checking with the FOH sound provider to ascertain what they have available is all that’s needed.

 

[Mark_T]

Thanks! The performance isn’t for a while so I’ll just practice at home for a bit to remember where the fingers go and I can talk to the house sound people when the season gets going again.

 

[DoubleMIDI]

You don’t need to own a DI box yourself at all if you have a high impedance buffer or preamp and put the technicians’s DI directly after it. That way the piezo is only loaded by the buffer/preamp and even a lower unbuffered impedance or passive DI can be driven by the buffer/preamp output. Then daisy-chain your amp to the DI box. A simple buffer or EQ-less preamp is best as you won’t be able to change the sound for the board and leave that all to the technician.

 

[Dr. Love]

As others said earlier, I'd contact the sound person/company and confirm it with them if possible. Every time I've had a gig with contracted FOH sound they have had their own DI boxes. For a sound company it's essential gear like cables and mics.

If you do decide to get a DI, since your electric bass has active EQ you don't really need anything complicated. Just get a simple, reputable brand and you should be fine. Mine are Radials, but I have used a bunch of others and never could tell a difference.