Preamp or not preamp, this is the problem

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francoran
Posts: 114
Joined: 16:03, 30 January 2013
Location: Italy

Preamp or not preamp, this is the problem

Post by francoran »

Do you think is a good idea to insert a preamp like this http://www.presonus.com/products/BlueTube-DP-V2 between JS outputs and the main mixer? I know it's not the best in the market, but I wonder if it could improve the sound and make it more clear and sharp in a band contest. Have you any experience of one of these machines?
JD Kross
Posts: 34
Joined: 03:36, 23 February 2012
Location: Australia

Re: Preamp or not preamp, this is the problem

Post by JD Kross »

I do live band mixing every week and never had a problem with keyboards cutting in the mix in full band situation. Even if you use the pre-amp effect, the sound guy will still cut the input gain coming in to the PA mixer if he thinks its too much. I would say, it would be pointless to have it. You're better of having your own rig mixer with compressor and clean eq so you have sonic control of your over-all output mix. You should develop a good ear to identify your sound's sweet spot and eq it to be able compete with soaring guitars.
francoran
Posts: 114
Joined: 16:03, 30 January 2013
Location: Italy

Re: Preamp or not preamp, this is the problem

Post by francoran »

So you say that preamp is just to pump the volume and doesn't improve the quality sound. Then, I don't need it, my volume is ok, but I need to sharp some sounds expecially pianos from JS, sometimes they seem very woody. I'm trying to edit some of them and I'll see how they work with the band on september. Thank you for advises.
Martijn
Posts: 83
Joined: 20:04, 8 May 2010

Re: Preamp or not preamp, this is the problem

Post by Martijn »

During the last 3 years I use a small mixer (Behringer X1204USB) to mix down the two stereo signals of my Juno Stage and XP-30. The two keyboards are connected to the two stereo inputs, the balanced stereo main output is sent to the PA-mixer, so no need for DI-boxes anymore. I route the main output back to the ALT3-4 bus and send the ALT3-4 bus to my wired in-ear headphones for monitoring purposes (no amp/speakers on stage). We have a mixer on stage for monitoring purposes. From that mixer I route some of the signals (mics, guitar) also to the ALT3-4 bus, to be able to get them on my in-ear monitors. This really works great! I have immediate control over monitor-mix, keyboard-mix, EQ's on all signals, etc. By using this mixer I replaced DI-boxes and headphones-amp and have better control over the in-ear mix and keyboard EQ's. I don't use the onboard FX-processor of the mixer, but the compressor on mic-signals is very useful. For those of you who are interested I can explain in detail how all the cables are connected and the signals are routed.
jalbert
Posts: 47
Joined: 06:50, 9 August 2014
Location: Pittsburgh, PA

Re: Preamp or not preamp, this is the problem

Post by jalbert »

A PA amp will normally accept +4dBu output, balanced or unbalanced. Some have a sensitivity switch to adjust the line level, often for mixing in a mic without the need for a separate mic preamp. But the output level of keyboards is all over the map. The Jupiter-50 is spec'd at balanced +4dBu, but the Juno Stage is not. Roland doesn't publish the output spec for this keyboard, and Roland customer support specifically refuses to provide it. Grrr.

I believe it likely is -10dBV or close to that as a default. It definitely is unbalanced. The manual does say you can amplify the JS with a home stereo, which is highly suggestive of -10dBV output as a hotter output can damage a home stereo amp. To run this to a PA amp, you do need a preamp in between to get the output volume from the PA you would expect at a given gain setting. There are a number of ways to do this:

1. Use a small keyboard mixer. This will enable you to use a multi-keyboard setup and not only mix the results before routing to a PA, but the mixer will have a preamp for each channel as needed. This also is used to standardize the line level of a stack of keyboards with disparate output levels.

2. Use something like this:

http://www.sweetwater.com/store/detail/ ... fgodxLAAGQ

to convert unbalanced -10dBV to +4dBu output. This device is passive, so no extra power cords needed.

3. Use a dedicated keyboard amp instead of a PA. These have pre amps built-in to support a wide range of keyboard line levels, even lower than -10dBV typically because some analog synths and vintage keyboards have fairly low output.

4. Set the Juno Stage System setting for output level higher. It can be set as high as +12dB. The difference between pro line level +4dBu and consumer line level -10dBV is 11.79 dB, further evidence that the default setting is -10dBV, and setting it to +12dB is changing the output to +4dBu pro line level (still unbalanced). While this may sound like the optimal choice, I've heard that there is distortion when set at +12 dB (I've not tried it). If this is true, it would suggest that the keyboard preamp doesn't have enough headroom to do this without clipping, which would make this the least desirable solution.

This is not unique to the Juno Stage, but is quite common, ie having output too low to get full volume out of a PA amp.

If you need to run a long wire to the PA, option 2 is good because it will be a long balanced connection, assuming your PA amp supports balanced connections. Option 1 is convenient if you have multiple keyboards in your setup. Option 3 has the convenience of an all-in-one package solution, and option 4 will require testing to see if you can get enough output without distortion (which might be true with less of a boost than +12dB also).
jalbert
Posts: 47
Joined: 06:50, 9 August 2014
Location: Pittsburgh, PA

Re: Preamp or not preamp, this is the problem

Post by jalbert »

I should have added that if choosing the EBTech convertor (http://www.sweetwater.com/store/detail/ ... fgodxLAAGQ) you would want to confirm the default output level of the Juno Stage to make sure everything is in spec.
oliv928
Posts: 42
Joined: 22:28, 23 February 2015

Re: Preamp or not preamp, this is the problem

Post by oliv928 »

very interesting subject.
I use the JS ( and used Yamaha MOX, XP30 and Fantom FA) with my band and the impression is : difficult to have a good mix, except with the FA. Maybe the FA has a better output level ? MOX was the worst: impossible to mix keyboard with rest of the band
i will try the different solutions soon. I have a Behringer MIC200 with a switch called 20dB PAD. I will have a look in the doc to see what it is also, and have a try with it.
jalbert
Posts: 47
Joined: 06:50, 9 August 2014
Location: Pittsburgh, PA

Re: Preamp or not preamp, this is the problem

Post by jalbert »

If you are running a Juno Stage into a mixer, the mixer will probably have a preamp that can increase the gain enough to feed a PA expecting +4dBu inputs.

If you are running straight into your own PA or keyboard amp, you'll want to be sure to match the line levels. I think if you are using a keyboard amp, you could run the Juno Stage into the CD inputs on the amp and would be fine if the amp doesn't have a preamp for the line inputs to raise the level. This would bypass effects, but the Juno Stage has plenty of on board effects that would be more convenient to use anyway.

When I ran a Juno Stage straight to a Peavey PA amp or to a JBL EON 515XT, SPL output was always lower than expected, although adequate for rehearsals or small venues with the JBL due to its high power rating.
francoran
Posts: 114
Joined: 16:03, 30 January 2013
Location: Italy

Re: Preamp or not preamp, this is the problem

Post by francoran »

So, running the Juno Stage into a mixer is it good to leave the output level in the System setting at 0dB, or is it better to increase it at +4dB?
oliv928
Posts: 42
Joined: 22:28, 23 February 2015

Re: Preamp or not preamp, this is the problem

Post by oliv928 »

i RUN WITH A basic Behringer Mixer
I will look if there is a switch for input gain on some channel, and ask the guy in the studio
thank You. That point is important
oliv928
Posts: 42
Joined: 22:28, 23 February 2015

Re: Preamp or not preamp, this is the problem

Post by oliv928 »

I wonder a lot about the quality / performance of the synth% other models and competitors. Let me explain my headache for months / years: to find a synth that, besides being lightweight, having 76touches pleasant to play, be ergonomic, well drilled by repeating and on stage to play in my pop rock group (2gtrs, bass, drums, vocals). Incidentally, I do not control the mixing desk and the amp sound that is lent me every time. This is often the low-end (behringer first prize). I put a note to all my keyboards tested:
ALESIS FUSION: 7/10, Roland Fantom FA76: 9/10, yam mox61: 3/10, ROLAND XP30: 7, and finally the JUNO STAGE: 6. For the internship is provisional because two rpeter for now .
For the FA76, I put a good score because the other musicians in the group have said spontaneously: Super your new synth sounds are clear, precise, pêchus!
Unfortunately, the FA is too heavy, I took him over ... He would 10KG less, I would have passed.
So ... I wonder if the quality of the preamp converters and Juno are up.
For sounds, I think the two machines are very similar: FANTOM series, SRX ...
With no mixing desk at home, I can not get into a comparative home
On forum Rolandclan US, there is a subject on its output level: in short, it says that the level is very low (about 0 dB), if up (to 8, 12 dB) sound to clipe Death: I confirm, I tried. Should we add a DI box to take up the signal?
Here, the subject is launched. In any case, the JS has plenty of qualities, that is why I want to dig this question to get the best of it.
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