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I went from the XLR out on the back of the Little Jazz into a Mackie SRM 350.
There are two buttons on the Mackie. One seems to boost highs and lows while lowering mids. Too bassy. I set that to "off".
The other is Mic/Line. I understand that Mic is somewhere around -50dbu and Line is around -10dbu. At least I think it's dbu -- tbh, I don't understand the various db(X) designations
If I set the switch to Mic, I barely have to move the volume knob off zero. If I go further, it's gets extremely loud, but very bassy -- to the point where it's unusable. And, that's with the bass control of the LJ all the way down.
If I set the switch to Line, the sound is fine but I don't get very much volume unless I rotate the knob most of the way. That seemed to work, but I wondered if there might be a better way.
So, it seems like the voltage coming out of the LJ is too hot for the mic setting and not quite hot enough for the line setting.
Something similar happened with the ALTO FX310. No switch on that unit. So, you just keep rotating the know, which makes the bass frequencies go crazy.
Can anyone explain why the bass frequencies seem to bloom so much with the Mic setting?
Is there any way to solve this problem without adding another component to the system? I have had success putting a Yamaha mixer between the LJ and the powered speaker. I roll the bass down with the mixer and I can run the whole thing as loud as I need to play.
I recently had the LJ running into a JBL line array and the sound was excellent.
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11-09-2023 11:20 PM
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owners manual
No ideas what the two buttons you mention might be, your description of line/mic seems to be backwards. Maybe your model is an earlier version, but just looking at the current manual online...
Make sure you aren't over driving the LJ
The "Solo" mode has the least low end bass response
Use channel 1 Gain set to "Line" and adjust as needed
Set the ch 1/ mix button to channel 1 (button up/out)
If those things aren't on your speaker, find the manual.
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I appreciate the response, but I don't understand it. Mic level is lower voltage than line level. I think I got the numbers about right.
Originally Posted by pauln
So, basically, switching to mic adds 40db of gain. And the low frequencies get loud and flabby sounding.
The other switch is a contour switch. There's a graphic next to it which looks like a tub - short high shelves at the left and right and a longer low shelf between them. It's a boost of the lows and highs. I leave it off.
And that's it for controls.
I have the LJ volume set at noon, which is well within its sweet spot and I have the bass on the LJ turned all the way down, which is my usual setting, or close. The LJ manual doesn't indicate the level of the XLR out but does say it's for a mixer or snake.
This manual shows the controls I have.
Perhaps the new version has those extra controls for exactly the problem I posted about.
file:///C:/Users/jpoll/Downloads/srm350_om%20(2).pdfLast edited by rpjazzguitar; 11-10-2023 at 04:31 AM.
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It’s not only the gain that differs between mic and line inputs. Input impedance and input sensitivity are critical performance parameters that affect both gain and sound quality. There’s no specific standard in Ohms for input impedance, although most balanced inputs are “low impedance” (generally under 1kOhm, with 600 Ohms being the traditional pro standard) and most unbalanced inputs are “high impedance” (typically >50 kOhms and often as high as a meg).
Old fashioned mic & line inputs had different impedances, and there was an additional gain stage at the mic input because mic signals are much lower voltage than line outputs. Now we’re seeing “combination” inputs that accept both but have variable gain in that first stage of pre amplification. Some now even have “multi-Z” input impedances that apparently sense input voltage and apply a kind of automatic gain & impedance control.
Mismatched impedances at the input cause gain issues like the one you experienced. And the combination of input impedance plus capacitance forms a filter that affects frequency response the same way a tone cap and a connecting cable affect the signal from a guitar pickup - highs are either rolled off (thus the aggressive bass) or increased if the values are not right. Impedance and gain mismatches also cause harmonic distortion.
I’ve never been able to find detailed specs on the LJ (or many other guitar amps), so we don’t know the output impedance or the voltage at rated output. I suspect that the LJ’s DI out is better matched to the JBL system that worked so well than it is to the Mackie SRM. Everything you described points to mismatch between the output impedance and/or voltage of the LJ and the Mackie’s input. There’s probably nothing wrong with either device. But the simple DI output on the LJ cannot be adjusted or controlled as fully as a good dedicated external DI.
How can you know what works and what doesn’t before you buy or plug into it? Without specs, you can’t. And most of the stuff we use comes with few or no usable specs.
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I think the Little Jazz direct out is before the preamp, so rolling off the bass on the amp has no effect on what goes to the PA. I'm going from a possibly imperfect memory, though, and I've never actually used the DI to a PA.
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Yes use the line setting on the Mackie and crank the gain up , that’s operationally absolutely fine …. Originally Posted by rpjazzguitar;[URL="tel:1297330"
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Thanks, nevershouldetc, for this info. Originally Posted by nevershouldhavesoldit
Do I understand correctly that the problem is addressed when I insert the Yamaha MG10XU mixer between the LJ and the Mackie speaker? That is, the mixer solves the problems with voltage and impedence? I've had good results with that setup - just more to carry.
Would a passive DI do the same thing? Or would it need to be an active DI?
As always, I'm looking for small, easy to connect, durable and, if possible, cheap.
I'm also willing to buy a different powered speaker (since the Mackie isn't actually mine) if I could figure out which one to get.
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The DV Little Jazz manual says the line out is post-EQ and reverb. Originally Posted by sgosnell
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Well, rather unsurprisingly, my memory is less than perfect.
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Well I wasn’t sure (even though I own one), I still had to check the manual!
Actually I have recorded from the line out a few times, it certainly works well for that.
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Haven't used these myself, but could be worthy of consideration...manuals can be found at Harbinger and Behringer..
Harbinger VARI V2408 Powered 8" 2-Way Loudspeaker With Bluetooth, DSP and Smart Stereo | Guitar Center
Harbinger VARI V2410 Powered 10" 2-Way Loudspeaker With Bluetooth, DSP and Smart Stereo | Guitar Center
Access to this page has been denied.
Access to this page has been denied.
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that Harb V2408 looks great it’s Originally Posted by MtnCat;[URL="tel:1297539"
got all the ins and outs you could
need and bass and treble controls
wedge shape
15lbs ….
(so for me competing with a Comp 60 or Bud 6)
but approx $200 !
thanks cat
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Yes Originally Posted by rpjazzguitar
Most passive DIs use transformers with ~12:1 ratios, which will significantly attenuate your input voltage. An active DI is needed if your pickup's output signal strength is too low. Originally Posted by rpjazzguitar
You want one with high input sensitivity. Many powered monitors have switchable inputs for -10dBv ("consumer" line level) and +4dBu. The -10 setting is designed to take input signals up to 0.316V. The pro level setting will accept signals up to 1.23V at its rated output and distortion levels. So you'll get higher gain from the same signal on the -10 setting than the +4 setting. Many monitors also have input sensitivity controls for even better fine tuning. Most of the powered speakers with both balanced and unbalanced inputs only switch the input sensitivity on the balanced input. The unbalanced inputs are all -10dB. Originally Posted by rpjazzguitar
As for which one to get, there are so many fine inexpensive powered speakers out there that a recomendation is tough to make. I have 2 pairs of JBL LSR305s that sound great and have switachable input gain/attenuation. I also have a pair of Edifier 1280 powered speakers that work fine with guitar preamp pedals - I had a Zoom 60 for a while that drove it to the highest levels I'd take a chance on from small drivers like that. But I'd suggest getting a powered speaker with a protective grille of some kind over the drivers. The JBLs and many other true studio monitors (which are great for live performance) lack protective covers of any kind over the speakers, which is a potential disaster if you gig with them. I was sorely tempted to cut some wire mesh material and fasten it over the JBLs when I first got them, but they live in my studio and I have a few good small amps and speakers for gigs.
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The 'Line Out' on the amp is, per the manual, a mic level output. It says it's designed to run to the console or snake. Unless somebody got real creative, this would mean it's a 600 ohm mic level output. Not like your going to be running a line level input into a mixer. That's what the mixer outputs (line level that is) after gain stages.
Based on that.. Mackie SRM 350 should be perfectly happy with it. From the manual:
Integrated 2-channel mixer featuring dual
Wide-Z™ inputs
• Handles anything from mics to guitars to
mixers with a single twist of the gain knob
The gain knob has a 'mic' setting. Should be the starting point. The 'Wide Z' part should be handling the 600 ohm (or so) impedance so it shouldn't sound funny. Should work with the 'Line Out' which is really a 'Mic Level Low Impedance' out just fine. Are you going into Channel 1 with the little push button set to 'CH 1' and not to 'mix'? The other buttons are 'mode' (DJ, solo, et al) probably drive EQ, a limiter, and a shelf filter with a few different settings (probably 150hz to 300hz) to deal with acoustic guitar feedback.
Side note: It's never simple and 'line level' can mean several things.. normally high impedance, -10db or +4db (consumer and pro levels respectively) and then there are RCA line ins and outs. To confuse things further the output of some guitar gear, say a pedal board with some boost, works to drive some powered speakers. Even without much gain my pedal board will drive my powered speakers. And then.. all that being said.. the 480 ohm 'Direct Out' which should be 'mic out' on the last pedal I got (a Joyo Cab simulator) is wayyyy too hot for the mic input on my board. Go figure.Last edited by Spook410; 11-12-2023 at 06:37 AM.
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Here’s a link to the LJ manual. It only says that the line out is balanced. I don’t think it’s mic level. I think it’s a 600 Ohm -10 dBV line level. It wouldn’t make sense to use a high impedance mic level output for a DI because it couldn’t drive long lines without signal loss and frequency aberrance, and it would be noisier than a balanced low Z line. I had one through the Covid years and used it for both gigs and recording. It did not behave like a mic level source and it didn’t have the high output level of a +4 dB pro line. Originally Posted by Spook410
But the auto-sensing inputs on the current SRM350 should be usable with both line and mic level sources, both balanced and unbalanced. The OP says there’s a mic-line selector button on the Mackie he’s using, but I don’t see this in the current owners’ manual on their website. I wonder if the one he’s using is an older model. As I recall, variable Z inputs replaced switchable level setting on devices that adopted them.
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Amp manual says the output is designed to connect to the console or a snake. That should make it a 600ohm mic level out. Originally Posted by nevershouldhavesoldit
If it's not it's not. Never owned one. But makes the manual wrong. You don't plug hi Z line levels into a console.
Per the Mackie manual, adjustments are made via a gain knob for different input levels. As opposed to a button.
We need a forum sticky on line levels and impedance, direct outs, and balanced line extenders. As we move into the era of amp modelers it's just going to come up more and more.Last edited by Spook410; 11-12-2023 at 04:27 PM.
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First off, many thanks for the help understanding this.
Here are my current questions.
My SRM350 is indeed an older one. The original. The current one is v3, and has more features. I'm guessing that the additional features might be there because of this sort of issue with the original.
My SRM350 has a knob and two buttons. Contour (amplifies highs and lows) and Mic/Line. The Solo switch and other settings are on v3, not mine.
The Yamaha MG10u mixer has a pad switch, a gain control, channel gain and output level knobs. There is a Peak LED on each channel strip and a stack of LEDs reflecting the output level.
So, I plug the LJ line out (XLR) into the Yamaha Channel 1 input.
Then, after turning down the volume on the Mackie to zero, I have to:
1. Put the Pad switch in, or not.
2. Adjust the gain knob (the manual says to increase until the Peak LED lights occasionally). In fact, I haven't been able to get it to light, but I've been using the Pad up to now. And, that is probably what I've been doing wrong.
3. Set the channel gain to unity (an arrow at around 3 o'clock).
4. Set the output level to unity (also an arrow around 3 o'clock)
5. At this point, the output level meter (the LED stack) should be flashing a bit, but if it isn't, I have to increase volume somewhere -- and the only option left on the mixer would be removing the Pad, if it's engaged.
6. Now, on the Mackie, set Mic/Line to one or the other. If I've got the mixer output level where it should be, I think the Line setting will be the correct one.
7. Turn the Mackie's volume knob to the desired volume and make sure I'm not getting blooming bass frequencies.
I would try all this right now but all my gear is in the car. I'll figure it out during the sound check.
Writing this post has helped me understand why Sound Guys are so irritable.
So it's guitar > ME80 > Little Jazz > Yamaha > Mackie (and there's a microphone into Ch2 on the Mixer for announcements and maybe a vocal).
This rig ends up with the following volume controls: Guitar (which has two, only relevant if I move the selector switch by accident, which happens, so I leave the bridge pickup OFF), Output level of the ME80 pedalboard, volume pedal in the ME80, (I won't count the individual parameters of the patches since I equalize them with no-FX volume), volume control of the Little Jazz amp, Mixer Gain, Channel Volume and Output level, Mackie Volume -- and I didn't count the pad and mic/line switches.
So, that's eight volume controls. What could possibly go wrong?
Actually, it's not that bad. Once I figure out how to get a decent loud-enough sound, it's set-and-forget while I use the volume pedal in the ME80 for all volume changes.
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You're obviously correct that you can't run a line level signal through a mic input. But the LJ manual clearly says that "[t]he Line Out signal is post-EQ and post-reverb" and from my experience gigging with my own, that's also correct. So it couldn't possibly be a mic level signal unless they ran it back through an attenuator, which is so unlikely that it doesn't justify consideration. Originally Posted by Spook410
I think what the manual means is that it's designed to be run into a line level input on a board. We have a very sophisticated sound system at the club in which I play twice a week. All lines from the stage go to the console (which is at the back of the house) through snakes. This incudes mic outputs and device outputs. We have multiple line level signals running through the same snakes as the mics. This includes a minimum of 3 DIs (two Radial Pro boxes and a Reddi Box), the DI out from the bass rig, and the DI out from our DVM Jazz 12 when it's being used.
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Pro boards may offer a XLR line level input but not many consumer boards guitar players are likely to own. Some do have pads and such which might be a work around. Not great engineering on the amp makers part. Yes.. they should have brought it down to mic level. With a transformer would have been nice but, as you alluded to, not an expensive amp. Thing is.. they should have made it clear in the manual that it's not what we normally consider a Direct Out and that it's not really designed to go to a console. Not that I was ever going to buy one of these amps anyway..
Have you considered writing up a candidate sticky on the subject? Not like anybody around here knows the difference between a balanced line out extension and a direct out.
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Most of the inexpensive small mixers with 4 or more channels that I've seen, owned, or used on gigs have at least one or two balanced XLR inputs that can be set to accept mics or -10 dBV line level signals. The only one I have left at my age is a Samson from the late 1990s, but it typifies the class. It's just a cheap working man's mixer, and it's been fantastic over hundreds of gigs and years of home recording. There's a trim pot on each XLR input that will attenuate to accommodate inputs from -50 to +4 dB. You could be right and there may be many lacking this ability - but I haven't seen them. Originally Posted by Spook410
The bottom line message for all is to check the specs first on all the equipment you consider buying. Make sure the pieces you want to use together are compatible. Do not rely on sales people, as most seem not to know much about these kinds of specifics. Read all manuals and spec sheets (which are generally available on line) before buying anything. And make sure it's all returnable if it doesn't mate up well.
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If you're trying to say that we can expect our mixers to handle balanced line levels in their mic inputs, this is where I take pictures of my ACUS, Mackie, and Allen Heath that don't accommodate a balanced XLR line in?
All the line in's are 1/4 unbalanced on the ones I've had. Or RCA. The mic inputs are for mic's.
You cannot assume a mixer will have a pad on the mic inputs. It's actually kind of odd that the Samson does. Guess it's designed to bring together a random set of gear. Also.. how does it deal with loZ vs. HiZ?
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XLR is low Z, RCA & 1/4" are high. Originally Posted by Spook410
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Ah.. there is a 1/4" input below the XLR on the Samson. Still.. having that sort of input range on the mic input is an odd exception. An input pad button might be more common. Not that this would be confusing to those trying to figure out how things are supposed to work. There's lots of things out there.. but for the most part, things work the way they are supposed to. Originally Posted by nevershouldhavesoldit
The way it's supposed to work: XLR LoZ Direct Outs are (almost) always mic level. And the DV Mark Little Jazz manual is wrong as is their design if it is otherwise. Which, apparently, it is. Would have been better to have a TRS and make it clear it's line level when saying it's destined for the console.
A better implementation can be found on the Quilter Tone Block.. TRS for the Sig Out, XLR for Direct Out with appropriate levels.Last edited by Spook410; 11-12-2023 at 11:09 PM.
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I know nothing about mixing boards and PAs; is there a good introduction for dummies somewhere on the Internet to learn more about this?
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It would have been nice if the LJ specs included the level on the XLR output.
Fortunately, I was able to get it all to work on the gig.
The problem was that I had been using the Pad switch (ON, lowering the input by 26db according to the faceplate of the mixer).
I can't say that I fully understand the Pad. Clearly, if you plug in a mic at -50db or so, you don't need to reduce the level -- you need to increase it. So, no Pad.
With the LJ at -10dbu (a guess, they don't specify) I didn't need the pad. Per the manual, I needed to increase the gain to the point where the peak indicator flashed occasionally. To my ear, though, the signal got distorted before that happened. I was better off just leaving the Gain at the suggested level (there's a little mark at 10 o'clock or so, or, around noon on the dial. Then I set channel volume and output volume to unity (indicated by the arrows). With that, the output level meter (the LED stack) flashed yellow and occasionally orange. Fine.
[So, when do you need a Pad? I guess if something, allegedly keys for example, comes in hotter than -10dbu. Would that be +4db pro line level or even hotter?]
I set the Mackie switch to Line. And, now that I had the Pad control on the Yamaha in the right setting (OFF) the signal to the Mackie was in the right range. Got plenty of clean volume.
The sound was icier than through the LJ's speaker. I managed that by rolling off highs a little bit at both the mixer and the LJ. Also inserting earplugs. Eventually, I stopped thinking about the sound and just played the music.
Thanks to everybody who responded!Last edited by rpjazzguitar; 11-13-2023 at 03:06 AM.
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