Different Speakers and DI -> Different effect of tone control?

Hey guys,

I am just wondering if any of the electricity-minded people could shed some light for me on why certain setups create different effects of tone controls?

On my DI -> Interface -> Speaker (designed as bass cab) (full range, neutral), there is very little effect from the tone controls.

On guitar amps, I get a really wide effect.

From another DI, output into a bass guitar amp (different, lower end) I also receive exactly the effect I expect, but slightly less exaggerated.

What causes this phenomenon? Is it the impedance of the circuit I am playing into? Or is there some other factor at play?

The biggest (usually negative) effect is due to poor impedance matching. This is most pronounced when a 'passive' guitar is plugged into a low impedance, particularly 10k Ohms as is the case with most hifi gear. The pickup really needs to work into a few hundred kilohms. The first thing to suffer in these conditions is the top end of the audio you're pumping out.
So, with reference to your DIs, do you know what the impedances are? Are they active or passive units? What happens if you go through a stomp first? (A lot of stomps have active outputs on Bypass). Keen to know what you find!

Quote:

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/<\\/p>[/<\\/p>[/<\\/p>[/<\\/p>[]<\\/p>/]<\\/p>/]<\\/p>/]<\\/p>/Quote from lawry on June 28, 2014, 12:13
The biggest (usually negative) effect is due to poor impedance matching. This is most pronounced when a 'passive' guitar is plugged into a low impedance, particularly 10k Ohms as is the case with most hifi gear. The pickup really needs to work into a few hundred kilohms. The first thing to suffer in these conditions is the top end of the audio you're pumping out.
So, with reference to your DIs, do you know what the impedances are? Are they active or passive units? What happens if you go through a stomp first? (A lot of stomps have active outputs on Bypass). Keen to know what you find!

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Hi Lawry,

Some of the gear is still at school. The DI I run into my hifi home gear (where the tone control has the least effect)is passive. It is using an OEP A262A3E into a mic pre and interface. The tranny isn't exactly high end. I am going to replace the DI soon with a stereo DI (since guitar is stereo) with a better tranny, but I'd like to find out the problem first so I don't have it again.

I don't know the resistance of the DI - where would I put my multimeter pins to measure that?

The input of my micpre is 10kOHM, the output is 150+150.

The other DI is in a Boss RC-300 loop pedal, which I assume is active because I can turn the input gain up and down. When I get the chance I'm going to take the interface output cables out of the amp with my high end speaker and plug my guitar straight into it and see how it works with that... And then also try it with my RC300

The setup I plug my guitar into at home at the moment also has a problem with my bass in some ways - it's regularly too bright compared to just plugging into your standard bass amp, but until now I have basically figured it's because my nails aren't as short as they should be, and it's much better at playing high frequencies than a standard bass amp. But my bass is active and I usually tweak it to fix the problem.

PS I don't know what a stomp is and I definitely don't have one. :)

Thanks Lawry.

I think you'll find he's talking about guitar pedals in reference to "stomps" or "stomp boxes"

Hi Chris. Just thought I'd have a quick forum scan before I shoot off to setup for a gig tonight. So I can't get too deep right now with your problem.
Firstly, Bargie is correct. A Stomp is any guitar pedal you 'stomp on' to turn it on or off (distortion, chorus, delay, etc.). Your RC300 is a stomp.

As for your problem it all seems a bit weird from reading how you're set up because it sounds right. The 10k input on the mic pre is probably right too but not suitable for a direct passive guitar input.
I have another question (and please don't think I'm having a go at your intelligence); with the DI, are you taking the output from the XLR (3 pin) socket? If you're just using the other 6.5mm jack output then that's no 'DI-ing' it. The two 6.5mm jacks are usually just joined together in parallel so you can feed your amp. I'm just asking because I've seen guys do this before.

Sorry man, gotta go and setup. I'll check this thread again later. Meanwhile, there are quite a few really switched on axe men in this forum who can probably pitch in with advice too.
Bargie, Jarrod, Eliot, Matt, this means you! ;)

1/4 input to XLR output, into the micpre.

The inputs are labelled instrument, line, speaker. And then there are the link/thru outputs for instrument and speaker. I am using Instrument "In"

I tested my friends tele clone through the same setup, which I know has a really harsh tone control (makes everything really muddy very quickly) compared to mine, and there is also "no effect" there.

I have a feeling it might the impedance problem you are mentioning, and maybe this DI isn't quite doing what it is supposed to be.

Good luck tonight m8

EDIT: I managed to piece together another setup that unfortunately cuts out both the micpre and the DI by using another DI (voicelive 3) straight into my interface -> amp -> Speaker, and it definitely works through this.

EDIT:: Using the "Thru" of the voicelive 3 (rather than the line outputs) makes the guitar sound similar to how it does through the DI, making it not work with the controls at all.

I think my DI isn't actually DIing. I need to either get my hands on another DI that goes into micpre or another micpre to make sure I am correct though. Thanks again

Sounds like your on your way to sorting this out yourself, Chris. What happens if you set the pre to line? Just curious.

Hey mate,

I tried running the signal through a stomp and then into the DI, and that seemed to give me some of my tone control back (but not perfect).

I reckon you got it right early on with the impedance problem. I am going to get some active DIs (probably a pair of Countryman DT85s - which give me the option of 10k input for my synths and 10M for my guitar).

Unless there is a more elegant solution to an active DI these days? Googling around and the consensus is about as clear as mud, so just looking for a "seems ok" before I lay down the 300 odd. Not that I won't get resale value if it doesn't work out...

Thanks

300 bucks sounds crazy insane for a DI box.
There's a couple of things that aren't quite making sense here...
*OEP A262A3E is a transformer not a DI
*you mention a mic pre, what is is?
*a guitar signal is not stereo, it's unbalanced. You're definitely using a guitar lead right?
*what's you're exact signal chain, things sound a little backwards from what I'm reading.
You might be better off taking a pic of everything plugged exactly how you'd have it.

http://www.ebay.com.au/itm/BEHRINGER...item43ba4479c5

Hi Barge,

The OEP A262A3E is the transformer in the passive DI I currently have
Mic preamplifier, the DI goes into my micpre. I am using a Line Audio MP8. (which has a floating ground, but I have managed to confirm this isnt the problem).
And the guitar I built with my kit is stereo, but yes, I have it running mono with a TS cable for this :)

$300 is pretty pricey, but since I need two channels my choice is basically either $50, $100, $300 or the insane $1000

I don't trust the $50 ones since I have incredible GAS

Wow. $300 for an active DI is pretty expensive considering they're all pretty much the same on the inside (despite the spin you may read). I'm actually with Bargie on this in that a Behringer DI is worth trying. I know quite a few bassists who use them and they work fine. If you want to make your own I can post a schematic of one I've built heaps of times (including selling 5 to a recording studio). However, by the time you've finished buying the bits you'll have spent about the same amount as the Behringer. And they have phantom power if required.

Alright thanks mates I'll give the behringer a try and post results when I get the chance to try it

:)

I'll admit right now I have zero experience with guitars with stereo outs and frankly can't see the point so I'll just bow right out of that conversation, but you mentioned you needed two DI's and I'm only guessing that you were using one for your gat and the other for your synth. What's stopping you going straight in to your pre amp with your synth, if it's digital it certainly shouldn't need a DI.
Then again you might have been talking about DIing your L/R gat channels in which case, as I mentioned I have no experience.
For the record those Behringer DI's are pretty much an industry standard.

Good luck man :)

Quote:

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/<\\/p>[/<\\/p>[/<\\/p>[]<\\/p>/]<\\/p>/]<\\/p>/Quote from bargeloobs on June 30, 2014, 17:32
I'll admit right now I have zero experience with guitars with stereo outs and frankly can't see the point so I'll just bow right out of that conversation

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It's just so I can record the neck and bridge pups at the same time into different tracks. I also find that these two tracks summed together isn't actually the same as the mono output - but I dunno why that is, as I haven't had the chance to investigate properly yet. I used an on/on/on to swap between L/R, Mono (L/L) and R/L, so it functions as a pickup selector in mono situations and a stereo split when I want to record both at the same time.

:)

Cool!

FYI the new DIs work as expected. I spoke to the person who designed my current DI again and they were able to bring up the old schematics. It was an impedance problem, causing my pickups to be loaded. It was a "vintage-style" (as much as I hate the term) boutique, which is why it wasn't treating the passive pups as nicely as more modern passives with higher input impedances.