Hello MPC3000,

Just to clarify... you have, for example, PGM 1 set to D1 and PGM 2 set to D2 and you hear the same track on both channels?

If not, please try explaining what is going on in a little more detail and we'll go from there;)

The term that is used for this in the Mackie Mixer community is called "bleeding" as in the source from one channel bleeds into another. My old Mackie use to have this problem if you turn up the gain too much and it seem to be doing the same with my TTM-57SL. The level of "bleeding" in volume is very low but audible enough to ruin the recording.

The Digital PGM are not effected as well as the Line PGM. This I mean if you set it to any of the following there is no "bleeding".

PGM1: D1, D2, A1 line select, A2 line select.
PGM2: D1, D2, A3 line select, A4 line select.

The source that is heard/bleeding into the selected PGM is any line source. Meaning

PGM1: A1 line select, A2 line select.
PGM2: A3 line select, A4 line select.
and AUX IN can be heard when not selected.

and it will bleed into any PGM that has a phono select. Depending on the configuration, the bleeding "noise" volume will differ.

I have concluded that it is not the fader sensors or knobs as I have switch fader reverse and channel revers on all possible configuration.

Since I did have this problem with my old Mackie link Mixer, I am starting to think it maybe because of my house electrical system. It is very old and there seems to be no proper ground setup on any of the outlets in my room. So I am going to take it to a friends house later and test it. Thanks for the reply.

Know that all electronics will bleed if the gain structure of your system isn't set right.
Some mixers may bleed more than others but if you have enough gain any mixer will do this.

With that said... my guess is your amps or speakers are turned up too much and your not running the mixer as hot as it should be ran.

I suggest having a look at this Rane note regarding Setting Sound System Level Controls--> rane.com
It will give you a comprehensive introduction to proper gain structure.

In short, you want to run the signal as hot as possible through each piece of gear/software.

Since your using Scratch Live this starts in the software.
Turn your speakers, amp, gain knobs, and any outputs controls on your mixer to 0.

You want to run the audio as hot as possible out of the software.
This means all your tracks should be hitting in the yellow when looking at the internal LED meter (next to the virtual decks).
Once the signal is running as hot as possible there, turn your gain knobs up on the channel strips so the signal is coming into the mixer as hot as possible without clipping. Monitor the LED on the mixer to see the signal coming into the mixer. If the tracks your playing have been mastered well you'll probably find that you'll need to turn these gain knobs up to around 12 o'clock.

From here, turn your Master, Aux, or Booth (depending on what output your running to your amp/speakers) to about 7 (unity gain on the 57).

If your running the output of the 57 into directly into an amp then at this point, turn your amps up as hot as possible without clipping the signal.
Now turn up your speakers to the desired volume.
The idea is that you've brought the noise floor down by running the signal as hot as possible through each piece of gear. Now you shouldn't hear any bleeding.

If your not using an amp but rather powered speakers, just turn the speakers up to the desired level after you've set the output knob on your 57 to 7.

Hopefully that will take care of the bleeding issue.

Let me know if you need further assistance:)

MPC, have you ever resolved the issue?

No i have not, but i dont have another 57 to test to see if this is normal or not. would you mind doing a quick test for me? thanks

Not at all, what do you want me to test?

Can you test the phono state of all the available analog PGMs to see if a line source bleeds in?

- Simple way is to unplug everything on the back except for power plug and studio monitors and headphones.
- set all A1 A2 A3 A4 PGMs to phono on the back of the mixer
- put PGM1 to A1 and PGM2 to A3 and turn both gains all the way down.
- now get a line source like a cd player and plug it into the AUX input make sure its input volume is respectable (hot).
- Turn the AUX input level knob on the 57 all the way down.
- now turn the volume on the booth (studio monitors) to a respectable level, say 3
- turn the volume faders on both PGMs all the way up and put the crossfader in the middle.
- now turn the gain all the way up on PGM1 (should be A1) and listen for the AUx input source.
- leave the gain all the way up and switch PGM1 to A2 and listen for the AUX input source
- now turn the gain all the way down on PGM1 and turn the gain all the way up on PGM2 (should be on A3) and listen for the Aux input source
- now leave the gain all the way up and switch PGM2 to A4 and listen for the Aux input source.

let me know if you get any bleeding on any of the analog PGMs (A1 A2 A3 A4) T

Thanks

As I said, this sounds like the issue is due to improper gain structure.
All mixers will "bleed" with an improper gain structure and enough gain.

Did you follow my instructions above?

yes but the bleeding is still audio when tracking out.

The test i suggested was ONLY to determine if this is normal. you say all mixer will bleed and if that is so then he should have bleeding too. BUT if he doesnt then we know who had a bad mixer.

Thanks

This is not entirely true. It can be very dependent on the other equipment in the chain such as amps, powered speakers, or anything other external processing units.

Check out this Rane note regarding Sound System Interconnection --> rane.com
It explains all of this very well.

If you set your levels properly, according to Rane note, do you still hear the bleed?

Thanks for the link, and sorry I was not clear... Yes i did properly set my levels (almost just before the clipping point) on every output source. It did not fix the problem, i still get bleeding when i track out, most audible on the silent part of the recording.

You also made a good point about possibility of other equipment in the chain that might have an effect on it. like i said before i have bad grounding in my house and when you use the same power strip and conditioner, you will have some interference. i still have not ruled that out because i have not had time to test my mixer elsewhere, i guess i just wanted someone to test it for me as it would be easier.

Thanks agian

What happens if you completely disconnect your speakers and just listen in your headphones.
Do you still hear the bleed when monitoring the master output?

Yes that is why i suggested both options in the test. It is also why I said to put the boot output volume of the mixer to 3 as that is somewhat low so if he did hear bleeding it would conclude that it would be more audible at a higher/normal room output level. Thanks

Bump, if someone can do a quick test for me, i would really appreciate it. Thanks

I had a look back at your suggested test and I'm not surprised your hearing bleed by doing that test.

The only time you'd want to set the dipswitches on the back of the mixer to phono is when your plugging turntables into those particular inputs.
The reason for that is because phono inputs will pick up more noise than line level inputs.


This is bringing the noise floor up and your definitely going to hear bleeding when doing so. Your signal to noise ratio isn't set correctly which is why your hearing this bleed.
Have you done my suggestions?

If so, do you still hear this bleed?

My guess is you won't because the signal to noise ratio would be set correctly.

Sorry if i wasnt clear, that test was the simple test. As i said, any line in source will bleed into a phono. In this test i wanted to use the AUX line to show how it bled in to all the phono PGMs. you could easily set one of the PGMs to line and it will bleed just like the Aux line did win that test... at least for me it did and that is why i want someone to try it out for me. thanks.

I did your test and as expected I do hear the bleed from the aux input.
This is expected because the signal to noise ratio is not correct.
Your boosting the level of the input (jacking the gain all the way up) which is bringing the noisefloor up and causing the cross talk.
In a real world situation this is not something you would do nor would want to do because it would cause the specific issue your having.

If you set all the PGMs to line and test you'll find that the crosstalk is substantially less.
This is because a phono level is much louder due to the phono pre amp but your still jacking up the input signal via the gain knob thus bringing the noise floor up.

If you follow my suggestion above, which is setting the proper signal to noise ratio, do you still hear the bleeding?

I can hear the bleeding on A1, A3. There is only a faint of bleeding on A2, A4.

I am *not* cranking up the volum. PGM1/2's gains are set to 12o'clock. Aux completely turned down. HEadphone at 9o'clock and I can hear the bleeding in A1 and A3.

What if you flip the phono/line switches to 'line' or plug a grounded turntable into the phono inputs?
My guess is the bleed ceases ya?

Sorry, I forgot to mention that I have plugged in a grounded TT to these inputs to avoid a floating/open input. So all my reports are done with connected, grounded TT's.

YES!!!! THANK YOU!!! I have it set up like this too. Gain at 10-12 o'clock with aux turn down will still bleed, and this is somewhat considered normal conditions!!! And yes A2 and A4 on mines is less noisy!!!! My old cheap Stanton does not have this problem!!!

Correct gain setting was never the problem, any line will bleed into the phono even if nothing is pluged into the phone pgm. Yes it is normal for preamps to pick up noise but at 12 o'clock gain, that's garbage! The only reason I asked to amp it up all the way in the test was so you heard how loud it was!!!

I have concluded that the preamps on the 57 suck... I mean for the price you pay you expect quality. Thanks for confirming, might try to sell it now or invest in external preamps. Thanks again to everyone.

worse possible situation??? 10-12 o'clock is normal gain setting. Why would it matter to set the swtches back to line, I want to use my Phono turntables. If I set all the switches to line for a quieter noise floor, i won't be able to use my turntables.

I have to turn off my aux/line sources before I use my phono pgm? My olds recievers didn't have to do this.

I know you work for Rane but come on. We shouldn't have to do anything extra to use the phono stage of the mixer.

No where in the manaul does it say unplug all other audio sources and set switches to line before using your turntables for best sound.

really no more replies from the experts? let me guess its not convenient for you guys anymore???

can i at least get a confirmation from the experts that the mixer just doesnt have quality phono preamps? and that my test can be recreated?? this way i can rule out its not a hardware problem. Thanks

Hm... but they are high quality. The input just leak ;)

Hey MPC3000,

We understand that you are getting some bleed between inputs where ideally there should be none. No excuses. It’s real, you hear it, and it shouldn’t be there. The 57 is a mature design that has been in production for nearly five years and I suspect that this has not been an issue for the majority of customers because, on this type of mixer, very few drive an input that is not selected or select an input that is not being driven. This is not to say that you shouldn’t be able to.

Some of the feedback you received was an attempt to figure out how you are using the mixer and to see if there was a way to improve how it works for you. This feedback should not be interpreted as saying you are doing anything wrong or that the product is working as well in this regard as you have a right to expect.

The mixer does have quality preamplifiers. The issue is a less than ideal layout of circuit board traces connecting signals to the selector switch. Unfortunately, there is no practical way to fix this on an existing board.

Your feedback is very valuable to us and will help us design better products in the future.

While you shouldn't have to, I hope that by adjusting the way you use the mixer, you can get it working and take advantage of its innovative design.

Thanks again for your input.

wow, either i am in a good mood, or im just glad i finally concluded this was not a fault on my part, or your response was just perfect. Thanks you, i am once again satisfied with seratos customer service, you guys/they are the best. i did not sell the mixer, i found way to work around it because i love the mixer so much. not implement midi mapping and take this mixer to a new level. thanks again for the response

Hey MPC3000,

Realy good to hear it's working for you.
Thanks again for the feedback.