[somestranger26]

Did you measure the voltage from your LPS?
Both initially and after several hours then when the popping starts?
That would be the 1st thing I'd check.

JJ

I did measure the voltage at approximately 6.3V and tried turning it down to 6.15V like you said you measured the SMPS output at. I thought that fixed it but then it came back again.

I will leave it on for a day and check the voltage again after the popping starts. Do you think it is OK to turn the voltage lower than 6.15V? Someone had said when they were mistakenly running it at 5V that it sounded off.

 

[johnjen]

Crank it down to 5.8 to 5.9 volts and see what happens.
That was the voltage that my 3+usb started to work properly.
And yeah I too measured the SMPS output voltage at ≈ 6.2 volts but I had to reduce it to get it to latch onto the AES signal.

I finally did get a reply to my inquiries from Mutec and asked them what the 'acceptable' voltage range is for the 3+ and the 3+USB.
They have yet to answer me back.

JJ

 

[johnjen]

And in other audio related stuff, I built another dual channel LPS dedicated to running the 2 Mutec 3+'s in my chain.
This one has dual 6Vac windings that feed the dual channel regulator board in a clam shell case that is physically smaller and easier to work on.

This unit makes much less heat so I don't need a fan to help cool it down, and the total cost was ≈$100.

JJ

 

[johnjen]

I did measure the voltage at approximately 6.3V and tried turning it down to 6.15V like you said you measured the SMPS output at. I thought that fixed it but then it came back again.

I will leave it on for a day and check the voltage again after the popping starts. Do you think it is OK to turn the voltage lower than 6.15V? Someone had said when they were mistakenly running it at 5V that it sounded off.

One last point.

Leaving the SMPS in the circuit may be the source of the noise and problem.
Since Mutec recommended it not be connected with another power source feeding their units as it's secondary would be active with the power from the LPS.
As such it might be overheating or behaving badly etc, causing your problems.

JJ

 

[Muziqboy]

I did measure the voltage at approximately 6.3V and tried turning it down to 6.15V like you said you measured the SMPS output at. I thought that fixed it but then it came back again.

I will leave it on for a day and check the voltage again after the popping starts. Do you think it is OK to turn the voltage lower than 6.15V? Someone had said when they were mistakenly running it at 5V that it sounded off.

That was me who said that and you had it the other way around.
I had the Mutec3+ (non-usb version) running at 6.3v and it did sounded off to me.

You can safely run the Mutec3+ (usb version) down to 5v. I have 2 in the chain and they both run perfectly at 5v each. Did not experience any popping noises ever.
If you are not using usb at all, you can remove that usb board out and it will sound better. at least it did IME.

 

[johnjen]

So most know that we got a puppy a few months back.
He is now 7.5 months old, is still in full puppy brain mode and is letting everyone know just what he expects when they enter his sphere of awareness.
He weighs 70lbs is tall and lanky but doesn't know it, yet.
This lack of awareness is decidedly a mixed blessing.

And as I mentioned previously he is smart, the smartest dog I have ever interacted with.

He figures crap out all by himself and then teaches it to our choc lab so they both know an ever expanding bag of tricks.
Now most would like to claim that their dog is smart, as sort of a badge of pride or being special etc.

But in our case it not a matter of pride but more like that of lamentation, as in 'oh schiit' what's he figured out now…

His latest is he wants to be into audio and so to get started he decided to 'familiarize' himself with a favored tool I recently acquired.
That being my XLR cleaner brush set with 5 different sized brushes to clean the female XLR contacts.

I'd show you what his intense interest and 'can do' attitude has yielded, but I can't upload a pic.
But all of the bristles are now full of dog hair, are bent at odd angles, but only 4 brushes, remain.
We still haven't found the 5th brush.
Maybe someday it'll show up, somewhere.

I'm just glad no one makes doggy headphones and that he doesn't know that it could be a possibility for him, or we'd in deep do-do.
I mean once you get the audio bug there is no leaving it behind and pretending you can live without it, right?

Oh and did I mention that his Chesapeake nature has surfaced, big time?

For those who know about Chesapeake's and their ability to concentrate their focus upon objects of desire, especially food like objects, this trait becomes more intense as they grow up.

Another Ches'e trait is drool.
And sure lots of dogs drool, especially food motivated dogs, but they usually don't leave a pool of drool behind.
But that's just one type of drool.
Type 2 drool are these long, hanging, swinging, stick to objects they touch, ropes of drool.

Now most would think this topic is a bit gross, but after a while it becomes a fascinating question of how can they do that?
I mean they are LONG, and of course MR Bear cares not for where they swing and touch, nor what they wrap themselves around.
But WE do…

This is where training comes into the picture and MR Bear is a quick learner, however since he is a Ches'e he then decides when, or if, to actually respond to the (as he sees it, I'm sure) Request for Action, or not.
Fortunately he IS food motivated so he can be sufficiently motivated but only as long as you actually have treats, in hand.
Which he will also be motivated to want to help you with, as in take them off your hands, literally.

But enough of 'Tails of the Dog' for now.
I need to go and order another set of brushes…

JJ

EDIT I CAN upload pics I just gotta use the back door to do it.

 

[johnjen]

snip
If you are not using usb at all, you can remove that usb board out and it will sound better. at least it did IME.

Yeah I removed my USB daughter board as well and used the hole it left in the back panel to get the LPS power cable into the unit.

And I figured that by not powering up the USB transceiver chip in the first place, the unit would generate less noise as well.
Unless Mutec only powers that chip up when the usb input is selected, but I doubt that's how it operates.

JJ

 

[gefski]

Staying on topic, here's Baxter and Chloe unfriending each other.

 

[somestranger26]

Crank it down to 5.8 to 5.9 volts and see what happens.
That was the voltage that my 3+usb started to work properly.
And yeah I too measured the SMPS output voltage at ≈ 6.2 volts but I had to reduce it to get it to latch onto the AES signal.

I finally did get a reply to my inquiries from Mutec and asked them what the 'acceptable' voltage range is for the 3+ and the 3+USB.
They have yet to answer me back.

JJ

I turned it down to 5.89V which is as low as it will let me. I tried turning the screw on the potentiometer another 15 rotations and it won't go any lower. *head scratch* my previous experience with adjusting these Chinese LPSes was that they could be adjusted pretty broadly. Noise is still there although seems better.

Thinking about removing the SMPS now. I recall you saying it was non-trivial to remove it, would it also be difficult to put back if it doesn't fix the problem?

That was me who said that and you had it the other way around.
I had the Mutec3+ (non-usb version) running at 6.3v and it did sounded off to me.

You can safely run the Mutec3+ (usb version) down to 5v. I have 2 in the chain and they both run perfectly at 5v each. Did not experience any popping noises ever.
If you are not using usb at all, you can remove that usb board out and it will sound better. at least it did IME.

I did remove the USB board already. I have another LPS set to 5V that I could try to see if that makes any difference.

 

[johnjen]

I turned it down to 5.89V which is as low as it will let me. I tried turning the screw on the potentiometer another 15 rotations and it won't go any lower. *head scratch* my previous experience with adjusting these Chinese LPSes was that they could be adjusted pretty broadly. Noise is still there although seems better.

That is odd that you can't adjust the voltage any lower.

Thinking about removing the SMPS now. I recall you saying it was non-trivial to remove it, would it also be difficult to put back if it doesn't fix the problem?

Removing the SMPS board requires a way of leveraging the two boards away from each other (mother board and SMPS daughter board) while applying heat to one of the 4 standoff/connections, at a time.

I did try to cut the standoff/connection posts, but they are rather substantial so I just forced the 2 boards apart using a large flat blade screwdriver as I 'walked' 2 of the 4 posts further and further out of their respective thru holes on one end of the SMPS.
Then I did the same for the other end.

Removing the SMPS board can only be done, with the mainboard free from the case, which in turn means the release push button for the xlr connector on the back panel has been either removed (see the special tool I used) or the bent 'tab' portion has been broken off (which is what I originally did).

As for putting the SMPS board back in place, that would be rather tricky in that the thru holes and the mating posts would have to be cleaned up enough to insert those pins back into their respective holes in the mainboard.
This would be a fiddly exercise in being able to refit all 4 of the pins back into mainboard before soldering.

I did remove the USB board already. I have another LPS set to 5V that I could try to see if that makes any difference.

I'd try using this approach 1st to see if the noises and problems are 'fixed' by using an even lower supply voltage.
But it may just be the SMPS is 'semi-operating' and adding the noise and problems you are experiencing, in which case removal is the only way to tell if this is the source of your problem.


JJ

 

[johnjen]

Staying on topic, here's Baxter and Chloe unfriending each other.

Our 2 dogs use a different approach.

Mr Bear wants to muscle in on the bed where Punkin has laid down, so she lets him and then just gets up and moves.
Much like if she has a toy, Mr Bear simply MUST possess it, so she lets him take it so that he leaves her alone.

Puppies are like that and she will choose objects that she just knows he can't resist.
Clever girl.

JJ

 

[rellik]

Obvi! You know you thought he was a man but he only was a muffin! You shure he just didn't need some food?.... .... .. . .. .. .. .

 

[rellik]

I'd try using this approach 1st to see if the noises and problems are 'fixed' by using an even lower supply voltage.
But it may just be the SMPS is 'semi-operating' and adding the noise and problems you are experiencing, in which case removal is the only way to tell if this is the source of your problem.


JJ

Nah dude, you just couldn't hear the noise of the SPST relay switching, now you can. Also it is fast enough to try and lock rather than just giving up. At least it isn't bouncing, catch my drift eh eh )
The clicking is to make sure the amp isn't you know putting out DC offset when there is no music. A solid blank is alright but a floating DAC Will get broken and you know have DC offset...AKA why include a transistor switch rather than a nice um big switch?

Yeah, back to topic, most definitely not a paintball gun. Digital circuitry needs korrect operating voltage to function. Slightly, and I mean ever so slightly reducing it will just mean it will have to find that additional voltage from somewhere else AKA adding a RLC loop aka a tone and a current loop for external noise to be picked up, like a wireless antenna.

 

[johnjen]

So now that I figured out how to post pics (D'Oh) here's one of our young miscreant his own bad self.

And he hasn't stopped growing yet.

JJ

 

[rellik]

Hey, hey Twhispers in ear), is that your actual Dog?

Please take a closer look.