Help with brainstorm💙 "SOLVED" 💙

[mollie]

Hi there,
Hum or buzz is mostly introduced into hifi systems by two possible main reasons:

1. An “earth-loop” introduced by interconnects between PC/MAC, DAC, cd/dvd/blue-ray player, Amps, RJ45 switch,Tuners, Tuner CAI connection to provider etc.
   (cai connection very often reason, because the signaal wire or screen carries very often a high voltage when measured against the real earth!!!
   This will introducé hum/buzz to the whole audio system. Test of by disconnecting the CAI cable!!!
2. Bad powersupplies, can introduce hum/buzz!
   Could also introduce Noise etc!!!

Start to check those possibilities by disconnecting the CAI system and try!!!
Of this doesn’t help, make your installation as smal as possible by disconnecting all boxes witch are not realy needed to play digital music files from PC/MAC to your stereo system.

Hopefully this guide helps to “repair” this problem

Cheers
mollie

[SteveE]

Hi Mollie, thanks for your response… appreciate it.

The things mentioned above i’ve bin thru already…
In my first post ever on this forum it was mentioned… or it was by sonore …
And i did all those things… Didn’t help.

Besides i have tried the things above that time, all my audio gear and cables or even my power isolation station is new and other then that time. I did mention this earlier in my posting.
So also the powersuply’s. (I changed them back to the original and vice versa)

It all started with switching from roon to audirvana…

And, correct me if i’m wrong; a groundloop can’t identify when a 16, 20 bithdept file is playing and then start to humm… and then, when i upsample it, or play a 24,32 bithdept file the groundloop thinks; now i stop the hummin…

And…it only hums when a file or song is played, and stops when paused.

It hums with microrendu and audirvana
It hums with Stack audio link 2 and audirvana

It doesnt humm with roon and microrendu.

And believe me; there is nothing more that i want than audirvana as software…but it has to implement as it has ment to implement.

So Mollie… please help me to solve this.
I don’t wanna be a know it all, but i don’y wanna constantly do the same thing…that’s why i won’t try again to do the things you mentioned… bin there,done that… Sorry

[Antoine]

Hi @SteveE, i took a look at your thread and the issue you encounter. You told that with upsampling the humming disappeared but it produce distortion. I saw that you used the option to use the max capacity of the device, have you tried with the other options?

[SteveE]

Hi Damien3… With my hand on my heart; i try every other bithdept with bitrate… And all the other options in the menu on or of etc etc.

The clicking and poppin is reduced when i play with; LOW LEVEL PLAYBACK FUNCTIONS, but then again the distortion becomes more frequent. It’s the one of the other.
Lower the upsampling seems to make the distortion less frequent…but minimal.
Using asio in stead of wasapi makes a BIG difference in the loudness of the distortion and it reduces the clickin and poppin… and believe me it sound terrifying…the poppin as the distortion.

That’s why i bought extra ram memory to hope to solve this…but it didn’t.

So…now all settings are set to max 24/192. When there is a lot of bitrate switching there is a little clickinn poppin…but that’s okay for me… The distortion seems almost gone, but who knows . I don’t dare to put the volume to sweet rockin…
But i have to test this for a while…
But…16 bithdepts,20 bithdepts are hummin. Pres pause, hummin gone… Volume louder, hummin stays the same level…

[mollie]

Hi SteveE,
Have you by any chance another dac laying around (or from frieds) which can handel up to 24bit/192KHz signals. With that you can try-out whether is than functioning ok for music.

Your cutest dac does the converting completely different as standard dacs (very special FPGA chip) and try to upsample all incoming signals also to higher frequencies as well.
Best use will be in principle that only one dac unit or one player does the up or downsampling.
It maybe could be that the the Audirvana software doesn’t work properly together with the Cutest FPGA’s software together.

Cheer mollie

[SteveE]

Hi mollie…thanks again. I will try the dac from my son… but he stays at his mom right now so maybe he will be here in the weekend.

But… Then everyone with the Qutest would have this problem? Everyone with a qutest and microrendu would…
But then again…if they don’t have problems…why do i?…

I will try to get another dac… It’s the only thing that i haven’t tried… I let it know when i have the results.

I just tried downsampling a 24/48 song to 16/48…and there’s that humm again…

Quote: Best use will be in principle that only one dac unit or one player does the up or downsampling.
How do i set these functions to do the thing above?;

ACTIVE DEVICE:

FOR BRIDGE DEVICES CONNECTED TO A DAC:

And how do i set these if i want it bit perfect?

[mollie]

Hi again,
A few other remarks:

1 for thd reasons:
Make sure that the output level of your dac is set to a level which comply best with the input sensitivety level of the amplifier.
Most amps work good with 1V input, some monoblock like best 2V and 3 V is normally not needed. So usually never use 3V out!!!
Most inputs are overloaded with 3V settings most amplifiers during loud music levels.

2 for level/thd reasons
Most DSD recordings are recorded on about a 6dB lower maximum level as usual for pcm recordings.
Some companies who are building f.i. DAC’s, do sometimes add some additional amplification for this reason. In that case you can imagen that probably overload will happen in the next stages of your dac chain.
For that reason it will be best to use a fixed 1:1 input/output stream with Audirvana.
Cheers, mollie
Your dac can do f.i. the upsampling.

[SteveE]

Mollie?..…
…
.
You are my hero of this week……

And i’m probably your “this weeks dumbest person”
you try to convince that audirvana is, what they say it is; all good…

Bitrazer; the dac…the dac was the thing you pointed at… And it was… In a different way you mentioned, but it was the dac… thanks for your help, and my apologies… but i really really worked hard to find a solution also… seriously. …so, thanks again bitrazer.

Damian3, thanks for looking at my thread and trying to help me… Appreciate it much… thank you, thank you

And Mollie​:crown:… I think you give me the
answer​:jigsaw:; It was the output on the dac.

I listen multiple times to 1 v , 2v and 3v and decided that the 3v sounds most open…no distortion noticed EVER, not even on louder levels. I asked people on forums what the best output is, and mostly, if not all preferred the 3v… So that was also the output i liked most…and choose the 3v output and used it from the beginning when i bought the dac.

Just a minute ago, after reading your remarks i switched to 2v…and the humm was less noticable…so i switched to 1v, and now it is almost not noticable…
And with almost i mean; i notice something in a far,far distance… And pretty much not noticable.
So… I’m back being an Audirvanian … Okay,okay…a pretty dumb/annoying Audirvanian… So my apologies to you all…and to the software of Audirvana.

Strange it has such an effect on the 16 and 20 bithdepts… but it’s like you said about dsd and amplification… probably.

I have tube monoblocks… No pre amp…
Probably i have to look for a pre amp because the max volume is just enough to drive the sound to a nice power level…maybe just “not” enough.
If you now an option in audirvana to help this a little it would be great… Otherwise, it’s all good.
AUDIRVANA

PS

And now, i will go stand with my face in the corner for a while… with some donkey ears on my head…
My punishment.

[mollie]

Hi SteveE again,
I am very happy to here that my posts did help to find the main course of your trobles and give moreless the right sound you was looking for.
I still have some remarks about your rig.
Is there any hum noticeble if you listen in the vicinity of the oudspeakers as the monoblocs are on ? If so, look at the specs of the monoblocks what level of hum could be there.
Most tube amplifiers produce nice warm sound but produce some hum and noise.Sometimes that could be improved, but that needs knowlegde to do, so there you have to be familiar with to do it yourself. (it’s for pro’s!!!)

Your dac can be upgraded by the use of a very good powersupply with less hum and noise too

I have good payable results with psu versions made by iFi , which is a switched psu with very little noise. Last new version X model gives only 1 microVolt output noise !!!
Apart of that you should also look for a the iFi iPurifier 3 which improves very much the usb connection, noise signal and many other things

I have no connection in any way with iFi but found these things during my search for better solutions for a reasonable price.

There are many other upgrades possible, but most of them are much more expensive!!!

Cheers, mollie
( yes i am an “audiot” with some background)

[Sionyn]

Excellent thread!
Problem-solving, members being consistently helpful and friendly, and finally a good result.
Well done, guys!

[SteveE]

Mollie​:crown:… There is absolutely no hum out of my drivers ofy speakers… No humm from my tube amps…deadquit… lucky me.

The ifi x you mentioned i have in use😊 dor the qutest. And yes, it’s an noticable upgrade… the microrendu also uses an ifi power supply.
I also have an isolator i use as an main supply for the amps and the other audio. Won’t believe what that brought me… incredible upgrade… holographic…

About the ifi purifier… I think it’s doing a same thing as the microrendu or the Stack audio link 2?. They have such a thing build in…(or something like that​:grimacing:)…or?

Once i had a dream as a little boy… A wish;
listen to music with some nice gear…
my dream and wish came true and even beyond that; … not just listening to the music, but experience the music… And i’m thankfull for that…

Sorry for being kind of poetic …but i’m dead serious…

3 new photos by Steven J. van der Meer

[SteveE]

Output power: 25 Watt.
Class of operation: Push-Pull (class A)
Tubes complement: 4x EL84 (6P14P-EV), 1x ECC82 per mono.
Outputs 4 – 8 Ohms.
Input sensitivity: 2.8V rms.
THD %: 0.03% – 1W/1KHz, 1% – 25W/1KHz.
Frequency bandwidth: 10Hz(-1dB)-95KHz( -3dB)
S/N Ratio: 82 dB.

Mollie when you look at the specs of my amps, what output you would theoretical choose for the Qutest?

[bitracer]

Keep it at standard 2V. This is not sound tuning parameter, you change it only if you have problems.

[mollie]

Hi SteveE,
I agree with bitracer that 2V out will be best for your case and that for several reason.
(the 3V setting can overdrive your amps during koud music passages)
I don 't know whether the impedance of your speakers is friendly or not.
Apart of the good musicallity habbits of an tube amp, have these also less good habbits as:
Low demping factor, the control of your speakers rely very much on that factor.
That can become even worse if the speaker is unfriedly for the amp. ( low impedance, high capacitive and/or inductive veriations in impedance curve could show that, difficult to measure, but may ask much more current from your amp as than available. Give both high thd and bad control of speaker during loud music!!!
By using 2V out you can only have about 71% of the maximum possible output power of the app so you speakers will not be overdriven easely.
If your speakers are unfriendly and/or show a low impedance in the bass area between 20-200Hz it still can go wrong by overloaden the amp.

I still can 't figure out why a 2V setting is better sounding as you say but still show some noise and thd and even the 1V setting is still not 100% noise/humm free.
This could show that there is perhaps something wrong with the dac concerning the powersupply, or there is a possible interfeerance between Audirvana and the dac by uo/downsampling methodes.
Please check the qutest with the standard powersupply works better, if so your ifi psu is not good enough. The newer X one can deliver 3Amps by 5Vdc

Cheers, mollie

[SteveE]

mollie​:crown:
Thank you for this very clear information. I’m gonna look this over and search the internet to make it more clear to me.

-Drivers are 97.2db 8 ohm
-Qutest powersuply is the ifi x. (Standard powersuply has the humm also)

What means a lot to me is that you mention why there is still a humm at 2v and even with 1v (noticable with quite classical music for example) …mollie​:crown:you really understand what the problem is/was…

Today i’m not in my listening room… Tomorrow i will and do some testing with the 1v 2v 3v…
Thank you

[mollie]

Your speakers are very sensitive, so even very low level of hum or noise produced anywhere in the total audiochain will you heared right away.
Any (earth)loop in the chain could add very easy even more of it. The same with p.s.u’s.
Make sure that there can 't be any (earth)loop, f.i. using the two BNC input will easely increase the amount of noise/hum.
How lower the impedance of your power supply’s how better it could be. (lower impedance/ more Amps is always quiter.
The hum mentioned from your monoblocks can you hear easely true your speakers. This amount of hum can only be lowered by a amp with better hum specs.
The hum is always there as soon your amp is on!

Cheers, mollie

[bitracer]

Since there was no hum when connected via USB directly to the computer, there must be something else at play here.

Same with the upsampling. Why should there be any difference with the hum when upsampled? The output level didn’t change.

I suspect that the variation in the output lavel just hides or reveals the problem.

[SteveE]

Hi bitracer… That’s right… Laptop directly connected to dac wuth usb there was no noise…dead quite. But a file/song of 16 bithdept (audirvana left corner) was placed as 32 bithdept (wasn’t it?.. i don’t know fur sure, otherwise 24 bithdept) in right corner of audirvana… as if it was upsampled (but upsampling was deactivated)

So tomorrow i’m gonna test with that part also and let you know about the outcome. I wanna try to put the max bithdept to 16 bithdept so it wil be placed in the right corner if audirvana as a 16bitdepth file. And then listen if there is a humm if i acomplish to do that…

Your question about the humm and output level make sense…

---- I suspect that the variation in the output lavel just hides or reveals the problem…— don’t know exactly what you mean…i’m gonna put that in place of my thinking…
Thank you bitracer…

[bitracer]

@SteveE

But a file/song of 16 bithdept (audirvana left corner) was placed as 32 bithdept (wasn’t it?.. i don’t know fur sure, otherwise 24 bithdept) in right corner of audirvana… as if it was upsampled (but upsampling was deactivated)

That’s not what is happening here. When you’re connected directly via USB to the DAC what you see for bit-width is what the USB interface is reporting. This is what Audirvana team claims and can be easily validated by playing MQA file to a MQA decoder. If it plays and MQA is detected, that means that the stream is bit-perfect (no upsampling).

What you can try is to connect the computer via USB to the SA (it has USB input) and then connect the Qutest again via USB to the SA. I’m curious if that too would produce the hum.

[SteveE]

…okay…nice thing to try out…
Nice… Al lot to test…

The first thing you mentioned above i have to think about. You try to explain to me earlier… Maybe it’s getting more clear to me as i try this thing tomorrow…

Thank you so much for thinking with me to make the solution more clear🙏🏻.