[Roasty]

i got the new sr1b filters off Mitch. loaded them up but ran into some issues.. bass sounded less full, less impactful, and the vocals/top end was too upfront and sharp sounding and thin.

given the glowing reviews of the new filters, I gathered something was wrong and emailed Mitch to troubleshoot. sent Mitch some screenshots and turns out i'm running into a bug with Roon and convolution filters, whereby on some bitrates, the convolution filter taps is reduced by half.

the link to the relevant Roon community thread is as follows:

https://community.roonlabs.com/t/roon-adjusting-convolution-filter-tap-length-fix-in-progress/161188

just sharing this in case anyone else encounters similar issues. i'd suggest click on the Roon signal path and check the number of taps, if/when swapping between albums with different bitrates.

 

[Aleksandar R.]

On MOST headphone/pre-amps all the volume pot does in attenuate the input, your just amplifying a smaller signal.
Coupled with the fact that almost all audio devices use logarithmic pots, so the pot at 1/2 travel is really only about 10% of the input voltage making it to the amp.

Good point that at 12 o'clock the pot is passing only ~10% of the input signal.
That is not good for signal to noise ratio.
Ideally, the input signal should be maxed and the gain of the amp low, to yield the best S/N ratio, otherwise, the gain of the amp will unnecessarily amplify the noise along with just 10% of the available input signal.

 

[lithiumnk]

i got the new sr1b filters off Mitch. loaded them up but ran into some issues.. bass sounded less full, less impactful, and the vocals/top end was too upfront and sharp sounding and thin.

given the glowing reviews of the new filters, I gathered something was wrong and emailed Mitch to troubleshoot. sent Mitch some screenshots and turns out i'm running into a bug with Roon and convolution filters, whereby on some bitrates, the convolution filter taps is reduced by half.

the link to the relevant Roon community thread is as follows:

https://community.roonlabs.com/t/roon-adjusting-convolution-filter-tap-length-fix-in-progress/161188

just sharing this in case anyone else encounters similar issues. i'd suggest click on the Roon signal path and check the number of taps, if/when swapping between albums with different bitrates.

I’ve stopped using roon for convolution as I use HQP embedded.
I use roon convolution filters(Raal) only on my portable fiio dap which has endpoint functionality. (Fiio dap LO> Jot R).
My Roon server is installed on a Linux (gentooplayer) machine & I’ve not updated it to the latest version.

 

[KaiSc]

Good point that at 12 o'clock the pot is passing only ~10% of the input signal.
That is not good for signal to noise ratio.
Ideally, the input signal should be maxed and the gain of the amp low, to yield the best S/N ratio, otherwise, the gain of the amp will unnecessarily amplify the noise along with just 10% of the available input signal.

Almost every amp is built that way:
A passive attenuator / Volume knob, followed by an amplifier with a relatively high, fixed gain, to deal with weak sources.

The reason is simple:
It’s not possible to change the gain of an amp’s power stage, by changing NFB, without significantly changing its characteristics.

If you find gain switches, like e.g. Hi, Mid, Low, usually there is in an additional amp’s inter-stage:
pre-or post volume control, which both have their advantages and problems.


The good thing for Raal users:
The ribbons are not that sensitive, so you hardly ever run into noise issues.

 

[GOKYO]

i'll be receiving the new ti-1c interface for my airtight ATM 300b set amp tomorrow.Huge thank you to everybody at RAAL.

I’ve been listening to the ti-1c/airtight 300b combo for a few hours.Gets to the emotional intent of the music better than anything I’ve heard before…PRaT!

 

[adornoWest]

just sharing this in case anyone else encounters similar issues. i'd suggest click on the Roon signal path and check the number of taps, if/when swapping between albums with different bitrates.

Thanks for sharing. I am having the same problem. How annoying.

 

[jlbrach]

i got the new sr1b filters off Mitch. loaded them up but ran into some issues.. bass sounded less full, less impactful, and the vocals/top end was too upfront and sharp sounding and thin.

given the glowing reviews of the new filters, I gathered something was wrong and emailed Mitch to troubleshoot. sent Mitch some screenshots and turns out i'm running into a bug with Roon and convolution filters, whereby on some bitrates, the convolution filter taps is reduced by half.

the link to the relevant Roon community thread is as follows:

https://community.roonlabs.com/t/roon-adjusting-convolution-filter-tap-length-fix-in-progress/161188

just sharing this in case anyone else encounters similar issues. i'd suggest click on the Roon signal path and check the number of taps, if/when swapping between albums with different bitrates.

I see the same thing but hear no problems sound wise....my assumption would be that the different bit rates would different filter taps but perhaps I am wrong...I have owned the filters including the new 1B version for some time now and always noticed the differences with bit rates and my guess is it has been the same for everybody else as well...I think we better be careful here trying to get Roon to create a fix for a problem that doesnt exist or may actually create one...again, I am no expert but

edit: Mitch tells me that the resulting change from the roon error would not be enough to cause degradation of sound which makes sense because otherwise we have all been nuts up till now lol

 

[rlawry]

I agree with the above. I have had the new Mitch filters with OBC built in and just listened to several Qobuz recordings of differing bitrates and resolution and all sounded better to me than with no filter or with Roon PEQ filters. If there is a degradation in sound I cannot hear it but perhaps if there is a "fix" I would be open to that option. I also agree that with Roon having no real customer service but referring customers to an ongoing forum, I would be concerned about fixing a problem that ain't broke.

 

[Roasty]

I had to assume it was the Roon bug. I'm listening with the filters now, and I definitely prefer it without the filters/peq.

unless my ears are so broken.. I can't figure out why everyone else is having such a good time with the filters. I've done everything as instructed, and I have used convolution filters before.

 

[jlbrach]

I am listening to both the filters and without and I hear no issue but what do I know?...this is nothing new by the way I have noticed the differences on my roon with different bit rates for the months I have owned the filters and I assume it has been the same for everyone else so somehow all of a sudden this raved about product has been faulty?...hmmm....I dont doubt there is some issue with different bit rates but as mitch tells me it is something likely not able to be heard....ah well, everything is complicated lol

 

[Roasty]

I don't doubt what you guys are hearing. I truly wish I was getting the same results.

perhaps it is down to preference, but it seems pretty lean throughout, the highs are pretty sharp, and I really can't say I hear fuller, more impactful bass with the filters when I honestly can't..

I have his filters for the Abyss TC and I don't use my TC without them. those filters correct many issues I have with the stock TC sound.

I'll see if I can get a second set of ears to have a listen to the Raal over the weekend.

 

[jlbrach]

the same issues are present with different bit rates on the abyss as well as the sr1a....I have both..with the filters I hear enhanced bass and more body and heft with the sr1a...interesting because as I said the same issue would be with the abyss as with the sr1a so perhaps you just dont care for the sr1a with the filters

 

[Litlgi74]

I don't doubt what you guys are hearing. I truly wish I was getting the same results.

perhaps it is down to preference, but it seems pretty lean throughout, the highs are pretty sharp, and I really can't say I hear fuller, more impactful bass with the filters when I honestly can't..

I have his filters for the Abyss TC and I don't use my TC without them. those filters correct many issues I have with the stock TC sound.

I'll see if I can get a second set of ears to have a listen to the Raal over the weekend.

Maybe your allergies are messing with your hearing? I've been struggling for the past few weeks.

 

[Roasty]

the same issues are present with different bit rates on the abyss as well as the sr1a....I have both

you're right. I just tried it with the abyss too.

Maybe your allergies are messing with your hearing? I've been struggling for the past few weeks.

Lol!

I suppose it's down to preference then. perhaps I should have gone with the free trial with the hang loose convolver before plonking down the cash.

If I have time this weekend, I'll swap back to the stock vm1a tubes and try it all over again. Will give it a go with the ti1b box as well.

 

[jlbrach]

for what it is worth I am listening with the VM-1a