[AdvoCat]

I'm experiencing oddness with my system and wonder if any of you can diagnose. 

My system: MusicVault (PC-based server) > Aqua La Scala DAC >USB>Epifania Preamp (rectifier, 2 AX7s and OA regulator tubes)>Rogue Zeus (12 x KT88, 4 x 12AU7, 2 x 12AX7 tube complement)>Maggie 3.7s and powered JL Audio 212v2 sub (direct output from the preamp)

It appears (sounds) that I have lost most of the midrange or at least tracks of songs when streaming from TIDAL.  For example, in Lovin' Spoonful's "Darling be Home Soon" (remember that one?) the vocals have disappeared almost completely and it's now a karaoke track.  Another is example is a complete loss of the trumpet during the bridge of Modest Mouse's "Spitting Venom." I have several other examples of Miles Davis tracks where the sax sounds as if its down the hall, while the piano track is normal. Perhaps this mix on the Davis tracks is similar to how the Lovin' Spoonful tracks are mixed; hence the same problem?

This was a sudden change.  The system went from sounding its best ever to almost unlistenable.    This is particular to this system as my other one (Laptop>Metrum Octive MKII DAC>ASL Orchid integrated>Omega Super 8s) sound just fine.

I recently had the capacitors in the preamp replaced with V-caps.  Things sounded great until this problem arose.  Could any one of the new caps have failed and caused this?

The reason I’m posting to this board is that I'm guessing this is an issue downstream of the MusicVault and DAC. I  wonder whether the Maggies aren’t getting power they need to drive the midrange panels.  Do I have an issue with the fuses, either in the Rogue or the Maggies themselves?  All tubes in the system seem to be fine, however, although I haven’t opened the Aqua DAC to check that tube. But if it were the DAC tube or any preamp tube, wouldn't I be unable to hear anything at all?  Or why would I be able to hear the (presumably mono) broadcasts from YouTube video (I don't have a loss of commentary, etc,).

I initially wondered whether the MusicVault and the DAC are communicating, but it doesn’t seem like a 0s and 1s issue if I'm able to hear the mono broadcasts and some of the tracks. 

Have any of you ever had a similar problem where you've lost midrange from your Maggies?  If so, what did you do to fixt it? If not, do you recommend a particular order of testing or trial/error method to diagnose this issue?

I have nice equipment, better than I probably deserve, but I am poorly versed in diagnoses or repair and need some help, which isn't readily available in my area.

Thanks in advance for your guidance and suggestions.

[JakeJ]

Sorry to hear about this AdvoCat!  I just took possession of a pair of 3.6R's Saturday and just got them up and running yesterday.

Do you have an SPL meter?  If so you could confirm the lowered output?  Is it both speakers or just one?  Did you try using the Omegas in the problem system to isolate if it is the Maggies or the preamp?  Really need to isolate the issue first.

Just some ideas.  Keep us posted as to your progress.

Best,
JakeJ

[richter250]

First thing to do is change the fuses in your Maggies.  It can be very hard to tell if one of them is blown.  There are fuses on the back for the tweeters and the midrange.

[AdvoCat]

Much to my great relief, and almost as much embarrassment, the issue was  1's and 0's after all.  Got some tech help and we determined that TIDAL was not cooperating with the music server but running through Windows instead (which it wasn't supposed to do).  Based on my best guess, not all of those 1's and 0's were making it to the DAC  in the first instance, hence dropping a range of mid-range bits, I suppose.  I'll check out the diskless circle board for grins.

In any event, playing through JRiver and the system is now its usual glorious self!  I'll deal with TIDAL another time.  Probably by playing it through Roon, once I have that set up.

This experience does raise the question of what preventive maintenance, if any, is suggested for the Maggies?  Do any of you have a routine or calendar for changing fuses or doing other check ups?

Thanks!

[JakeJ]

Glad to hear you solved your problem.  We all like simple fixes, how did you come to the conclusion that it was the digital side causing the issue?

[SteveFord]

Doing check ups?
No.  Every once in a while I'll kick a speaker wire loose with my clodhoppers and will have to reattach it but other than that, nothing.

[AdvoCat]

Glad to hear you solved your problem.  We all like simple fixes, how did you come to the conclusion that it was the digital side causing the issue?

Narrowing the hardware issues.  Checking tubes, ICs, cables, running other source materials through the system.  Maggies and sub worked just fine (albeit with YouTube mp3/mono playback through the DAC) so it couldn't be that the panels weren't functioning. And it couldn't be that the DAC wasn't working. So it had to be something TIDAL-related.  To test, I downloaded JRiver and played stored files through it and they sounded great. So it had to be a TIDAL playback issue.   Sure enough, we determined that the TIDAL desktop app was being controlled by solely by Windows rather than through the server or DAC. 

I'm guessing that Windows wasn't getting all the bits to the DAC.  But it was hard to wrap my brain around hearing familiar tunes without a vocal track and/or almost completely devoid of any midrange.  Why would that happen?  That's why I feared it was a panel issue with the Maggies. Tonight I installed a trial version of Roon and ran TIDAL through it, without loss of data--all sounds normal.  Lesson: TIDAL desktop is controlled by Windows, not by the server, at least how mine's configured.  I'm sure that with more guidance I can properly configure TIDAL set up without the need to use Roon, but I have two weeks to figure it out.

[Letitroll98]

Sounds like you were somehow running in theater mode thus losing the center channel info, vocals and other mid-range queues.

[JakeJ]

Congrats AdvoCat, good job sleuthing out the real culprit.  I haven't delved into the settings and controls in Tidal myself but I probably should familiarize myself with them.

Interesting theory, Letitroll98.  So there's a theater mode setting?  Or would that be a Windows control?

[Elizabeth]

For other upgrades, a lot of folks bypass the midrange fuses. THis depends on 'how loud' you like to play, to decide if it is safe to do... (Bypassing the midrange fuse also eliminates several poor quality connectors in the fuse area)
I waited for a few years before doing my 3.6 Maggies. and a year on the new 20.7 that replaced the 3.6
Another interesting fact is the midrange resistors are not to 'lessen the output'. Rather then change the TONE of the midrange. Lower resistance or just a wire, brighter tone, more resistance deeper tone.
With much experimenting I settled on 1.3 ohms using three 3.9 ohm resistors in parallel. One Duelund CAST and two Path Audio. (all 3.9 ohm)

[rollo]

The new caps are they Teflon caps ? If so they will take a serious amount of time to fully break in. Nice DAC.


charles

[AdvoCat]

The new caps are they Teflon caps ? If so they will take a serious amount of time to fully break in. Nice DAC.


charles

Charles,

The new capacitors are the V-Cap CuTF 1.0uF.   I have about 100 hours on them.  Now that everything is working properly, I'm quite pleased with the sound of the system, but curious as to how it will sound after they break in fully.  The Aqua LaScala is the non-optological DAC (purchased 2nd hand, like almost everything else), but I don't necessarily feel a need to upgrade.

Unlike Elizabeth, I'm not equipped to trade out the internals of the Maggies, perhaps other than fuses.  I'll check this forum for threads on fuses, but I am curious as to whether or how they change what I hear.

[Craig B]

I was about to post that it sounded more to me like a L-R channel issue until I saw it was resolved. I'm glad it got worked out.

I say it sounded like a left-minus-right channel issue because the specific symptom you described reminded me of the channel selection feature I had many years ago on my old Apt Holman preamp, a feature I've never seen on any other unit. Rather than the traditional "Mode" switch or button (for stereo/mono selection), it had a knob. The center detent was standard stereo, and turning it one way or the other gradually either summed the channels (labeled on the face plate as "L+R") for full mono at one extreme, or in the other direction it gradually subtracted the content that was common to both channels (labeled "L-R"), until, turned as far as it would go, you would delete all of those sounds. That made it extremely effective in removing lead vocals (your comment about Karaoke brought this to mind), though sometimes at the expense of the bass and some drums, which tend to be mixed in the center. But it was fabulous at isolating background vocals if the singers were recorded in either the left or right channels only. It helped me decipher the lyrics of the countermelody in Jackson Browne's "From Silver Lake" among others. I kind of miss that feature (I miss the preamp, too). It was a lot of fun to play with. You can see it in the photo.