Ultra is (digital) preamp for active 4 way dipoles

Valentino

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Hamar, Norway
In 2009 ha friend helped me costruct and have manifactured a 3-way dynamic dipole system with closed box subwoofers operating below 45 Hz. The dipoles themselves operate below the dipole peak up to appx 6 kHz where the tweeter becomes too large and beaming starts. We have to thank Rudolf Finke for his work on this way of thinking dipoles: A small baffle or maybe no baffle at all, trying to make the radiation pattern as close to a theoretic dipole as possible.
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Left main speaker in the nude. Two Beyma 12" in a small H frame, two nude SEAS W15CH and one nude Mundorf AMT2340. The pic is from before I replaced my Yamaha WXC-50 and Squeezebox Touch with the Ultra.
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Old pic from the rear wall. As you may understand I do not use the Ultra HDMI. Listening position pretty close about 1,5 m from the speakers. 10 cm acoustic tile above the listening triangle. Large distance to side walls, 1 m from speakers to front wall.
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I use a Topping L30 headphone amp instead of the onboard one. I also use a Cambridge Audio Alva Duo instead of the onboard Phono amp.
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My turntable is a modified but you cannot see that German treasure from 1973 with a new Bokrand tonearm (my father bought the record in 1963 or so).
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Details above. I've always used class D amplification and DSP crossovers/eq. To use something else you'd have to be dipole hero Siegfried Linkwitz. Until MiniDSP came along with their Flex Eight I had a PC running the filters under Console and a RME Fireface UD sound card. That PC is now running LMS for the setup. Peak volume in the listening position is a Mahlerian 108 dB(A).
 
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This is the system acoustic impulse response measured in the listening position. Linear scale, 10% is -20 dB. Such a behavior is impossible without DSP.
Please note that the WiiM DSP is not involved here, only the ones in the MiniDSP Flex Eight.
 
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Speaker system frequency response.
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Left speaker waterfall. Right speaker is quite similar.
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Bartok in the winter sun. A system upgrade now would have to be the new and modestly priced MiniDSP PocketADC between the phono amp and Ultra, and move the CD player to Line In. The Ultra analog input specs could have been better, but the CD player is only used for checking out if the music on a CD is worth ripping anyway. And look good of course. I love the Yamaha facias.
 
I took the full plunge and swapped my Cambridge Audio Alva Duo phono preamp for a MiniDSP ADept phono preamp/ADC.
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The ADept now handles all system analog inputs and feeds them to the Ultra on optical 24/96 (even if the Ultra display says 16/96. Known issue. I wish WiiM could revert to 24 bit since that’s what optical is anyway).
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The rest is just the same: Ultra feeds the speaker system on optical out and the headphone amp on analog out. Trigger out turns on the six main speaker amplifier channels. Some minor phono cartridge and major headphones EQ in is performed in the Ultra. The speaker system EQ/RC is all in the MiniDSP Flex Eight.
 
This is hardcore. I just had to make proper use of the differential (XLR) input on the MiniDSP ADept, so I got myself another analog source:
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The revised block diagram:
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I actually think they sound the same, at least on MC. I haven’t tried MM yet, but there it’s possible to trim the frequency response.
The big difference is functionality.
 
The place is nice "" open""
and the speaker's choice is original...
;-)
(with the help of dsp in strong low pass, have you observed pur sub in ripole? ;-) )
(The two minidsp ADCs were designed primarily to add analog inputs to their products.)
(It's funny that no more reactions ...probably until a few days after an "ASR" review...funny... **
but even minidsp seems to be barely invested in their promotion...surprising. minidsp is doing well?)


(**
even if for the phono part of the adept, it will be necessary to start again on new measurement bases in mm and ap555, which have proven to be faulty in certain cases due to its low input impedance and a need to be, quite classically, on a suitable fictitious load.. error of armim since many year...
"should make you think about the substance")
 
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Yes, it is a pity that Amir started his phono stage measurements without the proper knowledge of typical source impedances and phono equipment in general, and also that ASR has no listing of MC phono stages. That said the community effort is great on cartridges.

I’ve only read about ripoles. I’d love a DBA, but that’s not possible in this room.
 
Yes, it is a pity that Amir started his phono stage measurements without the proper knowledge of typical source impedances and phono equipment in general, and also that ASR has no listing of MC phono stages. That said the community effort is great on cartridges.

I’ve only read about ripoles. I’d love a DBA, but that’s not possible in this room.
If it's not necessarily to increase the frequency (40/50?) and if a means of abrupt cut-off thanks to active/dsp etc. the ripoles seem interesting to test if there is a need for "cleanliness", more audio than hc
;-)
(no personal experiences to give on them (me more basically clos/peq). just your efforts reminded me of this topic ripole , hframe ( more efficient) etc , contacts who used them with ESL etc. ;-) )
 
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I darkly remember a quote in the Holy Bible...something like "the adepts drinking from his lips" or something like that. 😉
 
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