AudioCircle
Industry Circles => GR Research => Topic started by: maty on 5 Jan 2020, 09:23 am
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Well, $ 895 to both loudspeakers. Different options to the amplification. Like an active monitor, with one or two amps, same or different technology.
Measurements: https://www.audiocircle.com/index.php?topic=167137.msg1774346#msg1774346
(http://gr-research.com/measurements/SM%20crossover%20response.jpg)
(http://gr-research.com/measurements/SM%20impedance.jpg)
It would be interesting to know the phase graph, which Danny never publishes. In this case, being 2-ways, minimum impedance of 8 Ohms and sensitivity of 88 dB is certainly not problematic, but it would be nice to know it.
Power requeriments to obtain certain SPL:
https://www.audiocircle.com/index.php?topic=167137.msg1774352#msg1774352
https://www.doctorproaudio.com/content.php?2273-calculators-proaudio-sound-dmx&langid=1#calc_spl
To 80 dBSPL average + DR15 = 95 dBSPL max
88 dB/W/m, 8 Ohms, random phase, 3 m -> 23 watts at 8 Ohms to have 95 dBSPL max
(http://maty.galeon.com/WP-imagenes/hum/GR-Research-Studio-monitor-SPL-88dB-8ohm-23watts-3m.png)
* 2 m -> 10 watts at 8 Ohms
* 3 m -> 23 watts at 8 Ohms
* 4 m -> 40 watts at 8 Ohms
If you listen to modern commercial recordings, then DR will be < or << 10 dB.
80 dBSPL + 10 dB = 90 dBSPL max
* 2 m -> 4 watts at 8 Ohms
* 3 m -> 7 watts at 8 Ohms
* 4 m -> 13 watts at 8 Ohms
******* ********
Very important.
* SS: watts at THD+N 0.1%
* Tubes: watts at THD+N 1%
Updated the title: GR Research Studio Monitor -> GR-Research NX-Studio
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Yesterday Archimago published:
An Inexpensive Hi-Fi Class-D Stereo Amp for the 2020's: Hypex nCore NC252MP (DIY Assembly)
http://archimago.blogspot.com/2020/01/an-inexpensive-hi-fi-class-d-stereo-amp.html (http://archimago.blogspot.com/2020/01/an-inexpensive-hi-fi-class-d-stereo-amp.html)
The amplifier module was announced back in 2016 and I believe became available in quantity starting in 2017. This single module contains everything in one place for a 2-channel dual-mono amplifier (rated 250W into 4Ω, 180W into 8Ω, at 1% THD, 1kHz signal) including input buffer and power supply. All you need to add is an enclosure with the proper input and output connectors, power switch, and power LED for basic functioning. Already, this component is at the heart of devices like the IOM NCore Pro (https://internetofmusic.nl/product/iom-ncore-pro/) (€550), the Nord One MP NC252 (https://www.nordacoustics.co.uk/product-page/nord-one-mp-nc250-stereo-power-amp) (£579), March Audio P252 (https://www.marchaudio.net.au/product-page/p252-stereo-250-watt-power-amplifier) (US$895), and Rouge Audio Studio N-4B (https://www.rougeaudiodesign.com/product-page/studio-n-4b-1?lang=en) (€655.00).
The best deal I've seen is for the Audiophonics MPA-S252NC (https://www.audiophonics.fr/en/power-amplifier/audiophonics-mpa-s252nc-xlr-class-d-stereo-amplifier-ncore-2x150w-8-ohm-p-14185.html) (€440); not sure how much more it would cost to ship to Canada though if I were to buy it from France and had to pay for border duties...
[Update] Apollon NCMP400 (https://www.apollonaudio.com/apollon-ncmp400-hypex-based-class-d-amplifier/) also uses Hypex NC252MP. In a big case, with low mass binding posts: WBT-0703 Cu (https://www.wbt.de/english/products/a/Detailansicht/Artikel/nextgenTM-pole-terminal-3.html)
[Big IMG] https://www.apollonaudio.com/wp-content/uploads/2019/06/ncmp400-inside-components.jpg
Resized and optimized
(http://maty.galeon.com/WP-imagenes/hum/Hypex-NC252MP-by-Archimago-inside-2.jpg) (http://maty.galeon.com/WP-imagenes/hum/Hypex-NC252MP-by-Archimago-inside-2.jpg)
Cheap class-D amplifier to the woofer and subwoofers. With tweeter I do not think it is a very good idea if you listen to very good recordings with high / very high DR with acoustic and / or electrified instruments like me. Surely we are very few and to whom we listen to such recordings.
Updated
MEASUREMENTS: Hypex nCore NC252MP Amplifier (+ Subjective opinions around objective testing, and CES2020)
http://archimago.blogspot.com/2020/01/measurements-hypex-ncore-nc252mp.html
A lot of graphs!
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Like active speakers: https://www.hypex.nl/product/fusionamp-fa252/156 (https://www.hypex.nl/product/fusionamp-fa252/156)
(https://www.hypex.nl/img/producten/2_fusionamp-fa252.jpg)
I think with only linear phase filters and not minimum phase filters (my choice without any doubt).
Hypex Filter Design, free soft
https://www.hypex.nl/product/hypex-filter-design/17
From the PDF:
Hypex Filter Design (HFD)
HFD is a free software tool needed to configure the FusionAmp. To protect your valuable drivers, the DSP
does not contain a filter out of the box. A filter needs to be configured and uploaded before the FusionAmp will produce an output signal.
HFD can be used to measure the frequency response of the speaker and this information can be used to
design your filter. 15 biquad filters are available per amplifier channel.
DSP Filters:
15 biquads per channel. A one-way Fusion Amp has 15 biquads, a two-way has 2x15 biquads and a three-way has 3x15 biquads. Amplifiers configured in BTL still have 15 biquads available.
Q: What is a “Biquad”?
A: A biquad is a filter section with 2 poles and 2 zeros. All of the biquads are in series so all kinds of filters can be made.
Q: What about the phase of the filters?
A: The biquad filters are all minimum phase, which means that phase is directly linked to magnitude response in exactly the same way as an analogue filter.
Since individual speaker drivers are minimum phase too, EQ'ing them flat also equalises the phase response.
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For the type of recordings I listen to, I do not want to know anything about OLD class D and high frequencies, that is, amplifying the tweeter.
Maybe the new PURIFI 1ET400A (https://purifi-audio.com/eigentakt/) modules with a better input board.
https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-purifi-1et400a-amplifier.7984/
(https://www.audiosciencereview.com/forum/index.php?attachments/purifi-1et400a-class-d-amplifier-module-teardown-optimized-jpg.28904/) (https://www.audiosciencereview.com/forum/index.php?attachments/purifi-1et400a-class-d-amplifier-module-teardown-optimized-jpg.28904/)
With the new Universal Buffer (https://neurochrome.com/products/universal-buffer) from Neurochrome (Tom Christiansen).
https://www.diyaudio.com/forums/class-d/339838-purifi-1et400a-measurements-post6018772.html
https://www.diyaudio.com/forums/vendor-s-bazaar/346956-universal-buffer-achieving-140-dbc-0-00001-thd.html
It is better to let some time pass I think. Let others experience and verify if the sound is as good as its specifications with high quality recordings with acoustic and / or electrified instrumentation and voices without processing with Autotune (vade retro satana).
Will continue with class A and class AB too.
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Class AB. Chipamp. LM3886.
An amplifier that I have been following for quite some time is Akitika (Dan Joffe). But having only one LM3886 per channel is more appropriate for real and higher 8 Ohms loudspeakers and not for my little coaxials with a minimum impedance of 3.9 Ohms and nominal should be 5 Ohms and not the 8 Ohms that KEF says.
Today it would be my choice if I lived in NA. I would make some modifications to the case (front) and back connectors. With RF /EMI filter, inlet (Schaffner) or inside (ATL audio) of course!
Akitika GT-102
https://www.akitika.com/GT102.html
https://www.diyaudio.com/forums/solid-state/345345-akitika-kits-post5977645.html
https://cheaptubeaudio.blogspot.com/2019/02/akitika-gt-102-power-amplifier.html
https://cheaptubeaudio.blogspot.com/2019/10/micromega-mygroov-mydac-meridian-200.html
https://www.audioshark.org/amplifiers-8/akitika-gt-102-power-amplifier-kit-assembled-16578.html
https://www.stereophile.com/content/akitika-gt-102-power-amplifier
-> https://www.stereophile.com/content/akitika-gt-102-power-amplifier-measurements
(https://www.audiosciencereview.com/forum/index.php?attachments/akitika-gt102-assembled-inside-jpg.29336/) (https://www.audiosciencereview.com/forum/index.php?attachments/akitika-gt102-assembled-inside-jpg.29336/)
(https://www.audiosciencereview.com/forum/index.php?attachments/akitika-gt-102-inside-diagonal-steel-separator-jpg.29411/) (https://www.audiosciencereview.com/forum/index.php?attachments/akitika-gt-102-inside-diagonal-steel-separator-jpg.29411/)
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Neurochrome Modules-x86
https://neurochrome.com/collections/power-amplifiers
Very good specs but much more expensive than Akitika. Modulus-286, with two LM3886 by channel it would not have problems with more complicated loudspeakers than those designed by Danny Richie. But more money!
https://neurochrome.com/collections/power-amplifiers/products/modulus-286
https://www.diyaudio.com/forums/chip-amps/309848-mod-286-build-thread.html
https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-neurochrome-modulus-286-amp.6443/
Poseidonsvoice built one and is very satisfied with its sound. He could share some photos.
Here, pictures: https://www.diyaudio.com/forums/chip-amps/309848-mod-286-build-thread-post5496246.html
(https://i1067.photobucket.com/albums/u422/nycavsr2000/Modulus%20286_2/IMG_5525_zps2mtpzrak.jpg) (https://i1067.photobucket.com/albums/u422/nycavsr2000/Modulus%20286_2/IMG_5525_zps2mtpzrak.jpg)
(https://i1067.photobucket.com/albums/u422/nycavsr2000/Modulus%20286_2/IMG_5529_zps7b0kk2cv.jpg)
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Apollon NCMP400 (https://www.apollonaudio.com/apollon-ncmp400-hypex-based-class-d-amplifier/) also uses Hypex NC252MP. In a big case, with low mass binding posts: WBT-0703 Cu (https://www.wbt.de/english/products/a/Detailansicht/Artikel/nextgenTM-pole-terminal-3.html)
[PDF] https://www.wbt.de/fileadmin/content/products/polklemmen/datenblatt/WBT-0703_Cu__E.pdf
[Big IMG] https://www.apollonaudio.com/wp-content/uploads/2019/06/ncmp400-inside-components.jpg
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Today the measurements, a lot of graphs!
MEASUREMENTS: Hypex nCore NC252MP Amplifier (+ Subjective opinions around objective testing, and CES2020)
http://archimago.blogspot.com/2020/01/measurements-hypex-ncore-nc252mp.html
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To finish with modern class D amps designed by Bruno Putzeys, maybe the new Purifi1 ET400A modules. The key, will be a good input board + buffer / gain with very good clean power.
https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6045723.html
by mocenigo
...While I cannot do a direct comparison, the little Purifi amp with the stock buffer NOT yet bypassed sounds so much better than the NC500 mono blocks (with hypex smps and a buffer with Sonic Imagery opamps) that I find it quite likely that it is not due to the amplification board alone.
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Yeah, have heard the Purifi numerous times in my system now.
Exellent amp with new Mivera gain stage implemented into an all in one
jay
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Here's my amplification idea (haha, I just got this as a new toy so had to post it somewhere):
(https://www.audiocircle.com/image.php?id=203345)
(https://www.audiocircle.com/image.php?id=203346)
EL84 push-pull, 17 watts. $750.
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nice where did you find that? a kit?
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Here's my amplification idea (haha, I just got this as a new toy so had to post it somewhere):
(https://www.audiocircle.com/image.php?id=203345)
(https://www.audiocircle.com/image.php?id=203346)
Sexy AF
EL84 push-pull, 17 watts. $750.
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nice where did you find that? a kit?
It's a prototype build from VTA (tubes4hifi.com), sort of a modern update of the Scott 222C, I believe. Even fresh out of the box it sounds great. Similar levels of clarity and immediacy as my Type 45 SET amp but with more power and punch.
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I built a pair of EL84 monoblocks but I want to rebuild them into a stereo amp. Essentially, a modified Dynaco ST35.
(https://live.staticflickr.com/4772/39014867020_ac7c3dcefe_z.jpg) (https://flic.kr/p/22rBoH3)
EL84 Monoblocks (https://flic.kr/p/22rBoH3) (https://www.flickr.com/photos/79446895@N00/)
I built a stereo version for my brother. I came up with layout and hoped it would work. It had zero noise when I turned it on.
(https://live.staticflickr.com/873/39580573880_ddce0576ed_z.jpg) (https://flic.kr/p/23iAMDA)ST35 v3 (https://flic.kr/p/23iAMDA) (https://www.flickr.com/photos/79446895@N00/)
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Off topic
Amps, like loudspeakers, there are a lot of. I focus on those of which we have measurements, especially if they are independent.
Measurements -> necessary condition but not sufficient to ensure quality sound. Let us say I understand it as a way to minimize the error risk in the purchase.
Unless the seller allows a 30-day trial period, like AVA and others. And live in that same region of the world (my problem: shipping + taxes to Europe).
- End off topic -
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Off topic
Amps, like loudspeakers, there are a lot of. I focus on those of which we have measurements, especially if they are independent.
Measurements -> necessary condition but not sufficient to ensure quality sound. Let us say I understand it as a way to minimize the error risk in the purchase.
Unless the seller allows a 30-day trial period, like AVA and others. And live in that same region of the world (my problem: shipping + taxes to Europe).
- End off topic -
True, but it's easier to end up with a bad sounding SS amp than it is a tube amp. Especially at the lower end of the price spectrum.
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Yeah, have heard the Purifi numerous times in my system now.
Exellent amp with new Mivera gain stage implemented into an all in one
jay
The key is the input board and very clean power. Purifibuffer:
https://www.diyaudio.com/forums/class-d/339838-purifi-1et400a-measurements-post6016119.html
They also have 6 ultra low noise power supplies built in to power all the various sections of the Purifi modules to perfection. Everyone else uses the dirty power from the Hypex supply, and shares the power regulation between multiple sections Yuck!
BTW, Mivera thread is closed now. Then it was freely available, hence I shared the image and the comment on diyaudio.com
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LJM L12-2
Re: I need a $300-$400 amp (new or used) to go with JBL Studio 530 Speakers.
https://www.audiocircle.com/index.php?topic=166640.msg1771784#msg1771784
-> https://www.audiosciencereview.com/forum/index.php?threads/chinese-jl-hood-1969-class-a-amplifier-off-aliexpress.3372/post-269888
-> https://www.audiosciencereview.com/forum/index.php?threads/chinese-jl-hood-1969-class-a-amplifier-off-aliexpress.3372/post-269889
(https://www.audiosciencereview.com/forum/index.php?attachments/ljm-l12-2-finished-l23-9-jpg.39355/)
(https://www.audiosciencereview.com/forum/index.php?attachments/ljm-l12-2-ver3-board-jpg.39360/) (https://www.audiosciencereview.com/forum/index.php?attachments/ljm-l12-2-ver3-board-jpg.39360)
(https://www.audiosciencereview.com/forum/index.php?attachments/ljm-l12-2-02-thd-01khz-jpg.39362/) (https://www.audiosciencereview.com/forum/index.php?attachments/ljm-l12-2-02-thd-01khz-jpg.39362/)
https://calvins-audio-page.jimdo.com/ideas-and-circuits/power-amplifiers/
https://sites.google.com/site/stevesstuffproject/l12-2-power-amplifier
***** https://calvins-audio-page.jimdo.com/ideas-and-circuits/power-amplifiers/ *****
https://sites.google.com/site/stevesstuffproject/l12-2-power-amplifier
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How about Dodd 120s?
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How about Dodd 120s?
Perfect match since Danny uses Dodd stuff to voice his speakers.
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Are you getting the "THX Reference Level" in the listening position? Do we really need such an output level in our home-theater rooms? by trl
https://www.audiosciencereview.com/forum/index.php?threads/are-you-getting-the-thx-reference-level-in-the-listening-position-do-we-really-need-such-an-output-level-in-our-home-theater-rooms.11105/
Audio files to do the measurements are -20dB and were grabbed from https://www.atsc.org/refs/a85/ (also attached here) and I had them "checked" with foobar and its Peak-meter visualization and these are indeed -20dB files. To protect our hearing, the audio files used for such test are usually -20dB instead of 0dB, so we will need to measure a listening level of 85dB SPL, which is much safe for our hearing than 105dB SPL...
https://www.audiosciencereview.com/forum/index.php?threads/are-you-getting-the-thx-reference-level-in-the-listening-position-do-we-really-need-such-an-output-level-in-our-home-theater-rooms.11105/post-314030
I'm fine with peaks getting somewhere close to 95-100dB SPL. On music this means an average SPL of 75-80dB, while on movies this might be 5dB lower due to the different movies dynamics, so 70-75dB SPL.
The THX standard is only referring to peaks, so your recommended 78dB SPL seems too low for me for a living room, where the background noise is probably up to 30dB SPL.
With music, I always made the calcs with 80 dBSL + 15 dB = 95 dBSPL to estimate the power required with the speakers selected at 3 meters.
Films, peak: 20 dB.
(http://maty.galeon.com/WP-imagenes/hum/GR-Research-Studio-monitor-SPL-88dB-8ohm-23watts-3m.png)
Remember: in a room, with so many reflections, less power is required than in the open field to obtain the same SPL.
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What do you guys think about PS Audio M700 monoblocks for those studio monitors? They are class d and I believe they use a 700asc module.
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I know you don't need the extra power but, the IP AS1200 is a much better souinding amp as opposed to the 700's.
Look for a used one if you can find it
jay
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What do you guys think about PS Audio M700 monoblocks for those studio monitors? They are class d and I believe they use a 700asc module.
Bad idea. The IcePower 700 has not harmonics, OK. With the PS buffer -> dominant H3 !!!
https://www.stereophile.com/content/ps-audio-stellar-m700-monoblock-power-amplifier-measurements
And bad HF intermodulation spectrum, the last graph. And too much hoise at HF (tweeter). The guilty of the problems is the PS buffer.
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BTW, Billie Eilish,
http://dr.loudness-war.info/album/list/year?artist=Billie+Eilish
(https://www.audiosciencereview.com/forum/index.php?attachments/dr-loudness-war-billie-eillish-png.47842/) (https://www.audiosciencereview.com/forum/index.php?attachments/dr-loudness-war-billie-eillish-png.47842/)
Only the live recordings have good DR. The others, studio, only we need with a cheap audio system and few watts to obtain the SPL at the room.
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IFI Retro 50 is another great sounding EL84 amp. It also has the added bonus of a good DAC and Phonostage built in.
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Look for a used Mivera or Nord amp that uses the IP1200AS module, far better soiunding than the 700's.
jay
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Yesterday Archimago published:
An Inexpensive Hi-Fi Class-D Stereo Amp for the 2020's: Hypex nCore NC252MP (DIY Assembly)
http://archimago.blogspot.com/2020/01/an-inexpensive-hi-fi-class-d-stereo-amp.html (http://archimago.blogspot.com/2020/01/an-inexpensive-hi-fi-class-d-stereo-amp.html)
...
Updated
MEASUREMENTS: Hypex nCore NC252MP Amplifier (+ Subjective opinions around objective testing, and CES2020)
http://archimago.blogspot.com/2020/01/measurements-hypex-ncore-nc252mp.html
A lot of graphs!
Here is ASR's measurement of the March Audio Hypex NC502MP OEM module (238 watts @8, 454 watts @4, both channels driven). I have this amp, and it runs great on my Revel m126be - transparent, clean, no coloration. I plan to use this with the Studio Monitors and see how it goes.
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ooops, here's the LINK https://www.audiosciencereview.com/forum/index.php?threads/march-audio-p502-stereo-amplifier-measurements.10909/
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Audiophonics HPA-S400ET Amplifier Class D Stereo Purifi 2x400W 4 Ohm *** 1,490.00 € tax incl. - 1,241.67 € tax excl. ***
https://www.audiophonics.fr/en/powe...ass-d-stereo-purifi-2x400w-4-ohm-p-14393.html (https://www.audiophonics.fr/en/power-amplifier/audiophonics-hpa-s400et-amplifier-class-d-stereo-purifi-2x400w-4-ohm-p-14393.html)
Rotated, clarified and optimized
(https://www.audiosciencereview.com/forum/index.php?attachments/audiophonics-hpa-s400et-amplifier-class-d-stereo-purifi-2x400w-4-ohm-jpg.49869/)
Audiophonics Interface Card
[ Both modules are driven in opposite phase, to cancel out the «Power-Supply Pumping» effect. This allows greater stability in the power supply by alternately distributing current draws on each rail, thus increasing its overall capacities.
We opted for a regulation with two voltage levels in order to optimize the power supply to the PDOs and the auxiliary voltage supplied to the modules. This allows the OPAs to be powered with a high voltage (18V) for better overall performance, and allows them in turn to provide the voltage needed to reach the amplifier's maximum output level. While still maintaining the auxiliary voltage required by the modules.
Each channel uses its own Analog Devices OP275 AOP. They are based on a hybrid Bipolar / JFET technology. Bringing precision and musicality. They are mounted on a socket allowing their possible replacement.
To suit all uses we opted for 3 gain settings adjustable by jumper on the interface card:
* Gain of + 9.5dB, for a total of 22.3dB (default) Maximum power reached with a signal of ~ 3.2V RMS
* Gain of + 15.5dB, for a total of 28.3dB Maximum power reached with a signal of ~ 1.6V RMS
* Bypass: in this case the signal passes directly from the inputs to the modules, allowing the lowest possible gain of 12.8dB. This mode can be interesting when using a powerful preamplifier, capable of driving a load of 2 to 4kOhm and reaching a voltage of ~ 10V RMS ]
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Mocenigo has finished the DIY PURIFI 1ET400A with Universal buffer (Neurochrome) and other components.
https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6085262.html
(https://www.audiocircle.com/image.php?id=204628&size=huge)
A lot of pictures: https://ibb.co/album/nyCoaa
He has had a dual mono Hypex NC500 with Sonic Imagery 994 discrete opamp. Apollon NC800, Input Buffer Rev B (https://i.ibb.co/M6ZWf5K/IMG-0452.jpg) x2.
A lot of images: https://ibb.co/album/gu8Bdv?sort=date_asc
Versus new DIY PURIFI 1ET400A:
https://www.diyaudio.com/forums/vendor-s-bazaar/281361-hypex-ncore-nc500-build-post6085383.html
I may stand corrected. The NC500 is in my opinion a stunning amplifier, but in comparison to the 1ET400A it has one big advantage (more power) and one disadvantage which is difficult too evaluate (the eigentakt treble is much smoother, and the bass is a bit better controlled). Two fine amps, but on sound quality the eigentakt is better, or with some abuse of words, the NC500 has some treble flaws.
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I have nothing to power the monitors. Majority of the replies go beyond my head. Do any of you think Schiit products are reasonable audio component wise? I am thinking of building a stack to power the monitors. Or i could go with a Sonos amp.... (not first choice) second choice would be NAD M10 or M33. I am going from a $600 price point to $5000. I clearly need some guidance.
I want to connect my TV to my dac/amp for 2.1 or 2.2 (with NAD) for occasional movies but mostly use it for music.
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I have nothing to power the monitors. Majority of the replies go beyond my head. Do any of you think Schiit products are reasonable audio component wise? I am thinking of building a stack to power the monitors. Or i could go with a Sonos amp.... (not first choice) second choice would be NAD M10 or M33. I am going from a $600 price point to $5000. I clearly need some guidance.
I want to connect my TV to my dac/amp for 2.1 or 2.2 (with NAD) for occasional movies but mostly use it for music.
For amps, you have some great options nowadays. If you want solid state amps, then I'd recommend Schiit, First Watt and Odyssey Audio (also here on AC). If you want more power and higher efficiency (less heat) from the amp, then the Cherry and/or Maraschino digital amps that DAC (also here on AC) makes would be a good match.
If you want tubes, then the VTA ST70 is a good choice as is their ST35. I like them because they are built in America so you don't have to ship them to China if you need service on them.
For a DAC, for movies I'd recommend Schiit, for music I'd recommend iFi. What is the source of your music? Are you using a computer as a source or something else?
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For amps, you have some great options nowadays. If you want solid state amps, then I'd recommend Schiit, First Watt and Odyssey Audio (also here on AC). If you want more power and higher efficiency (less heat) from the amp, then the Cherry and/or Maraschino digital amps that DAC (also here on AC) makes would be a good match.
If you want tubes, then the VTA ST70 is a good choice as is their ST35. I like them because they are built in America so you don't have to ship them to China if you need service on them.
For a DAC, for movies I'd recommend Schiit, for music I'd recommend iFi. What is the source of your music? Are you using a computer as a source or something else?
Music will be through my PC, watching movies I'm planning on hooking my tv to what ever is recommended directly.
I don't want to have great speakers and poor quality equipment feeding them.
I noticed you did not say anything about NAD have you not had experience with NAD and not able to have an opinion or will i be paying mostly for the brand name markup with inferior parts?
I don't have an opinion on tubes
Thank you for the reply btw
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My advice.
There are almost as many amplifiers as loudspeakers. Better to focus on those of which we have independent measurements.
If not, the seller allows the return within 30 days.
Studio Monitor -> I think is better idea amplifiers with no color or little.
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What type of outputs does your TV have? HDMI only? Or optical or coax? Or analog?
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For amps, you have some great options nowadays. If you want solid state amps, then I'd recommend Schiit, First Watt and Odyssey Audio (also here on AC). If you want more power and higher efficiency (less heat) from the amp, then the Cherry and/or Maraschino digital amps that DAC (also here on AC) makes would be a good match.
If you want tubes, then the VTA ST70 is a good choice as is their ST35. I like them because they are built in America so you don't have to ship them to China if you need service on them.
For a DAC, for movies I'd recommend Schiit, for music I'd recommend iFi. What is the source of your music? Are you using a computer as a source or something else?
Quickly browsing i did like the Stratos Stereo from Odyssey Audio.
I could stick with Schiit Ragnarok Amp since it does have L&R balanced pre outs. I would like to pair the studios with the servo sub kit2 (stereo subs) but those don't seem to have a balanced input, just the servo sub kit 1. (that's what i can make out from the low quality picture) am i correct? or do my eyes deceit me?
For a DAC maybe Cambridge Audio?
(https://www.audiocircle.com/image.php?id=204633)
(CXN V2)
or
(https://www.audiocircle.com/image.php?id=204637)
(Azur 851C)
Any thoughts on the combos? Will it be feasible for the stereo subs?
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Quickly browsing i did like the Stratos Stereo from Odyssey Audio...
http://www.odysseyaudio.com/sales-usa.html
We offer our customers a no questions asked 30 day return policy. Audition our products in your home system for 1 month to make sure you will love it. If for any reason you're not "blown-away" by its performance, send it back for a full refund. You would only have to pay for the cost that occur to us, that of shipping and small credit card reimbursement fees.To further our customer service, there is no usual re-stocking fee at all, but with special options, we might have to charge for the labor for any reversals thereoff. The driving factor for this move is the desire to serve you, the customer, in a much better and more value oriented way. Nobody is more knowledgeable about the odyssey products or committed to them than us...
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Folsom all the way
(https://www.audiocircle.com/image.php?id=200738)
(https://www.audiocircle.com/image.php?id=204639)
(https://www.audiocircle.com/image.php?id=204638)
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I think is better idea to post the link of the last Folsom amplifier.
Folsom EC7293: PVI Powered Frontend Amplifier, 60/120w 8/4ohm, 0.0005% THD
https://www.diyaudio.com/forums/group-buys/338275-folsom-ec7293-pvi-powered-frontend-60-120w-8-4ohm.html
The EC7293 uses 2 chip amps in parallel for high power with a discrete error correction frontend which reduces distortion; and has very low memory distortion. High sensitivity makes it perfect for a variety of sources with 8 ohm and 4 ohm speakers.
Input impedance: 27k
Gain: 32db
Distortion 1 khz; 8 ohm; full power w/Antek AS-3225: <0.0005%
(https://www.audiocircle.com/image.php?id=204640&size=large)
http://www.sengpielaudio.com/calculator-thd.htm
Full power at 8 Ohms -> 60 watts.
At 20 kHz about 0.01% -> -80 dB
I would like to see more measurements and graphs of the Folsom EC7293.
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Akitika GT-102, by Dan Joffe
https://www.akitika.com/GT102.html
Output Power: greater than 50 Watts per channel into 8 Ohms
Small Signal Bandwidth: typically wider than 5 Hz to 100 kHz at -3 dB points
Slew Rate (typical) 14 Volts/microsecond
Damping Factor @ 1 kHz wrt 8 Ohms: >80
Signal to Noise Ratio: typically 136 dB below 50 Watts into 8 Ohms, A-weighted, referred to a shorted input.
Harmonic Distortion: typically 0.003% at 50 Watts into 8 Ohms at 1 kHz. Clipping occurs at a bit more than 60 Watts into 8 Ohms at 1 kHz.
Intermodulation Distortion: 0.004% typical, SMPTE 4:1, 60 Hz, 7 kHz
Separation: >90 dB at 1 kHz, >70 dB at 10 kHz
Input Impedance: 51 K Ohms
Sensitivity: 1 Volt RMS input produces 20.59 Volts RMS output
Dimensions: 15” Wide x 10” Deep x 4.5” Height (includes height of the feet)
Input Power: 120 VAC 60 Hz, IEC connector (power cord supplied)
Input Power Fuse Rating and type: medium acting 3 Amps or 3.15 Amps, 5x20 mm
220-240 Volt operation also possible with the V240 kit, which uses a 1.5 Amp fuse
Weight: 15.5 lbs
Shipping Weight: 19 lbs
https://www.akitika.com/GT102.html
Output Power: greater than 50 Watts per channel into 8 Ohms
Small Signal Bandwidth: typically wider than 5 Hz to 100 kHz at -3 dB points
Slew Rate (typical) 14 Volts/microsecond
Damping Factor @ 1 kHz wrt 8 Ohms: >80
Signal to Noise Ratio: typically 136 dB below 50 Watts into 8 Ohms, A-weighted, referred to a shorted input.
Harmonic Distortion: typically 0.003% at 50 Watts into 8 Ohms at 1 kHz. Clipping occurs at a bit more than 60 Watts into 8 Ohms at 1 kHz.
Intermodulation Distortion: 0.004% typical, SMPTE 4:1, 60 Hz, 7 kHz
Separation: >90 dB at 1 kHz, >70 dB at 10 kHz
Input Impedance: 51 K Ohms
Sensitivity: 1 Volt RMS input produces 20.59 Volts RMS output
Dimensions: 15” Wide x 10” Deep x 4.5” Height (includes height of the feet)
Input Power: 120 VAC 60 Hz, IEC connector (power cord supplied)
Input Power Fuse Rating and type: medium acting 3 Amps or 3.15 Amps, 5x20 mm
220-240 Volt operation also possible with the V240 kit, which uses a 1.5 Amp fuse
Weight: 15.5 lbs
Shipping Weight: 19 lbs
The next measurements show 1 kHz THD+N measurements as a function of output power across an 8 Ohm load. Note the clipping occurs around 63 watts. Both left and right channel measurements are shown. One channel was driven at a time for these measurements. The nice in THD+N at low output power levels is the usual rise that happens at low levels as a fixed amount of noise becomes a greater percentage of the THD+N as power drops.
(https://www.akitika.com/pictures/1khz8ohmthdplusnoise.png)
It's also handy to get a look at the spectrum of the harmonics. The following graphs show the harmonics of a 1 kHz fundamental. They are shown in dB relative to 53 Watts into 8 Ohms. Note that the largest harmonic, the 3rd, is almost 100 dB below the fundamental. The remaining harmonics are typically more than 120 dB below the fundamental.
(https://www.akitika.com/pictures/FFT53W.png)
From other source: Stereophile.
https://www.stereophile.com/content/akitika-gt-102-power-amplifier-measurements
(https://www.stereophile.com/images/718Akitikafig6.jpg)
Fig.6 AkitikA GT-102, THD+N (%) vs frequency at 8.95V into: 8 ohms (left channel blue, right red), 4 ohms (left cyan, right magenta).
With one LM3886 by channel... But Studio Monitor is 8 Ohms and, if I am not wrong, cuts at 70 Hz at -3 dB.
http://www.sengpielaudio.com/calculator-thd.htm
At 20 kHz, 8 Ohms, 10 watts, THD+N= 0.04% -> -68 dB
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Folsom EC7293
Full power at 8 Ohms -> 60 watts.
At 20 kHz about 0.01% -> -80 dB
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@maty - Have you built one of these? I just ordered a set of boards to give it a try.
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Nope.
After ruling out several DIY class A designed by Hugh Dean for lack of power (KEF Q100: true 85 dB and minimum 4 Ohms) and excess heat, I focused on the DIY PURIFI 1ET400A. I am not in a hurry because I enjoy a great sound. Let others be the ones who first count the problems and weaknesses, if any. Of course, without Hypex SMPS. DIY Cresnet SMPS probably.
It is the only class D that really interests me because it does not suffer from the usual problems that of the technology, specially in the HF. The criticism I have received in other forums for reporting these deficiencies!
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Akitika
I was about to buy the first Akitika model, the GT-101. I did not do it because I wanted more power for my little coaxials, 3 meters away. Keep in mind that I usually listen to excellent recordings with very high dynamic range, usually excellent 24/192 or 24/96 vinyl rips. I have a multitude of tracks with DR > 15 dB.
Then I discarded the successor, the GT-102. Why? Because the Q100: 49 Hz at -3 dB, and really is like 5 Ohms nominal (KEF says 8 Ohms, as LS50, false).
It is a chipamps problem, for slightly demanding speakers, they require two per channel.
Studio Monitor: 88 dB and true 8 Ohms nominal, and about 70 Hz at -3 dB. Stereophile graph OK with it, even if the impedance was lower.
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Neurochrome
The same restrictions. Only Mod286 (two chipamps by channel) or Mod686 (six chipamps).
Two inconvenients.
* Expensive (I would like more watts) or very expensive using chipamps.
* I do not have a good relationship with Tom Christiansen.
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Folsom EC7293
I want more measurements! And reviews too. Maybe in the future but not just now. That they are others who boast of their new acquisition, I prefer to bet on insurance or, in other words, reduce the risk of error in the purchase, that is my usual practice.
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To finish,
I have always been a very questionable person, of those who preferred to sit in the front row.
Dan Joffe (Akitika). I haunted him (e-mail) with many questions and doubts I had. He always responded with good manners and giving the explanation I was looking for. It is very important to know that you are going to have a good after sales service, just like Danny Richie or Frank Van Alstine (AVA Hifi), at least for me.
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Neurochrome
* I do not have a good relationship with Tom Christiansen.
That's unfortunate. I hear he's a really nice guy... ;)
You're right, though. You and I don't see eye-to-eye. Part of that is that I've pointed out the fallacies in your arguments and refused to take your word as gospel. I approach audio design from a perspective rooted in science and engineering. I also have the perspective of someone who has designed circuits for mass production. The circuits I designed for National Semiconductor and Texas Instruments have been produced by the millions. I apply this perspective and the learnings from my experience in my designs. I have no plans to change that.
It's sad that you find it necessary to trash my reputation both here and on DIY Audio (https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6079964.html), but that is your choice. (BTW, those who know Maty and his communication style may find my response insightful, if not quite entertaining. It also outlines the root of our disagreement: https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6080256.html).
I have always been a very questionable person, of those who preferred to sit in the front row.
You and I actually have something in common then. However, in my experience, such students tend to fall into two categories: 1) Those who reflect on the topic taught and ask questions to test their understanding; and 2) those who crave the attention of the instructor and want the lecture to be about them and their issues. I've always preferred students who fell in the former category and do my absolute best to be a member of that category as well.
He always responded with good manners and giving the explanation I was looking for. It is very important to know that you are going to have a good after sales service, just like Danny Richie or Frank Van Alstine (AVA Hifi), at least for me.
It's interesting you mention that, actually. In my market surveys, a vast majority of my customers find me to be polite, honest, and to the point. Many also commend me for my ability to deal gracefully with the various noise makers in forum threads (one guy referred to this as my BSRR, which I found to be a fitting term). I tend to get around 100 participants in my surveys before they close, so I think I'm reaching a representative sample of my customers.
That said, my communication style does tend to be pretty direct, fact-based, and science-based, which rubs some the wrong way. Also, while I do my best to be patient, my patience is finite. So I probably become a bit rough around the edges when someone forcefully argues that I should change my products to suit their pet ideas - in particular when they completely lack perspective and it becomes impossible to reach them with fact- and science-based arguments. See this discussion for example: https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-neurochrome-modulus-286-amp.6443/post-143471
It's unfortunate that you don't like my direct, no-BS approach. I have no plans to change. I would rather sell my products with evidence-based arguments than with sappy marketing verbiage. You're free to disagree.
Now back on topic: Here is one review of my Universal Buffer + Purifi 1ET400A: https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-32.html#post6064187 with further clarification here: https://www.diyaudio.com/forums/class-d/347137-brainstorming-purifi-1et400a-amps-post6064216.html. Here's a summary:
The first impression is that it is smoother and the sound more "plastic" than with the EVAL1 buffer, or bypassed. Plastic as in plastic arts, in particular sculpture, not as in the synthetic material. [...] [T]he soundstage is very precise and natural, wide and deep, with very precise layers and everything has the right size and placement. As if sculpted.
The noise floor is also lower (my test was not too scientific but it is still a measurement: I bypassed the autoformer on the tweeter of the B&C coaxial so that it has a 110Db sensitivity, then measured the noise with my umik microphone and, with gain matched, I get a measurement of the hiss which is almost 10Db lower).
With the gain at unity it sounds relaxed and with slightly understated dynamics – with the gain at 7.3 or 13 it is much more dynamic. I chose to keep 7.3. I matched the level with the DAC's control, so this may also be due to the DAC behaving in a different way at various attenuation levels, but I would consider this case unlikely.
It's good to know that at least one person in the world likes my circuits and is willing to work with me. :) He and I are currently working on a buffer designed specifically for the Hypex NC500 and Purifi 1ET400A.
Tom Christiansen
Neurochrome - www.neurochrome.com
Tom Christiansen Audio - www.tomchr.com
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Tom you are a class act and a valued member of the diy community. Please filter out the noise and continue to support us!!!
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Tom you are a class act and a valued member of the diy community. Please filter out the noise and continue to support us!!!
+ gazillion! :green:
Best,
Anand.
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Tom you are a class act and a valued member of the diy community. Please filter out the noise and continue to support us!!!
Thank you. I appreciate it. I'll do my best. :)
Tom
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YouTube GR-Research NX-Studio, NX-Otica and NX-Treme Sound Clips (https://www.youtube.com/watch?v=i3SGjBL4Ffg)
Clarified and optimized
(https://www.audiocircle.com/image.php?id=204978&size=huge) (https://www.youtube.com/watch?v=i3SGjBL4Ffg)
If I had a very large room and, above all, for my enjoyment, the two Big NX-Treme with the same two Big subwoofers would be my choice without hesitation.
In smaller rooms, NX-Studio, with at least two subwoofers.
PS: updated title thread: Amplification ideas to GR-Research NX-Studio
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As a curiosity, here you are Ron Brenan (New Record Day) audio "arsenal"
https://www.youtube.com/post/UgxqOemUxaI7A8knbR54AaABCQ
(https://www.audiocircle.com/image.php?id=204992&size=huge) (https://yt3.ggpht.com/YNLXlKZebXYj0X8GVUg4QJakuPu_kVDs_o7sQVesx261zWiLbolLlt_T6EhA8jwlOJdbvdZVqZowIvo=s1600)
[Big IMG, link] https://yt3.ggpht.com/YNLXlKZebXYj0X8GVUg4QJakuPu_kVDs_o7sQVesx261zWiLbolLlt_T6EhA8jwlOJdbvdZVqZowIvo=s1600
You know, you always have to go well equipped if you travel to Texas to visit Danny Richie :D
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+ gazillion! :green:
Best,
Anand.
Anybody who has heard any of Tom’s designs knows how good they are. In a word, outstanding.
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Quickly browsing i did like the Stratos Stereo from Odyssey Audio.
I could stick with Schiit Ragnarok Amp since it does have L&R balanced pre outs. I would like to pair the studios with the servo sub kit2 (stereo subs) but those don't seem to have a balanced input, just the servo sub kit 1. (that's what i can make out from the low quality picture) am i correct? or do my eyes deceit me?
For a DAC maybe Cambridge Audio?
(https://www.audiocircle.com/image.php?id=204633)
(CXN V2)
or
(https://www.audiocircle.com/image.php?id=204637)
(Azur 851C)
Any thoughts on the combos? Will it be feasible for the stereo subs?
You can get any amp you want withthe kit, just let Danny know what you need. TA370PEQ has SE, Balanced, and a LFE input I believe. Likely a very small upcharge.
jay
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If you can find one, a Music Reference RM-10 Mk.2. 35w/ch from a single pair of EL84's per.
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I can recommend and amp for the Studio Monitors. I am using two Emerald Physics EP 100.2SE class d amps in my system and they are currently powering the Studio's. These are great little amps that are under appreciated in my view. They are a great value also. They can be had second hand for around $600. $700. Check HiFi Shark. There are a few listed now.
They come in black or silver.
(https://www.audiocircle.com/image.php?id=206654)
(https://www.audiocircle.com/image.php?id=206655)
Special Edition version of 100.2
Fully balanced design
100 watts RMS @ 8 ohms
150 watts RMS @ 4 ohms
275 watts RMS mono operation
450 watts in mono @ 4 ohms
I'm running these as mono blocks in balanced mode. They sound great with NX Studios. They have none of the harshness of early class d designs. I also liked it so much when I got the first one that I bought a second one. Very happy with these.
My preamp is a Wyred 4 Sound STP-SE with stage 2 upgrades Very Very nice Preamp. True reference grade.
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Purifi 1ET400A / Hypex NC500 Input Buffer
https://neurochrome.com/products/purifi-1et400a-hypex-nc500-input-buffer? (https://neurochrome.com/products/purifi-1et400a-hypex-nc500-input-buffer?)
(https://cdn.shopify.com/s/files/1/0036/4960/1606/products/PuriPex_R2p0_ASSY_800x544.jpg?v=1588735284)
(https://cdn.shopify.com/s/files/1/0036/4960/1606/products/PuriPex_wVreg_wText_800x544.jpg?v=1588735284)
[ This input buffer is intended for use with the Purifi 1ET400A and Hypex NC500 Class D amplifier modules.
Unlike other buffers, including the Purifi EVAL1 and the Hypex NC500 Evaluation Board, this Input Buffer will provide a differential output for the Class D amplifier, even if the input to the Buffer is single-ended. This ensures that even a single-ended source can drive the 1ET400A and NC500 to clipping, something the Purifi EVAL1, Hypex NC500 Evaluation Board, and many other input buffers cannot do. Many also report improvements in sound quality when the Purifi 1ET400A and Hypex NC500 are provided a differential input.
The buffer is a single-channel (mono) buffer, with the following features:
- Differential (balanced, XLR) input, which can easily be configured for single-ended (unbalanced, RCA) operation as well.
- True differential output with common-mode feedback, which ensures a differential output, even when used with a single-ended source.
- Jumper-selectable gain: 0 dB and 13.2 dB for a total amplifier gain of 12.8 dB and 26.0 dB, respectively, when used with the Purifi 1ET400A.
- Gain can be further customized by adding a resistor (1206 size SMD and leaded/PTH supported).
- Plug-and-play connection with Hypex SMPS1200 and future Purifi power supply.
- Opamp power supply: Use the AUX supply provided by the SMPS1200, or add your own regulator. A small daughterboard with support for the Hypex HPR/HNR, LM7812/LM7912, and LM78L12/LM79L12 is available as a product option.
- Status indicator LED output (NC500: CLIP and READY; 1ET400A: READY).
- Speaker output is provided both on 6.3 × 0.81 mm quick-connect spades and a terminal block accepting up to AWG 10 (5.2 mm2) in size.
In addition, the following options are provided for advanced users:
- The buffer can be disabled by removing two resistors. A three-pin connector footprint provides direct access to the Purifi 1ET400A / Hypex NC500 input.
- A two-pin connector footprint provides access to the remote sensing pins of the Purifi 1ET400A / Hypex NC500. ]
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Hello all. This noob is a musician working from his home studio and I'm in need of monitors for mixing/mastering. I plan on buying the NX studios for this purpose as soon as I'm finished building my custom PC. I'm not the biggest audiophile or diy-er. But I do need good sound quality in my set up. Not perfect but certainly of "hifi grade" if possible.
Haven't read this entire thread yet but was wondering if a combination of 2 or possibly 3 Crown XLS gen 2 amps might be able to supply clean power to the L/R studio monitors and a servo subwoofer? My audio interface, the Motu M4, has L/R balanced xlr stereo outs. I'm not sure how I'd get the LFE channel out from my audio interface. I know the crowns allow for eq tweaks and splits and mono setups etc. maybe the solution lies in their settings. But this is just an idea with my very facile understanding of audio gear.
Would this be feasible to carry the entire spectrum of sound successfully from my computer to the studios/servo sub? My only other minor concern is that apparently the crown dacs downsample to 24 bits. But they're still quality Ice power class d amps. Each can be bought under 250$ usually. And obviously no assembly. (Though I am still VERY tempted to build archimagos diy hypex dual monoblock amp).
Other amps I've considered are those with balanced inputs made by Rotel, Teac, Cambridge, and SPL. Any other suggestions or ideas on how I might be able to get my setup running adequately would be so appreciated.
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Hello all. This noob is a musician working from his home studio and I'm in need of monitors for mixing/mastering. I'm not the biggest audiophile or diy-er. But I do appreciate sound quality and integrity. I plan on buying the NX studios soon.
Haven't read this entire thread yet but was wondering if a combination of 2 or possibly 3 crown xls gen 2 amps would adequately supply clean power to the L/R studio monitors and a servo subwoofer? (Though I'm not sure how I'd get 3 channels out from my audio interface. But this is just an idea with my very facile understanding of audio gear. Would this idea work? I know someone once said that they do resample the signal internally (I suppose that's due to their onboard dacs). But they're still quality Ice power class d amps I've heard. Each can be bought under 250$ usually. And obviously no assembly. (Though I am still tempted to build archimagos amp). Any suggestions would be awesome.
I don't know anything about the Crown amps but the GR/Rythmik servo sub drivers have to be paired with a Rythmik servo amp. Amp and driver(s) are an integrated system.
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I don't know anything about the Crown amps
Only thing I know about them is from a friend YEARS back. He played in a band. I got the impression 'loud' was their thing. Not 'finesse'.
Guitar Center has a "Crown XLS1502 2-Channel 525W Power Amplifier with Onboard DSP" for $440 as a point of reference.
Take that with a grain of salt. I have no first hand experience. But I think they are geared towards PA type concert systems.
Hope that helps to keep this in mind.
ps. I have a Rotel PRE amp that set me back around $750 used and it's pretty decent for the money. I would expect their amps to be on par. It all depends on your needs and budget.
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Topping PA5 Review (Amplifier)
https://www.audiosciencereview.com/forum/index.php?threads/topping-pa5-review-amplifier.28512/
(https://www.audiocircle.com/image.php?id=233084&size=huge)
(https://www.audiocircle.com/image.php?id=233085&size=huge)
(https://www.audiocircle.com/image.php?id=233086&size=huge)