A second review of the new DVA 225 Monoblock amps

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mr_bill

Re: A second review of the new DVA 225 Monoblock amps
« Reply #40 on: 12 Jul 2021, 07:08 pm »
Do you have an estimated price yet for the new digital preamp?

Any update on this Frank or maybe I missed it,

avahifi

Re: A second review of the new DVA 225 Monoblock amps
« Reply #41 on: 12 Jul 2021, 11:58 pm »
Still figuring out how much time it takes for one of my experienced technicians to put our new Digital Preamp together and test it.  Will know in a couple of weeks.

Frank

vinylrecordust

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Re: A second review of the new DVA 225 Monoblock amps
« Reply #42 on: 8 Aug 2021, 12:16 pm »
Hello all, I would like to know what the class A level of power before moving to class A/B is for the 225s?  Also, would I need a converter to use with a bottle head 300 pre/bee preamplifier with a xlr output as I would like to have a tube front end.

Thanks!
Mike

vinylrecordust

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Re: A second review of the new DVA 225 Monoblock amps
« Reply #43 on: 8 Aug 2021, 12:25 pm »
Any chance there will be a black face option?
Thanks!

mav52

Re: A second review of the new DVA 225 Monoblock amps
« Reply #44 on: 8 Aug 2021, 03:47 pm »
Hello all, I would like to know what the class A level of power before moving to class A/B is for the 225s?  Also, would I need a converter to use with a bottle head 300 pre/bee preamplifier with a xlr output as I would like to have a tube front end.

Thanks!
Mike

I think its noted on the first page of the post "  Class AB designs biased on to about 20W chassis A. "

EclecticSeeker

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Re: A second review of the new DVA 225 Monoblock amps
« Reply #45 on: 5 Sep 2021, 03:26 am »
RETURN TO THE FAITH
Well, I’m back. 
“Who are you, where are you back from, and why should I care?” I hear you ask.

I am a Van Alstine disciple of the last 43 years, and have owned Frank’s gear from the days of Jensen’s Stereo Shop.  I sort of fell away from the path of True Faith about seven years ago, and though I’ve always kept an AVA amp and preamp on hand, was seduced by the spell of gear with copious reviews and higher prices.  It’s a long story, and boring too, so I won’t burden you with details.  But even in my time of being lost in the hi-fi wilderness, I continued to recommend AVA gear to friends and family as a superb, cost-effective means to sonic enlightenment. 

The shining audio beacon that lights my return to the AVA fold is the DVA M225 amp.  For the last year I have owned two very highly regarded Pass Labs monoblocks, and was initially quite happy with them.  But I gradually became aware that although these amps did depth and detail and gravitas extremely well, I was missing out on at least a couple of attributes I really wanted.  I was able to identify the lacking qualities as – to use the vernacular of our passion – soundstage and dynamics.  No doubt the many adherents to the faith of Pass amplification will, at a minimum, be quick to call me crazy and question the acuity of my hearing.  So be it.  I am willing to go so far as to attribute my perceptions of problems to poor system synergy. 

But after a trial with the M225s, I have sold the Pass amps – which list at four times the price of the M225s – and am now enjoying music that calls out to me, demands my attention, and pulls me in.  The M225s render a very accurate, clean and clear audio picture, and present a soundstage to die for.  I am convinced that they are world-beaters, certainly at anything near the price point and probably several multiples of it.  Some have called it the best amp Frank has even come out with, which is a bold statement but one I must agree with. 

To answer my opening questions:  I am a happy audiophile, I have returned from a sojourn into non-AVA gear, and – OK, so you might not really care – I hope more audiophiles can experience this audio achievement that AVA has wrought. 

System Equipment:  Martin Logan CLX speakers and BalancedForce subs, Audio Research Ref 6 preamp, PS Audio Stellar phono pre, Exemplar-modified Oppo UDP-205 CD deck, Denon DP-75 TT/Kuzma 4 Pt tonearm/My Sonic Labs cart. 

Onadifferentnote

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Re: A second review of the new DVA 225 Monoblock amps
« Reply #46 on: 5 Sep 2021, 05:04 am »
Well!
The cat is really out of the bag now!  Universal agreement that our brand new M225 mono amps are something very special.

$1699 each and actually available right now!  The pair I just send to an Audiophila reviewer is not coming back, the reviewer bought them the same day he unboxed them.

One spare pair ready to ship in house now, but another batch will be ready within a couple of weeks. 

Dimensions are 9" wide, 10" deep, 4" high and shipping weight of 18 pounds. Note that they are pure differential balanced designs with XLR inputs only.  We will have a small outboard stereo RCA to XLR adaptor available soon.

These are not soulless Class D switching amps, the are true Class AB designs biased on to about 20W chassis A. There is just an unbelievable lot of high class stuff packing in this small AVA designed chassis including mirror imaged audio boards and separate regulated power supplies for each channel and regulated output mosfet transistors too.

Can't wait to get mine Frank!! Thank you.

KLH007

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Re: A second review of the new DVA 225 Monoblock amps
« Reply #47 on: 10 Oct 2021, 03:25 pm »
I'm employing a pair of M225s for my review of Alta Alec floorstanders on Mike Levy's recommendation and I'm so happy he made me aware of them. My system has never sounded better! Don't let their small size or reasonable weight fool you, the M225s are explosively dynamic, produce powerful impactive propulsive bass, and vocals never sounded more real, I'm loving them! You'll be able to see and hear them in my system when the review of the Alecs is posted on YouTube later this Fall on AV Showrooms' YT site.

gryphongryph

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Re: A second review of the new DVA 225 Monoblock amps
« Reply #48 on: 13 Nov 2021, 08:48 pm »
I have a pair of the DVA M225's in to review for Part Time Audiophile. I can indeed confirm they are some of the finest sounding amps I've ever heard at ANY price.
Unlike a previous comment, in my system, they have an extraordinary midrange texture of an almost tube-like nature. Imaging is off the charts great. Huge bass with a vice-like grip. Super clean and classy top.
My system currently consists of:
Rega P10 with a Charisma Audio Signature One cart
VAC Master Preamplifier
Pass XA-200.8 monos or Audio Hungary Qualiton APX-200 II
Acora SRC-2 or QLN Prestege Five speakers
Innous Zen mini with a variety of DACs
All Cardas Clear Light cables and power bar



Dave


How do you feel they did on low volume ? Do you know how many watts they are bias into class A ? Sorry, see it has been answered already, anyone knows if they come with a black faceplate also ?

lovelexicon

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Re: A second review of the new DVA 225 Monoblock amps
« Reply #49 on: 3 Jan 2022, 03:43 am »
I have the Magnepan 1.7i speakers---86db sensitivity, 4ohm.

How will the DVA SET 600 monos and the DVA M225 monos sound differently driving that pair of speakers?

I.Greyhound Fan

Re: A second review of the new DVA 225 Monoblock amps
« Reply #50 on: 3 Jan 2022, 04:24 pm »
I have the Magnepan 1.7i speakers---86db sensitivity, 4ohm.

How will the DVA SET 600 monos and the DVA M225 monos sound differently driving that pair of speakers?

Maggie owner, 1.6's.  I reviewed the 225's.  They worked well with the 1.6's.  The 600's might work better though depending upon how loud you like to play and the type of music.  The tweeters on the Maggies according to GR Research, present a 2 ohm load.

I am a believer that the more current, capacitance, voltage and watts you have the better with Magnepans.

rwolters

Re: A second review of the new DVA 225 Monoblock amps
« Reply #51 on: 24 Jan 2022, 07:46 pm »
Are the DVA-225 amps compliant with the AES-48 standard for balanced line connections? I've seen comments in forums about the importance of meeting that standard. Apparently it's very beneficial in reducing, or eliminating the impact of different interconnect cables.

RonN5

Re: A second review of the new DVA 225 Monoblock amps
« Reply #52 on: 25 Jan 2022, 12:49 am »
I have 3 questions about the 225s…

1.  Does reducing the gain mean that more input voltage will be needed to drive the amp to full output?

2.  If the amps stays in class a for the first 20 Watts, does it run hot.

3.  What is the downside of using a Neutrik balanced to rca adapter… will it not work? Or will it require more preamp output voltage to drive the amp to full output? Or will it just sound poor?

danielgk

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  • AVA engineer/technicion
Re: A second review of the new DVA 225 Monoblock amps
« Reply #53 on: 25 Jan 2022, 12:09 pm »
1.  reduced gain will require more input to drive the amp to full power.  However the M225 is fairly "hot" to begin with due to its differential design, which adds 6db of gain.

2.  The amp runs cool at low power

3.  inexpensive rca to xlr adapters, like the Neutrik NA2MPMF, run the RCA hot signal to XLR pin 2 (the + pin) and RCA ground to XLR pins 1 (the ground pin) AND pin 3 (the - pin).  The result is the - side amplifier board of the M225 gets ground as an input.  This means that you have effectively converted your M225 to a SET120.  It works.  It produces about 60w.  It is not differential.  It doesn't sound bad, but it is no where near the amplifier a M225 is.  The DVA R2X, on the other hand, uses proprietary solid state circuitry to convert the RCA input to a 180 degree phase shifted copy of the original signal.  It then feeds the original signal to pin 2 and the phase shifted copy to pin 3, and ground to pin 1.  The result is 225w of glorious full differential audio bliss.


Dan

RonN5

Re: A second review of the new DVA 225 Monoblock amps
« Reply #54 on: 25 Jan 2022, 04:10 pm »
Dan...thank you for the great, easy to understand explanation.  So, for further clarification, does it mean that an rca output only preamp into your rca/xlr convertor into the M225s needs to deliver 1.7 volts to the convertor to drive the amp to full power?

If yes, does that then mean that reducing the amp sensitivity by 6db means it will take 2 volts to drive the amp to full power?

Does reducing the sensitivity make the amp even quieter and possibly sound better since you would be using more of your preamps volume range?

The reason for the questions is that I really like the dac tone/presentation/etc. in my OPPO 205 so I'm a little hesitant to try the new digital preamp and want to better understand the M225 sensitivity and options....

Thanks

mav52

Re: A second review of the new DVA 225 Monoblock amps
« Reply #55 on: 25 Jan 2022, 05:14 pm »
Dan...thank you for the great, easy to understand explanation.  So, for further clarification, does it mean that an rca output only preamp into your rca/xlr convertor into the M225s needs to deliver 1.7 volts to the convertor to drive the amp to full power?

If yes, does that then mean that reducing the amp sensitivity by 6db means it will take 2 volts to drive the amp to full power?

Does reducing the sensitivity make the amp even quieter and possibly sound better since you would be using more of your preamps volume range?

The reason for the questions is that I really like the dac tone/presentation/etc. in my OPPO 205 so I'm a little hesitant to try the new digital preamp and want to better understand the M225 sensitivity and options....

Thanks

The OPPO 205 from what I read in my manual, Output Level: (RCA) 2.1±0.2Vrms. (XLR) 4.2±0.4Vrms

RonN5

Re: A second review of the new DVA 225 Monoblock amps
« Reply #56 on: 25 Jan 2022, 06:35 pm »
mav52

my questions to dan are not related to using the oppo to drive the M225...although maybe that would work, I'm not sure if it is fully balanced as would be required by this amp.

my questions are more about the voltage input requirements of the M225 with the gain reduced and what that will do to the voltage input requirement and the sound.

The upside of the digital preamp to drive the M225 is that it is designed to be a perfect match..the downside is if one doesn't prefer the sound of its dac vs say my oppo...or anything else then you are locked in...although, I'm sure its pretty good.

The upside of the rca to xlr convertor is that any preamp can be used.

hmm will the FET VALVE CFR PREAMPLIFIER be offered fully balanced, that could be the ultimate.








mav52

Re: A second review of the new DVA 225 Monoblock amps
« Reply #57 on: 25 Jan 2022, 07:44 pm »
mav52

my questions to dan are not related to using the oppo to drive the M225...although maybe that would work, I'm not sure if it is fully balanced as would be required by this amp.

my questions are more about the voltage input requirements of the M225 with the gain reduced and what that will do to the voltage input requirement and the sound.

The upside of the digital preamp to drive the M225 is that it is designed to be a perfect match..the downside is if one doesn't prefer the sound of its dac vs say my oppo...or anything else then you are locked in...although, I'm sure its pretty good.

The upside of the rca to xlr convertor is that any preamp can be used.

hmm will the FET VALVE CFR PREAMPLIFIER be offered fully balanced, that could be the ultimate.

Understand,  Looking forward to his comments

danielgk

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  • AVA engineer/technicion
Re: A second review of the new DVA 225 Monoblock amps
« Reply #58 on: 26 Jan 2022, 12:21 am »
RonN5

I will try and answer your questions:

Old rule of thumb in amplifier design is (was) to set the gain so the amplifier puts out full power into an 8 ohms load with a 1 volt input.  This 1 volt has been creeping up over the years to 1.5, 1.7. even 2 and higher.  I don't know why.  But one of the consequences is that some sources can't drive some amplifiers to full power necessitating the REQUIREMENT of having a preamp (with gain).  I have always been of the philosophy that "the best preamp is no preamp" so designing an amplifier that requires a preamp doesn't make sense to me.

The two amplifier boards in the M225 have a gain of 24.  This means that 1 volt in gets you 24v out.  But there are 2 amplifier boards, running out of phase, so the differential output is double, or 48v.  48v into 8 ohms is 288w, a little over the M225's 225w.  Turns out the input needed to drive the M225 to full power is a little less than 1v, more like 0.9v.  0.9 x 24 = 21.6v out of each amp board = 43.2v differential into 8 ohms = 233w.

Our R2X has a gain of 2, but that's a little misleading.  The gain from input to positive output is 1, the gain from input to negative output is 1, and the gain from input to differential output is 2.  But each amp board in the M225 only uses the positive OR the negative input.  There is nothing in the M225 that uses the differential input.  So the R2X does not add any gain.

If you reduce the gain of the M225 by 6 db, it will require 1.8v input (1.8v + input AND 1.8v - input which is 3.6v differential) to run it up to full power.

I have seen no appreciable noise differences in the low gain vs the normal gain M225's.

So, clear as mud - right?


Dan


rwolters

Re: A second review of the new DVA 225 Monoblock amps
« Reply #59 on: 26 Jan 2022, 03:25 am »
Hi Dan,

Do you know the answer to my question as to whether the DVA 225 amp's balanced connections are AES-48 compliant?

Thanks,

Bob