MvX upgrade?
 

Pardon me if this was already discussed -- has anyone had a chance to hear the latest Momentum amps with the MvX upgrades and compare them to the previous versions?

https://dandagostino.com/products/mo...lock-amplifier

From the website:

Advancements in Every Area

Every major section of the amplifier - power supply, input, driver, and output stages - have all been enhanced in this advancement. A new transformer winding pattern provides over 50% more current output from the same transformer footprint. This additional current offers greater headroom during dynamic passages.

A reinvisioned input stage combines a brand new circuit topology with advanced components feeding the driver and output stages. Crucial to the new circuit are the bipolar transistors powering the front end of the amplifier. In the Momentum M400 MxV amplifiers, new devices deliver ten times the current and power of the original devices. These wider bandwidth, higher power components extend low and high frequency performance with reduced distortion in both frequency extremes.

Energizing the driver stage is a new bias stability circuit providing a nearly 50% increase in operating bias. Increasing Class A operation directly correlates to better sound quality. However, there is a limit to bias level in any amplifier. With this new circuit topology and our unique Copper heatsinks, thermal issues are not a practical concern in the Momentum M400 MxV amplifiers.

The new bias scheme ensures bias consistency, preventing excessive temperatures even under the greatest demand. Additional power transistors in the output stage reduce workload for each device. By minimizing stress on each individual device, the entire output section works more efficiently. The result is a richer, more dynamic, intimate presentation regardless of musical genre.

The final output stage features new output transistors that were originally sourced for the flagship Relentless Monoblock Amplifier. The high-output transistors used on the Momentum M400 MxV are among the fastest available. Using 26 on the Momentum M400 MxV amplifiers they run at a blistering 69 MHz, permitting the Momentum M400 MxV to achieve incredible bandwidth. Each transistor mounts with two stainless steel fasteners—a rarity among flat-package transistors—for maximum thermal transfer to the copper heat sinks.

A capacitor/resistor network connected to the base of each transistor ensures stability even at high frequencies and with low-impedance speakers. Additionally, every output transistor is measured and only devices that match the required performance specifications are included in the production of Momentum M400 MxV amplifiers. As with all D'Agostino models, the Momentum M400 MxV amplifiers feature discrete, direct-coupled balanced circuitry, the most accurate circuit platform possible.

I spoke with Alex at the D'Agostino factory and the upgrade sounds like they jack up the case and drive a completely new amplifier underneath. $10K for the S250 stereo amp. I didn't ask about the M400 monos, but I'd guess it would come in at $10K per.

Steve Z

I haven’t heard them, but think I’ll reach out to my dealer. Do you know if the amp has to go back to Cave Creek, or can the upgrade be performed at the dealer?

For all the upgrades listed on the MvX and for 10K, I would highly doubt that would be a dealer upgrade. Probably similar to the 200 to 250 upgrade, where mostly all but the chassis was changed.

Update from my dealer is that they’ll start doing upgrades in mid-January, and it has to be done in Cave Creek. $10k plus shipping, and the upgrade will take 1-2 weeks plus shipping time.

So Tony, are you gonna go for it or wait until some feedback? Of course as goes with this hobby, you’re never gonna read anything that’s gonna say, “the upgrade is terrible!!!!” :D:D

- Buck

And you guys make fun of Audio Research for the endless "SE" upgrades :smoking:

Don’t get me started now……..

MvX upgrade?
 

I’m thinking…I might have jumped in line if my dealer had offered me a loaner amp for a month. No surprise he didn’t offer me one, eh Marc?

Yeah, I'm doing well to even get a reply from that dealer a lot of the time.

Steve Z

Not surprised at all. Although they did give me a loaner once, which was like 5 rungs below the amp I sent in. You'd think it would be an opportunity for them to upsell you or show you something impressive, but nope.

Steve, do you shop Bellevue or Seattle?

Seattle, Tony.

Steve

I also deal with Seattle, with Hans Brackmann. For what it’s worth, I find a text or call to his cell usually gets a response, but email can be very slow.

Hans is great [emoji106] - and always willing to help on site when you are swapping out speakers, amps etc.

I have a brand new S250 with the MvX upgrade. I got very lucky; I was waiting on a regular S250, using a loaner S250, for a few months. My dealer asked me last month if I wanted the MvX version (for some extra $$). I said yes.

So, I've had the standard S250 in my system for a few months, and yesterday installed an ice cold S250 / MvX. It's a big difference. First thing I noticed was added space, air, and scale. Then I noticed additional resolution. Then I noticed some serious torque/grip. For me, it feels like I moved into a new, better, line of gear -- not just a tweak. For those of you like me, who moved from the Progression amps to Momentum, it was like that.

I could go on; but I hate reading posts like this ("OMG; it's soooo awesome. And now, let me show you how many audio-adjectives I've learned.") I'll just say this: after some recent weeks of fiddling with various cartridges, SUTs, phono stages ... and pulling my hair out at times ... my 2-second reaction when I turned on this S250 was "Hey, dumbass, amps are pretty damn important." IOW, the diff was way bigger than the analog close-calls I had been fiddling with.

Let me start by saying, I hate you John!

No, seriously -- thanks for the report. What I hate is the sound of $$$$ just flying out of my bank account.

Guess I need to start back on the PB&J for lunch while I save some shekels for the inevitable MvX upgrade to come. Of course, all my best wounds are self-inflicted -- I just sold my S250 to Wayne and now have two M400s from Ed to upgrade!

New cars are vastly over-rated. Besides, no one can get a new car in 2022 unless they're willing to make a couple of the car dealer's mortgage payments. . .

Steve Z

Glad I only have one to upgrade. Funny I just shot you an email about waiting to hear more about the MvX upgrade, I open this thread and here it goes. Lol
In the meantime will be enjoying the S250 as is.

Wayne

thanks for the update, the MxV upgrade sounds like the real deal.

Has the sound changed any in the one month since this post?

I own a S250, so seriously thinking about the upgrade, however my system is sounding so good now - do I really need to?

Turntable — yes it has changed. It went through a spell of sounding very hard. Break-in if you ask me. Back to 100% goodness now.

Hey fellas. Anybody else take the plunge and do the upgrade?

I'm considering upgrading my S250.

I've debated buying a used S250 and bi-amping my setup.

Wondering if the "cheaper" option to run with 1 (which has already had more than enough grunt on it's own) to the MxV would be "better" sounding-

Thoughts?

That good huh! ;)

Wish I could help you, but I'm on the fence myself. I also am not keen on the idea of having my amp gone that long given today's shipping issues. The dealer told me 4-6 weeks, I figure 6-8.

What’s the upgrade price in the US?

I thought it was $10k per amp-

MvX upgrade?
 

Yup, that's what my dealer quoted me.

Hi everyone. A New UK owner of a Momentum HD preamp and S250 power amp here!

I got a very good deal on a five month old, mint condition HD preamp (the original owner immediately had a change of heart and ordered a Relentless pre/power combination!

My dealer sent the Momentum S250 back to the States on 21st March and it arrived back in the UK, fully updated to MxV specification, Wednesday of this week. My dealer delivered it to me yesterday and as I Am still waiting for my balanced cables, the S250 is hooked up to my Conrad Johnson GAT2 preamp with my MIT Oracle MA-X single ended interconnects driving the S250 with the XLR adapters in place!

My front end is dCS Vivaldi full stack and speakers are TAD CR1MKII.

As I had not previously heard the S250 in pre-MxV mode, I can’t really compare the two and comment on any noticeable improvements.

All I will say, is that the new pre/power combination looks a million dollars and the sound with the CJ preamp is very refined, detailed and expansive!

The HD preamp is plugged Mo in and “burning-in” awaiting delivery of my balanced cables!

I thought a 45 day turn around from UK to USA shipping and back, with promised two-week turnaround at the D’Agostino factory, was worth sharing with you guys!

Regards,
Steve

I assume that all that is left of the original S250, following the upgrade, is the casework.

The display dial and rear panel now sport the MxV nomenclature and there is a new MxV user manual and test paperwork. Interestingly, the serial number has changed from the original 5115, to 5204!
https://live.staticflickr.com/65535/...99116fe2_k.jpgCAF11229-9595-45EB-852A-631396F1682A by , on Flickr

45 day turn around was pretty good. Love the new meter ! I’m traveling the month of November so thinking this wold be a good time for me to send mine in as well.

Looks great, I'm still probably going to upgrade to the MxV at some point, although I'm gonna have to work out something with my dealer for some kind of loaner amplifier. With supply chain issues etc, it wouldn't surprise me if something like this would be delayed even further. I guess so far so good here as far as parts etc.

- Buck

Buck, what about buying a new one, wait until it arrives, send the old one in for upgrade, then sell it? This sounds like a tremendous upgrade, well worth the money. The issue is the anxiety caused by system down time, which is totally unknown. And who wants to listen with an inferior amp. Put the minimum down payment down required by the dealer for the new amp. It truly is a beautiful piece. :yes:

Best

Charles

Charles, not a bad idea, wonder what the turnaround time is for a new one? I bet it's out there as well, I can't imagine they have MxVs just sitting around waiting for dealer orders but I could be wrong. The real issue is trying to not spend money on audio gear right now.....trying to behave myself. :D

- Buck

Buck, in a year you probably would make money if you did this. Having upgraded MxV's in unopened factory boxes puts you in the driver's seat, as you can ship them out immediately. I realize that you would be out some funds for a short period of time, but I would find the down time unacceptable. I have decided to keep my 1.25's just in case I have a tube failure with my new 3500's to prevent down time. I had a good offer but decided against it.

In today's world, who knows when you will ever see the unit within a reasonable length of time, making upgrades very difficult. I think manufacturers must guarantee the upgrade time to make it feasible or the dealer must provide a demo.

Best

Charles

Happy guy!

Upgrade well worth the coin. Took about 2 months!

Congrats ! Wow 2 months. I was hoping closer to 6 weeks. Will have to get in touch with them in October. I’m out of the country month of November so plan was to send in a week before and hope to recieve a week after I return or close to it.
What difference are you noticing most with the upgrade ?

Better control top to bottom. Better detail retrieval. Deeper soundstage.

New Upgrade Pricing
 

Just to let everyone know that D’ag has raised the MXV upgrade price to 15K per unit. So now purchasing a good used S250 or M400’s will be getting you mighty close to the price of a new unit