Jeff Rowland Design Model 525 Bridgeable Power Amplifier

[GuidoCorona]

During CES 2013, Jeff Rowland Design Group has announced the Model 525 -- a new 250W class D stereo amp, bridgeable to an impressive 1000W in mono operations. The M525 is based on new class D technology from Pascal in Copenhagen, and does not contain any ICEpower modules. I have not seen the amp yet, but I have been told that M525 is housed in a compact chassis derived from the now withdrawn M501, with the addition of a standby button on the front panel. The new amplifier has been released during the 2nd quarter of 2013. Here is some initial info:

• MODEL 525: class D stereo/bridgeable amplifier
• Stereo Power Amplifier OUTPUT POWER: 250 watts @ 8 ohms/500 watts @ 4 ohms 1000 watts @ 8 ohms BTL (bridge-tied load)
• Active Power Factor Correction (PFC): integrated -- ABSOLUTELY NOT compatible with external PC-1
• FREQUENCY RESPONSE: 5 Hz - 70 kHz, -3 dB
• INPUT IMPEDANCE: 40k ohms
• THD + NOISE: < 0.05%, 20 Hz - 20 kHz
• DAMPING FACTOR: > 1000 @ 1 kHz
• OVERALL GAIN: 26/32 dB BTL
• AMPLIFIER WEIGHT: 14.5 lb / 6.6 kg
• AMPLIFIER DIMENSIONS (H/W/D): 2.85" x 8.4" x 13" 72mm x 213mm x 330mm
• List price: $4500.00
• Status: Released 2nd quarter 2013

I will add more information as it becomes available.

Guido

 

[wizard]

View attachment 7777

525

 

[DonH50]

Will it drive 4-ohm speakers in bridged mode?

 

[GuidoCorona]

Hi Don, excellent question. I also would love to know if M525 can drive 4 Ohms loads bridged to mono, and with what power rating. Little is known yet about the new JRDG products. I will ask the factory, and post an answer when I obtain it.

 

[DonH50]

Thanks, just curious. Very few amplifiers actually achieve 2x power with 4 ohm and fewer 4x power bridged (the theoretical limits). That is one impressive set of specs either way!

 

[GuidoCorona]

Deleted

 

[mep]

I'm still blown away at the advertised weight of these amps when the faceplate looks like it weighs more than the advertised weight. The weight to power ratio reminds me of the Carver Cube amps.

 

[Elberoth]

Are they NCore based ?

 

[GuidoCorona]

Hi Elberoth, M525 does not contain Ncore technology. Instead, M525 is based on a yet unspecified power conversion module made by Pascal in Copenhagen.

As soon as I find out more, I will post the information here.

Guido

 

[GuidoCorona]

I corrected the thread header: M525 is not compatible with the JRDG PC-1 external rectifier... DO not feed M525 with PC-1, lest sparks shall fly, after which you will be left with one or two cute and expensive boat anchors. G.

 

[butler]

Brand of Power Conversion Module for M525

Are they NCore based ?

Just happened to be reading the winter newsletter from Jeff Rowland retailer Galen Carol Audio, which states:

The digital design departs from the ICE module found in the predecessor,
opting for a Class D module designed by the Norwegian firm Pascal.

http://www.gcaudio.com/newsletter/2013_winter4.html

Price is $4200

 

[wizard]

Just happened to be reading the winter newsletter from Jeff Rowland retailer Galen Carol Audio, which states:

The digital design departs from the ICE module found in the predecessor,
opting for a Class D module designed by the Norwegian firm Pascal.

http://www.gcaudio.com/newsletter/2013_winter4.html

Price is $4200

Pascal is from Denmark.

Link

 

[GuidoCorona]

M525 does not contain Ncore technology. Instead, M525 is based on a yet unspecified power conversion module made by Pascal in Copenhagen.

Guido

 

[butler]

Hi Guido,

Any idea yet if you will be reviewing/listening to any of Jeff's new products (or if anyone else is planning to do so)? Of particular interest to me is the new integrated, the updated Capri and this new amp. Even though I promised myself to forego purchasing new equipment when I retired a while back, these new Rowland goodies may reignite that old itch again.

Thanks.....

 

[GuidoCorona]

Hi Butler, I will be receiving a pair of M925 mono amps soon. I will post my gradual break in findings to WBF... As for M525, Capri S2, and Continuum S2, those remain fascinating review projects for the future.

Guido

 

[GuidoCorona]

I have spoken to Jeff Rowland....

M525 in bridged mode does support 4 Ohm impedance speakers at somewhat reduced power (at least 500W per side): there is a switch to toggle the feature on/off.

This weekend, M525 will be featured by Jeff Rowland at the Newport Beach Audio Show in the Lawrence Audio suite. If anyone attends, please post your sonic/musical impressions of the amp here.

G.

 

[jpetek]

Hello Guido,

did you compare the 525 against the 625 or 725 or 925?

Josef

 

[GuidoCorona]

Hi Joseph, as I have had no direct experience with M525, my answer is a little conjectural, and is based on my direct experience with M625, M725, M925, and a number of Rowland legacy products, including the M501 (M525 predecessor).

M525 is a product designed to meet the best possible performance at a specific price point -- just under $5K. As such, Rowland did not incorporate into M525 many of the more sophisticated technologies and refinements that he progressively adopts for the higher end products in the amplifier lineup: M625, M725, M825, and M925.

In its stereo mode, I venture to guess that M525 may be a little more transparent than M625, but may not reach the harmonic resolution density of M625. Judging specs alone, it is likely that M525 stereo with its damping factor over 1000, may handle some difficult loads even better than M625, but at 250W per channel, might generate stage and images that are slightly smaller than M625 which delivers 300W per channel.

What I have heard about M525 in bridged mode is that it has an absolutely astonishing authority that exceed that of the M725 monos.Conversely, M725 will likely exceed bridged M525 for resolution, low level information, and general refinement.

My personal experience with M925 is that it outperforms the wonderfully refined M725 for all parameters by, uhrn... a Texas mile… Which is a kind of very large “country mile”. By extension, I fully believe that the M525 will not faintly approach the refinement of M925 or M825… However, in sheer authority on nominal 8 Ohm loads, bridged M525 can yield 1000 Watts per channel, which once you factor in difeerences in power supplies, might put it in the general authority area of M925.

Hope this helps, Guido

 

[jpetek]

Dear Guido,

thank you for the answer.

Josef

 

[seriouslyhifi]

Dear Guido,
Any experience with the M 525. A friend of mine is getting it soon and I will get a chance to hear them.
I am considering the M 925 or M 825.