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  3. 148670-2497

Bridging an amplifier

I recently watched a YouTube video, a few years old, that featured Flemming Rasmussen, the highly regarded founder and engineer for Gryphon (now retired I believe). Flemming was speaking of his class A monoblock amplifiers in the Antileon Evo, Colloseum and Mephisto. Flemming was expressing his disdain for Monoblocks that are actually 2 internally bridged amplifiers, (such as DNA 500,Clayton M300s and also class A Luxman that can be used as Monoblocks in the BTL mode (bridged tied load), calling these types of Monoblocks inferior and not true Monoblocks. He claims dedicated Monoblocks where all push pull transistors are paralleled, are vastly superior to summing the two channels via bridging (antiphase summing). I’d love to know if most audiophiles and engineers agree with Flemming. I have owned and found both the DNA Monoblocks and Clayton M300 Monoblocks to sound excellent, and a friend uses two M-800A Luxman class A amplifiers in bridged tied load mode (BTL switch) with great clarity and power. Thank you for your thoughts!
audiobrian

Showing 10 responses by audiobrian

audiobrian OP
183 posts
 
Hi millercarbon & auxinput 

Thanks for your input. I guess I’m still not fully understanding the difference between a ‘true’ mono-block vs bridged monoblock....maybe I’m getting stuck on terminology. I thought it was more than a robust power supply? BTW, the Clayton M300s have been described as a bridged Balanced Class A design with essentially two M100s internally bridged in each monoblock....guess I need to read a little more about paralleled vs bridged amplifier designs.
audiobrian OP
183 posts
 
After some research I find that some excellent manufacturers that design dedicated internally bridged Monoblocks such as McCormack DNA 500 and Clayton M300/S2000 can build designs that are technically and often sonically superior to units that are switchable from stereo to bridged monos. According to Clayton and McCormack the dedicated internal bridging and large power supplies make the difference. Opinions are appreciated.
audiobrian OP
183 posts
 
Al,
Many thanks for your comprehensive and  understandable post....very helpful indeed!
Thanks to all respondents....I must remember that dedicated Monoblocks designed as internally bridged, with potent power supplies and fully balanced, like Clayton M300s, may not suffer the co͏mpromises of bridgeable stereo amplifiers. 
audiobrian OP
183 posts
 
I am now aware that some of the finest amplifiers around, including the Constellation Reference series, and Naim Reference series, are also balanced bridged designs. Even Atma-Sphere circlotron circuits are a variant of balanced bridged design. Great designers take different roads to audio nirvana. 
audiobrian OP
183 posts
 
Hi George:

Thank you again for your ‘input’.  I’m just wondering why designers/engineers from Constellation, Naim, Clayton, McCormack and other fine manufacturers, who obviously are aware of these compromises, choose to use balanced bridged designs in their reference products. Do you believe their decision is based partly on cost, generating maximal wattage without the robust power supplies and output stages needed to generate 200 wpc in a non bridged, high current, class A design?  Interesting...thanks again!
audiobrian OP
183 posts
 
Hi bigjoe.

I agree with you. Although there are some technical/electrical drawbacks to bridging, if implemented well it can sound as great as any non bridged design. Years back, reviewer Peter Montcrief named his two best sounding solid state amplifiers in the world, the McCormack DNA-500 and the Clayton Audio S-2000, both just happen to be dedicated balanced bridged design Monoblocks.... expert implementation seems to be most critical. Thanks
audiobrian OP
183 posts
 
For those interested:

http://www.iar-80.com

Just one reviewers opinion.
audiobrian OP
183 posts
 
Everyone’s tastes and ears are different, of course. Mr Moncrieff may have, indeed, needed additional haloperidol in 2004, I believe, when that volume of IAR was published. Just found it interesting that his choices for the two most natural SS amplifiers (at that time) were bridged designs....proves nothing....just his opinion without mention or possibly knowledge of circuit design. My personal SS favorites for natural sound are the Gryphon Antileon Evo, GamuT M250i and Clayton S-2000, two non bridged and one dedicated bridged design, two class A and one class AB, and two bipolar and one mosfet design....lots of flavors and excellent designers.

audiobrian OP
183 posts
 
I only recently viewed the additional contributions to this thread I started 19 months ago. I appreciate the additional input. From what I gather, audio2design, dedicated bridged amplifiers can be every bit as good or better than non bridged parallel designs if implemented well. Perhaps this is why Constellation, Naim, PS Audio, McCormack, Clayton, and others build dedicated bridged amplifiers to great success.
As these manufacturers use robust power supplies, the extra current required with bridged designs is not terribly compromising even with lower impedance loudspeakers? Thank you!
audiobrian OP
183 posts
 
Thank you, George!  I thought the Clayton S2000, a dedicated bridged balanced design, sounded too good to be characterized as an inferior topology. Just stay away from switching  stereo amplifiers into bridged mode. Got it.

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