Cambridge Audio 640P-B Phono Preamp - Black

by Cambridge Audio

Product Details

• Shipping Weight: 5 pounds (View shipping rates and policies)
• ASIN: B00106E67G
• Item model number: 640P-B
• Average Customer Review: 4.4 out of 5 stars  See all reviews (9 customer reviews)
• Amazon Best Sellers Rank: #8,580 in Electronics (See Top 100 in Electronics)
  • #8 in Electronics > Home Audio & Theater > Stereo Components > Receivers & Amplifiers > Component Preamplifiers
• Date first available at Amazon.com: November 28, 2007

Product Description

Extending the functionality of Cambridge Audio's critically acclaimed integrated stereo Azur amplifiers and AV receivers it the 640P phono preamp. The 640P features a highly specified moving magnet stage, as well as the higher gain needed for compatibility with high-end Moving Coil (MC) cartridges. This model features single ended "class A" gain stages and use discrete transistors instead of the more common integrated circuits. This gives less crosstalk and interference across the signal path, with both designs delivering high gain and linearity. Tthe 640P uses passive audiophile RIAA eq, the optimum type for phono stages thanks to its complete lack of phase error. The 640P also uses superior amplification circuitry for its MM and MC stages to provide the lowest possible distortion and noise. In addition, this flagship model employs multi-parallel capacitors to achieve exceptional RIAA accuracy of +/- .3dB up to 50 kHz. It also features a defeatable subsonic filter. This combination of technologies offer a hugely dynamic, involving and open sound.

Customer Reviews

Most Helpful Customer Reviews

11 of 12 people found the following review helpful:

5.0 out of 5 stars Can't go wrong at this price, March 23, 2010

By 

Kensimons "kensimons" (Seattle, WA) - See all my reviews

This review is from: Cambridge Audio 640P-B Phono Preamp - Black (Electronics)

After carefully auditioning the 640P for over a month (~60hrs of music), I can now say that this preamp is an incredible value.

PROS: Overall it has a pretty wide sound stage with a flattish frequency response. The treble is not at all bright or shrill... it's, in a word, "pleasant". The bass response and attack are not overwhelming but rather what I would call, "accurate". The mids and vocals are especially warm and soothing. I was very pleased at how warm this amp was. Ear fatigue is virtually non-existent. It especially excels at Classical and Pop tracks. Guitar notes are beefy and have some edge, but are not shrill. This is a very quiet amp with very little THD and crosstalk - there is some, but it doesn't affect performance.

The overall package is well made. It's light weight and the blue light is very dim and not a distraction. You can also upgrade the opamps! I'm thinking of playing around with some BurrBrown OPA627APs soon.

Of my three carts, the AudioTechnica AT440MLa was the best overall pairing. My Goldring Elektra had a greater bass response and a more forward presentation but with a reduced soundstage. Strangely my Shure 97xe was the poorest performer (once my 2nd favorite). The Shure on this preamp sounded overly flat (more than usual) and there wasn't enough attack. Overall, it made a flat cart sound even flatter.

CONS: At this price, there really are no cons. However, it's not dead silent on the MM channel (although it's the quietest preamp I've owned thus far). Snare and cymbals have a somewhat relaxed presentation. I also would've liked an option from Cambridge to upgrade the power supply for aesthetic reasons (it's the only part that looks "cheap").


EQUIPMENT USED:
Audio-Technica AT440MLa
Shure 97xe
Goldring Elektra

Other Equipment used: Onix SP3 with TungSol 12ax7s (mullard), ElectroHarmonix 6922s, 12AU7s and ValveArt 350B power tubes. PureAV power conditioner. Energy EXL-16Bs full range speakers.

OTHER THOUGHTS: For those of you that are thinking of using a low output MM cart and feeding it through the MC channel to make some kind of "high-gain" channel... all I can say is it didn't work for me. I couldn't get any of my three MM carts to artificially rig the MC channel (they're not supposed to but I tried). They all just badly clipped the high and low frequencies. Also note that the 640P is not just a 540 with a MC channel. The internals are different.

I had almost no burn in time. The first few hours it sounded excessively warm, but after that it started to sound how it sounds now.

11 of 12 people found the following review helpful:

5.0 out of 5 stars Great sound!, July 18, 2009

By 

R. King (LA, CA) - See all my reviews
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Amazon Verified Purchase

This review is from: Cambridge Audio 640P-B Phono Preamp - Black (Electronics)

This sounds great with my older Dual turntable. Very clean sound, great instrument separation. The single blue LED on the front is small and not overly bright or distracting. Plus it supports MC cartridges if/when I should ever upgrade to one of those.

BTW, the MM and MC inputs use completely different circuitry (from my research), if that's important to you.

5 of 5 people found the following review helpful:

5.0 out of 5 stars Quality preamp!, February 25, 2010

By 

V. Ojha (FL, USA) - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Cambridge Audio 640P-B Phono Preamp - Black (Electronics)

My phono preamp in my older Sansui receiver started dying out and I had been reading about options for some time. I came across many glowing reviews of the Cambridge Audio 640P phono preamp and decided to take the plunge, given the low price. The unit arrived well-packaged and the instructions were clear. Setup was a breeze and in no time I was listening to my vinyl once again. I can say that after 50 hours, the sound has changed a bit as the burn-in process continues. Bass is getting tighter and better defined. Definitely a quality unit for a very good price. The subsonic filter is a nice feature to have and let's face it... the unit is very easy on the eyes too! Cuteness aside, it all boils down to performance, sound and value... and this unit excels in all three areas.