Benchmark AHB2 Power Cable Upgrade

I have a few of the Audience forte 3 and like them on some pieces. However, I did not notice a difference with the AHB2 and the Audience forte 3.

Today, I tried, for the first time, an Audience forte 3 power cable instead of my “go to” Shunyata Venom 14 power cable. The forte 3 provides much better flexibility and sound quality at least good as the Venom 14.

Thanks for all the commentary. The system is pretty resolving and that's what is special about the AHB2 amps.  I tried Signal Cable Silver PCs with narrow body Furutech IEC connectors and can't say there's any difference over the stock cord with these amps.

I have had the AHB2 many times over the past decade. I no longer have it but I did a lot of speaker cable comparisons before I sold it. Mainly because the AHB2 was the best amp to hear the gear.

The speaker cable that Benchmark sells is really good for most systems. If the system is highly resolving, then you will hear the limitations on the BM speaker cable. I heard this with cables costing $7K to the $100 BM cable. Though the issues were evident at different frequencies with each of the cables. The BM cable is what I would use if you cannot hear the BM cable gremlin in your system. I used it for years in my office system which was not uber revealing.

My favorite speaker cable is the Audience FrontRow cable. I got those terminated by Audience with the SpeakON connectors and used them with the AHB2 and headphones. I also used a customized CODA #8 amp with this cable and headphones. I could not hear any improvement in the sound with the regular spade or banana speaker cables with either amp. I now have 2 sets of Audience FrontRow with non-SpeakOn termination and both amps were sold.

With power cables I could not hear any change in sound on the AHB2 and the stock cable vs audiophile PC’s. Now I do not have anything extravagant to test with, but I could not hear any difference with the cables I had.

I also found no difference in sound using the BM stock XLR’s between my BM HPA4 preamp and the AHB2. The XLR or RCA into the HPA4 made some difference but nothing major. For example, a tuner into the HPA4 sounded mediocre with a cheap RCA into the HPA4 but an Audience AU24 SE RCA made a positive improvement.

I wonder what Benchmark’s response would be if you asked them about a power cord upgrade? They know their products best.

Answer from Rory Rail at BM to me was don’t waste your money with a non-stock cable for the AHB2.

Wireworld might work, as they use molded plugs. 

You would think an amp that gets widespread praise as objectively one of the best out there from a company that is held in highest regard for its engineering acumen would include a good quality power cord . I would be inclined to not worry about it.

I wonder what Benchmark’s response would be if you asked them about a power cord upgrade?  They know their products best.

Hello @timothy_m

This may not be helpful, but — I installed a (used) Cardas Clear Beyond PC on my AHB2, and it was a game-changing upgrade. More PRaT, more clarity, better dynamics…really brought my system to life. That said, the connector is quite beefy, and it may not work with the Speakon connector(s).

I’m running the Beyond Clear PC from a dedicated 20A line, which also has a Cardas duplex outlet installed.

I recently replaced the stock PCs on my Lumin U2, DAC3 HGC, and HPA4 with Cardas Clear Cygnus PCs, and the effect was more subtle, but they improved the instrument separation and clarity further.

Best, JAMES

I think a 10awg Audience Forte F3 might work as it uses similar size plugs as factory cords. It’s a really nice power cable that won’t break the bank. It made a positive difference on my pass labs X260.8 mono amps. You won’t know if it makes a difference on Benchmark until you try and if it doesn’t, you’re out $175 And you know you have a 10awg cord on the amp which is what you should be using on your amps. 

I've tried a number of power cords on my AHB2's, and nothing has been consistently better. 

Different, yes. But nothing actually better. 

I also have a pair of Atma-Sphere M60s that I use the Benchmark power cords on. They're just really good, neutral power cords.

@timothy_m Glad to help. I'm thinking about going to monoblocks, so it was good to find out now about a potential problem. I ran a quick scan for cables that might work, and it appears some of the Audioquest cables could fill the bill.

@ho249 Thanks for checking it out.  If comments are like yours where there's not much bang for the buck I may stick with the OEM cords.  I've found significant improvements upgrading PC's with some pieces of equipment and not so much with others and that's why I'm looking for user experiences as well as figuring out what fits.

@timothy_m Good question. I moved one of the Speakon connectors to the center (monoblock) position and then tried to install the Power Plus cable. No success, it wouldn't fit!

Hope you can find power cables with less bulky connectors. I'd be interested to know what you find.

Thanks for the comments they are helpful.  To be clear, do the DH Labs "Power Plus" fit when using the Speakon connectors?  It looks to be a large IEC fitting.

I'm using DH labs "Power Plus" cables with my AHB2 and other Benchmark components (LA4 and DAC3B). They are a very tight fit in all cases!

I noticed some beneficial results with the new power cable installed in the AHB2, but not nearly as significant as when I upgraded my interconnects.

If I had the chance to do it over again, I'd pursue other upgrades before the power cables.

Hi Jerry,

There’s a lot to like about the Benchmark AHB2 amps but the compact chassis makes for very tight connections for everything around back.  Used as mono blocks with the Speakon connectors really limits power cord choice.

Voodoo Cable makes an adjustable right angle IEC adapter that might work, and I believe that cables terminated with a Furutech FI-C15 slim body might also work.  I did try an old Cardas Hexlink 5C that has an integrated IEC, and it fits but I didn’t listen since I have just one.

I’d be interested in hearing if anyone has found significant improvement using a upgraded cord with my configuration and what fits.

T

Your post intrigued me as I didn't know Benchmark was using better connectors.  I moved my crossovers external and used speakon connectors from the crossover to the speaker.  I agree they are superior.

I then looked at the Benchmark power cord.  The locking plastic tabs on the power cord are not a bad idea.  but to add a 50c piece of plastic and try to say it makes a 14 awg cord adequate doesn't cut it for me.

So if there isn't room for an upgraded power cord I'd say benchmark screwed up pretty bad.  

Audioquest and some generics make 90 deg adapters that seem to be slimmer.  While they may not be perfect they are likely better than a long small power cord.  Reistance is additive.  The longer a piece is the HIGHER the resistance.  So this short piece, even if of mediocre quality,  should add minimal resistance.  It isn't like a water hose where a kink acts as an orifice.  

If it were mine, and I really liked the amp, I might pull the female IEC out, replace it with a strain relief to pass the cord through, and hard wire my upgraded cord inside the amp.

Jerry