JA

Have you tried the new cables one at a time to see if possible one of them is terminated improperly. That's not likely but it is possible. It also sounds like it might be a capacitance problem but Nordost claims to be a low capacitance cable.

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i bought a set of 3 metre red dawn version 2 and received it yesterday. it is terminated identically to my blue heaven. i wired everything up in the usual manner. i started at low volume and things sounded good, eventually, at about 75% power, the protection circuit kicked in on the bass channel. lowering volume and waiting restored power. i tried many combinations including reversing polarity, switching the amp assignments, standard bi-wiring with only the integrated amp. these all caused the same results. the only thing that worked was to use only 1 of the leads in the integrated run to the speaker with the speaker connections bridged as if i was only using one standard wire. this permitted full volume.

As I read this, it is unclear just what you were trying with all of your cable switching. It sounds as if at one point you had the grounds of two amplfiers tied together.

That's not good.

Since you just bought the speaker cable I would contact the retailer and discuss this issue with their service department. If there is a fault in the cable, they are responsible for replacing the cable. Otherwise, they have more experience with the product than anyone other than the manufacturer.

However, as a guess, I would say the real issue is to be found in the last sentence of the above quote, "this permitted full volume." Depending on just what "full volume" means to you, the problem with the new cable might just be coincidental to the new cable.

Are you using the old and new set of cables (one for the "top" and one for the "bottom")? If so this may sound like a silly question but have you removed the jumpers? If you hadn't it shouldn't have worked before so I bet you have.

Arcam amps aren't muscle amps made to drive super difficult loads. That said Arcams will certainly run 4 ohm speakers. I've used them extensively with Magnapan and Thiel products. However if your speakers have a really wild impedance curve that could contribute to the issue too. I don't have any hands on experience with your speakers.

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the only thing that worked was to use only 1 of the leads in the integrated run to the speaker with the speaker connections bridged as if i was only using one standard wire. this permitted full volume.

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jan: i have been very careful about the routing of the wires and am certain that none have been crossed as you suggest might be the case. up until the time that the protection circuit kicks in, everything sounds great. my goal is improvement, more definition, the usual reasons. it is just strange that a cable that should be an upgrade should create such problems. any other thoughts? in regard to the volume, there are 72 steps and it would previously play comfortably at step 65; no i don't crank it all the way. also, the combined output rating is 130 watts per side at 8 ohms.

I wasn't really suggesting you crossed any wires. I was suggesting you're driving the amp too hard into a less than easy load. It's possible the amp now has some problems and the cables are just coincidental to the issue becoming obvious.

You are confusing how far the volume knob will turn with how much power the amplifier can produce. Full power does not occur at full rotation of the knob. At "65" out of "72" you are more than likely clipping the amplifier's outputs.

What do you mean "the combined output rating is 130 watts per side at 8 ohms." Are you taking the rated power output of both amplifiers and adding them together? I just keep getting the impression that loud is important to you.

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these speakers are power sucking pigs, but sound great at strong volume. the maker says they are 4-6 ohms, but i suspect on big transients, they dip lower.

The transient material does not determine where the impedance falls. And you need to consider both impedance and electrical phase angle before you make any decisions regarding what sort of load the speakers present to the amplifier. But your reference to "big transients" still has me believing the amp is simply being stressed beyond its limits.

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my suspicion is that the new cables have so little resistence that they exceed the amp's ability to provide power on dynamic transients.

That would be impossible. Capacitance and inductance are the most common cable related issues when an amplifier shuts down.

Does the system play properly when you have the old biwire cables in place?

Why not give the retailer a call?

Hi Tom,

This sounds an awful lot like what happened to another user in this thread at Audio Circle. Briefly, he changed cables on the amp used to power the woofers in his biamped setup to ones having a higher capacitance per unit length. For reasons explained in that thread, this combination caused his woofer amps to oscillate and shut down.

Does the problem go away again when you switch back to nordost blue heaven on the woofer amp? If not, then you have introduced some inadvertent wiring error and should re-check your wiring. If so, just for experiment, if you have any zip cord lying around, also try that on the woofer amp. Zip cord has very low capacitance per unit length (though the inductance is high), which helps prevent amplifier oscillation. If the zip cord and blue heaven both work okay on the woofer side, but the red dawn does not, I'd recommend sticking with the blue heaven for the woofer side.

Hi Tom,

Sorry you ended up having to sell the red dawn cables. Have you tried using them only on the mid/tweet, with the blue heaven on the bass? This may be stable for you while allowing for some improvement in sound. Just a thought.

A speaker cable and amp combination having a capacitance incompatibility that can shut down the amp is a pretty rare occurrence. Which is why only two of us (myself and Andy) thought of it as a possibility. I'm glad that you've decided to continue experimenting with cables. There are many great cables that will NOT cause the amp to oscillate.

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first: thanks to all who offered suggestions.
second: i sent them back this morning as the seller is a great guy who offered to buy them back at no penalty.
third: an individual in my audio club who make wires is making me a custom set. he understood the problem i had with the red dawns and has successfully dealt with it on other amp/speaker applications and offers 100% money back guarantee for satisfaction. after hearing the red dawns at lower volume levels and what an improvement that can be had, i just have to try again.
thanks again guys.

Yes. Capacitive problems with cables and amps, etc...show up as dynamic combinations -not as static test bench measurements.

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the sound is not as intense in the top end as with the nordost. in fact, i can play music without the speaker covers on. this seems to have allowed the rest of the range to open up a bit with more detail. i can also listen at higher levels for longer periods of time without fatigue. guess i'll have a nice pair of blue heavens for sale soon.

Not surprising, I consider the Nordost stuff to be pretty darn bright. They wouldn't have been my first suggestion to pair with Arcam.

You need very low resistance and very low capacitance in your speaker cables; the ones you have are neither!

Do what I did to solve the problem.

Buy a 100 foot spool of 10 gauge Alpha hookup wire, cut 8 12-foot lengths of wire, and terminate them with Audioquest Gold-plated spade lugs carefully soldered to the wire ends. This will give you much lower resistance than any commercially made cables that I know of, and lower capacitance than most. The resistance of each wire, properly soldered, will be approximately .015 ohm.

This wire has over 100 30-gauge strands and is fairly flexible. DO NOT use ties or anything else to "bundle" them. Let each wire lay separately on the floor or use some heat-shrink sleeving every 2 feet or so to keep them from tangling too much, but nice neat "bundling" that keeps the wires right next to each other adds lots of capacitance between wires; bad!

For my application, bi-wired Vandersteen 3A's, I used 8 individual 1/4" spade lugs on all 8 wires for the speaker ends, and FOUR 5/16" lugs for compatibility with the Bryston amplifier binding posts. The cost was about 260 dollars total, and I challenge anyone to buy a better set at any price.

To solder the amplifier end, I stripped each wire back 1 1/4 inches and then soldered the first wire of each pair into a large lug (I slipped 3 3-inch pieces of 3/8" red or black shrink tubing onto both wires of the pair first), and then took the second wire, split 50 strands off and twisted them, and then did the same with the other 50. Then I spiraled one bundle around the bare part of the first wire, then the second bundle alongside them, and then thoroughly soldered the two wires together behind the lug (completely flood and saturate with solder), and then used a heat gun to shrink the tubing over the soldered area.

Make sure that you push each wire end into a can of rosin flux before soldering, or you may not get good flow between all of the strands; be sure to solder very thoroughly and use 63/37 rosin core solder only. Get good flow through the wire and around the lug ends.

This will give you lower resistance than any commercial cable I have yet seen; most of them give you a lot of fancy insulation, a lot of total bullshit about their perfect copper or whatever, and resistance that isn't really that low! Anywhere from 70 to 90 percent of what you pay goes for cosmetics and some sort of fancy configuration that supports the bullshit index in the brochure; it doesn't contribute to a better cable.

It will also give you very low capacitance if you let the wires be mostly free of each other and don't bundle them tightly.

You can buy the Alpha 10-gauge hookup wire in several colors from Mouser Electronics for about $200 for a 100-foot spool; I like the blue. I use small pieces of red and black heat-shrink tubing at each end for color-coding. The Mouser part # for blue is 602-3081-100-06; the last number varies the color. Alpha wire is available from most electronics stores.

The "too bright" part is almost always caused by too much capacitance in combination with poor amplifier stability.

Very glad you solved your problem!