Alpha Core Goertz
@ketchup I don't believe you need zobel networks with Macs on second thought due primarily to the autoformers.  I installed MI2's on my 501's and they sound great with no problems. They did send my old Classe amp into oscillation back in the day requiring me to use the RC links which solved the problem.  And you are correct -  connecting theils especially big ones are a major PITA. |
@pops Thiels are a pain (I had a pair once). I would attach the Zobels to the amp end if using Thiels. @ozzy I soldered ring terminals to my Zobels to make attaching them a breeze. You could also use spades. Easy peasy. These don't have to be expensive audiophile spades. I am under the impression that Zobels are required with some amps to prevent them from oscillating and overheating. I installed my Zobels and played the system all day, periodically measuring the amplifier's heatsink temperatures and recording the results. I then removed the Zobels and did the same thing. There was no difference in temps, so I concluded that they were not necessary for my particular amplifier. |
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@jacobsdad2000 Probably not. Tube amps are not likely to go into oscillation and blow up as spectacularly as we used to see with solid state amps made in the 1970s and 80s sans ZOBEL networks, when subjected to a highly capacitive speaker cable. That lesson was not ignored so many solid state designs have them built in (and the more competent ones from the 70s and 80s did too). But high end audio can sometimes be a bit of the Wild West and the design school of By Gosh and By Golly, so if you have a solid state amp from a smaller manufacturer its at least worth a phone call to see if the ZOBEL network might save a trip back to the manufacturer for repairs. |
A little too early to decide. I am comparing them to the bi-wire Clarus Crimson cables. The Clarus has a very open sound stage but perhaps lacks in the deep bass. At this time, I am actually using both. The Goertz on the bottom end and the Clarus over both hi-and low speaker binding posts, since they are bi-wire. Sorta like mixing the cables to accomplish what perhaps one version does not. I should add that my amp specs (Michi 8 1800 WPC @4 ohms.) call for larger gauge than standard speaker cables due to its design. "Speaker Wire Selection" "The size and quality of the wire can have an audible effect on the performance of the system. Standard speaker wire will work, but can result in lower output or diminished bass response, particularly over longer distances. In general, heavier wire will improve the sound." ozzy |
@ozzy how are you liking the Goertz Ml 3 Divinity cables. They worth a $250 investment?? |
That’s what I originally thought, then I read about different opinions about whether to use them or not. First off, after now actually trying them, I don’t think they are as transparent as they claim. And, their usage, I think, depends on the Amp design and perhaps the age when it was built. I don’t think todays modern amps will find the Zobel’s necessary. For the relatively inexpensive cost it was good insurance to get them anyway. ozzy |
@ozzy - I have MI 3s and don’t think they have Zobels built in. I don’t think it’s even an option, but maybe the previous owner of yours had them custom made. Who knows. I tried Zobels on the bass side of my bi-amped system and noticed no difference at all, so I removed them. |
I just received the Goertz Ml 3 Divinity cables. I connected it up with the Zobel’s and then without. They are installed only the bass side of a bi-wire speaker connection. With the Zobel’s the bass seemed not quite as articulate, and the midrange seemed more pronounced. When I removed the Zobel’s just the opposite occurred. Thus far the amps (Michi 8) do not seem to be having any issues sans the Zobel’s. Is it possible the Goertz cables already have the Zobel’s installed internally, and I just may be adding a second set? If so, is it something I could visibly tell? There may be a bump underneath the jacketing, it is very hard to tell. The Zobel’s that I purchased separately are very miniscule. I have emailed the seller and am waiting his reply. Can someone with these cables chime in? ozzy |
Thank you for the help. I just received the Zobel’s and I must say I am way underwhelmed. They look like 2 toothpicks! I wonder how long the little thin bare wire will last? I put them in some stackable spades, hopefully, to minimize wear. The actual used Goertz cables are to arrive tomorrow. ozzy |
The issue here is that the Goertz cables have high capacitance. If connected to an amplifier with a poorly designed feedback loop, the result can be an oscillation that can damage the amp (and probably a tweeter) in very short order. This was a much bigger problem in the 1970s and early 80s. But just because an amp was made in the 21st century does not guarantee its immunity; its best to check with the amp manufacturer to be sure there isn't a problem. The ZOBEL network may or may not help (but won't harm) depending on the amplifier's design. |
If I was to give my OPINION, I would place them between the + and - of the speaker’s woofer connections. I have read and in my experience the zobel networks have no impact on sound. Out of an abundance of caution for your beautiful system it would be great if Ralph @atmasphere would chime in. |
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They are about 4 inches long and the connection points are bare wire. From my own use and reading they are usually used at the speaker end and one network is placed between the positive (+) and negative (-) ends of your terminals. As you know, they are used to prevent amps from oscillation. It is my understanding that only a few amp designs are susceptible to oscillation due to the cables. But so easy to use I always used them. |
ketchup and jetter, Yes, I was able to order the Zobel’s from Goertz-Bridgeport Magnetics for $15+ $20 shipping. I should have them soon. It’s just that no one that works there knows if they are bare wire, spades etc. I guess I’ll find out. And/or if they go at the amp or speaker end. How can they all be so clueless? Not to mention not very good at speaking English, it was definitely a challenge to place an order. ozzy |
I found Alpha-Core cables non-linear properties simply FASCINATING. It's a true champion on excessive capacitive reactance perhaps made to emphasize trebble. Overall, the Alpha Core cables are excessively overpriced and definitely have design "glitch" to make phools believe that they "bring audible differences". Nordost is another scam polygon.  |
So, it’s amazing as I found this old thread to read about the poor customer service and that it still exists. A day ago, I contacted them (Goertz-Bridgeport Magnetics). I talked (transferred) to 3 different people (who did not speak very good English) and not one of them knew anything about the Zobel Networks that they sell. Hard to believe after all these years, they are still as inept. ozzy |
when i saw this thread a while back, i was going to pile on, but then i decided to just let it go. last summer, i sent a query to alphacore about the use and necessity of their zobel network in my system. in reply, i was told the zobel was to be put on my amp. i responded with i'm pretty sure the zobels go on the speakers and then asked to get a total cost on the zobels being shipped to me. i waited and waited and never received a response. eventually i sent them a personal check and received the zobels. i have bi-wireable speakers and decided to get away from the stock brass jumper plates. i emailed alphacore with a question about how many jumpers were included in their $20 set. i never received a response and then proceded to buy 2 sets...i only needed 1. alphacore's audio sales dept. seems to be made up of people who don't have much of an understading of audio playback. and they seem to be overly sensitive when u question them about it. that said, i do like their speaker wire. |
I have long forgotten this thread. To go back and respond to Willster's questions. I was referrring to (and rather poorly in retrospect) the "reactive oscillations" that you more properly described. I don't consider the zobels as either a tweak or as a band aid, but more as minor and easily reversible if need be, modification. Nelson Pass the designer of the amp in question suggests such a modification on his web site, Thiel's tech support suggested the use of these cables with the zobels if needed and of course so did Alpha-Core. FWIW, I discovered all of this prior to implementation and your question. While it may appear less than elegant to you, I can assure you that the unobstrusive use of the zobels and Goertz cables have provided me with the most satisfactory sound to date and I am not tempted to change. |
Swirl, Thank you for mentioning the Cable Company.. I asked them questions re: pricing, and they were very fast to respond with a full price quote and ordering information within a day. Based on our experiences, I would not suggest contacting Alpha-Core directly... they seem to just not care about direct sales. Props to Cable Company for wanting business, and being helpful. Will |
Just wanted to put in my two cents... I read this thread months ago, and coincidently decided to purchase some AG1 speaker cable from them. Alpha-Cores online shop did not have the length I needed, so I called them directly. The person I spoke to on the phone told me they only take orders online, and they suggested I email. So, I emailed and was told of course I could get them in any lenth I desire, and to consult the pricing chart (I had already told them the exact length and terminations in my email- I only needed an invoice). Since then, I have emailed once a week for almost a month, and never received a reply back again. No ordering instructions- nothing. I have never had a company ignore my business as well as that one did. Not recommended based on my (non)customer experience. Will |
unsound, by "feedback from the speakers" would you be referring to back emf? Do you have any technical background, by the way? I'm wondering if you actually know what a zobel does. Let me restate that the reason amp designers put networks at the output of their amps is to prevent the amp going into oscillation with reactive loads. Many designers feel that the sound of the amp is more open without the network but, of course, this makes them more suscepible to oscilation from very reactive speakers or, perhaps, low inductance cables. I fear I am belaboring the point but I keep getting the impression that I'm not getting that point across. Perhaps you are thinking of a zobel as a "tweak" rather than a bandaid. When speaker designers build the passive crossover networks for their speakers they can incorporate elements into the design that would effectively be a built in zobel. I would have to assume that if the speaker designer did not use this technique it would be because it was felt that it changed the voicing of the speaker in undesirable ways. So if your amp doesn't have it and your speakers don't have it, it's likely because the designers didn't want it. So, wouldn't it be better to contact Threshold, in your case, tell them what speakers you are trying to drive and ask them to recommend a cable that would work most effectively in that configuration? And/or, you could talk to the speaker manufacturer. System synergy and component compatibility might be improved, i.e. it could sound better. Then again, maybe you're satisfied with what you currently have. I am just trying to clarify my reasoning. |
The zobels needed for some amps with Alpha-Core Goertz (or other designs with similar characteristics for that matter) is due to feedback from the speakers. Placing the zobels at the speaker terminals easily and unobstrusively resolves this dilemna. I'm not alone in finding the Alpha-Core Goertz speaker cables to be particularly compatible with the wide-bandwidth Threshold amps. In no way am I arguing that it's not the amps that neccesitate the use of zobels, only that there is a very easy solution that accomplishes the desired end result, and it does so with out any compromise. If needed, there is no sound reason not use zobels. |
Unsound, it is a normal design practice to put a network at the output of an amplifier. In effect, it accomplishes the same thing as adding a zobel, i.e. keeping the amp stable into reactive loads. There are designers who feel that this network effects the sound of the amp in ways they find undesirable. Some designers leave them out for this reason. The question for the owner of one of these amps is, do I find speaker cables that the amp can drive or do I bandaid the design with a zobel, effectively putting back what the designer avoided in the first place. My solution is to use an amp that doesn't need help in this area. Were I to choose an amp like the one you describe, I'd also choose cables that the amp was compatible with. YMMV |
FWIW...I run a biwire setup with the top end being AC MI-2's & the bottom braided Cat5...both are high capacitance/low inductance cables. Amp is a McCormack DNA-1. No zobels...no issues. I'll be switching out the Cat 5 cables in favor of a second set of AC MI-2's..don't plan on adding zobels. I don't think the capacitance will be much different between the Cat5's & the MI-2s...actually it'll probably be a bit less. I have no issues with zobels & would use them if they were needed. When I asked Steve McCormack about the need for zobels in the DNA1 he said, "Hmmm...not sure if you'll need them. Try the cables & if you need zobels you'll know right away as the you'll hear a squeal." I installed the cables & very gently fired things up...no issues & that was a year ago. |
Willster, many fine wide bandwidth amps such as my Threshold and I would imagine Spectral need the zobels. It is not necessarily an indication of poor design that zobels may be needed. One might even argue that it might be be an indication of better quality. I would suggest using zobels in most applications, they can only help and do no harm. |
Amazing how all those years of good service can be negated by one bad employee. I sure don't blame anyone for not doing business with a company that doesn't seem to value you as a customer. I'd probably have taken my business elsewhere under the described circumstances. I've had AC speaker cables for several years. I don't use terminations, I just shape the end of the wide flat cable so that it fits on my binding posts. Neve had any shorting problems but I was carful connecting them non the less. A direct connection is superior to using added terminators such as spades. As to Zobels and amps, I'd be more inclined to rid myself of amps that need a zobel to function with these cables than to get rid of the cables. Most techincally knowledgeable people agree that, for speaker cable, low inductance cable such as the ACs are best. Amps that can't handle low inductance speaker cable are suspect to me. My Krells don't have any problems with the AC stuff and I haven't added any zobels. |
