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Would you change your amp selection knowing...?

OK - so this thread was promted by some comments on another thread - not wanting to hijack that thread I created this one...

ISSUE: some high current designed amps have an issue with speaker cables that have a high capacitance.
- the amp can be driven to self destruction because of internal oscilation caused by the high capacitance of the speaker cable
- this does NOT apply to Tube amps - i.e. to my knowledge

The amps I know of that are affected in this way are Ayre, Gryphon and NAIM
- only NAIM warns of this up front AND instruct their dealers to let customers know about it

So why don’t other brands warn about the possibility?

QUESTION:
- would it put you off?
- would you select a different amp if the manufacturer warned of this "issue" up front?

Cheers



williewonka
ieales's avatar
ieales
1,201 posts
 
If bi-wiring, how would these capacitance numbers work...simply additive? or something else??
Parallel doubles capacitance and halves inductance and resistance.

Bi-wiring separates the load into two parts. Response for each part differs from a single drive.

Don't know a thing about Clear Day and they provide no technical information. From reading their information, it seems their product comes from 'messing about' and may be very specific or just generic. Solid core will be stiff. Price seems too low for pure silver of a reasonable gauge, say 18. That's about 4oz of pure silver ~$65. 18ga solid silver hookup wire is about $9/ft. 32 feet for two 8' runs is ~$288. Add in connectors, heat shrink and labor and the price is too low.
ghosthouse's avatar
ghosthouse
4,319 posts
 
ieales -
Thanks for the bi-wire capacitance info.

Don’t want to sidetrack this thread into a defense of Paul Laudati and Clear Day Cable though I will say I’m inclined to take him at his word. Paul has been around a while and it would be a fairly easy task to "autopsy" one of his cables and refute his solid silver claim if it were bogus. To my knowledge, that has not happened. I can report the Double Shotguns were better with my gear than Morrow Audio SP-4 silver plated copper...and not by a little bit. They are also preferred in one amp/speaker combination I have over Cardas Parsec cable. The review at the link below, while largely anecdotal, might be of interest.

http://www.highfidelityreview.com/clear-day-audio-cables.html
almarg's avatar
Ag insider logo xs@2x
almarg
9,670 posts
 
@unsound
I found a link to the paper from which the excerpt shown at the link you provided was taken:

http://sound.whsites.net/cable-z.htm

My conclusion reading all of this is that I wouldn’t worry about his allegation that the resistor value chosen by Goertz is not ideal. As he even said, based on his simulations: (Comments shown in brackets are mine):
Even 100nF in series with 10 ohms restores the amplifier phase margin to normal.... 4.7 ohms is preferable, but the phase margin is barely affected. The speaker end response has a small ’lump’ with 10 ohms [between about 5 and 10 MHz!], and phase goes ’wobbly’ at above 20MHz. This is probably not a concern, and you will almost certainly get away with it.
I don’t, however, see any reason to doubt his statement that:
It is very evident that this particular cable [Goertz MI 1] should never be used without a Zobel at the speaker end....
Best regards,
-- Al

unsound
7,336 posts
 

Al, As I suspected.

 I thought I could count on you to illuminate this topic. Let me say that I am humbled that you went out of your way to research the hidden links, and offer your considered thoughts on the subject. I sincerely appreciate it; thank you.

cycles2
208 posts
 
Would speaker cables that use separate jackets for the + and - speaker have zero (no) capacitance?

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