I learned the hard way

Some (not all) solid state amps that use a high-current design can self destruct due to internal oscillation when a speaker cable having a high capacitance is connected to them.

This is NOT an issue with TUBE amps to my knowledge

Ayre, Gryphon and NAIM are three amps that I know of that can be effected in this way

Regards

@williewonka ,

I wonder...? is this particular issue one that a reputable dealer would have knowledge of and then convey that to a potential buyer?

@slaw - I became aware of this issue because I have a NAIM amp and they promote the use of low capacitance cables as stated on their web site, probably because they have had to deal with the issue before.
Their NACA5 cables have pretty low capacitance values

The acquaintence that had the Ayre amps went on to borrow the Gryphon after the Ayre had the issue.

Unfortunately the Gryphon suffered the same fate - OUCH!

Neither Ayre or Gryphon had anything posted on their web sites at the time (over 2 years ago)

Even the technician that fixed the Gryphon had never heard of the issue. He was quite nervous when I hooked up my Van den Hul D352 cables - also very low capacitance - he even asked "are you sure" - YES was the reply - they presented no problems.

The cables that caused the issue were Cardas - I don’t recall the model - but a few of their cables do have quite high capacitance and they do publish the capacitance values, so perhaps they are at least aware of the possibility?

As for the Dealers - I have only found NAIM dealers I have dealt with do advise customers of this issue - probably in order to sell you the NACA5 cable :-).

Is this a case of "Buyer Beware" - or should the manufacturer "state the obvious"

I think it should be - ON THE BOX - at least in the manual - in BIG RED LETTERS!

It’s funny to think the manuals contain text that warn you of electric shock hazards - but not this issue?

It would be interesting to know if it is covered under related warranties?

All I know is - the Ayre and the Gryphon were in the $10k snack bracket - they should have a $0.50 sticker on the top stating the obvious

Regards - Steve

I learned twice that the stylus guard protects the stylus only when installed.  I also learned when buying a used cartridge the same rule aplies for a total of three stylus guard lessons.  

@slaw , did the same exact thing about 2 to 3 years ago, still have about 1/4 bottle left because I only use it once in awhile.

@williewonka - This amplifier/ high capacitance speaker cable issue is discussed by Roger Russell (former Macintosh designer) in the attached URL below.  Scroll down to the "Amplifier Stability and Amplifier Performance" section.

http://www.roger-russell.com/wire/wire.htm#silverwire

@mikexxyz - Exactly so.  Pathological cables connected to pathological amplifiers may well cause sonic (and electronic) problems. Put another way, cables designed to affect the frequency response (i.e. tone controls) and/or amplifiers designed to have a particular 'sound' (i.e. a tone control with gain, versus a straight-wire with gain approach), will indeed affect the sound, and/or result in liberating smoke previously trapped within the electronics...

@mikexxyz - I took a read of the article and stopped when I got to...

It can be solid, stranded, copper, oxygen free copper, silver, etc.--or even "magic" wire--as long as the resistance is kept to be less than 5% of the speaker impedance. There is no listening difference as long as the wire is of adequate size.

The statement is flawed and he really shows his ignorance about the nuances of cable materials and geometries.

This statement trivializes the scale of the issue...

Unfortunately, in addition to sounding different with a small amount of overshoot, a few unstable or borderline amplifiers can even go into oscillation.

NAIM, Ayre, Gryphon are three I know of that suffer fron oscilation and I would not consider any of them "borderline"

Sorry - but then that's just my opinion :-)
 

@williewonka - I totally agree with you that NAIM, Ayre, and Gryphon are not borderline designs.  

I was using stylus cleaning gel on my Lyra Skala after every record played. During one listening session I lifted the arm from the gel, lowered it onto the lead in groove & watched it skim across the record... The gel had pulled off the tip.

I own a Sound-Smith Zephyr MIMC Star cartridge and the maker/manual recommends lowering the stylus 2/3 times into a flat piece of Blue Tack, before/after each record is played. Seems to work very well.

williewonka, by now you probably know that to prevent the oscillation you would want to buy a pair of zobel networks for $20 from Goertz Audio which is owned by Bridgeport Magnetics Group.

Do not plug a 220v LP12 (which you rewired for 110v last year and forgot) into a step up transformer and apply 220v to the now 110v board.

@jetter - would that be - after the amp has oscilated to destruction? :-)

Actually, I had not heard of zobel networks until your repsonse (thanks)
- I purchased a NAIM and the dealer warned me of the issue
- so I bought cables that worked with the amp.

I think the issue is, manufacturers should warn about the possibility
- then the customer could take the appropriate action to prevent it - whatever solution they choose.
- perhaps the manufacturer should include a Zobel network in the box?

Thanks for the info - sharing benefits everyone.

RE: oscilation...
I don't want to hijack this thread - topic is continued here...

https://forum.audiogon.com/discussions/would-you-change-your-amp-selection-knowing

Cheers

Did this thread get mixed up with the "Would you change your amp selection knowing...?"  one???

I actually let my wife influence me into replacing a really lovely pair of Boston Acoustics T-830s with a Bose Acoustimass set-up because it fit into her design plans better. I still can't believe it!

It took me years to stop chasing Audio Perfection as portrayed by some Audio magazines and  some High end Audio stores and build a system more for the enjoyment of music! Throwing a lot of money at your perceived system short comings can lead you into a series of sideway steps.