Has the dealer gone mad?
giroux
Posts: 3
I find it hard to believe the dealer would sell me an amp that wasn't compatible with my SDAs. That said, he sold me an NAD 2400 back in the late 80s. At that time I just assumed he new what he was selling me. Along with my Carver CT- 7 and Vector Research EQ, it sounded fantastic! Then, one day, no audio. Since then, everything has been sitting in the basement for 3 decades, unused. Just recently I hooked everything up, minus the EQ and experienced BIG distortion. Swapped out preamps, and same result. Could it be the 2400 is not common ground? NAD support told me, just the other day that the 2400 does not use a common ground. So, I'm confused.
Comments
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Grounds are connected in that amp.
That said, they go through a 0.1uF cap to the amp's circuit ground, but I dunno if that matters for SDAs.
my 3.1TLs
I will fix your shifted magnets for free.
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I find it hard to believe the dealer would sell me an amp that wasn't compatible with my SDAs. That said, he sold me an NAD 2400 back in the late 80s. At that time I just assumed he new what he was selling me. Along with my Carver CT- 7 and Vector Research EQ, it sounded fantastic! Then, one day, no audio. Since then, everything has been sitting in the basement for 3 decades, unused. Just recently I hooked everything up, minus the EQ and experienced BIG distortion. Swapped out preamps, and same result. Could it be the 2400 is not common ground? NAD support told me, just the other day that the 2400 does not use a common ground. So, I'm confused.
Your amplifier is almost FORTY YEARS OLD! It is perfectly compatible with your speakers, however it needs a refresh. Electrolytic capacitors only last 25-30 years…“Human beings are born with different capacities. If they are free, they are not equal. And if they are equal, they are not free.”
― Aleksandr Solzhenitsyn -
Grounds are connected in that amp.
That said, they go through a 0.1uF cap to the amp's circuit ground, but I dunno if that matters for SDAs.
It does.
Back in the day the dealers couldn't even set up the SDA's correctly let alone understand the requirements for them. I lost count on how many in the dealer showrooms were toed in like regular non-SDA speakers.
Which model SDA are we talking about here?
If you have a digital multi-meter set it to ohms, put each test lead in both negative speaker binding post and see what it reads. Make sure the amp off with no speakers hooked up.
Report back your readings, I'm guessing it may have a high ohm reading.
Post edited by pitdogg2 on -
Too late to edit - I obviously meant "speaker grounds" aka negative terminals are connected!
Good to know SDAs need speaker negative terminals connected to each other AND to circuit ground! my 3.1TLs
I will fix your shifted magnets for free. -
Are you sure that cap would not effect the common ground architecture?It is perfectly compatible with your speakers.
Maybe I'm thinking a resistor?
Gosh I'm getting old I vaguely remember something between the negatives would affect the common ground. -
I find it hard to believe the dealer would sell me an amp that wasn't compatible with my SDAs. That said, he sold me an NAD 2400 back in the late 80s. At that time I just assumed he new what he was selling me. Along with my Carver CT- 7 and Vector Research EQ, it sounded fantastic! Then, one day, no audio. Since then, everything has been sitting in the basement for 3 decades, unused. Just recently I hooked everything up, minus the EQ and experienced BIG distortion. Swapped out preamps, and same result. Could it be the 2400 is not common ground? NAD support told me, just the other day that the 2400 does not use a common ground. So, I'm confused.
Your amplifier is almost FORTY YEARS OLD! It is perfectly compatible with your speakers, however it needs a refresh. Electrolytic capacitors only last 25-30 years…
THIS!!!
Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Yes - it’s the negative speaker terminals that must share a ground plane for an amplifier to be common ground. For example, a Carver 1.0t is a common ground IF it is a “non-inverting” model (speaker terminals that are red/black/black/red). HOWEVER, the “inverting” model (red/black/red/black) is NOT common ground amplifier, as one channel is inverted - meaning one negative speaker terminal and one POSITIVE terminal share a ground plane. The havoc comes in when the interconnect cable is used, which couples the negative speaker terminals. This is a serious issue when amplifier channels do not share a ground plane.“Human beings are born with different capacities. If they are free, they are not equal. And if they are equal, they are not free.”
― Aleksandr Solzhenitsyn -
Using a multimeter set to "Ohms" and putting both leads on the negative speaker terminals, it reads Zero ohms. Oh, I'm speaking of the NAD 2400. NAD support told me the 2400 does not use a common ground config. So apparently they are wrong.
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Is it possible my SDA's crossover networks have gone bad over the years?
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Yes- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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Using a multimeter set to "Ohms" and putting both leads on the negative speaker terminals, it reads Zero ohms. Oh, I'm speaking of the NAD 2400. NAD support told me the 2400 does not use a common ground config. So apparently they are wrong.
You would be surprised at how many manufacturers get this wrong.
