Did I kill my power amp?

Archived from groups: rec.audio.pro (More info?)

Jonny Durango wrote:

> My Adcom 535 II seems to be dead, and I'm afraid I *may* have been at
> fault. I say "may" because I bought it off eBay and never got the chance
> to properly test it (yeah I know, spare me the lecture).
>
> I was trying to get it to work with my newly finished LS3/5A monitors
> and external crossover. Unfortunately I had the crossover incorrectly
> wired at first so the HF drivers were NOT in the circuit. Everything
> else was wired correctly (ie. the inputs and LF outs) so the amp was
> powering the LF drivers only.
>
> At first it did pretty much nothing and would only make crackling sounds
> in the speakers when I turned the preamp way up, to the point of
> distortion....I could get the "clip" light to light up on the 535, but
> all the speakers did was crackle relatively quietly.
>
> Now it won't make any sound at all (even crackling) and I can't get the
> clip light to come on even by heavily overdriving the preamp.
>
> Would it be possible that the impedence load due to the lack of a HF
> driver killed the amp?

That's pretty much a vanishingly small possibility.


> Also, I'm using my mixing console (Mackie
> 1604vlz) as the preamp, could that be the problem?

LOL ! Not in the sense that that it makes crackles but you might get the
piss taken for owning one !


> I think it's more likely that I got ripped off...what do you think?

Yes - sounds like it.


> Anyway, I'm pretty sure it's dead. Does it sound like it's an easy fix
> (ie. worth fixing) or should I find something else? Thanks!

Depends on you I guess. What bothers me more is that you'd use an unproven
amp to power some new presumably home made monitors.

Graham

Archived from groups: rec.audio.pro (More info?)

dale wrote:

> where was the fuse??

Where the sun shines not, along with the OP's head! ;-)

Archived from groups: rec.audio.pro (More info?)

In article <LqadnTdhebHHv-bfRVn-sQ@comcast.com> jonnydurango1BUSH_FROM_OFFICE@comcast.net writes:

> My Adcom 535 II seems to be dead, and I'm afraid I *may* have been at
> fault. I say "may" because I bought it off eBay and never got the chance
> to properly test it (yeah I know, spare me the lecture).

> At first it did pretty much nothing and would only make crackling sounds
> in the speakers when I turned the preamp way up, to the point of
> distortion....I could get the "clip" light to light up on the 535, but
> all the speakers did was crackle relatively quietly.

You bought a broken amplifier.

Lecture spared.

> I think it's more likely that I got ripped off...what do you think?

Of course you did. (still trying to spare the lecture)




--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

Archived from groups: rec.audio.pro (More info?)

Jonny Durango wrote:
> My Adcom 535 II seems to be dead, and I'm afraid I *may* have been at

> fault. I say "may" because I bought it off eBay and never got the
chance
> to properly test it (yeah I know, spare me the lecture).
>
> I was trying to get it to work with my newly finished LS3/5A monitors

> and external crossover. Unfortunately I had the crossover incorrectly

> wired at first so the HF drivers were NOT in the circuit. Everything
> else was wired correctly (ie. the inputs and LF outs) so the amp was
> powering the LF drivers only.
>
> At first it did pretty much nothing and would only make crackling
sounds
> in the speakers when I turned the preamp way up, to the point of
> distortion....I could get the "clip" light to light up on the 535,
but
> all the speakers did was crackle relatively quietly.
>
> Now it won't make any sound at all (even crackling) and I can't get
the
> clip light to come on even by heavily overdriving the preamp.
>
> Would it be possible that the impedence load due to the lack of a HF
> driver killed the amp? Also, I'm using my mixing console (Mackie
> 1604vlz) as the preamp, could that be the problem?
>
> I think it's more likely that I got ripped off...what do you think?
>
> Anyway, I'm pretty sure it's dead. Does it sound like it's an easy
fix
> (ie. worth fixing) or should I find something else? Thanks!
>
> Jonny Durango

Are you sure you had the amp connected correctly? In most amps that I
have worked with functioning clip indidicators suggest the OP stage is
OK unless they are hard on all the time with no signal input. It seems
to me you were driving it into a short. If you are lucky you just have
blown fuses. You need to give it to a tech to look at.

Steve Lane

Archived from groups: rec.audio.pro (More info?)

Jonny Durango wrote:
> My Adcom 535 II seems to be dead......
>
> .......I was trying to get it to work with my newly finished LS3/5A
monitors
> and external crossover. Unfortunately I had the crossover incorrectly
> wired at first so the HF drivers were NOT in the circuit......
>
> .....I could get the "clip" light to light up on the 535, but
> all the speakers did was crackle relatively quietly.....
>
> .....Now it won't make any sound at all (even crackling) and I can't get
the
> clip light to come on even by heavily overdriving the preamp.....
>
> ......I think it's more likely that I got ripped off...what do you think?
>
> Anyway, I'm pretty sure it's dead. Does it sound like it's an easy fix
> (ie. worth fixing) or should I find something else? Thanks!

I bought an Adcom 535 MkII off ebay. It was dead the first time I
turned it on. I replaced the fuse outside the case. I peered at the two
fuses inside the case. I took it to a tech. After six weeks the amp
was ready. I asked the tech what was wrong with the amp. He
shrugged his shoulders. He said he cleaned it up and resoldered joints.
The amp runs hot (no cooling fan) and stresses the solder joints, he
said. Cost $40. I thought wow, he only spent an hour on it.

A few weeks later the amp was dead agian. This time I took the
case off the amp. There were dust bunnies and cat hair, etc. I
thought, hey, I thought the tech cleaned in here! I replaced the
outer fuse. The amp worked again. I figured I had blown the fuse by
turning the amp on and off using the power strip. I had heard a surge
of energy coming through the speakers. Now I make sure the amp
itself is turned off whenever I turn the power strip on and off.

My theory is that the tech never opened the amp case. He changed the
outer fuse and charged me $40. I'd have been fine with: "I changed the
fuse, it'a forty bucks".


Tim Sprout

Archived from groups: rec.audio.pro (More info?)

Johnny, odds are that it simply needs the supply rail fuses replaced. These are on the circuit
board for each amp channel. These amps are pretty damn hard to blow up.
Tim, the 535 & 535II are not supposed to run hot at all, unless driving it hard for a while.
At idle, shouldn't be more than a bit warm. I've had a 535II running in my system for the last
few days straight, with a tube preamp sitting right on top, and the amp is nowhere near hot.
Your amp has either mis-adjusted bias current, or has a strange problem.

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Tim Sprout" <tman@ptialaska.net> wrote in message news:117na21tiaf9o9e@corp.supernews.com...
> Jonny Durango wrote:
> > My Adcom 535 II seems to be dead......
> >
> > .......I was trying to get it to work with my newly finished LS3/5A
> monitors
> > and external crossover. Unfortunately I had the crossover incorrectly
> > wired at first so the HF drivers were NOT in the circuit......
> >
> > .....I could get the "clip" light to light up on the 535, but
> > all the speakers did was crackle relatively quietly.....
> >
> > .....Now it won't make any sound at all (even crackling) and I can't get
> the
> > clip light to come on even by heavily overdriving the preamp.....
> >
> > ......I think it's more likely that I got ripped off...what do you think?
> >
> > Anyway, I'm pretty sure it's dead. Does it sound like it's an easy fix
> > (ie. worth fixing) or should I find something else? Thanks!
>
> I bought an Adcom 535 MkII off ebay. It was dead the first time I
> turned it on. I replaced the fuse outside the case. I peered at the two
> fuses inside the case. I took it to a tech. After six weeks the amp
> was ready. I asked the tech what was wrong with the amp. He
> shrugged his shoulders. He said he cleaned it up and resoldered joints.
> The amp runs hot (no cooling fan) and stresses the solder joints, he
> said. Cost $40. I thought wow, he only spent an hour on it.
>
> A few weeks later the amp was dead agian. This time I took the
> case off the amp. There were dust bunnies and cat hair, etc. I
> thought, hey, I thought the tech cleaned in here! I replaced the
> outer fuse. The amp worked again. I figured I had blown the fuse by
> turning the amp on and off using the power strip. I had heard a surge
> of energy coming through the speakers. Now I make sure the amp
> itself is turned off whenever I turn the power strip on and off.
>
> My theory is that the tech never opened the amp case. He changed the
> outer fuse and charged me $40. I'd have been fine with: "I changed the
> fuse, it'a forty bucks".
>
>
> Tim Sprout
>
>