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I think an amp sounds best when the speaker impedance matches the transformer.
Also, the way I understand is when you put a n 8ohm speaker on a 4ohm
transforme, the stress on the primary windings of the transformer is
doubled, and can allow arcing though the laminations. It is increased further
by the greater th e mis-match. A friend of mine blew up a really nice 2ohm
brown Concert Amp in just a few minutes after connecting it to a 16ohm
Marshall Cabinet.
-dave
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Dave,
Matching impedance is good, of course. <g> I think what
we've been talking about, for the most part, is using
what one has on hand in a less-than-desirable situation,
i.e. you own an 8 ohm cab, and you just bought a 4 ohm
output amp head - can you hook it up to try out the amp,
without fear of blowing anything? That's the kind of
scenario for which I have no qualms about answering 'Yes'.
Otherwise, you're correct in saying that one is asking
for trouble if one runs a mis-matched combo for any
length of time. How long can it be done? Well, that's
up to one's wallet. Suffice it to say, the longer one
does this, the greater the risk. It may be OK to go for
a several hours, over a month or so, but that's a bit
risky. For a year? No way, not at all.
Let's put a total number of hours on it. And this time,
I freely admit that I'm shooting from the hip, so if
anyone wants to contest this, then the group can only
benefit from your input. I'll say, any mis-match, be it
up or down, by only one step, should be limited to 20
hours or less, in total. I've certainly gone longer than
that my own self, but I knew what I was in for. (Not to
mention that I can afford my own labor costs to repair any
damage. <g>) You should never mis-match by a gap greater
than one step, not even in an emergency. If the combo
lasts for even just a few minutes, count yourself very
lucky. After that, you deserve whatever happens. Dave's
friend with the Concert/Marshall combo is a case in point.
unlunf
--- In , dave wronski <stickmandw@y...> wrote:
>
> I think an amp sounds best when the speaker impedance
> matches the transformer.
>
> Also, the way I understand is when you put a n 8ohm
> speaker on a 4ohm transformer, the stress on the primary
> windings of the transformer is doubled, and can allow
> arcing though the laminations. It is increased further
> by the greater the mis-match. A friend of mine blew up
> a really nice 2ohm brown Concert Amp in just a few minutes
> after connecting it to a 16ohm Marshall Cabinet.
>
> -dave
I think the risk is greater if you're talking about older amps where the
natural chemical formulation of the binders of the laminations are beginning to
break down. Arcing can occur easier, I think. And, if you ever need a good
replacement, try Obsolete Electronics, or Mercury Magnetics.
unlunf <> wrote: Dave,
Matching impedance is good, of course. <g> I think what
we've been talking about, for the most part, is using
what one has on hand in a less-than-desirable situation,
i.e. you own an 8 ohm cab, and you just bought a 4 ohm
output amp head - can you hook it up to try out the amp,
without fear of blowing anything? That's the kind of
scenario for which I have no qualms about answering 'Yes'.
Otherwise, you're correct in saying that one is asking
for trouble if one runs a mis-matched combo for any
length of time. How long can it be done? Well, that's
up to one's wallet. Suffice it to say, the longer one
does this, the greater the risk. It may be OK to go for
a several hours, over a month or so, but that's a bit
risky. For a year? No way, not at all.
Let's put a total number of hours on it. And this time,
I freely admit that I'm shooting from the hip, so if
anyone wants to contest this, then the group can only
benefit from your input. I'll say, any mis-match, be it
up or down, by only one step, should be limited to 20
hours or less, in total. I've certainly gone longer than
that my own self, but I knew what I was in for. (Not to
mention that I can afford my own labor costs to repair any
damage. <g>) You should never mis-match by a gap greater
than one step, not even in an emergency. If the combo
lasts for even just a few minutes, count yourself very
lucky. After that, you deserve whatever happens. Dave's
friend with the Concert/Marshall combo is a case in point.
unlunf
--- In , dave wronski <stickmandw@y...> wrote:
>
> I think an amp sounds best when the speaker impedance
> matches the transformer.
>
> Also, the way I understand is when you put a n 8ohm
> speaker on a 4ohm transformer, the stress on the primary
> windings of the transformer is doubled, and can allow
> arcing though the laminations. It is increased further
> by the greater the mis-match. A friend of mine blew up
> a really nice 2ohm brown Concert Amp in just a few minutes
> after connecting it to a 16ohm Marshall Cabinet.
>
> -dave
.
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Dave,
Good point about the age thing.
Over the years, I've heard both good and bad things
about Mercury Magnetics. Anyone got any stories to
share about them, pro or con?
FWIW, I've been a happy camper for a long time with
WeberVST's parts, including their transformers.
(Now located at >
unlunf
--- In , dave wronski <stickmandw@y...> wrote:
>
> I think the risk is greater if you're talking about
> older amps where the natural chemical formulation of
> the binders of the laminations are beginning to break
> down. Arcing can occur easier, I think. And, if you
> ever need a good replacement, try Obsolete Electronics,
> or Mercury Magnetics.
>
> Dave
>
I have never heard a bad word about Mercury Magnetics. A few years ago I neaded
an output transformer for my original four input tweed Bassman. The original
went bad a couple of years before, and I just didn't like the sound of the
replacement sounded, and the way acted. Putting in the MM trans. gave me back
everything the original used to deliver and more. This had to do with acoustic
coupling, and coherancy, and richness of sound. I also put a MM trans. in my
Slacktone amp, which is a modified Super reverb. I needed 2/4 ohm outputs.
Sergio, the owner of MM, tried to talk me out of the second tap, he said it
would degrade the performance. But, I told him I needed it for touring and it
had to be flexible.
An interesting story about Mercury Magnetics... Jimmy Page got one of the
first 100 watt Marshalls. Built in 1965. He used in the Yardbirds, to early
Zep, then it blew the output trans. He kepted it for many years vhoping he
could get the very unusual design trans. fixed. He finelly met Sergio, who
fixed the original, and made several clones for him. I think he now offers
that design for sale.
Another note. Mercury Magnetics has the original book of Triad transformer
core formulations. This is vital information needed to make all those great
Fender transformers aas replacements.
-- dave
unlunf <> wrote: Dave,
Good point about the age thing.
Over the years, I've heard both good and bad things
about Mercury Magnetics. Anyone got any stories to
share about them, pro or con?
FWIW, I've been a happy camper for a long time with
WeberVST's parts, including their transformers.
(Now located at >
unlunf
--- In , dave wronski <stickmandw@y...> wrote:
>
> I think the risk is greater if you're talking about
> older amps where the natural chemical formulation of
> the binders of the laminations are beginning to break
> down. Arcing can occur easier, I think. And, if you
> ever need a good replacement, try Obsolete Electronics,
> or Mercury Magnetics.
>
> Dave
>
.
Visit for archived messages,
bookmarks, files, polls, etc.
SPONSORED LINKS
Guitar music theory
Stringed instruments Guitar music book
Guitar sheet music Guitar music sheets
Guitar technique
---------------------------------
YAHOO! GROUPS LINKS
Visit your group "SurfGuitar101" on the web.
To unsubscribe from this group, send an email to:
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
---------------------------------
---------------------------------
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