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I need to replace the blown 6" speaker on my Danelectro Cadet amp. I
notice the speaker has a transformer type thing on it (on the speaker
housing). Can I replace the speaker with one that doesn't have that
on it?
I'm looking at the MOD 6-15 from Jensen. Will this work?
Thanks,
Mike
Mike,
I can't find a definitive history of the Cadet on the web, but
the several models I saw were from the mid 50's and later, so
I'm surprised at the speaker being straight out of the late
30's or early 40's. The "transformer" on the back is what we
called a "field coil", it did double duty.
In a nutshell, it was the standard technology before permanent
magnets came on the scene. It created the magnetic field around
the voice coil while it was energized (whenever the power was on),
and it also served as the choke coil in the power supply circuit.
This made the thing "half as expensive" from a manufacturing
standpoint, doing two jobs instead of one like that.
In theory, you shouldn't replace the old speaker with a new type,
but I've seen it done, and it didn't sound any worse than when
the amp was new. (These things were notoriously noisy.) To do
this, you'd have to carefully remove the coil from the old speaker's
frame, and mount it somewhere inside the chassis. You also have an
impedance matching issue, many of those older beasts didn't have
their ohms rating marked at all, let alone clearly enough to stand
the aging of several decades. 8 ohms is a good start, and unless the
sound is wildly distorted, that should be good enough for general use.
HTH
unlunf
--- In , "urbansurfkings" <surfkings@...> wrote:
>
> I need to replace the blown 6" speaker on my Danelectro Cadet amp. I
> notice the speaker has a transformer type thing on it (on the speaker
> housing). Can I replace the speaker with one that doesn't have that
> on it?
>
> I'm looking at the MOD 6-15 from Jensen. Will this work?
>
>
>
> Thanks,
> Mike
>
There are some small amplifiers from the '50s, '60s
that had the output transformer mounted to a standard
permanent magnet speaker. I think the "field coil"
type speaker went out of use around the late '40s.
--- unlunf <> wrote:
> Mike,
>
> I can't find a definitive history of the Cadet on
> the web, but
> the several models I saw were from the mid 50's and
> later, so
> I'm surprised at the speaker being straight out of
> the late
> 30's or early 40's. The "transformer" on the back
> is what we
> called a "field coil", it did double duty.
>
> In a nutshell, it was the standard technology before
> permanent
> magnets came on the scene. It created the magnetic
> field around
> the voice coil while it was energized (whenever the
> power was on),
> and it also served as the choke coil in the power
> supply circuit.
> This made the thing "half as expensive" from a
> manufacturing
> standpoint, doing two jobs instead of one like that.
>
> In theory, you shouldn't replace the old speaker
> with a new type,
> but I've seen it done, and it didn't sound any worse
> than when
> the amp was new. (These things were notoriously
> noisy.) To do
> this, you'd have to carefully remove the coil from
> the old speaker's
> frame, and mount it somewhere inside the chassis.
> You also have an
> impedance matching issue, many of those older beasts
> didn't have
> their ohms rating marked at all, let alone clearly
> enough to stand
> the aging of several decades. 8 ohms is a good
> start, and unless the
> sound is wildly distorted, that should be good
> enough for general use.
>
> HTH
>
>
> unlunf
>
> --- In ,
> "urbansurfkings" <surfkings@...> wrote:
> >
> > I need to replace the blown 6" speaker on my
> Danelectro Cadet amp. I
> > notice the speaker has a transformer type thing on
> it (on the speaker
> > housing). Can I replace the speaker with one that
> doesn't have that
> > on it?
> >
> > I'm looking at the MOD 6-15 from Jensen. Will this
> work?
> >
> >
>
> >
> > Thanks,
> > Mike
> >
>
>
>
>
>
>
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Hey Mike---If you're still confused, just look where the transformer
thingie is mounted. If it's on the frame of the speaker, it's just the
output transformer that would ordinarily be on the chassis in most amps
(I also have a bigger Dano amp with a 12" that has the transformer on
the speaker). In that case, just replace the speaker and mount the
transformer anywhere that's convenient. If it is a field coil speaker
(it will have wires going into the magnet), that's more of a hassle, as
they need to be reconed (good luck) and you have to remove the thing
from the circuit. One more thing: On some small amps, like Fender
Champs, they used oddball 3.2 ohm speakers. Be sure to find out the
impedence of yours before ordering a replacement. If it's fried, try
to find some numbers on it. If it's just ripped, you can still measure
it with a meter. You want to get the correct one for best
performance. Good luck, Matt Q.
Bill,
While I don't recall ever seeing this kind of thing, I looks like
at least two others here have. So my next question would be to ask
you how many wires are coming out of the chassis to that "unit"?
Four or five, and it's very likely a field coil as I previously
mentioned. Two, and it's probably a small Class A amplifier with
the output xformer mounted on the speaker as noted by Dave and Matt.
unlunf
--- In , "reventlos" <matt@...> wrote:
>
> Hey Mike---If you're still confused, just look where the transformer
> thingie is mounted. If it's on the frame of the speaker, it's just
> the output transformer that would ordinarily be on the chassis in
> most amps (I also have a bigger Dano amp with a 12" that has the
> transformer on the speaker). In that case, just replace the speaker
> and mount the transformer anywhere that's convenient. If it is a
> field coil speaker (it will have wires going into the magnet),
> that's more of a hassle, as they need to be reconed (good luck) and
> you have to remove the thing from the circuit. One more thing:
> On some small amps, like Fender Champs, they used oddball 3.2 ohm
> speakers. Be sure to find out the impedence of yours before
> ordering a replacement. If it's fried, try to find some numbers on
> it. If it's just ripped, you can still measure it with a meter.
> You want to get the correct one for best performance. Good luck,
>
> Matt Q.
>
Thanks for all the help.
"Two wires, and it's probably a small Class A amplifier with
> the output xformer mounted on the speaker as noted by Dave and
Matt."
That's the one!
mike
--- In , "unlunf" <unlunf@...> wrote:
>
> Bill,
>
> While I don't recall ever seeing this kind of thing, I looks like
> at least two others here have. So my next question would be to ask
> you how many wires are coming out of the chassis to that "unit"?
> Four or five, and it's very likely a field coil as I previously
> mentioned. Two, and it's probably a small Class A amplifier with
> the output xformer mounted on the speaker as noted by Dave and
Matt.
>
>
> unlunf
>
>
> --- In , "reventlos" <matt@> wrote:
> >
> > Hey Mike---If you're still confused, just look where the
transformer
> > thingie is mounted. If it's on the frame of the speaker, it's
just
> > the output transformer that would ordinarily be on the chassis in
> > most amps (I also have a bigger Dano amp with a 12" that has the
> > transformer on the speaker). In that case, just replace the
speaker
> > and mount the transformer anywhere that's convenient. If it is a
> > field coil speaker (it will have wires going into the magnet),
> > that's more of a hassle, as they need to be reconed (good luck)
and
> > you have to remove the thing from the circuit. One more thing:
> > On some small amps, like Fender Champs, they used oddball 3.2 ohm
> > speakers. Be sure to find out the impedence of yours before
> > ordering a replacement. If it's fried, try to find some numbers
on
> > it. If it's just ripped, you can still measure it with a meter.
> > You want to get the correct one for best performance. Good luck,
> >
> > Matt Q.
> >
>
Mike,
Please pass the salt for my crow. <g>
unlunf
--- In , "urbansurfkings" <surfkings@...> wrote:
>
> Thanks for all the help.
>
>> "Two wires, and it's probably a small Class A amplifier with
>> the output xformer mounted on the speaker as noted by Dave and
>> Matt."
>
> That's the one!
>
> mike
>
