Gibson BR-9 Amp - speaker replacement

[red strat]

I have been given an old Gibson BR-9 amp. I think it's from the late
40's.
I need to replace its speaker. Having never bought/replaced speakers
for a guitar
amp, I'm wondering if I can get a recommendation on where and what to
buy for it's replacement.
It's an 8" speaker. Also I'm a bit confused how to replace it, as it
has 4 wires
coming out of the amp chassis that go to the speaker - 2 to the magnet
area in the center
and 2 to a part (which I don't know the name of) attached to the
speaker chassis.
Any suggestions would be appreciated.

Thanks,

Red

[Phil S.]

Post by red strat
I have been given an old Gibson BR-9 amp. I think it's from the late
40's.
I need to replace its speaker. Having never bought/replaced speakers
for a guitar
amp, I'm wondering if I can get a recommendation on where and what to
buy for it's replacement.
It's an 8" speaker. Also I'm a bit confused how to replace it, as it
has 4 wires
coming out of the amp chassis that go to the speaker - 2 to the magnet
area in the center
and 2 to a part (which I don't know the name of) attached to the
speaker chassis.
Any suggestions would be appreciated.
Thanks,
Red

The thingy you don't know the name of is a transformer. This type of
speaker is known as a "field coil speaker" and cannot be replaced by any old
speaker. You need the right kind of field coil speaker. If you can't find
what you need by trolling ebait, it needs to be reconed.

You might want to call Orange County Speaker or Ted Weber to see if one or
the other can enlighten you about what exactly you need.

BTW, when you bolt in a speaker, if you torque the nuts too tight you warp
the frame and ruin the speaker. Be careful.

[J.P.]

On Wed, 17 Oct 2007 22:26:48 -0400, "Phil S."

Post by Phil S.

Post by red strat
I have been given an old Gibson BR-9 amp. I think it's from the late
40's.
I need to replace its speaker. Having never bought/replaced speakers
for a guitar
amp, I'm wondering if I can get a recommendation on where and what to
buy for it's replacement.
It's an 8" speaker. Also I'm a bit confused how to replace it, as it
has 4 wires
coming out of the amp chassis that go to the speaker - 2 to the magnet
area in the center
and 2 to a part (which I don't know the name of) attached to the
speaker chassis.
Any suggestions would be appreciated.
Thanks,
Red

The thingy you don't know the name of is a transformer. This type of
speaker is known as a "field coil speaker" and cannot be replaced by any old
speaker. You need the right kind of field coil speaker. If you can't find
what you need by trolling ebait, it needs to be reconed.
You might want to call Orange County Speaker or Ted Weber to see if one or
the other can enlighten you about what exactly you need.
BTW, when you bolt in a speaker, if you torque the nuts too tight you warp
the frame and ruin the speaker. Be careful.

Mark the wires before you remove them...

[J.P.]

Post by red strat
I have been given an old Gibson BR-9 amp. I think it's from the late
40's.
I need to replace its speaker. Having never bought/replaced speakers
for a guitar
amp, I'm wondering if I can get a recommendation on where and what to
buy for it's replacement.
It's an 8" speaker. Also I'm a bit confused how to replace it, as it
has 4 wires
coming out of the amp chassis that go to the speaker - 2 to the magnet
area in the center
and 2 to a part (which I don't know the name of) attached to the
speaker chassis.
Any suggestions would be appreciated.
Thanks,
Red

How do ya know the speaker is no good? Might want to take this amp to
a qualified tech since it is in the vintage collectable era. Let them
check the whole amp out for ya. Likely worth taking good care of and
tech maintence is part of good care of.Try not to alter or modify
original parts if you can.Save all old parts for the new owner if you
sell it. Not worth a whole lot but worth keeping. Probably make a good
harp/lap steel amp also ...J.P.

Schematic for it..might want to print and plastic bag this for
later/tech..
http://www.gibson.com/Files/schematics/BR-9%20Amp.pdf

[red strat]

Post by red strat
I have been given an old Gibson BR-9 amp. I think it's from the late
40's.
I need to replace its speaker. Having never bought/replaced speakers
for a guitar
amp, I'm wondering if I can get a recommendation on where and what to
buy for it's replacement.
It's an 8" speaker. Also I'm a bit confused how to replace it, as it
has 4 wires
coming out of the amp chassis that go to the speaker - 2 to the magnet
area in the center
and 2 to a part (which I don't know the name of) attached to the
speaker chassis.
Any suggestions would be appreciated.
Thanks,
Red

Thanks Phil and J.P. this helps alot. Now I know what I'm dealing with
and have some options.

Red

[Mike Schway]

Post by red strat

Post by red strat
I have been given an old Gibson BR-9 amp. I think it's from the late
40's.
I need to replace its speaker. Having never bought/replaced speakers
for a guitar
amp, I'm wondering if I can get a recommendation on where and what to
buy for it's replacement.
It's an 8" speaker. Also I'm a bit confused how to replace it, as it
has 4 wires
coming out of the amp chassis that go to the speaker - 2 to the magnet
area in the center
and 2 to a part (which I don't know the name of) attached to the
speaker chassis.
Any suggestions would be appreciated.
Thanks,
Red

Thanks Phil and J.P. this helps alot. Now I know what I'm dealing with
and have some options.
Red

And if you can't find a replacement field coil speaker, your options are:

1) recone the original. Probably the best option ...even better than
replacing the original. especially if the OPT is still OK.

2) Use a permanent magnet (conventional) 8 ohm speaker Mount the
tranny onto the chassis, or to be more authentic, onto the basket as
before (if possible). Instead of the field coil, substitute a 4H/125mA
choke hidden inside the chassis.

Disclaimer: Normally I do NOT like putting the tranny directly on the
speaker, you'll have old wire carrying high DC voltages outside of the
chassis. DEFINITELY not up to code these days.

3) in lieu of the choke, you can use a 3.3K/10W resistor between the
first two power supply caps. Note that if you use a resistor, you'll
also decrease B+ and increase sag.

--Mike

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