Ampeg Gemini I Blows Up! Need advice on 'lytics

Ampeg Gemini I Blows Up! Need advice on 'lytics

I replaced the multi-section original filter caps and other 'lytics in
my Gemini I about a year ago when the original 1965 cap finally gave
out. I've used the amp maybe 5 times since then and it worked OK up
until last week when it started sizzling and then the multi-cap blew
up. It is one of those Aero multi caps 80 mf, 40 mf, 30 mf, 20 mf
all at 525 volts.

I see that Mallory makes one of these and Antique Electric supply
carries them. I also see that I could leave the multi cap in place
and solder in separate 80 mf, 40 mf and 20 mf caps (the ampeg didn't
use the 30 mf section). One concern is that the 80 mf caps I've seen
are rated at 450 volts, which according to the schemo is OK, but line
voltages are higher now than they were in 1965 according to some
articles I've read. I could, I suppose put together two caps in
parallel -- a 47mf 500 volt and 22 mf 500 volt to replace the 80 mf
section (the schemo shows this as 70 mf 450 volt). Any suggestions as
to how to fix this amp so it won't blow up anymore? I like it when
it's working.

Thanks!

Paul

Re: Ampeg Gemini I Blows Up! Need advice on 'lytics

On Mon, 19 May 2008 21:33:04 -0700 (PDT), Lovguitar
<lovguitar@aol,com > wrote:

>I replaced the multi-section original filter caps and other 'lytics in
>my Gemini I about a year ago when the original 1965 cap finally gave
>out. I've used the amp maybe 5 times since then and it worked OK up
>until last week when it started sizzling and then the multi-cap blew
>up. It is one of those Aero multi caps 80 mf, 40 mf, 30 mf, 20 mf
>all at 525 volts.

How old was the Aero?

>I see that Mallory makes one of these and Antique Electric supply
>carries them.

Mallory doesn't make them anymore. CE has their machines.

> I also see that I could leave the multi cap in place
>and solder in separate 80 mf, 40 mf and 20 mf caps (the ampeg didn't
>use the 30 mf section). One concern is that the 80 mf caps I've seen
>are rated at 450 volts, which according to the schemo is OK, but line
>voltages are higher now than they were in 1965 according to some
>articles I've read. I could, I suppose put together two caps in
>parallel -- a 47mf 500 volt and 22 mf 500 volt to replace the 80 mf
>section (the schemo shows this as 70 mf 450 volt). Any suggestions as
>to how to fix this amp so it won't blow up anymore? I like it when
>it's working.
>
>Thanks!
>
>Paul

You *could* use individual caps, but...

http :// tinyurl,com /5zx54o

-DC

Re: Ampeg Gemini I Blows Up! Need advice on 'lytics

Are you saying that the Aero was replaced, and after playing it 5 times it
blew up? Bad cap? NOS cap?

Get the can from AES. Their cap cans are good, and its voltages are correct
for your application. While you can replace with seperates, it will be more
work, might result in lead dress issues, and will reduce the value of the
amp farther than replacing the can with a compatible can.


"Lovguitar" <lovguitar@aol,com > wrote in message
news:e1428fa7-45a9-4f26-8dc4-ef500fd059fc@d45g2000hsc.googlegroups,com ...
>I replaced the multi-section original filter caps and other 'lytics in
> my Gemini I about a year ago when the original 1965 cap finally gave
> out. I've used the amp maybe 5 times since then and it worked OK up
> until last week when it started sizzling and then the multi-cap blew
> up. It is one of those Aero multi caps 80 mf, 40 mf, 30 mf, 20 mf
> all at 525 volts.
>
> I see that Mallory makes one of these and Antique Electric supply
> carries them. I also see that I could leave the multi cap in place
> and solder in separate 80 mf, 40 mf and 20 mf caps (the ampeg didn't
> use the 30 mf section). One concern is that the 80 mf caps I've seen
> are rated at 450 volts, which according to the schemo is OK, but line
> voltages are higher now than they were in 1965 according to some
> articles I've read. I could, I suppose put together two caps in
> parallel -- a 47mf 500 volt and 22 mf 500 volt to replace the 80 mf
> section (the schemo shows this as 70 mf 450 volt). Any suggestions as
> to how to fix this amp so it won't blow up anymore? I like it when
> it's working.
>
> Thanks!
>
> Paul

Re: Ampeg Gemini I Blows Up! Need advice on 'lytics

On May 20, 8:55=EF=BF=BDam, "Steve L" <sur...@sliberty,com > wrote:
> Are you saying that the Aero was replaced, and after playing it 5 times it=

> blew up? Bad cap? NOS cap?
>
> Get the can from AES. Their cap cans are good, and its voltages are correc=
t
> for your application. While you can replace with seperates, it will be mor=
e
> work, might result in lead dress issues, and will reduce the value of the
> amp farther than replacing the can with a compatible can.
>
> "Lovguitar" <lovgui...@aol,com > wrote in message
>
> news:e1428fa7-45a9-4f26-8dc4-ef500fd059fc@d45g2000hsc.googlegroups,com ...
>
>
>
> >I replaced the multi-section original filter caps and other 'lytics in
> > my Gemini I about a year ago when the original 1965 cap finally gave
> > out. =EF=BF=BDI've used the amp maybe 5 times since then and it worked O=
K up
> > until last week when it started sizzling and then the multi-cap blew
> > up. =EF=BF=BDIt is one of those Aero multi caps =EF=BF=BD80 mf, 40 mf, 3=
0 mf, 20 mf
> > all at 525 volts.
>
> > I see that Mallory makes one of these and Antique Electric supply
> > carries them. =EF=BF=BDI also see that I could leave the multi cap in pl=
ace
> > and solder in separate =EF=BF=BD80 mf, 40 mf and 20 mf caps (the ampeg d=
idn't
> > use the 30 mf section). =EF=BF=BD One concern is that the 80 mf caps I'v=
e seen
> > are rated at 450 volts, which according to the schemo is OK, but line
> > voltages are higher now than they were in 1965 according to some
> > articles I've read. =EF=BF=BDI could, I suppose put together two caps in=

> > parallel -- a 47mf 500 volt and 22 mf 500 volt to replace the 80 mf
> > section (the schemo shows this as 70 mf 450 volt). =EF=BF=BDAny suggesti=
ons as
> > to how to fix this amp so it won't blow up anymore? =EF=BF=BDI like it w=
hen
> > it's working.
>
> > Thanks!
>
> > Paul- Hide quoted text -
>
> - Show quoted text -

Thanks for the advice. The aero was supposedly new. I bought it from
fliptop,com , the guys that specialize in ampeg stuff. I was pretty
shocked when it blew up as the original lasted a long long time. I
don't know if it was a bad cap or what. What could cause a cap to
blow up (literally) other than the di-electric getting pierced by too
much voltage? The fuse didn't blow, the tubes are fine, the trannies
seem fine. My brother was using it then put his guitar down to go have
some pizza. The volume on the guitar was turned down. All of a
sudden sizzling bacon sound and smoke pouring out of the amp. I hate
when that happens, and the old Ampegs seem especially prone to it.

I ordered the multi section can cap from AES today and will give it a
shot.

Best,

Paul

Re: Ampeg Gemini I Blows Up! Need advice on 'lytics

On Tue, 20 May 2008 21:37:26 -0700 (PDT), Lovguitar
<lovguitar@aol,com > wrote:

> The aero was supposedly new.

Perhaps sold as 'new old stock'?

It might have a date code on it. I don't think Aerovox has made 'twist
lock' cans for quite some time.

http :// www .aerovox,com /products/shopdisplaycategories.asp

FWIW, Fliptops are selling new CE units now. Maybe you could give them
a call and explain what happened. I wouldn't expect them to do much,
but it's worth a shot.

-DC