The Mellotron Group

-----Original Message-----
From: tronbros@aol.com
Sent: Dec 4, 2007 7:55 AM
To: newmellotrongroup@yahoogroups.com
Subject: Re: [newmellotrongroup] Capacitor Source?

In a message dated 04/12/2007 12:11:47 GMT Standard Time, astroboy@cinci.rr.com writes:

Is there a current source for those big blue Caps in the M400 Power
Supply, 1600 and 2500uF - 40 volt, respectively? I've spent the weekend
trying to track some down, and while I can match the capacitance and
voltage, they don't come anywhere near the size of fitting in the
mounting straps of the originals.

John,

�

I know this will be a bitter pill so you had better sit down.� Wait for it...................they don't make the blue ones anymore....................and...............you are going to have to change the straps on the SMS2.� There was no other way to break it to you.� Pour yourself a stiff Frank Stickle and relax.

�

Best, -� Martin

�

�

�

�

Greetings John,Martin and Gang,

�

�

Modern electrolytic capacitors are about 1/3 to 1/5 their original size,

with much improved internal construction over their 1960s-1970s versions.

Due in most part by the huge need for high-quality filter caps used

in computer power-packs.

�

�

Anyway, from tech/eng'g. viewpoint, you can substitute a larger

cap value or higher DC working voltage ,but� NOT the inverse.

Higher capacitance translates to less� AC power-pack ripple.

�

�

I automatically replaced all paper/wax/foil capacitors� on two antique

TV sets and three valve-based radios in the last 1.5 years.

You'll see these fully functional units on forthcoming MONEYPIT pages.

Mellotrons, like other electronic bits of vintage technology WILL

require all caps replaced.�

�

�

You'll have to wrap some tape around the base of replacement caps,

to secure them within the original clamps.�� I use paper masking tape,

as the plastic variety sometimes� "slides" when clamed tightly.

�

�

In 2006,� I decided to replace all 40+ yr.old power-pack capacitors within

MK-I #124 "Julia." Result is a stable DC power-source , and much

quieter than before (85% reduction).� KL has clearly heard these results

during our last two MONEYPIT gatherings.

�

�

Hope this helps. Good Luck !���� -- Jerry Korb�( at the capacitor� ranch )

�