Hi,

I've been replacing all the caps in my vintage Wurlitzer Jukebox amp.
The problem was one channel was buzzing quite badly. Now ive done it
all, the bad channel has stopped working altogether (only a slight
hum). I checked my wiring and noticed one of the caps I changed is
the wrong value (22uF instead of 150uF). This cap is in the faulty
channel. Does anyone know if it would make that much difference?

Marky P.

"Marky P" wrote in message
...
Hi,

I've been replacing all the caps in my vintage Wurlitzer Jukebox amp.
The problem was one channel was buzzing quite badly. Now ive done it
all, the bad channel has stopped working altogether (only a slight
hum). I checked my wiring and noticed one of the caps I changed is
the wrong value (22uF instead of 150uF). This cap is in the faulty
channel. Does anyone know if it would make that much difference?

Marky P.


It depends what the capacitor does. If it's a cathode decoupling capacitor,
the low value will cause the bass to roll-off early. If it's a power supply
decoupling capacitor, the low value will give you less smoothing and/or
decoupling at low frequencies, and so possibly give you low frequency
instability, which could manifest itself as a low-frequency "motor-boat"
type of sound.

Neither will stop the channel working altogether, so you need to look
elsewhere for a reason.

S.
--
http://audiopages.googlepages.com

Marky P wrote:

Hi,

I've been replacing all the caps

Coupling / decoupling ?

in my vintage Wurlitzer Jukebox amp.
The problem was one channel was buzzing quite badly. Now ive done it
all, the bad channel has stopped working altogether (only a slight
hum). I checked my wiring and noticed one of the caps I changed is
the wrong value (22uF instead of 150uF). This cap is in the faulty
channel. Does anyone know if it would make that much difference?

I think you need to stop messing around and consult a proper tech. I
doubt you have the skills to fault find.

Graham

On Sat, 02 Aug 2008 17:24:36 +0100, Eeyore
wrote:



Marky P wrote:

Hi,

I've been replacing all the caps

Coupling / decoupling ?

in my vintage Wurlitzer Jukebox amp.
The problem was one channel was buzzing quite badly. Now ive done it
all, the bad channel has stopped working altogether (only a slight
hum). I checked my wiring and noticed one of the caps I changed is
the wrong value (22uF instead of 150uF). This cap is in the faulty
channel. Does anyone know if it would make that much difference?

I think you need to stop messing around and consult a proper tech. I
doubt you have the skills to fault find.

Graham

You're right, I don't have the skills to find fault, which is why i'm
referring it to The Jukebox Hospital. But I do have basic soldering
skills, which is why I replaced all the electrolytic and paper caps.

Marky P.

In article , Marky P
scribeth thus
On Sat, 02 Aug 2008 17:24:36 +0100, Eeyore
wrote:



Marky P wrote:

Hi,

I've been replacing all the caps

Coupling / decoupling ?

in my vintage Wurlitzer Jukebox amp.
The problem was one channel was buzzing quite badly. Now ive done it
all, the bad channel has stopped working altogether (only a slight
hum). I checked my wiring and noticed one of the caps I changed is
the wrong value (22uF instead of 150uF). This cap is in the faulty
channel. Does anyone know if it would make that much difference?

I think you need to stop messing around and consult a proper tech. I
doubt you have the skills to fault find.

Graham

You're right, I don't have the skills to find fault, which is why i'm
referring it to The Jukebox Hospital. But I do have basic soldering
skills, which is why I replaced all the electrolytic and paper caps.

Marky P.


Well unless its priceless bit of gear thats not a bad way to learn

And I wish a few more people would try its worrying how many young
people these days can use a PC but not a soldering Iron;(...
--
Tony Sayer

On Sun, 3 Aug 2008 13:26:42 +0100, tony sayer
wrote:

In article , Marky P
scribeth thus
On Sat, 02 Aug 2008 17:24:36 +0100, Eeyore
wrote:



Marky P wrote:

Hi,

I've been replacing all the caps

Coupling / decoupling ?

in my vintage Wurlitzer Jukebox amp.
The problem was one channel was buzzing quite badly. Now ive done it
all, the bad channel has stopped working altogether (only a slight
hum). I checked my wiring and noticed one of the caps I changed is
the wrong value (22uF instead of 150uF). This cap is in the faulty
channel. Does anyone know if it would make that much difference?

I think you need to stop messing around and consult a proper tech. I
doubt you have the skills to fault find.

Graham

You're right, I don't have the skills to find fault, which is why i'm
referring it to The Jukebox Hospital. But I do have basic soldering
skills, which is why I replaced all the electrolytic and paper caps.

Marky P.


Well unless its priceless bit of gear thats not a bad way to learn

1960's Wurlitzer amps are pretty priceless. Certainly not cheap to
replace or restore.

And I wish a few more people would try its worrying how many young
people these days can use a PC but not a soldering Iron;(...

Well, I'm very pleased with my soldering on the board, though my
modification of using seperate caps to replace the nulti-sections
looks a bit of a mess. I reckon the Jukebox Hospital won't be too
happy with my modifications :-( Anyway, the fault is most likely the
output tranformer in that one channel, which can be fixed but it ain't
cheap!

Marky P.