4002 Data

316mark · Post by **316mark** » Sun Dec 31, 2006 2:14 pm

Hmm.. I just looked at the 4002 schematic and it's a wierd setup. The tone control is a high pass filter at one end and a low pass filter at the other end. With the pot at the middle, it would be a fairly flat frequency output, but I would expect there would be a slight volume loss with it. The 10Meg resistor does nothing as far as tone is concerned; perhaps it was originally that value to control switch or pot movement noise. But a 300k resistor would limit the amount of bass that is attenuated when the tone control is fully clockwise.

rickfan60 · Post by **rickfan60** » Sun Dec 31, 2006 2:14 pm

The impedance of the XLR on my bass is about 700 Ohms. John Hall said the pickup is bifilar. The low Z winding is parallel the normal winding. I would guess that the low Z probably spans both coils in the treble pickup. I believe the pickups are identical except for the low Z winding.

rickfan60 · Post by **rickfan60** » Sun Dec 31, 2006 2:18 pm

Thanks for the confirmation Mark. I don't understand this stuff as well as I would like.

johnallg · Post by **johnallg** » Sun Dec 31, 2006 2:29 pm

XLR (balanced) audio is spec'd at 600 ohms so you are in the ballpark. Bifiliar means the coils are interwound with each other but electrically seperate.

40014002 · Post by **40014002** » Mon Jan 01, 2007 3:24 am

Ted my bass was made in February 1982 and all original so it is very interseting to find out about the resistors 560K in my bass and yours at 300K and the schematic says they are 10M?

all the best Dave Carr

ginger_lee · Post by **ginger_lee** » Mon Jan 01, 2007 1:44 pm

hmmmm..I didnt bring mine to Maryland with me as Donna has a fretless Jazz for me to play while I'm here and I didnt want to take a chance flying with mine..re lost luggage etc..mine was ordered September of 81..I wont be back to her til the end of Febuary but now I'm curious as to what values are in mine..I'm the original owner so I know its exactlee as it was made..on that note...OMG do I ever miss my bass!

rickfan60 · Post by **rickfan60** » Mon Jan 01, 2007 1:55 pm

Mine is going to live with Jeff Thomas for a while. That will be the first time in 26 years she will be away from me.

rickfan60 · Post by **rickfan60** » Mon Jan 01, 2007 6:23 pm

I am beginning to wonder if the 4002 was a work in progress. Maybe the factory was tweaking experimenting along the way.

40014002 · Post by **40014002** » Mon Jan 01, 2007 6:49 pm

You could be right there Ted.

gregson1 · Post by **gregson1** » Mon Jan 01, 2007 7:09 pm

I believe that Rickenbacker never made enough of them to really finalize the design. John Hall killed their production to make way for the steady sellers. Might have been a sound business move, but I can't help but wonder how the product might have matured had production continued.

I have to admit that I really like the 4004 product line. I hope they work through the pickup difficulties on the 5 string and get it back into production soon. Like the 4002, the 4004Cii5 is a design with serious promise.

basse · Post by **basse** » Tue Jan 02, 2007 4:43 am

Ted, just saw this thread... Do you still need photos? I can open up my 4002 tonight if you need more...

rickfan60 · Post by **rickfan60** » Tue Jan 02, 2007 6:09 am

The more the merrier David!

You can never have too many 4002 pictures.

basse · Post by **basse** » Wed Jan 03, 2007 7:39 am

Sorry, just caught your answer this morning...

I'll post the pix for you tomorrow!

basse · Post by **basse** » Fri Jan 05, 2007 5:46 am

Hi Ted, sorry for being a day late, here are the inside shots of my '78...

The body:

Back of pickguard:

Electronics close-up:

Sorry, I have no idea of the figures on the capacitators/resistors... Let me know if you'd like me to e-mail you larger, more detailed photos.

Dave

rickfan60 · Post by **rickfan60** » Fri Jan 05, 2007 6:02 am

Thanks Dave. Yours match mine too. You have 300K resistors and all of the same caps.