Board index » Just Basses




Post new topic Reply to topic  [ 7 posts ] 
Author Message
 Post subject: 3001 Bass electronics
 Post Posted: Wed Nov 17, 2021 7:39 am 
Offline

Joined: Mon Oct 01, 2018 5:43 am
Posts: 5
So, I finally decided to try refurbishing the electronics in my 1977 3001. I ordered new pots, caps, and 1 resistor, all according to the official Ric schematic. The sound after installing everything was BAD. No effect on the bass tone at all. Something made me check the caps I had removed and they are not what is shown on the schematic! It shows both caps (marked C1 and C2) as .047. I assumed that means .047mFd for both, so that's what I ordered - great big orange ones - they barely fit in the cavity! These new ones check exactly .047mFd on my meter. The ones that came out, however, check .001mFd for C1, and .1mFd for C2. What the #$%!!! I put those caps back in along with the new pots and voila! Everything went back to normal. So, I'm wondering, should I buy some new caps with the same readings as the originals? Or should I assume that C1 is supposed to be .0047 and C2 is supposed to be .047? Or just leave well enough alone. I've also been reading alot about "magnet fade" in these old instruments so my next project might be to try refurbishing my spare pickup. I'm just really confused about these caps and why the schematic seems to be wrong. Any thoughts?


Top 
 Profile  
 
 Post subject: Re: 3001 Bass electronics
 Post Posted: Wed Nov 17, 2021 10:50 am 
Offline
User avatar

Joined: Wed Jan 16, 2008 3:58 am
Posts: 1346
Location: En Zed
What are the markings on the caps you took out? They usually say what their value is. It is possible for old caps to change value over time. It's also possible that someone changed them to non-stock values (assuming you didn't buy this bass new).


Top 
 Profile  
 
 Post subject: Re: 3001 Bass electronics
 Post Posted: Wed Nov 17, 2021 5:06 pm 
Offline

Joined: Mon Oct 01, 2018 5:43 am
Posts: 5
@cjj: I did buy the guitar new and no one has worked on it but me. The C2 cap is white on the pin end, then red, white, yellow, black, and brown on top. I found one chart that (if I was reading it correctly) said the white stripe would mean it was 0.1mFd - exactly what it measures. The C1 cap is a little tiny thing that is dark green all over with some numbers on it I didn't try to look up - I'll write them down next time I mess with it. Those readings seem so odd compared to about everything else most guitars use...and Ric's own schematic. I've got a .047 and a .0047 Orange Drop, so I'm going to try them in there and see what happens. I'll probably order a 0.1 and a 0.001 just to play around with and see if I can tell the difference. I don't mind experimenting with it but I get antsy when I can't play it, even though I've got three other basses!


Top 
 Profile  
 
 Post subject: Re: 3001 Bass electronics
 Post Posted: Thu Nov 18, 2021 7:40 am 
Offline

Joined: Mon Oct 01, 2018 5:43 am
Posts: 5
The markings on the (little green) C1 cap are: EDI on one side, and .001k 100TSC on the other.
The "k" kind of throws me but I don't think I've ever seen caps called out in KiloFarads. If it means .001uFd then my measurement is correct. I'm leaning more towards that, so I'll probably get new .1uFd and .001uFd caps just so I know everything in there is fresh. On to rewinding and re-magneting the pickup!


Top 
 Profile  
 
 Post subject: Re: 3001 Bass electronics
 Post Posted: Fri Nov 19, 2021 11:08 am 
Offline
User avatar

Joined: Wed Jan 16, 2008 3:58 am
Posts: 1346
Location: En Zed
Yes, that is a .001uF capacitor, the k means 10% tolerance, not kilofarads.

Caps are usually marked with either microfarads (uF) or a code denoting picofarads (pF) the the pF codes it is 2 digits of values the a digit for an exponent. So, 103 would be 10e3 or 10000pF (10nF or .01uF).


Top 
 Profile  
 
 Post subject: Re: 3001 Bass electronics
 Post Posted: Fri Nov 19, 2021 12:17 pm 
Offline

Joined: Mon Oct 01, 2018 5:43 am
Posts: 5
Interesting! Do you think I analyzed the stripes on the C2 cap correctly? I came up with it should be .1uF. On another note, on pickups: In a previous post someone commented that this pickup is epoxied and it is not. I was looking at replacing the magnets, but apparently they can be "recharged" using neo mags. If so, does anyone know what the gauss reading should be? It looks like it's pretty simple (and cheap) to build a gauss meter with Arduino.


Top 
 Profile  
 
 Post subject: Re: 3001 Bass electronics
 Post Posted: Sat Nov 20, 2021 11:17 am 
Offline
User avatar

Joined: Wed Jan 16, 2008 3:58 am
Posts: 1346
Location: En Zed
Cap colour bands are sometimes confusing since it makes a difference which way you read them. I would guess that yours starts with the brown end so you would have:
Brown = 1
Black = 0
Yellow = 4, or 4 zeros

So, 100000pF which is 100nF or 0.1uF.

The white means 10% tolerance, red is a voltage rating which depends on the actual type of cap. That doesn't really matter for guitar circuits, but is probably either 250V or 300V.


Top 
 Profile  
 
Display posts from previous:  Sort by  
 
Post new topic Reply to topic  [ 7 posts ] 

Board index » Just Basses


Who is online

Users browsing this forum: No registered users and 20 guests

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

Register    Login    Forum    Search    FAQ
X