It is currently Mon Mar 16, 2020 2:20 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 7 posts ] 
Author Message
Post subject: 74' Twin Reverb Filer Caps
Posted: Fri Aug 22, 2014 1:43 pm
Offline
Roadie
Roadie

Joined: Sat Mar 09, 2013 12:27 pm
Posts: 207
Hi Ya'll
I'm replacing the filter caps on my 74' twin. It has 2 100uf/350v. Should I use 100uf/350v or 100uf/450v. I normally use Spragues. Than Q.


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: 74' Twin Reverb Filer Caps
Posted: Fri Aug 22, 2014 1:46 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
I suggest F&T caps. I used 100mfd/450VDC in the first stage of the 1968 Bassman I redid. Nice quiet PSU. Good reserve. Been very reliable. Note: Bassman has an extra 20mfd stage for the BASS input.

-----




Image


Top
Profile
Post subject: Re: 74' Twin Reverb Filer Caps
Posted: Sat Aug 23, 2014 1:59 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Both 100 MFD 350 volts caps are in serie for 700 volts power supply .

Your amp power supply is 450 volts .......

350 volts caps will do the job , you 'll be over with 250 volts.

Think to replace bias capacitor too , 80 MFD 75 volts . Bias power supply is 65 volts on schematic . Put 100 MFD at 100 volts minimum.


Top
Profile
Post subject: Re: 74' Twin Reverb Filer Caps
Posted: Sat Aug 23, 2014 2:25 am
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Extra voltage rating won't hurt and can add life to the PSU.


Top
Profile
Post subject: Re: 74' Twin Reverb Filer Caps
Posted: Sat Aug 23, 2014 2:45 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
BMW2002Ti wrote:
Extra voltage rating won't hurt and can add life to the PSU.



Can't hurt ; +1 , cap is just more expensive and or bigger, is it right for these F & T ? I did not check .

Add life to PSU ; I can't see how between 250 volts and 450 volts safety margin.

Many vintage Fender amp use 50 volts bias caps where are 60 volts PS.

But it is just my opinion


Top
Profile
Post subject: Re: 74' Twin Reverb Filer Caps
Posted: Fri Sep 12, 2014 7:35 am
Offline
Roadie
Roadie

Joined: Sat Mar 09, 2013 12:27 pm
Posts: 207
I used the 350v since they're in series. Also, replaced bias cap 80uf/150v. The amps sounds great with lots of punch. Thanks for the input as always.


Top
Profile
Post subject: Re: 74' Twin Reverb Filer Caps
Posted: Fri Sep 12, 2014 8:12 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
If you have a chance to replace all the 25 MFD , 25 volts caps on the main board ( 5 caps ? ) this may help you amp sound better .
These are electrolitycs caps and like filters caps they could be dry and /or value drift a lot .
These caps are bypass cap, a cheap invest.

I use Sprague 50 volts , cheaper than the 25 volts


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

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 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

Search for:
Jump to: