Fender 5C1 Choke - diyAudio
Go Back   Home > Forums > Live Sound > Instruments and Amps

Instruments and Amps Everything that makes music, Especially including instrument amps.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 17th December 2010, 06:43 PM   #1
diyAudio Member
 
chrismercurio's Avatar
 
Join Date: Aug 2006
Location: Silicon Valley
Default Fender 5C1 Choke

All,

I'm putting together a Fender 5C1 clone and want some advice on the choke in the CLC supply for the B+. Simulated at 10H, ripple is ~20mV and at 5H ripple is ~40mV. I believe original Fender chokes were ~4H.

What are the advantages/disadvantages to going with the 5H over the 10H and vise versa?

Thank you,
  Reply With Quote
Old 17th December 2010, 08:23 PM   #2
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
I would suggest using the same as Fender did - valve amplifiers are really about low quality, improving the quality of the design will probably affect the sound in ways you don't want. Part of the 'valve sound' which some people seem to find appealing is partly down to poor power supplies, bad regulation, and excessive mains hum. This is why some modern designs have switchable rectifiers, modern silicon ones for higher and cleaner output, and original valve ones for lower power, higher distortion, and a nice 'droopy' HT rail.
__________________
Nigel Goodwin
  Reply With Quote
Old 17th December 2010, 08:32 PM   #3
diyAudio Member
 
chrismercurio's Avatar
 
Join Date: Aug 2006
Location: Silicon Valley
I want low noise. Fender did what they did as a "good enough" solution not to create "the sound". "The sound" came from timeless recordings made using what was available. So bigger choke, lower noise and less sag? (I want less sag.)
  Reply With Quote
Old 18th December 2010, 01:06 AM   #4
Enzo is offline Enzo  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Lansing, Michigan
You making a 5C1 or a 5E1?

5E1 - choke, 6V6, 12AX7, 5Y3.

5C1 - 500 ohm resistor, 6V6, 6SJ7, 5Y3.

First, this is a single ended amp - one power tube. it is running in class A, so you are not getting sag to begin with.


Are you using those tiny little 8uf filter caps as in the original? Bump those up to 20uf and see how that smooths things.
  Reply With Quote
Old 18th December 2010, 08:51 AM   #5
diyAudio Member
 
chrismercurio's Avatar
 
Join Date: Aug 2006
Location: Silicon Valley
5c1 variant...
clc ps
cathode bias
Attached Files
File Type: pdf champ-1.pdf (31.2 KB, 42 views)
  Reply With Quote
Old 18th December 2010, 04:01 PM   #6
diyAudio Member
 
Join Date: Dec 2008
Location: Victoria, BC
Chris-
I think your amp will be 'quiet enough' when you get it built, with the design 'as is'. Pay attention to your grounding in the build.
Most guitars are so noisy (especially single coil PUs) that amp noise is a minor thing...ie amp is quiet, plug in guitar and the fun starts.
All in the game.....

John
PS- make sure you use a decent speaker (eg Weber speaker for Champ or better); the 'original' speakers that Leo used were pretty cheap. (I've owned a few tweed Champs).
  Reply With Quote
Old 18th December 2010, 04:28 PM   #7
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
Quote:
Originally Posted by VictoriaGuy View Post
Chris-
ie amp is quiet, plug in guitar and the fun starts.
All in the game.....

Yeeeeeeah! Unless he plays with his avatar's guitar.
Most electric guitars are so noisy that worrying about the size of the choke sounds funny.

Quote:
I want low noise.
Quote:
I want less sag
So, why are you building this one? SE with tube rectifier.
  Reply With Quote
Old 18th December 2010, 08:38 PM   #8
diyAudio Member
 
chrismercurio's Avatar
 
Join Date: Aug 2006
Location: Silicon Valley
I have a 2 ch EL34 PP with SS rectifier and tone stack. I want something different, simple, and not quite as loud.

For speaker I haven't decided between the Scumnico 12", the ToneTubby 12" or the Weber NeoMag 15". I like the clean sound of the old JBL D130 a lot.

Best,
  Reply With Quote
Old 18th December 2010, 09:11 PM   #9
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
OK, go with the choke with less resistance (5H). Hum should be low. I like the pentode preamp but your guitar pickups need to output a strong signal, otherwise gain might not be enough. Depending on how loud you want it to be the speaker sensitivity will be very important.
  Reply With Quote
Old 19th December 2010, 12:17 AM   #10
diyAudio Member
 
chrismercurio's Avatar
 
Join Date: Aug 2006
Location: Silicon Valley
I figured I could alter my overall SPL output via speaker choice.

Most guitar amplifier schematics I have looked at only have volume controls as gain attenuation at the amplification stage. Are there any advantages to adding a pot at the input so that the gain at both the preamp and the power amp can be attenuated?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Help replacing a PSU choke - How to choose choke Hubba Tubes / Valves 2 10th September 2010 02:33 PM
Fender Champ 5C1 help needed! Spasticteapot Instruments and Amps 12 27th July 2010 11:45 PM
Choke rating for choke input duty cbutterworth Tubes / Valves 14 9th November 2007 04:43 PM
Swinging choke vs std. choke in PS Curly Woods Tubes / Valves 2 5th March 2007 08:30 PM
Fender amplifier.. burnt choke ?? rainerm_au Tubes / Valves 2 22nd February 2005 10:21 AM


New To Site? Need Help?

All times are GMT. The time now is 09:45 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2