Question about weird diode arrangment - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 27th April 2006, 11:49 PM   #1
diyAudio Member
 
Join Date: May 2003
Location: Winnipeg, MB, Canada
Default Question about weird diode arrangment

I have a question regarding the following schematic (for a Fender guitar amp):

http://www.st-andrews.ac.uk/~jcgl/Sc...oax/page6.html

If you look at the upper-left corner of the schematic you'll see two branches with three diodes in series. I was wondering what the purpose is of having these three diodes in series like that, and also why they have the markings on the diodes "-" then "+" instead of the other way around? With a typical diode, wouldn't you indicate the "+" on the anode (non-stripe) and "-" on the cathode (stripe)?

Me thinks that it's to drop the voltage, but the voltage is so high that I don't imagine that you'd get significant drop across the diodes.

Thanks for any input.

-Brian
  Reply With Quote
Old 27th April 2006, 11:59 PM   #2
infinia is offline infinia  United States
diyAudio Member
 
infinia's Avatar
 
Join Date: May 2005
Location: Californication
Hi
Your link is broken?
Didn't find amp schematic.
__________________
like four million tons of hydrogen exploding on the sun
like the whisper of the termites building castles in the dust
  Reply With Quote
Old 28th April 2006, 12:34 AM   #3
diyAudio Member
 
Join Date: May 2003
Location: Winnipeg, MB, Canada
doh! sorry about that. The link I originally posted was for another thread I was working on at the same time.

I could not find the original schematic I was referring to but I found the same arrangement in the following schematic (look at the bottom-center of the image):

http://www.guitar-parts.com/images/reverb6g15.JPG

Are they zeners?

-Brian
  Reply With Quote
Old 28th April 2006, 01:02 AM   #4
infinia is offline infinia  United States
diyAudio Member
 
infinia's Avatar
 
Join Date: May 2005
Location: Californication
Series Si diodes to increase PIV (peak inverse voltage) of total string. Probably 1N400x 1 amp diodes. Does that make sense?
__________________
like four million tons of hydrogen exploding on the sun
like the whisper of the termites building castles in the dust
  Reply With Quote
Old 28th April 2006, 02:05 AM   #5
diyAudio Member
 
Join Date: May 2003
Location: Winnipeg, MB, Canada
Ahh yes that makes perfect sence. It didn't click in but yea it's pretty obvious now. Thanks bud!
  Reply With Quote
Old 28th April 2006, 08:14 AM   #6
edl is offline edl  Hungary
diyAudio Member
 
edl's Avatar
 
Join Date: Oct 2004
Hi,

As I see, the supply is 300V-DC, then in my opinion a lonely 1N4007 will do the job, instead of the three diodes.

Regards,
  Reply With Quote
Old 29th April 2006, 04:09 AM   #7
diyAudio Member
 
Join Date: Mar 2005
Location: California
... and a better job, since the voltage across each diode may not be the same, and if you're a little unlucky one diode shorts followed very shortly by the others. Much better to use one diode, I believe that one can use resistors across the diodes to equalise the drops, still better to use one diode if possible.
  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
Weird question about impedance revans Multi-Way 10 24th September 2008 08:52 PM
Sound levels - weird question! peter_m Everything Else 5 15th August 2007 03:36 PM
Diode Question TunaFish Tubes / Valves 8 13th October 2003 11:53 AM
Would this driver arrangment work? Hybrid fourdoor Multi-Way 6 10th July 2003 02:09 PM
Diode question Holger Barske Solid State 2 14th October 2002 02:44 PM


New To Site? Need Help?

All times are GMT. The time now is 08:22 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