NewBee PPEL84 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 30th December 2011, 08:51 PM   #1
diyAudio Member
 
Join Date: Dec 2011
Location: France
Default NewBee PPEL84

Hi, EveryBody. I just find this forum at the good time for me. Indeed, I'm building my own PPEL84 Amp and I need some advice to continue. This Amp will be used to understand tube amplification and to improve my knowledge in this field.
Above, my schema build on spice.
I don't knnow how to simulate the output transfo so don't be careful to the 4 resistor at the right of EL84, it's in fact the place for the transformator.

If you have some advice or if you see some trouble ou my schema!! I'm interested in!
  Reply With Quote
Old 30th December 2011, 10:39 PM   #2
GloBug is offline GloBug  Canada
Banned
 
Join Date: Jun 2011
Hi there, you just found this site now?

I can't see you pictures.

Upload your pictures using the "Manage Attachments" button just below where you were writing. Make sure your pictures are not too big, it will make for a faster upload.

Grab a chair you will be here for a while.


Salut à tous, vous venez de trouver ce site maintenant?

Je ne peux pas vous voir des photos.

Téléchargez vos photos en utilisant le "Gérer les pièces jointes"(Manage Attachments) bouton juste en dessous, où vous avez écrit. Assurez-vous que vos photos ne sont pas trop gros, il fera un rapide téléchargement.

Prenez une chaise, vous serez ici pendant un moment.
  Reply With Quote
Old 30th December 2011, 10:48 PM   #3
diyAudio Member
 
Join Date: Dec 2011
Location: France
Sorry, so the schema is below! Thank's !
Attached Images
File Type: png juxPushPull.png (160.8 KB, 156 views)
  Reply With Quote
Old 30th December 2011, 10:51 PM   #4
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Globug's advice to post pix directly here is excellent. If you do not see "Manage Attachments" you will see an option for "Go Advanced" click this and you will see "manage attachments."

Which version of spice are you using? Usually for a simple transformer model you calculate the inductance ratio between primary and secondary based on the square of the numerical ratio, select a reasonable primary inductance. Use the K directive K1 L1 L2 Lx 1 (coupling coefficient) to make a simple transformer where Lx is the last inductor to be combined into the transformer - should see the specifics under help. This will give you an ideal transformer which for most purposes is reasonable.

Welcome to the forum..
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 30th December 2011, 11:55 PM   #5
diyAudio Member
 
Join Date: Dec 2011
Location: France
OK, thank's for the advice! I changed resistor by linear transformator. It seem's that's working. Fine.

What do you think about the volume Control and the impedance of the input?
  Reply With Quote
Old 1st January 2012, 08:55 AM   #6
diyAudio Member
 
Join Date: Dec 2011
Location: France
How can I reduce the gain of the preamp stage without reducing the bandwith of this stage. With 2V peak to peak the gain is to much higher for the EL84 . I need a gain about 5 to 8.

I tried with resistors before the first tube but the bandwith reduce proportionally with the value of the resisor. I suppose that I need a high impedance input for CD player?

I hope you can help.
  Reply With Quote
Old 1st January 2012, 02:49 PM   #7
Fenris is offline Fenris  United States
diyAudio Member
 
Join Date: Jun 2004
Location: The last frontier
Use a tube with less gain like a 6n1p. Alternately, replace the 47K anode resistor of the first tube with two resistors that sum 47K and serve as a voltage divider. This way you can adjust the gain.
__________________
Listen to the music through the stereo, not the stereo through the music.
  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 for a newbee ben595 Everything Else 18 30th November 2010 10:40 PM
Newbee first project audiophile36 Full Range 4 23rd August 2006 07:14 PM
California Newbee ToE Introductions 1 7th February 2006 04:38 PM
newbee question daveyboy426 Car Audio 7 8th October 2005 07:05 AM
Newbee question: Can this be done (well)? Jennice Multi-Way 18 16th July 2004 03:37 AM


New To Site? Need Help?

All times are GMT. The time now is 04:52 PM.


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