6C45P Spud - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 26th January 2007, 10:52 PM   #1
diyAudio Member
serengetiplains's Avatar
Join Date: Feb 2004
Location: Canada
Default 6C45P Spud

I finally got around to wiring this little firecracker into a single-stage amplifier ... sounds very good. I'm using 150VDC regulated supply feeding 5uF of film capacitance on the supply. To reduce the effect of power supply noise, I played around with various topologies, including WE cathode capacitor, using a transformer as a choke + attaching the secondary to the cathode (call it a WE cathode transformer), etc. These measures improved the sound, but left me unsatisfied. I also added inductance to the power supply (15H, 25H, 125H) but felt the inductor dulled the sound considerably. I then settled on wiring two tubes in parallel, feeding them with opposite phase inputs from an input transformer, powering them from the same supply, each with its own output transformer, and cross wiring the output transformer secondaries to the speaker (call it inverted, cross-wired parallel single ended). Lovely sound. Now to my question

Can someone pinpoint for me what I should look for on a scope to see if either of the tubes is oscillating?
  Reply With Quote
Old 12th September 2015, 01:24 AM   #2
Bigun is offline Bigun  Canada
diyAudio Member
Bigun's Avatar
Join Date: Jan 2009
Location: Waterloo, ON or Herefordshire
Blog Entries: 2
sorry of the late reply, it required a lot of thinking. You're looking for signs of very high frequency waves riding on the signal, or on the ground, or at the heater supply - possibly in bursts.
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote


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
6C45P Anode choke or resistor? Peter K Tubes / Valves 37 27th September 2011 02:21 AM
Spud anyone? Tubelab_com Tubes / Valves 88 12th January 2010 12:22 AM
Which Spud Amp? ambience exists Tubes / Valves 0 23rd July 2008 09:43 PM
Is this a Spud Amp ? mod_sonic Tubes / Valves 7 12th July 2006 11:11 AM

New To Site? Need Help?

All times are GMT. The time now is 12:17 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2