Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki 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

IXCP10M45S
IXCP10M45S
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 Yesterday, 04:27 AM   #11
Eli Duttman is offline Eli Duttman  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
Apply Ohm's Law to calculate the cathode resistor value. You need a 600 part.
__________________
Eli D.
  Reply With Quote
Old Yesterday, 04:29 AM   #12
6A3sUMMER is offline 6A3sUMMER  United States
diyAudio Member
 
Join Date: Jun 2016
mr2racer,

For your triode with a CCS as the plate load: Set the CCS to 10 mA (many CCS use a single resistor to set the current, calculate for 10 mA, and use that resistance). Connect the grid through its grid return resistor to ground (0V) Calculate the cathode resistor, 6V/0.010A = 600 Ohms. The self bias resistor is 600 Ohms, connect the cathode through a 600 Ohm resistor to ground. Turn the filaments on, and the B+ on. The voltage on the cathode Will Be 6V (600 Ohms x 0.010A) Done.

You may or may not want to use a bypass capacitor across the 600 Ohm self bias resistor. The cathode impedance is as high as it ever can be, because the plate is loaded by an extremely high impedance (CCS). The grid resistor of the next stage is quite often lower than the impedance of a good CCS plate load.

Example gain of the circuit:

Suppose the circuit has the plate and CCS plate load, driving a coupling cap, driving the next stage grid resistor: Suppose the CCS is not real good, so it only has an impedance of 100k Ohms.

Suppose the grid resistor of the next stage is 100k Ohms. The plate load is effectively 50k Ohms. Suppose the triode has a Mu (u) of 20. Suppose the triode has a transconductance, Gm, of 1000 micro mhos. That is 1000 Ohms cathode impedance. With a u = 20, and a transconductance of 1000uMhos, rp = 20,000 Ohms (u/Gm = rp)

But the 1000 Ohm cathode impedance is raised by the 'plate load/u' 50k/20 = 2500 Ohms. The total cathode impedance is 1000 Ohms + 2500 Ohms = 3500 Ohms.

3500 Ohm cathode impedance is in parallel with 600 Ohms = 512 Ohms.

If you use a capacitor that has 51 Ohms of capacitive reactance at 10 Hz, the low frequency will be no more than -3dB at 10 Hz, and only -1dB at 20 Hz (single pole roll off). 51 Ohms = 2 x pi x f x C C = 1 / (51 x 2 x pi x 10Hz) C = 312 uF With the bypass cap, the gain will be 20 x (50k/(20k + 50k)) = 14.3

If the CCS impedance is 400k, and the next stage grid resistor is 400k, the plate load is 200k. Now the gain is 20 x (200k/(20k + 200k)) = 18, much closer to u.

And do not forget that the impedance at the cathode is 600 Ohms in parallel with the cathode impedance (1000 Ohms in series with 200k/20) = 1,000 + 10,000 = 11,000 Ohms. You can see that 11,000 Ohms is much much greater than 600 Ohms, so the bypass capacitor is Not needed in this case (and some people are very happy when they do not need to use a bypass capacitor).
  Reply With Quote
Old Today, 06:28 AM   #13
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Quote:
Originally Posted by mr2racer View Post
...CCS...10ma ... 6N6P.
You have picked a current, and a tube.

You must also pick a Plate voltage. Usually near mid-point of your B+.

The plate-cathode voltage will be somewhat larger than Mu times the grid-cathode voltage.

It *really* helps to work this out on the tube curves.
  Reply With Quote

Reply


IXCP10M45SHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: ixcp10m45s albertob Swap Meet 0 12th September 2012 12:04 PM
IXCP10M45S (50pcs) FrancoB Swap Meet 1 26th July 2011 05:47 AM
Wtb - ixcp10m45s Dagwood Swap Meet 3 29th August 2010 09:11 AM
Wtb: Ixcp10m45s Junior Swap Meet 3 16th January 2010 02:14 AM
WTB IXCP10M45s woody Swap Meet 0 6th July 2007 02:28 AM


New To Site? Need Help?

All times are GMT. The time now is 11:11 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki