Problems with cathodyne

tAB · 15th January 2006, 09:40 AM

Hi!

I built a driver for PL500. The schema and the pictures of the cathodine signals is in the attachment. The upper side of cathodine has a big distortion

I was tried with other tube, but nothing changed.

If I pull out the second ECC85, the two signal is full symmetric.

What's the problem?

Geek · 15th January 2006, 09:52 AM

Hi,

Some first impressions - R10, R13, C2 and C3 are all too big.

You have 1M gridleaks on the second ECC85 - make them 100K to 220K and C2, C3 0.1uF and try again.

tAB · 15th January 2006, 10:51 AM

Ok. Thx. I'll try it now.

tAB · 15th January 2006, 11:36 AM

I tried it.

I soldered a 180k paralell with the two 1M, and replaced the 1uF with a 100n. On the picture, you can see that the anode signal have biger distortion.

SY · 15th January 2006, 11:59 AM

Clearly, the last stage is the issue- you're drawing grid current. Check wiring first. Do a DC voltage map (real voltages, not sims).

tAB · 15th January 2006, 03:21 PM

I checked the wiring, about 10 times

On the pic, you can see the real voltages with red, I think that's OK.

________________

tAB

SY · 15th January 2006, 03:55 PM

Is that 137V plate to cathode or plate to ground?

tAB · 15th January 2006, 04:12 PM

137V plate to cathode. Voltage of VM3.

jane · 16th January 2006, 11:31 AM

I agree with SY, you are drawing grid current in the last stage..
What is the voltage over R14, about 2.3v?

tAB · 16th January 2006, 08:05 PM

Quote:

Originally posted by jane
I agree with SY, you are drawing grid current in the last stage..

And what can I do?

Quote:

What is the voltage over R14, about 2.3v?

I'll check it tomorrow.

_____________

Thx, tAB

15th January 2006, 11:59 AM	#5
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	Clearly, the last stage is the issue- you're drawing grid current. Check wiring first. Do a DC voltage map (real voltages, not sims). __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

15th January 2006, 03:55 PM	#7
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	Is that 137V plate to cathode or plate to ground? __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

16th January 2006, 11:31 AM	#9
jane diyAudio Member Join Date: Jul 2004 Location: Norway	I agree with SY, you are drawing grid current in the last stage.. What is the voltage over R14, about 2.3v? __________________ Life is hard - Then you die.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Cathodyne Questions	dsavitsk	Tubes / Valves	7	28th June 2009 07:36 PM
Can you use a MOSFET as a cathodyne	aardvarkash10	Tubes / Valves	6	14th February 2009 11:11 PM
Cathodyne follower? :)	mashaffer	Tubes / Valves	6	16th February 2008 08:18 PM
Problem: attenuation after cathodyne and CF	diegot	Tubes / Valves	2	7th December 2007 06:05 AM
Cathodyne phase splitter with CCS?	andrew_whitham	Tubes / Valves	42	1st February 2007 09:07 PM

15th January 2006, 09:52 AM	#2
Geek diyAudio Member Join Date: Sep 2004	Hi, Some first impressions - R10, R13, C2 and C3 are all too big. You have 1M gridleaks on the second ECC85 - make them 100K to 220K and C2, C3 0.1uF and try again.

15th January 2006, 10:51 AM	#3
tAB diyAudio Member Join Date: Jan 2006 Location: Hungary	Ok. Thx. I'll try it now.

15th January 2006, 04:12 PM	#8
tAB diyAudio Member Join Date: Jan 2006 Location: Hungary	137V plate to cathode. Voltage of VM3.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read