Phase Splitter Name - 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 10th February 2008, 04:52 PM   #1
diyAudio Member
 
Gold_xyz's Avatar
 
Join Date: Dec 2005
Location: Italy
Default Phase Splitter Name

Hi to all

Can I call this Splitter Catodyne?

A complete scheme can be seen here (use Acrobat 6.0 or more):
http://www.velleman.be/downloads/0/i...k4040_rev1.pdf

Tnx !
Attached Images
File Type: gif split.gif (3.9 KB, 767 views)
__________________
My English originates from here
  Reply With Quote
Old 10th February 2008, 06:04 PM   #2
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
It depends on the relative resistor values. If Ra1 >> Rk1 and Ra2 = Rk2, then it is a voltage amplifier coupled to a cathodyne (or concertina or split-load).
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 10th February 2008, 06:19 PM   #3
jane is offline jane  Norway
diyAudio Member
 
jane's Avatar
 
Join Date: Jul 2004
Location: Norway
This is one of the few split load inverters I have seen with grid leak bias.

Jan E
__________________
Life is hard - Then you die.
  Reply With Quote
Old 10th February 2008, 06:30 PM   #4
diyAudio Member
 
Join Date: May 2005
Location: near Duesseldorf
Probably this is a mistake of the schematic: R23 is to small for grid leak bias.

Regards Andreas
  Reply With Quote
Old 11th February 2008, 08:44 AM   #5
diyAudio Moderator Emeritus
 
ray_moth's Avatar
 
Join Date: Jan 2004
Location: Jakarta
That is a very poor circuit, IMHO. There is no way a 12AX7 concertina splitter should be driving parallel PP EL34s in UL mode. Putting a 12AU7 common cathode amp stage on the front is a bad idea because of the tube's poor linearity and the splitter's bias circuit is wrong too.
  Reply With Quote
Old 11th February 2008, 11:04 AM   #6
diyAudio Member
 
Join Date: May 2005
Location: near Duesseldorf
The same concertina PI i found in the Telewatt VS 35 amplifier

http://www.audioantik.de/Stereo/VS55.pdf

Regards Andreas
  Reply With Quote
Old 11th February 2008, 03:09 PM   #7
diyAudio Member
 
richwalters's Avatar
 
Join Date: Sep 2003
Location: Alps:Tube amp designs over 150W, SMPS guru.
Ray ok (agreement to the worst of all specs)--I'm no fan of this kit stuff as I've had a couple to repair. ( and modded them to autobias)...

Interesting claim to spec, 0.1% thd at 1W o/p... that must surely be a mistake. Anyone else spot this ? Interestingly no thd figure is mentioned near full o/p.
Appro 3rd harmonic thd. Morgan Jones p.188 < mentions B9A ECC82 dual triodes are particulary gastly>. That's a published fact. so why use'm ?

The only way to get sensible performance with parallel pairs with low thd is either to use cathode follower drivers or an intermediate balanced push-pull voltage driver stage as per Williamson. I favour the latter as it cushions the split load.. I fail to understand why the authors of the kit haven't attempted this avenue.

Academically, readers can come to a swift sum-up by browsing Morgan Jones 3rd ed, classic amplifiers p. 412 onwards "the inherent driver defects of the Mullard 5-20". That's only with a conventional p-p pair not paralleled.
No hiding facts here.

richj
  Reply With Quote
Old 17th February 2008, 10:27 PM   #8
diyAudio Member
 
Gold_xyz's Avatar
 
Join Date: Dec 2005
Location: Italy
Quote:
Originally posted by jane
This is one of the few split load inverters I have seen with grid leak bias.

Jan E

Quote:
Originally posted by AndreasS
Probably this is a mistake of the schematic: R23 is to small for grid leak bias.

Regards Andreas
Hi

It seemed me that there was something strange.
In the scheme (k4040) I see a 0V grid polarization.
Also ECC82 as preamplifier and ECC83 as Splitter

This other scheme seems me correct, ECC81 with R12

http://www.velleman.be/downloads/0/manual_k8010.pdf

also

http://www.velleman.be/downloads/0/manual_k8011.pdf

__________________
My English originates from here
  Reply With Quote
Old 18th February 2008, 12:00 AM   #9
diyAudio Member
 
Join Date: May 2005
Location: Pretoria, South Africa
Oh boy...

The ECC83 split load as given will give a maximum peak signal output of about 40V before it runs out of steam (quickly hooked up) - and that is at quite visible 2nd harmonic distortion on the scope. (A 47K plate load in parallel with only 110K next grid resistors is looking for distortion.) Then grid-leak bias only works well when fed with a low impedance source. A feeding ECC83 is definitely not, apart from the grid leak resistor being too low - at least 10meg should have been there. Or it could have been direct coupled, although hardly successfull with an ECC83. I have said in the past that I do not see the ECC83 as a good choice for any kind of duty in a power amplifier. A pentode input to low mu triode phase-splitter would run circles round the above (ECF80, ECF82, 7199 etc. - and no comment from the "pentode-is-noisier" clan. That is in theory; certainly not audible in this kind of application.

I thought this kind of circuit has already been thrashed out to such an extent over 6 decades that should no longer appear compromised, . My apologies, but if this is the best Velleman can come up with, they have lost me.

Sorry Gold_XYZ, but that is not it.
  Reply With Quote
Old 18th February 2008, 03:35 PM   #10
diyAudio Member
 
Join Date: May 2005
Location: near Duesseldorf
The ECC83 (EF86, triode of the ECL86, ECLL80) are tubes, that can work with grid leak bias.
So this concertina phase inverter with grid leak bias we also meet in other amplifiers: Revox G36, Telewatt VS55, Grundig NF10.

The datasheet for the ECL86 (triode) gives an output voltage of 9 Volt RMS with THD 0,4%.

Regards Andreas
  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
Is this a phase splitter? tom-vdl Solid State 9 15th October 2009 08:21 PM
phase splitter with Tr ? sam8888ysl Tubes / Valves 9 22nd October 2008 11:28 AM
HELP; DIY PP amp - it's phase splitter, or buy Chineese. WE91 Tubes / Valves 19 30th October 2007 04:01 PM
6DJ8 as phase splitter. kegger Tubes / Valves 5 21st August 2006 03:03 PM
Phase splitter transformers kopite Tubes / Valves 2 15th July 2005 06:50 AM


New To Site? Need Help?

All times are GMT. The time now is 11:16 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