6AS7GA as push pull output?
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
Shef
diyAudio Member

Join Date: Nov 2015
Location: Vancouver, BC
Quote:
 Originally Posted by mr2racer .. .all the answer I needed.
From how your design is progressing I feel that without those my other words your last reply would not be such a short sentence. You got what you asked for. .. be grateful ))

artosalo
diyAudio Member

Join Date: Feb 2010
The problem with CCS at the anode is that the voltage swing is highly limited.
With normal PP circuit, the transformer at the anode, the voltage swing is almost from 2 x +Ub to Uk but with CCS only from +Ub to Uk.

In practice this means that with normal transformer coupled PP, with 375 V +Ub the max. voltage swing at the anode is some 550 V to 190 V = 360 Vpp.

With CCS at the anode the max. voltage can not be more than +Ub, less the voltage required by the CCS to operate.
In case of the below simulation the voltage swing is some 300 V - 90 V = 210 Vpp.

And as we know the power is: UČ : R. Therefore the latter voltage swing produces only 1/3 of the power of the first.

Second problem is the OPT. It seems to be 4k. This is not optimum for parallel PP.
Some 2k to 2k5 would be ideal.

With your last circuit, only some 5 W of output power is expected.
One advantage is however achieved, the THD is very low.
Attached Images
 6080_PP_CCS.gif (130.5 KB, 63 views)

 10th December 2017, 12:52 PM #173 mr2racer   diyAudio Member     Join Date: Jul 2009 Thanks very much Arto. I have a Japanese LCR meter on the way that can measure up to 2 kilo-henries. My current meter's limit is 40 henries so I couldn't even measure the interstage. When I recieve it I'll be able to really model the amp in Spice and that will make things much easier for me. And I won't have to lean on you guys as much. The output transformer isn't ideal but they were free. My winder can build me custom outputs for about \$90 each. So I may go that way instead. Thanks again, Kevin __________________ Artificial intelligence is no match for natural stupidity- Red Green
goldenbeer
diyAudio Member

Join Date: Jan 2014
Quote:
 Originally Posted by mr2racer Hey anyone, I'm back to TL783 as a constant current sink at the cathode of the outputs. [...]I?
I'm afraid your post makes aboslutely no sense to me. If used as ccs, the drop across the regulator will be whatever it takes to achieve the desired current. The 1.3V is just the minimum to get the regulator chip working. If using a ccs, you don't need to add resistors here or there to adjust. In fact, the additional resistors will do more harm than good. The ccs will automatically adjust its voltage drop as stated above.
If you want to burn less heat in the ccs, just lower your Ub+.
You will need to bypass the ccs'es if you're going to use 1 per cathode.

goldenbeer
diyAudio Member

Join Date: Jan 2014
Quote:
 Originally Posted by Shoog Running the 6080's with CCS in the cathodes has specific benefits which have to be understood as they come at the cost of limiting the circuit to low power class A operation (good for low distortion and DC intolerant transformers but little else).
Almost all 6080 pp circuits operate in class A anyways due to plate voltage limitations (250V) and the yuge voltage swing required for the drivers (~280Vpp for 5K Ra-a opt @13W class A power).

 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 Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Aussie Amplifiers         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post hilbert_mostert Tubes / Valves 12 8th March 2009 06:10 PM SpreadSpectrum Tubes / Valves 6 7th March 2008 12:38 AM om kalsoum Tubes / Valves 7 7th May 2007 10:48 PM chungtat Tubes / Valves 12 4th November 2005 12:25 AM 316a Tubes / Valves 4 10th February 2003 02:04 AM

 New To Site? Need Help?

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