On the subject of pentode constant current sinks
Does anyone have any links to articles on applying these properly to long tail pairs
I'm not having much luck finding info on the Interweb.
Steve
Search found 10544 matches
- Sun Nov 25, 2007 6:34 pm
- Forum: Everyones Projects
- Topic: 6AS7 Push Pull
- Replies: 261
- Views: 164017
- Sun Nov 25, 2007 6:05 pm
- Forum: Assorted Stuff
- Topic: While the cat is away ....
- Replies: 12
- Views: 7800
One thing I know is that since Virgin took over from TeleWest my broadband speed is extremely variable, the TV pixellates at least once per day and my Internet has gone down three times in the last month for an hour at a time with no explanation, plus I was without a phone line for three days until ...
- Sun Nov 25, 2007 5:45 pm
- Forum: Beginners
- Topic: Going PSE.
- Replies: 17
- Views: 12775
SRPP? What's the world coming to? Something needs to be done about this creeping pushing and pulling behaviour before it takes over this forum. Nothing wrong with these disgusting little push-pull perverts that a damned good thrashing wouldn't sort! Bah! http://homepage.mac.com/scress1958/.Pictures/...
- Sun Nov 25, 2007 5:38 pm
- Forum: Everyones Projects
- Topic: 6AS7 Push Pull
- Replies: 261
- Views: 164017
- Sat Nov 24, 2007 9:46 pm
- Forum: Assorted Stuff
- Topic: A little giggle!
- Replies: 9
- Views: 7371
- Sat Nov 24, 2007 4:37 pm
- Forum: Everyones Projects
- Topic: 6AS7 Push Pull
- Replies: 261
- Views: 164017
Right, I've been doing quite a lot of modifying this week, playing with LM317s as constant current sinks for the input and driver stages. Taking advantage of the flat loadlines generated by the CCSs I took the opportunity to reduce the current passing through both stages. The 6SN7s and 6SL7s both ha...
- Sat Nov 24, 2007 12:22 pm
- Forum: Everyones Projects
- Topic: CCS rules supreme!
- Replies: 31
- Views: 20831
In a word Philip.......yes Or..... you could peruse the characteristics for the 834, look for a current draw that will give the max linearity and use that by recalculating the resistor value. Don't get hung up over voltages. (Nick cured me of that one a few months ago) Bias current is the important ...
- Sat Nov 24, 2007 12:35 am
- Forum: Everyones Projects
- Topic: CCS rules supreme!
- Replies: 31
- Views: 20831
Hi Nick, That's one way around it. :D One of the many good things I found when using the LM317s as CCSs in the input and driver long-tail pairs has been the fact that the perfect balance obtained has killed most of the power supply noise stone dead. Once the power stage is sorted I'm fairly confiden...
- Fri Nov 23, 2007 11:47 am
- Forum: Everyones Projects
- Topic: CCS rules supreme!
- Replies: 31
- Views: 20831
Steve: At 70v I would have thought you were in the range of a pentode CCS? Hi Nick Forgot about how good pentodes are at CCS duties. Should be no problem implementing a pair of pentodes as CCSs on the output valves. A couple of EL34s will handle the current very nicely and at zero additional cost, ...
- Thu Nov 22, 2007 10:23 pm
- Forum: Everyones Projects
- Topic: CCS rules supreme!
- Replies: 31
- Views: 20831
Thanks Andrew, After a bit of searching I managed to find a nice regulator that could also be used. The Texas Instruments TL783 high voltage regulator is rated at 125V and 700mA; available from Farnell. This is ideal for low voltage/high current regulator triodes being used as output devices. Great ...
- Thu Nov 22, 2007 9:32 pm
- Forum: Everyones Projects
- Topic: CCS rules supreme!
- Replies: 31
- Views: 20831
- Tue Nov 20, 2007 7:00 pm
- Forum: Assorted Stuff
- Topic: A little giggle!
- Replies: 9
- Views: 7371
Yes that was me. 13 years ago with the Linn pretek/powertek and LP12 plus Index IIs. It was a nice system: very enjoyable until upgraditis set in. I was never as satisfied again until I stepped off the elevator, thousands of pounds lighter and started again with valves. I can't remember now, but if ...
- Mon Nov 19, 2007 1:02 pm
- Forum: Beginners
- Topic: Going PSE.
- Replies: 17
- Views: 12775
What you need to do if you want more drive is to up the HT on the driver stage to around 500V. This will give a much greater voltage swing into the EL34s than you have at the moment. EL34s are pretty powerful tubes, and knowing a bit more now, than I did when I first put the circuit together, I woul...
- Sun Nov 18, 2007 10:06 pm
- Forum: Beginners
- Topic: Going PSE.
- Replies: 17
- Views: 12775
Hi Al All I can say is I tried going PSE with the exact same circuit as you have. trouble was that although it sounded a bit more meaty, there was an accompanying hardness that pervaded the sound. This was possibly due to the high standing current being drawn by the four valves in single ended mode ...
- Sun Nov 18, 2007 11:04 am
- Forum: Assorted Stuff
- Topic: Share a thought
- Replies: 11
- Views: 8048