 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
In Reply to: Looking for a GOOD 211 / VT4-C Schematic posted by Super_BQ on July 17, 2003 at 23:47:58:
The fi and Kondo schematics both rely on class A2 operation, and so also rely on cathode follower drive. This is how to get power out of a 211 at low voltages (yes sub 1kv is low voltage when discussing transmitting bottles).That said the 211 is made for a little class A2 operation.
If you prefer to stay in A1 you could adapt many schematics.
Determine how much power you want, and we'll see if that's possible in A1 and at which operating point, into which load.
When we know the quiescent bias voltage we will know the required drive voltage, and can work backwards form there. It now depends upon how much power you require at the output and how much input volatge (sensitivity) your system can provide, as to whether you will need one stage or two before the 211.
Give more info.
Follow Ups:
Hi Paul!!Power isn't really a concern for me. I will be using very efficient speakers which you can see at my website
http://www.geocities.com/super_bq/HiFi.html
I prefer to stay in A1 (full Class A operation). With 104db/1w/1m efficient Klipschorns, a few watts can go pretty loud.
Part of the reason why I was looking at the Fi is because of the 211 says "Ongaku style". That caught my attention as these amps generally sell for $50,000 and up. I dunno why (perhaps silver OPT and all that boot).
BQ
"It now depends upon how much power you require at the output and how much input volatge (sensitivity) your system can provide, as to whether you will need one stage or two before the 211."I forgot to mention that the pre-amp I plan to use is an active type. It has quite the output gain (at least 2v output).
Powerwise, i'm happy with around 10 watts but then again, i've never seen 211/VT4-C wired for that low wattage output. I guess it wouldn't do justice running such a tube under 1KV so wattage would normally be a lot higher.
Actually the power output at higher voltages in the case of the 211 is usually lower because to get power out of a 211 you must use A2. Just answering on the fly I'd expect to see perhaps as little as 15 watts, very unlikely 20 watts, but 10 watts is sufficient for your needs. This is good because it possibly allows a "better" valve choices elsewhere. There is nothing worse than having to use valves because of their parameters rather than their sound.
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
