In Reply to: How to Improve It posted by Triode_Kingdom on October 19, 2014 at 10:13:44:
Here are my suggestions. Note, this is only a half way point, simple modifications that would provide VERY tangible benefits despite the compromise of type of tube used and lower than ideal HT voltage. Two large improvements are a result of swapping out the bypassed cathode R in the driver for Schottky diodes and DC coupling.
A little power is given up by increasing the R value on the cathode of the OP tube but the ability to transition well into A2 will more than make it up.
The driver is far more linear with a choke instead of an R and I find that a choke in this position is not detrimental to sound in the way a typical plate choke is.
I still prefer the sound with drive taken from the bottom tube's plate but you lose any worthwhile A2 transition (call it headroom).
Naz
Edits: 10/19/14
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Follow Ups
- OK, for the sake of furthering the discussion ... - Naz 17:39:38 10/19/14 (3)
- That's a different topic, so I'm out - Triode_Kingdom 20:04:58 10/19/14 (2)
- Not so fast ... - Naz 21:34:27 10/19/14 (1)
- Simulation - Triode_Kingdom 12:50:34 10/20/14 (0)