Audio Note Kits support forum, in co-operation with Audio Note UK
Return to Audio Note Kits Forum
68.61.71.108
In Reply to: RE: Kit1 2A3 experience (vs 300B if useful) posted by GTCharlie on October 21, 2009 at 16:57:23
Well ,the impedance of kit 1 OPT is 2.5 or 2.7K perfect for 2A3.If you use choke input PSU (PQ doesn't like it) the B+ should be in a ball park (one can always use a different PT)My guess is that comparison should be quite trivial to achieve. Unfortunately (or not) most (if not all) AN users trust Peter more than their own pair of ears (and what's behind;) so ask him directly and you'll have (mostly correct;) your answer.
Hi W. My "ears" prefer primary Z for 300B OPT around 5k4 - 6k. That's what I use. For 2A3, the same ears prefer 2k5 primary. This is just a conjecture : but I suspect a 2A3 plugged into the Kit One should do very good (after assuring proper current and voltages that is). The 2A3 does not demand as much drive as the 300B and the SRPP 5687 might fare better.
thanks you for your interest.
I have a very recent Kit1 (signature version + TKD + ELMA upgrades) with AN Improved HiB OPTs (you can find it's picture on ANK site), so 2K7 on primary.
Switching to 2A3 would simply require to:
- change 4 resistors on the same heater board you see in monoblocks
- change mains HT voltages (different wires for 2A3 and 300B operation, 5687 and 6SN7 voltages will be reduced a little too...)
- buy and change power triode
in my experience 300B focus is on instruments against voice (Kit1 with Sovtek 300B 90hrs burn in), 2A3 has the opposite behavior with tighter bass and some roll off on highs (other brand amplifier). I have 102db speakers (down to 34Hz), power is not an issue at all.
the questions are:
- does Kit 1 performs equally better in 2A3 or in 300B mode?
- which power triode would be the most accurate according to comparison by contrast method in Kit1 circuit with Tantalum, black gates, AN copper Caps and HiB OT components?
I have to choose between buying a better 300B tube that has more focus on mids and less bass related to Sovtek, or to switch to a very good 2A3.
thanks a lot in advance.
You seem to have answered your own question. As it is a simple matter to change the Kit1 to 2A3 operation and Sovtek 2A3's are cheap, why not try it yourself and see which is better to you. Then you can decide whether to move on to something else. Let us know what you find out. When I find some time I would like to do the same with my basic Kit1.
Post a Followup: