Micaddict:
Of the earlier, related, samples, I very much liked the D-67 with the Neumann K67 capsule (there were two Neumann capsules tested actually and one was better or better preserved maybe than the other).
The sample of the D-269b (fixed bias) with the Peluso K67 I liked a little less (although I simply loved the D-49b with the Peluso K47).
This D-269c (self bias) with the Neumann capsule sounds great to my ears. It is somewhat brighter than the typical U67 sound and the self bias may play a part in that. Different tube and setup, too. But the esses are pretty precise (I'm sensitive to that) and the mic is in no way harsh sounding. It sort of sounds like a cross breed between a U67 and a Brauner tube microphone. The latter has a K67-family capsule too, as well as a 5840 tube. But Brauners have a more straightforward circuit, AFAIK without any negative feedback at all, let alone tricks with transformer windings.
Still, some of that velvety, musical compression I hear in U67s is still present here, albeit with a little less thick midrange character and some extra air on top. So it's not just the EF86 in the U67 causing that velvety compression. It's the nature of the U67 family of microphones. The EF86 (and fixed bias) only adds to it.
In contrast, the M49 sounds smoother, creamier.
The U/D-269c is possibly even more versatile than the U/D-67. With the added air it should be brilliant for more distant recording, too. And up close, it sounds more modern than a U67 (i.e. without EQ).
Desert island microphone?
Poctop:
Thanks For the comment Henk, With all my experience building mics i have found that there is 2 world of difference between self biased tube circuit(c) and filament biased tube circuit (b) , When i built the pair of 49 b and 49c i could see a world between the 2 , from what i have seen so far and all my reasearch self bias microphone will be much more airy and the register will be shifted on the air , I could hear the difference very well just listening to the ambient noise, the filament bias type as in a U47 per example will have much more bass response and biff to it than a self bias version , Well noted also that filament bias microphone are very sensitive to power supply noise and that i did learned it the hard way
, i cannot speak generally for this as some other mic , but my comparison was between the exact same model or very very close ( M49 b, c) and (U67c and M269b) , in both case that is what the difference was in both case , with same capsule and transformer
IMO we would have had a totally different scenario if that would be the M269C self bias later version , in my case i needed somthing different and complementary to the U67 and by doing the earlier filament bias M269 (1962) i think this will be the perfect complement to the U67 ,one grabs the air and the other one the bottom but in a very nice way
, the final application will be the judge but i cannot wait to stick the M269 in front of a piano
and listen.
Micaddict:
According to Klaus, the U67 and the M269b sound basically the same. The M269c is less dense with more top-end clarity. Klaus has said the difference between non-c and c versions of the M269 is bigger than the difference between the U67 and M269 non-c
Micaddict:
I wouldn't worry about it, Mike. Dany's own prototype with 5840 was as far from anemic as you could imagine, "even" with the T49 tranny.
I would go for M49b rather than M49c, though.
Henk
Klause:
The first M49 was introduced around 1951. Though not marked as "a" this was the first series, and used the Hiller MSC2 triode tube, M7 capsule and a single-leg output transformer optimized for the MSC2.
Around 1955 the tube was changed to AC701, but aside of the supply voltages and its corresponding components, everything else inside the mic remained the same.
Around early 1959 (transition periods always make it hard to pinpoint a date with accuracy, as mics would be shipped to different clients at different times) the 'b' version was introduced. From then on the mic had a humbucking transformer with 4dB more output which also could be switched between 50 and 200 ohms output impedance. The mic received the new Mylar/Polyester K49 capsule and had a few additional circuit updates, like solderable low-end cut, wire switch for cardioid only operation, etc.
In late 1961, the serial number plate started to be punched with a small suffix "c' after the printed letter "b". When the "b" serial number plates ran out, all subsequent M49 plates were printed only with suffix "c" (around late 1963)
Fairly soon after, all M49s were equipped with a printed circuit board instead of the earlier point-to-point wiring.
The M49b/c had as improvement a new way of biasing of the tube (self biasing) which lowered the internal noise floor of the mic's tube and reduced stray hum and noise interference from outside sources as well.
The mic was discontinued in the early 1970s, with some stragglers having been shipped through the late 1970s.
Original spare parts were shipped until quite recently.
o3misha:
With self bias you have better "attacks" at the starts of notes - because of stable anode current, but not "natural" behavior at the sustain area of long notes ( you loose "body" of U47), because of floating of operation point when signal amplitude is changing , I think. Also, there is influence of the cathode cap. Excess cap in signal path affects on sound. Thats why M49 and M49c are different in sound for example. But, of course, self biasing method has it's own benefits: less noise, for example. Better transients are very good for recording of percussion sounds, for speach, for ambience.
