Input trannies for G9 (and matching to certain mics)

My G9 uses Lundahl 1530 for input, 1:7, 200:10k

I was wondering about possible "better" options.    More gain is not really needed, less is ok. 

First I looked for higher level handling / lower distortion.  This lead to Jensen 13k7, Lundahl 1538XL and Sowter 9045.  These are 150ohm (Jensen) or 200. 

It then occured to me that my mics are on the high side:  200ohm for the DPA 4011, and (I think) 660 for the G7 mics. In these I have used 16k:660  Sowter 9995 transformers.

Since ideally the preamp input impedance should be several times higher than the mic output (right?) it seems I might need to look at other options too.    Lundahl 7905? 

What am I missing when the mic impedance is higher than the pre imp?  In real my G7 has plenty of bass and is quite loud hooked to the G9.  If anything, I would like more treble. 

Thanks...

I guess I am getting this whole input impedance all wrong.  For example the Pendulum mdp-1 tube preamp uses Jensen 13k7 for the inputs.  1:5, 150:3.8k.  The input imp is given as 1500 ohm. 


---

Looking around some more, Sowter 9062 is 600ohm primary, offers 1:4 or 1:8

Would also be interested in some input transformer options for the G9. Escpecially some older UTC models or equivalents.

Merlin, off-topic, but if you are also curious about output, I can recommend the Sowter 9063 (that is what I have now).    in 1:2 they stay flat all the way down with lower overall thd and imd than the 5402.  In 1:4  the distortion is about double, probably a nice option for getting more color. 


On topic, what if I pull out one of mine and try it as 1:4 input?  Should show pretty well what happens if I'd buy a 9062. 

Hello, it looks like the Lundahl 1530's primaries are hooked up in parallel for 1:7, 200:10K, according to the datasheet. You could rewire them in series to get 1:3.5, 800:10K. I don't know really anything about the G9, though...

Searching for my own informations, I came across this that might help.

https://groupdiy.com/index.php?topic=41499.0

Hi, thanks for chiming in.  Will check the thread.

After posting and not getting much feedback I did manage to try the 1530 in 1:3.5.  I also tried a Sowter 9063 in 1:2 and 1:4  (600ohm primary)

The higher primary imp brought a very definite clarity boost with the tube microphone.  Also, even the 200ohm mic sounds a bit more clear, more direct when hooked to 600 or 800.  I can't decide if this is an impedance thing still, or the doing of the lower ratio that colors the signal less. 

I also found that despite the usual wisdom, it is the Lundahl that gives slightly more color than the Sowter.  The Sowter came as the most clean and clear sounding, I guess definitely from having a much larger core. 

Good news. Thank you for your reports!

You have some very nice transformers.