Gyraf G7 improvements

i purchased a beezneez  k7 capsule from the group buy and was considering another 47 type build. BUT...  since funds are a bit low and i have all boards tranny and components to put together another G7 Mic. i have 3 different tube mic PSUs all underheated for 6.3 heater, different B+ voltages to choose from, all " pinned out"
the same, so it makes more sense to put together another g7. some members have suggested that the circuit can be improved upon. i was hoping those members could share some theory and/or hints as to where the circuit can be altered. i have the PSUs i need so im looking for improvements in the mic only. any help is appreciated.

Main improvement is probably using a PF86 tube in stead of the originally recommended EF86, as the EF86 is nearly impossible to find in a decent quality anymore. The PF86 is plenty and cheap, and mainly produced during the golden era of tube manufacturing. PF86 requires an adjustment to heater voltage (see data sheet) - and generally takes underheating much better than EF86 (must be different cathode construction, not only different heater wire)

Next would be to change polarisation voltage into +/-60V in stead of 80. Matters with many new capsules.

Also, using the Beyer mini microphone transformers (1:8 or 1:10) sounds really good.

Jakob E.

There's nothing really wrong with the G7 mic design, but the PSU part is underwhelming. Most of the time you won't have any problems, but since you're DIYing, might as well brute force it to begin with. The passive PSU some people are using for the MK7 mic works very well for a G7 as well.

Then there's the recommended LL1538 transformer. Output impedance of the mic will be a bit high with this low-ish 5:1 ratio. Again, most of the time you won't hear a problem, but with some tube preamp input transformers (very low input impedance) it's going to be bye-bye-bass.

But this one is an easy fix. LL1578 is pin compatible, even same physical size, but is 10:1 ratio. There, fixed.

thanks for the replies.  one of the PSUs i have is for max's mk7 mic.it works well with my G7.  my G7 PSU is "modded" to about 130V B+  because in my unscientific tests i found it sounded less harsh (peluso cek-12,jj ef806). i am just looking to not repeat myself. i imagine the beezneez capsule, a different tube( i have a few ef86 to choose from) and different grill will be enough to give me a different sounding mic. i just tend to over analyze my options. when i get around to this project i'll post results