Freddy G

G7 Capsule Recommendations Please!
« on: November 22, 2018, 06:47:36 PM »
Hi!

I built a pair of G7s quite a long time ago. One of the members here at that time built the capsules for me. I'm just wondering if there is a consensus on what everyone's favorite capsule for this mic is....now that there are so many more capsules available to buy as aftermarket parts.

Thanks!
PRR wrote:
Use #18 wire for rock-n-roll, #16 wire for classical.


Re: G7 Capsule Recommendations Please!
« Reply #1 on: November 24, 2018, 07:13:58 AM »
Well it's a flat circuit, so i guess c12 or k47/m7 are the way to go. Tim Campbell's CT12 or Thiersch m7 would be my higher end favorites.

mhelin

Re: G7 Capsule Recommendations Please!
« Reply #2 on: November 24, 2018, 01:48:03 PM »
I assume you've got Tim Campbell's CT12, right?  Dan's (poctop) D7 is also a good alternative:
http://www.vintagemicrophonepcbkit.com/Caspsule.html

Also there are the Beesneez and Maiku capsules (K-47 or CK12 style).

It may though be that the they are not "better" what ever it means to you than Tim's capsule. I think G7 was designed to be more like a U47 or a U67, so I guess any Neumannish capsule would fit the bill except that G7 has no eq correction required for a K67 type capsules. 3U audio though has a new capsule ("super smooth 87") thats K67 like but doesn't need the eq (well maybe some 2dB raise at 6kHz or so in some cases which you can fix in the mix).

One thing you could do, swap the tube and use an EF806 or an  E80F instead of EF86, or replace the transformer. Is there something wrong with your G7, aren't you happy with it?
« Last Edit: November 24, 2018, 02:41:02 PM by mhelin »
Mikko

Freddy G

Re: G7 Capsule Recommendations Please!
« Reply #3 on: November 24, 2018, 02:26:20 PM »
thanks for the reply guys!

I have a pair of Dale's m7 capsules. Got them in 2007 or 8. The transformer is a Lundahl.

No, it's not that I'm unhappy or anything is bad....just thought maybe I could do something to make me really dig these mics again.  I've been using a couple of U87s from the early 70s for vocals and I like the quality they have in the midrange....totally different than the G7. Very thick and forward. Perhaps that tube change might be an inexpensive experiment to start with.
PRR wrote:
Use #18 wire for rock-n-roll, #16 wire for classical.

e.oelberg

Re: G7 Capsule Recommendations Please!
« Reply #4 on: November 24, 2018, 05:40:23 PM »
I doubt a tube change makes that big difference, but if you drop the  high z resistors down from 1g to 200mOhm that might go into the direction you'd like to hear....

e.oelberg

Re: G7 Capsule Recommendations Please!
« Reply #5 on: November 24, 2018, 05:43:35 PM »
as far as I remember there is also a small value bypass cap for the output capacitor, take that out too.

maybe post the circuit again, that's all just vague remembrances

Re: G7 Capsule Recommendations Please!
« Reply #6 on: November 25, 2018, 05:17:02 AM »
G7 has nothing in common with u47 or u67. It's very clean and transparent design.

I have one of Dale's capsules and i like it very much. However it's possible you got tired of it.

I would recommend in that case CT12. I believe Jacob had that capsule in mind when he designed the mic. But he might chime in.

iprovlek

Re: G7 Capsule Recommendations Please!
« Reply #7 on: November 25, 2018, 05:55:43 AM »
Yes CT12 is great capsule and can change sound a lot!!!


I had Microphone parts RK12 in my Elam and when I changed  capsule difference was huge....

So you can't go wrong with CT12....

 ;)

ln76d

Re: G7 Capsule Recommendations Please!
« Reply #8 on: November 25, 2018, 06:12:33 AM »
Here's what you can do with the circuit.
100M as example, it can be 150M, 200M, 250M, 300M etc. I wouldn't go higher than 470M.
Also i recommend E80F tube if you will be able to fit it.
Dale M7 is good capsule i would definately keep it here.
Also for it i would reccomend to lower polarisation voltage if it's 80V like in original circuit.
Adjust bias on cathode doesn't hurt also ;)

Murdock

Re: G7 Capsule Recommendations Please!
« Reply #9 on: November 25, 2018, 09:27:27 AM »
Sorry for going offtopic, but who made the bodies? They look great!  ::)


Freddy G

Re: G7 Capsule Recommendations Please!
« Reply #10 on: November 25, 2018, 10:43:11 AM »
G7 has nothing in common with u47 or u67. It's very clean and transparent design.


That's the thing. These mics have never sounded that clean. Actually kind of 'creamy' especially in the top end. I often have a problem with singers....dirty "esses"
PRR wrote:
Use #18 wire for rock-n-roll, #16 wire for classical.

Freddy G

Re: G7 Capsule Recommendations Please!
« Reply #11 on: November 25, 2018, 10:46:22 AM »
Here's what you can do with the circuit.
100M as example, it can be 150M, 200M, 250M, 300M etc. I wouldn't go higher than 470M.
Also i recommend E80F tube if you will be able to fit it.
Dale M7 is good capsule i would definately keep it here.
Also for it i would reccomend to lower polarisation voltage if it's 80V like in original circuit.
Adjust bias on cathode doesn't hurt also ;)

Thanks for this info! That's quite a lot of changes to the schematic. Even the output cap is very small. Can you explain the thoughts behind these changes?

PRR wrote:
Use #18 wire for rock-n-roll, #16 wire for classical.

Freddy G

Re: G7 Capsule Recommendations Please!
« Reply #12 on: November 25, 2018, 10:47:35 AM »
Sorry for going offtopic, but who made the bodies? They look great!  ::)

Thank you! I made the bodies myself. Fashioned from 2" brass bar rail, then sandblasted and nickel plated.
PRR wrote:
Use #18 wire for rock-n-roll, #16 wire for classical.

iprovlek

Re: G7 Capsule Recommendations Please!
« Reply #13 on: November 25, 2018, 11:28:48 AM »
Freddy which sort of capacitors you have in your G7!!!

If you have Wima get rid it off this caps in this mic, for that 100n put Vishay Roederstein MKT1813, put some NOS styroflex for 1nF and 10nF, and get some PIO for 2.2uF output capacitor and you will get rid off that bad dirty sibilance!!!

Sound of this mic is great and need a little more care off it... Stay with EF86 I had E80F but change it when I change caps!!!

But you can put PF86 but than you must decrease heaters on 4.5V!!!

« Last Edit: November 25, 2018, 11:39:41 AM by iprovlek »

iprovlek


Kingston

Re: G7 Capsule Recommendations Please!
« Reply #15 on: November 25, 2018, 11:52:52 AM »
Capsule or tweaking of the circuit is not going to make any meaningful difference. Dale m7 with the Lundahl is as good as it gets.

What you want is a different grill shape and pattern, possibly more layers of it. Those mic bodies look awesome, but you may have simply gotten unlucky with the capsule position and grill design.

Re: G7 Capsule Recommendations Please!
« Reply #16 on: November 25, 2018, 12:06:04 PM »
Kingston, with all due respect i can not understand how you can claim such a thing without hearing or measuring the mics.

There is no way one can judge effect of the body/grille/placement just by seeing the mic.

On the other hand the tweaks ln76d sugested will make dramatic impact to the tone, and will focus the sound towards mid range by taming the low end.

Rebiasing might help with the distortions and harsh 'S' sounds, and if the polarisation voltage really is 80v it should be lowered, and will impact the sound and headroom.

iprovlek

Re: G7 Capsule Recommendations Please!
« Reply #17 on: November 25, 2018, 12:06:27 PM »
I have this microphone for five years now and try everything...

But grill and shape body of this microphone will not change sound too much....

Capsule, tube, transformer and components will change a lot....

iprovlek

Re: G7 Capsule Recommendations Please!
« Reply #18 on: November 25, 2018, 12:13:48 PM »
Freddy did you solder trimmer and a capacitor on pcb which lowers distortion of this microphone and output impedance!?

And cancels tubey sound of it...

http://gyraf.dk/gy_pd/g7/gic.htm

« Last Edit: November 25, 2018, 12:19:08 PM by iprovlek »

Kingston

Re: G7 Capsule Recommendations Please!
« Reply #19 on: November 25, 2018, 12:59:00 PM »
Kingston, with all due respect i can not understand how you can claim such a thing without hearing or measuring the mics.

G7 is a transparent circuit and the mics of this thread happen to feature practically the highest end capsule and transformer. You can not fail with that combination.

If it doesn't sound quite right the problem is literally staring at your face.

Playing with component changes is quite silly. You already have the best parts.


 

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