Headless_Harry

changing capsules in Bock 195
« on: May 10, 2019, 05:50:04 PM »
This would be my first time working on a microphone (I have done some modding/DIYing on guitar amps, preamps, and pedals) so forgive my ignorance here.
 
I have a Bock 195 that had the capsule replaced with a cheap no name thing due to damage on the original -- I want to buy a beesneez k7 and try swapping them, my thinking is it will make the mic smoother and maybe more forgiving (plus their k67 is 7 months out on delivery, according to Reverb), but I know I will need to work on the 'bias voltage' changing from a 67 style to a 47 style...also it looks like there is one less wire

I shot Ben And Veronica S. a message about what their k7 can safely handle, but in the meantime does anyone have some/enough familiarity with this circuit to recommend what few caps/resistors need to be changed to balance that? Or how to calculate it for myself?

Thank you
PS I know David Bock is on here at times, but I don't want to rudely approach him about this directly.


Also, is there a relatively simple way to add a variable voltage to the back of the capsule so I can have additional polar patterns?
« Last Edit: May 11, 2019, 10:53:49 AM by Headless_Harry »


Re: changing capsules in Bock 195
« Reply #1 on: May 10, 2019, 07:51:27 PM »
I don't think it would be rude to aproach Bock directly, it's his mic, so some kind of product support should be available.

I believe that microphone uses 797 audio capsule stock. You can find it in Behringer b2 or several SP mics, or just order it from 797 audio.

If you want to go k47 way, you don't need to change polarization voltage.

We would also need to have schematic of the thing.

Just make sure that circuit doesn't have some kind of HF attenuation. In that case k47 will be too dark for stock circuit.


Delta Sigma

Re: changing capsules in Bock 195
« Reply #2 on: May 10, 2019, 11:09:32 PM »
Did you hear back from Ben/Veronica? Ben might have a better idea of what capsule would suit the mic. They make both K67 and K87 capsules (named, K6 and K8 I believe) as well. I've used their K6, CK12 and M7 capsules and they are all extremely good capsules.

David also may have a recommendation of what Beesneez capsule would work.

Headless_Harry

Re: changing capsules in Bock 195
« Reply #3 on: May 11, 2019, 10:13:45 AM »
I haven't heard back yet, but I think kingkorg is right -- I see the 195 is already biased in the upper 40s which should be safe enough for a k47 style capsule....(as far as ive read!). Having seen a frequency chart of the 797 capsule, and one for the 195, it would appear there is some kind of attenuation but I don't think there is enough to put me in danger of making the mic too dark considering this is somewhat of an 'airier u87' -- also, the more recent and updated soundelux version uses a "smoother" k67 capsule than the one that would have come in mine.

I am definitely interested in the beesneez k6 capsule, ill have to reach out to them directly because their reverb.com listing says delivery won't take place until December.
« Last Edit: May 11, 2019, 10:54:02 AM by Headless_Harry »

Khron

Re: changing capsules in Bock 195
« Reply #4 on: May 11, 2019, 10:16:50 AM »
Just to be on the safe side, might reverse-engineering the circuitry be feasible? I would figure that beats guesswork, educated as it may be...
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

Headless_Harry

Re: changing capsules in Bock 195
« Reply #5 on: May 11, 2019, 10:41:05 AM »
That’s very true, I’ll try to jot something down and upload it when I get the chance to.

Also, has anyone “added” polar patterns to a mic? I am very curious about the process

Khron

Re: changing capsules in Bock 195
« Reply #6 on: May 11, 2019, 11:41:53 AM »
That depends on what is or isn't already included in the circuitry.

For a solid-state mic without any DC-DC converter,  at best you can add a switch for omni.

If there's already a DC-DC converter, see above-mentioned addition, plus by adding a couple diodes and capacitors, you could also derive a negative voltage, to have the option of fig-8 as well.

References:
Omni: http://audioimprov.com/AudioImprov/Mics/Entries/2013/8/8_Mic-Parts_RK-47.html
Omni + fig-8: http://audioimprov.com/AudioImprov/Mics/Entries/2015/12/20_Modding_a_BM-800_Mic.html

Also, has anyone “added” polar patterns to a mic? I am very curious about the process
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

Headless_Harry

Re: changing capsules in Bock 195
« Reply #7 on: May 11, 2019, 04:11:25 PM »
Hmm, that may be more complicated than I'm looking to get right now. Omni would be useful, thank you Khron

Re: changing capsules in Bock 195
« Reply #8 on: May 13, 2019, 09:00:50 PM »
This would be my first time working on a microphone (I have done some modding/DIYing on guitar amps, preamps, and pedals) so forgive my ignorance here.
 
I have a Bock 195 that had the capsule replaced with a cheap no name thing due to damage on the original -- I want to buy a beesneez k7 and try swapping them, my thinking is it will make the mic smoother and maybe more forgiving (plus their k67 is 7 months out on delivery, according to Reverb), but I know I will need to work on the 'bias voltage' changing from a 67 style to a 47 style...also it looks like there is one less wire

I shot Ben And Veronica S. a message about what their k7 can safely handle, but in the meantime does anyone have some/enough familiarity with this circuit to recommend what few caps/resistors need to be changed to balance that? Or how to calculate it for myself?

Thank you
PS I know David Bock is on here at times, but I don't want to rudely approach him about this directly.


Also, is there a relatively simple way to add a variable voltage to the back of the capsule so I can have additional polar patterns?

Hi Harry,

Sorry we haven’t replied, I have looked for your message but havn’t Been able to find it?

The K7 will work very nicely in the 195.  I have replaced a few already with the k7 and the result is very nice.

As for the k6 (k67) we have many of these in stock also.

Thanks.

Ben

Headless_Harry

Re: changing capsules in Bock 195
« Reply #9 on: May 14, 2019, 07:26:24 AM »
Thank you Ben, I appreciate the input. I'm leaning heavily towards the k7, but would you be able to shed any light on what you found the differences to be like in application? 
Not sure about the message, I've been traveling and internet can be spotty, so its entirely possible it never went through...but thank you for reaching out to me here!

Hi Harry,

Sorry we haven’t replied, I have looked for your message but havn’t Been able to find it?

The K7 will work very nicely in the 195.  I have replaced a few already with the k7 and the result is very nice.

As for the k6 (k67) we have many of these in stock also.

Thanks.

Ben


Delta Sigma

Re: changing capsules in Bock 195
« Reply #10 on: May 15, 2019, 02:27:44 PM »
Just to be on the safe side, might reverse-engineering the circuitry be feasible? I would figure that beats guesswork, educated as it may be...

Whatever you decide on, spend the time tracing the circuit and marking up a schematic as Khron suggested. It will help you learn more about mic design - capsule, transformer, caps and most importantly the circuit. I sold a Beesneez Arabella to raise funds for a build so I traced the circuit before selling. I love the design and refer to the schematic for reference often. I miss that mic too; as much as I love the M49 I built with the cash it doesn't have that Arabella magic.

Re: changing capsules in Bock 195
« Reply #11 on: May 17, 2019, 03:24:13 AM »
Thank you Ben, I appreciate the input. I'm leaning heavily towards the k7, but would you be able to shed any light on what you found the differences to be like in application? 
Not sure about the message, I've been traveling and internet can be spotty, so its entirely possible it never went through...but thank you for reaching out to me here!

Hi Harry.  Whilst the k67 can sound great in many applications, it can be a little harsh.  There are a few ways to combat this though.  If you want to make a mechanical improvement, change the center backplate spacer to a 46-48um and this will increase the time that it takes the standing wave to return to the diaphragm skin.  Due to the reversing of the phase of the returning wave, the top end is reduced. 

As for the k7, it just works.  The frequency response sounds more ofe to what we hear on a daily basis.

In my opinion, this is why the k47and M7 capsules have been so well used through mic history.

Thanks.

Ben

Re: changing capsules in Bock 195
« Reply #12 on: May 17, 2019, 01:24:51 PM »
This is abdolutely subjective, and might be untrue, could never confirm with measurements.

I can swear i hear smearing in high end on every k67 i've ever heard including original. Like on hi hats, and other sources of this type. I could get rid of this by changing delay by few samples between front and rear diaphragm in my dual output mic in DAW.

My theory is that k67 is not ideal for this, and simply inferior to k47 design.


 

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