Official C12 Clone - Build and Support Thread

[Coop]

I will chime in here as I am building a C12 too right now. Still looking for a nice capsule. Originally wanted to use a CT12 but I heard Tim is quite busy...

 

[andYz00m]

I hit up Eric Heiserman on instragram and ordered a HK12 through them. It said "Sold Out" on their website so I hit them up and ordered directly. They said about 3 weeks lead time.

 

[Coop]

Oh, good to hear. So the HK12 is back on my list Really difficult to find the right caspsule. They are all really good.

 

[andYz00m]

Seems like everyone is really happy with Tim's stuff and the Beesknees stuff as well. Its pretty cool that we have multiple excellent sources for capsules.

 

[Coop]

That's true. And I think it is a really personal choice which one sounds "the best". Even two original CK12 capsules will probably sound different when compared. And who knows if they still sound the same as they did back in the 50s

 

[andYz00m]

Dude, this donor mic sounds great. If this stock cheapo mic sounds this good, I'm expecting to be absolutely floored with the upgrades.

 

[wjohn]

Dude, this donor mic sounds great. If this stock cheapo mic sounds this good, I'm expecting to be absolutely floored with the upgrades.

Can you tell us about the fit and finish of that NOS mic? It looks like a typical Alctron HT-11a but their photos don't show very much despite being fancier than most.

 

[soliloqueen]

I will chime in here as I am building a C12 too right now. Still looking for a nice capsule. Originally wanted to use a CT12 but I heard Tim is quite busy...

OPR has a new true ck12 too that I've heard is quite nice

 

[andYz00m]

Can you tell us about the fit and finish of that NOS mic? It looks like a typical Alctron HT-11a but their photos don't show very much despite being fancier than most.

Here is the link to the mic below.

It seems totally decent. I was actually surprised by the quality of the sound of the stock mic. Excited for the upgrades.

Sound clip here. Pre>slight compression>converter.

• Case seems decent quality, will easily serve as protection and storage of a high end mic.
• Build quality seems similar to other mics of this price point.
• The 7 pin connectors are garbage and the pins bend easily.
• The 7 pin cable is decent but cheap.
• The shockmount is the squeeze tension type and I hate it. Would certainly replace this.
• The soldering and components of the mic and the power supply dont seem particularly high quality. These solder joins would clearly NOT be going to space.
• The mic body only slides on one way but the logo badge is on the back side of the mic when in cardioid. Which was surprising.
• Capsule looks ok, dont know much about how to evaluate it from the look of it.
• Didnt take the transformer out.

Photos:

 

[wjohn]

Here is the link to the mic below.

It seems totally decent. I was actually surprised by the quality of the sound of the stock mic. Excited for the upgrades.

Sound clip here. Pre>slight compression>converter.

• Case seems decent quality, will easily serve as protection and storage of a high end mic.
• Build quality seems similar to other mics of this price point.
• The 7 pin connectors are garbage and the pins bend easily.
• The 7 pin cable is decent but cheap.
• The shockmount is the squeeze tension type and I hate it. Would certainly replace this.
• The soldering and components of the mic and the power supply dont seem particularly high quality. These solder joins would clearly NOT be going to space.
• The mic body only slides on one way but the logo badge is on the back side of the mic when in cardioid. Which was surprising.
• Capsule looks ok, dont know much about how to evaluate it from the look of it.
• Didnt take the transformer out.

Photos:
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Awesome - thanks for the details and photos. Very consistent with the "Bad Aax" branded one that I have, including poor soldering. (The NOS one has a better headbasket.)

 

[wjohn]

Here are some photos of the Bad Aax version. Worst name ever , but a decent and afforable donor. The mic is surprisingly heavy: 800g / 28oz, with a 2.16mm thick brass tube. Anyone else have one of these?

 

[doqmemory]

Anyone else have one of these?

I have 4 of these, populated with Matador's C12 board. Pretty much identical to the Apex 460b kit, except nickel finish instead of black powder coating.

I have been buying the the JRR Shop NOS12 for my latest builds, since it already has a decent head basket, JJ 12AY7 tube, nicer case, and edge-terminated capsule (K67 style backplates). I have also scrounged the PIO caps for later use.

 

[Coop]

I just finished building two PSUs with the Matador C12 supply board. Using a toroidal transformer with 3 secondaries (220V, 9V and 5V). Everything seems to be working besides two thing.

Can't get B+ lower than 124V, I guess because of the higher voltage on the secondary winding. Probably need to adapt the circuit for that.

And the heater circuit is not working at all. I do get 0V DC but 50V AC if I measure at the output. It is doing the same thing on both PSUs so I don't think it is a bad diode or anything else. Also double checked if I have installed everything correctly and I haven't found any wrong installed component.

 

[andYz00m]

Anyone heard from Chunger?

I know he’s backed up but have an order from about a month ago still nothin.

Of course, I’m willing to be patient, just wondering if everything is still moving. I ordered stuff that was “in stock”

 

[Trickyricky]

Anyone heard from Chunger?

I know he’s backed up but have an order from about a month ago still nothin.

Of course, I’m willing to be patient, just wondering if everything is still moving. I ordered stuff that was “in stock”

Hmm good question I just placed an order on Friday for a 251 build.

 

[andivax]

Anyone heard from Chunger?

I know he’s backed up but have an order from about a month ago still nothin.

Of course, I’m willing to be patient, just wondering if everything is still moving. I ordered stuff that was “in stock”

Mailed him 2 weeks ago. No response (

 

[andYz00m]

I got my stuff from Chunger! He contacted me regarding one of the components not being in stock but we got it sorted.

He's crankin through orders.

I have everything bessides the new capsule, quesstion: Can I use the capsule from the NOS audio mic with all the rest of the upgraded parts and then swap in the new capsule down the road?

 

[doqmemory]

Quesstion: Can I use the capsule from the NOS audio mic with all the rest of the upgraded parts and then swap in the new capsule down the road?

Yes, it should work fine.

 

[andYz00m]

Alright build is in progress.

My mains voltage is 122V which is high but not uncommon in my area. Im testing my power supply with the 180k resistor stropped across B+/ground. The voltage coming out of the power transformer are as follow:

200V Lines: 120v/122V
9.5V Lines: 12.8/8.4
Heater: 10.8V (Im using the 33k resistors as I plan to use a 12AT7) The heater trim pot does nothing. I have checked the solder connection and it looks good. I need to retest the component but when assembling it tested fine. EDIT: Tested component out of th board and its fine. EDIT 2: I put the component back in and it seems to be working properly now but I still cant get the heater voltage up to what it should be (Heater for series 12AT7 is 12.6V)
B+: 133V with the trim pot all the way CCW (lowest it will go)
Bias: -1.02 easily adjustable with the trim pot to the correct value.

These values are close but wondering about the higher voltage from the power transformer. Might change when I get the mic built.

Thank you!

 

[andYz00m]

New question, everything is done and wired up with the original capsule for testing, but the original capsule only has three leads:

Front, back and both of the sides of the capsules together in one wire.

Where would I connect these? On the schematic there are 4 leads. :/