Unmarked Microphone bodies and parts (SYT-5, CU-49, HT-11A, GT-2B, and U47)

[chunger]

I purchased all of the colors

Why not just yellow?



Good move, chunger.

Well, I did purchase yellow  ;D  If you want a 100% yellow kit for enhanced sonics, please let me know.  I'm certain as long as you are able to keep track of where all the wires go, it would sound WAYYY better than the standard multi-color kit.

 

[Melodeath00]

Hey chunger,

Are you still planning to offer a kit that includes EVERYTHING (pcb, electronics, headbasket, transformer, and capsule)? Or maybe you never were and I misunderstood.

Just wondering if I will have to wait months on a Tim Campbell capsule straight from Tim (I think there's months of lead time), or If I should just wait for your complete turn-key package. Thanks!

 

[chunger]

I'm going to attempt to carry a full kit at some point, but I do not know when that will happen.  Piece by piece, I am getting closer, and I am making all of the individual parts available on the webstore as I gather them at volume.  So, it's up to you to decide when and how to buy.

I recommend getting on Tim's build queue for his capsule though.  There really isn't any way for him to significantly ramp up production volume, so I have to get in line just like everyone else and the lead times would be the same.  FWIW, I am waiting for his evaluation of the kit before ordering a few more capsules.  Other people have contacted Tim already to secure a slot in his queue for capsules.  There will be no cost penalty to sourcing the capsule yourself.  Actually, there will be no cost penalty for sourcing any of the parts yourself besides shipping.

 

[Melodeath00]

Thanks. I was actually asking because I didn't know if maybe you were already in the queue for the capsules if you were preparing complete kits. Any idea how long the queue is?

 

[chunger]

Thanks. I was actually asking because I didn't know if maybe you were already in the queue for the capsules if you were preparing complete kits. Any idea how long the queue is?

At last report, the lead time is 8 weeks.  I am not in the queue because I'm waiting for confirmation of the final capsule specification.  It may likely end up being the stock configuration, but I won't know until Tim has a chance to build the kit and test.

 

[chunger]

We will likely be out of stock on all donor microphones within the next few days.  A follow up shipment from China is in process, and I have significantly increased my order quantities because I do not want to keep things in stock longer.

Because I am making design improvements on all of the donor microphone models being offered to get closer to original specs and based on design requests from poctop, there may be a longer-than-normal lead time for this 2nd batch, but there should be plenty of microphones to go around once it arrives.  Please monitor this thread for up-to-date information on progress.

At this time, the earliest I can foresee receiving the shipment is 2 months.

 

[chunger]

Shipments of C12 parts kits are incurring a slight delay.  I had been sourcing knobs for the 9 position pattern switch from an actual electronics supply store that is local to me.  In the internet age, it is nice to see an actual physical store still open near me and I like to support them whenever possible  .  But, apparently, I have cleaned them out on chicken knobs.  A re-supply order is en-route to me, but shipments of C12 parts kits will be delayed by a few days.

Sorry for the inconvenience.  Due to demand, I am still generally running about 1 week behind in shipping all products.  Your patience is much appreciated.  I am still trying to streamline my order fulfillment process.

 

[micaddict]

There are plans for the Ela M251 type project, but we are having some serious debate about whether a new pcb is needed after revisiting the pcb layout.  There are a couple of issues at play.

1.  The Ela switches polar patterns from the microphone and currently, the HT-11A body does not have provision for a switch
2.  The turret board layout of the pcb easily accommodates the required circuit changes to get very close to the Ela.

The conclusion is we can build the Ela type circuit with the only key difference being the way the capsule is polarized (retain the 9 pattern switch at the PSU).  We bypass the bias voltage section of the psu as well for the Ela build.

Essentially, we get an ELA with the more flexible patterning options of the C12.  We are at this point reasonably sure this can be done on the existing pcb layout with a few easy component changes.

I'm preparing for the ELA in whatever iteration it ends up being released in by lining up the hard-to-get parts (mainly the headbasket) now.  Right now, I'm strongly leaning towards focusing on building the ELA circuit on the current pcb.  But, the first priority is to finish out the C12 project and get all the ducks lined up on that front.  I'd like to get the capsule finalized and headbaskets in stock and shipping before turning my attention to the ELA build.

I reckon that will include Matador's attention? 
One of the nice things of this GroupDIY project is the collaboration.
And regarding the Ela M251, I even see a possibility for a threesome, so to speak.

The Ela M251 as described in the quote is actually the Ela M251E, with the E from Export. That one uses the 6072a tube. The European version (and this is a European microphone) used the AC701. Now we all know that that tube is very expensive and hard to come by. But the 5840, when used as a triode, is a pretty good alternative. Its use in modern M49 clones is just one example. And it is used in any more microphones. It is readily available and affordable. The 6072a, however, is not so easy to get in NOS high quality. Even if you're lucky enough to get, and willing to pay for, a GE five star, there's a good change it has been tested and rejected by others before you. Fortunately for the C12 project, the situation isn't yet hopeless. But with the 251 we have the choice between two versions, which could be used as an advantage.

So here's a plan. Make the Ela M251 in the non-E version, or at least have that as an option. That version could then be used with poctop's fine new PSU (PCB) which he designed for the D-49 and D-269. Apart from being able to feed self biased mics, it has even been made stable enough to feed filament biased ones. But that's not necessary here. It doesn't hurt to have it on board, though.

What do you say?


Henk

 

[micaddict]

Oops, double post.

 

[kidvybes]

...it shouldn't be overlooked that there may be another 9-pin dual-triode tube that is more readily available and cost efficient than the current supply of 6072 tubes for use in a "251" type microphone...David Bock has recently implemented the 6021 (12AT7WA) into his 251 (previously used 6072 and briefly, a 5670)...granted there may be some tweaks necessary in the circuit to make the best of the higher (mu) gain rated 6201...I have been using GE 5 Star 6201 tubes in a few of my tube mics with excellent results...the swap results in slightly different voicing, but in some cases preferable over a 6072...in a couple of my tube mics, the 6201 offered a more mid-forward voicing, with less top-end push than a 6072...IMHO, ended up being the better choice for that particular mic...

...just a thought!
http://www.bockaudio.com/251.html

...as an interesting side note, David Bock sources his capsule from MBHO (Germany), who's chief engineer is a former Schoep's engineer:
http://www.mbho.de/pdf/ka1000n_ka1100k.pdf

 

[micaddict]

Yep, I thought about that, too, and figured (hoped actually) you'd chime in, kidvybes.  Thanks.
But the 5840 is a great choice, as well, and it can be a new standard for more than one microphone. Sort of like the old AC701 standard for broadcast in Germany etc. And, like I said, it would be closer to the actual 251 (not the E adaption).

 

[kidvybes]

Yep, I thought about that, too, and figured (hoped actually) you'd chime in, kidvybes.  Thanks.
But the 5840 is a great choice, as well, and it can be a new standard for more than one microphone.

...definately!...David Royer's subminiature tube of choice for his tube microphones...and subminiatures like the 5840 are less likely to exhibit excessive microphonics...these were the latter examples of pentode tube evolution...

 

[Bowie]

Yep, I thought about that, too, and figured (hoped actually) you'd chime in, kidvybes.  Thanks.
But the 5840 is a great choice, as well, and it can be a new standard for more than one microphone. Sort of like the old AC701 standard for broadcast in Germany etc. And, like I said, it would be closer to the actual 251 (not the E adaption).

  It's a very good choice.  They are cheap, built well, less inclined toward noise issues, and similar to the original.  That gives them a huge advantage over most of your other options.  I'm in touch with a number of mic builders and several of them have reported positive things about their 5840/251 mic builds.  If you plan to offer a kit or board, let me know and I can see about offering some pre-screened and burned-in 5840s.

 

[chunger]

Hey guys,

Technical details about alternate tube implementation are quite a few levels above my pay grade. . . I'll alert Matador to this line of discussion.  I know the first iteration of the Ela M251 in our use will be the 6072A because no changes are necessary to the pcb's so we can basically build it at any time.

But, if anyone wants a pretty picture taken of something, give me a call 

hopefully Matador will be able to chime in soon.

 

[micaddict]

The 6201 as an alternative for the 6072 could be discussed further in the C12 build thread, I guess.
But I didn't want to hijack that thread with my Ela M251 ravings.
Also, my post was in reply to one of chunger's posts in this here white market thread.

I've PM-ed Matador. 

 

[Matador]

Using a 12AT7/6201 would be pretty simple with a few BOM changes.  The plate resistor would need to be dropped to about 47K, and idle current would need to increase up to about 1-1.5mA with a -1V bias.  Gain would be similar as well.  The series PSU filters (90K) might need to be lowered to keep B+ in the right range.  Input headroom would be about the same as well (about 2VPP).

A miniature pentode like a 5840 should work as well with similar tweaks.  It takes much more bias current (when wired as a triode).  It could be wired directly to the tube PCB interposer (just leaving off the 9-pin socket):  one of the reasons I provided 3 copies of the tube board on the panel.

In terms of ELA 251:  I think a lot of that sound comes from the 1000pF plate cap that is not there on the C12.  I've found if you stick a cap on the plate on the existing C12 board, it tames down the high end a bit and makes it sound much more "251" like (although to be honest, the same can be done with a low-pass filter after the recording is done).

There are those that would argue that the 251 is "cathode bias" and the C12 is "fixed bias":  however that isn't true.  They are both (in reality) cathode bias.

 

[micaddict]

Thanks!

 

[Songguy]

Hi chunger,
I'm looking for a very inexpensive mic capsule to use as a temp until I can afford the peluso.
With that said would your k67 capsule work with ioaudio's mk47.
Thanks,
Chris

 

[chunger]

Hi chunger,
I'm looking for a very inexpensive mic capsule to use as a temp until I can afford the peluso.
With that said would your k67 capsule work with ioaudio's mk47.
Thanks,
Chris

Yes, it will work. . . not only will it work, but you may be shockingly surprised at how good it is.  My mk47 that I put into the studio with my cheap 35mm K67 capsule ended up getting used for main vocals on a big (for us) project.  I was absolutely shocked when I heard that's the mic they used.

Certainly not the traditional U47 sound, but a good sound.  I have 2 beesneez capsules coming this week, and I may have to build another mk47 because they want me to leave this mic alone at least for this artist.

 

[Songguy]

That's just what I need 

Chris