Tab Funkenwerk M49 build + questions

Hello everyone, stepping out of lurking status with this project - I'm stoked but need some help.

I'm building an M49 from the kit at the Tab-Funkenwerk site - with all of the metalwork, power supply, capsule, etc. It's my biggest step with DIY yet, as while I've built a few things previously (guitar pedals, CAPI VP28s) they've been from a more straightforward kit. I'm learning a lot and it's great.
I've found though, that while Oliver sends a parts kit with the mic, the parts included's values don't match with the component list and schematic on Tab's website (http://www.tab-funkenwerk.com/id89.html). It's difficult to get ahold of Oliver for answers about these, and I am considering just ordering parts that match the component list exactly. Here are my questions for folks that have done a build like this or have insight:

- Should I just order the parts exactly from Oliver's component list and be done with it?
- Have you used 1GΩ resistors in the build? (these aren't easy to source!)
- For C5, the layout says to use a 25µF 250V cap - but the 250V capacitors that I'm finding seem pretty physically large, and in Oliver's parts he sent is a 47µF 25V cap, and it looks like that's what's in his other M49 builds...  Am I missing something with the 250V thing, or is that not necessary?
- Any thoughts or suggestions for the capacitor at the capsule (C1) and the output capacitor (C3)?

Thanks!

Hi,

No experience, but just looking at the schematic.

C5 is the decoupeling C for R3, the voltage across this resistor sets the tube in its working area Uneg. mostly low voltage,  so 25 volt should be oke. Build use a higher voltage example test and meassure the voltage across to be 100% shure adapt to the measured value.

C3 influences sound a lot, a nice MKP or Russian cap will doe nicely, if you are not happy with the sound the easiest mod to start.

C2 Use a good quality, styroflex 250V.

Hope this helps.

DJN

Hi,

Checked the AC701 data sheet, operation point at 120V = 1.6V Ug so 25V should be fine.

DJN

- Should I just order the parts exactly from Oliver's component list and be done with it?

Click to expand...

Sure

- Have you used 1GΩ resistors in the build? (these aren't easy to source!)

Click to expand...

Mouser: 279-RGP0207CHK1G0

- For C5, the layout says to use a 25µF 250V cap - but the 250V capacitors that I'm finding seem pretty physically large, and in Oliver's parts he sent is a 47µF 25V cap, and it looks like that's what's in his other M49 builds...  Am I missing something with the 250V thing, or is that not necessary?

Click to expand...

I agree with djn111 about caps.  For C5, seems like a typo, 25v will do fine here

C1: polystyrene or MKP
C3: I like mallory 150. Others like PIO, etc...

You might want to look up the actual M49c schematic. The AMI schematic you linked to is simplified in a few ways to remove feedback paths. Not that it won't sound great, I have built a few mics very similar to that schematic using a 5840 tube.  Note also the original did not use 1G pulldown resistors, but 1G do work well.

Thanks all - good advice all around!
@dmp, actually this build is with a 5840 tube - good to hear!

I'm going to order the parts in, but will update back once I'm building. Very excited.
Thanks again,
J

Hello all,

I hope this reply is related enough to earn community response.  I write this with a great degree of sadness and renewed determination after learning of Oliver's passing.  I had wanted to solder up his M49 kit and emailed him the following drawing for his response (Attached).  I really need to build this mic more than ever and just need some help on plotting the solder points.  Perhaps it can serve the larger DIY community for M49 builds as the kit is unclear on some aspects (values etc). I am building it around a 5840 that Oliver chose for me. An excerpt from my last email to him with my drawing:

"I have devised a map (attached) and a key that describes without question all the point to point connections on your plexi decks.  If you could plot the remaining parts in an email like I did for the ones I could see in the pictures, then we could be close. i.e. "R8 100m = 5 -> 9" .  If there is a wiring procedure for the hookups that could be plotted out similarly, that would be great.  I will call now..."

Thank you DIY !

Basecamp said:

Hello all,

I hope this reply is related enough to earn community response.  I write this with a great degree of sadness and renewed determination after learning of Oliver's passing.  I had wanted to solder up his M49 kit and emailed him the following drawing for his response (Attached).  I really need to build this mic more than ever and just need some help on plotting the solder points.  Perhaps it can serve the larger DIY community for M49 builds as the kit is unclear on some aspects (values etc). I am building it around a 5840 that Oliver chose for me. An excerpt from my last email to him with my drawing:

"I have devised a map (attached) and a key that describes without question all the point to point connections on your plexi decks.  If you could plot the remaining parts in an email like I did for the ones I could see in the pictures, then we could be close. i.e. "R8 100m = 5 -> 9" .  If there is a wiring procedure for the hookups that could be plotted out similarly, that would be great.  I will call now..."

Thank you DIY !

Click to expand...

I bought my kit last year but am just now getting around to building it.  Would love to see more info gathered here.  I had so many questions to ask Oliver but alas it's too late.

Unless you're just dead set on PTP with turrets, you could use Dany's PCBs. I'm thinking of going that route on my upcoming M49C build.

Also, regarding Oliver's removal of the feedback paths, I've heard nothing but good things about getting rid of them....

Man, I'm missing him a lot. I was hounding him to write a book, but he would just laugh when I brought it up. I think it was the idea of finding that much free time that was so amusing....

Robert Mokry
Austin,TX

Hey Guys,

I bought the M49 kit as well and I'm having trouble mostly with not having any kind of layout or pictures of a good way to position everything.
I can read the schematic but I need a good visual.... Can any of you guys send me pictures of your build and layout?

Thanks!

Jordan

Does this help?:

http://www.tab-funkenwerk.com/id88.html

Hello all,
About a month before Oliver passed, he sent a link to this page for building his M49 kit: http://www.tab-funkenwerk.com/id183.html
Really detailed and great info, and answered some lingering questions that I had. I'm still working on getting my mic up and running when I have some free time (which hasn't been much), but am hoping to be able to update soon.
Thanks all for the help and info!

justgold said:

Hello all,
About a month before Oliver passed, he sent a link to this page for building his M49 kit: http://www.tab-funkenwerk.com/id183.html
Really detailed and great info, and answered some lingering questions that I had. I'm still working on getting my mic up and running when I have some free time (which hasn't been much), but am hoping to be able to update soon.
Thanks all for the help and info!

Click to expand...

Wow, I'd have built mine months ago had I known about that. Thanks!

justgold said:

Hello all,
About a month before Oliver passed, he sent a link to this page for building his M49 kit: http://www.tab-funkenwerk.com/id183.html
Really detailed and great info, and answered some lingering questions that I had. I'm still working on getting my mic up and running when I have some free time (which hasn't been much), but am hoping to be able to update soon.
Thanks all for the help and info!

Click to expand...

Hey, thanks for this. It does help answer a couple of questions but not all of them. Here's what I'm needing help with.
My kit came with these extra resistors:
270k ohm
2k ohm
8k ohm
1.8k ohm

Did you guys kit come with these extra parts? I have no idea what to do with them.

Also, here are a few things that I received that look wrong to me:

•For the C5 (25uf) that it calls for, I received a 47uf with the kit. ?
•For the C2 and C4 (.01uf) I received a 103k and a 473k with the kit. ? Also 1 is bigger than the other. These are both supposed to be the same value.
Here's a pic of the capacitors that I received with the kit. Any help would be greatly appreciated.


Thanks.

stringmachine1 said:

justgold said:

Hello all,
About a month before Oliver passed, he sent a link to this page for building his M49 kit: http://www.tab-funkenwerk.com/id183.html
Really detailed and great info, and answered some lingering questions that I had. I'm still working on getting my mic up and running when I have some free time (which hasn't been much), but am hoping to be able to update soon.
Thanks all for the help and info!

Click to expand...

Hey, thanks for this. It does help answer a couple of questions but not all of them. Here's what I'm needing help with.
My kit came with these extra resistors:
270k ohm
2k ohm
8k ohm
1.8k ohm

Did you guys kit come with these extra parts? I have no idea what to do with them.

Also, here are a few things that I received that look wrong to me:

•For the C5 (25uf) that it calls for, I received a 47uf with the kit. ?
•For the C2 and C4 (.01uf) I received a 103k and a 473k with the kit. ? Also 1 is bigger than the other. These are both supposed to be the same value.
Here's a pic of the capacitors that I received with the kit. Any help would be greatly appreciated.


Thanks.

Click to expand...

I won't be doing mine for a couple more weeks but if you still need help I can chime in then.

Hey @stringmachine1 - I had similar questions about the parts that accompanied the kit, you can see in my original post! I ended up just re-ordering everything based on the schematic, just to be safe (it's my first tube-mic build, and have been trying to cut out uncertainties where possible).

@stringmachine1 and @Bowie, note that on the on Oliver's new construction guide that on the schematic, the XLR-power supply list connections don't match the schematic!  (Unless I'm reading things wrong!)

My mic is built but I need to do some troubleshooting - I wish I would have had Oliver's new guide when I was building my mic! Hoping to get it working great asap!

Oh man - this has been great but in the face of some big life change for my wife and I, I'm throwing in the towel on this project. So close!! Here's everything for sale - check it out if anyone's been interested to dig into this project:
http://groupdiy.com/index.php?topic=59676.0

Thanks all for notes and insight!