Neumann M49 Clone : Build Thread Puck Style (TLM49 Conversion To M49 b-c)

[Delta Sigma]

Both of mine have their leads running through their own holes.

Is it uncommon for two identical mic builds to have a ~2db difference in output?

That would depend on your components. Capsule, tube, transformer. The only pair I've built were C12s. My CT12s, 6072s and Moby T14/1s are all similar, so the mics are nearly identical.

You could try swapping tubes (you have to rebias), or capsules and see if the quieter output follows either component. If your transformers are the same, they would be the least likely culprit.

I'm sure there's other things that could cause the lower output, like wiring, but try the component swaps first.

 

[egroys]

That would depend on your components. Capsule, tube, transformer. The only pair I've built were C12s. My CT12s, 6072s and Moby T14/1s are all similar, so the mics are nearly identical.

You could try swapping tubes (you have to rebias), or capsules and see if the quieter output follows either component. If your transformers are the same, they would be the least likely culprit.

I'm sure there's other things that could cause the lower output, like wiring, but try the component swaps first.

Good to know that it's unlikely to be the transformer. I have Moby's, BeesNeez M7's, and 6S6B-V's.

I did just replace my tube so that might be a good swapping start.

But I am realizing that, while doing so, I heated and accidentally disconnected then reconnected the wire that goes to capsule front (since it's shared with tube F Grid). While this may or may not explain a 2db loss, could it explain a slight increase in high frequencies?

Thank you again!

 

[Delta Sigma]

Good to know that it's unlikely to be the transformer. I have Moby's, BeesNeez M7's, and 6S6B-V's.

I did just replace my tube so that might be a good swapping start.

But I am realizing that, while doing so, I heated and accidentally disconnected then reconnected the wire that goes to capsule front (since it's shared with tube F Grid). While this may or may not explain a 2db loss, could it explain a slight increase in high frequencies?

Thank you again!

Probably not. When you biased the tubes, did you bias to the same anode current?

 

[terry setter]

It's possible that the 2dB difference could be due to differences in the tubes.

 

[egroys]

Probably not. When you biased the tubes, did you bias to the same anode current?

Please let me know if I am misunderstanding, but I just took measurements at the mics and this is what I got.

Mic A:
A+ (and R10) 43.3V
K+ 1.09V
H+ 6.0V
B+ 116.9V

Mic B (the brighter one that is 2db quieter)
A+ (and R10) 43.4V
K+ 1.15V
H+ 5.85V
B+ 117.1V

Also, the PSU's were set to 6.05v H+ and I understand the cable runs and varying voltage makes them slightly less at the mic.
Should I adjust to the mic or to the PSU?

 

[doqmemory]

Please let me know if I am misunderstanding, but I just took measurements at the mics and this is what I got.

Mic A:
A+ (and R10) 43.3V
K+ 1.09V
H+ 6.0V
B+ 116.9V

Mic B (the brighter one that is 2db quieter)
A+ (and R10) 43.4V
K+ 1.15V
H+ 5.85V
B+ 117.1V

Also, the PSU's were set to 6.05v H+ and I understand the cable runs and varying voltage makes them slightly less at the mic.
Should I adjust to the mic or to the PSU?

The voltage at the mic (in other words, the voltage in the circuit) is what matters, since that is "where the action happens".

 

[Delta Sigma]

100k load resistor? Sounds like they're biased very closely. 0.736mA and 0.737mA

Next, you should try swapping the tubes. Check the bias after, see of the 2dB loss follows the tube.

 

[egroys]

100k load resistor? Sounds like they're biased very closely. 0.736mA and 0.737mA

Next, you should try swapping the tubes. Check the bias after, see of the 2dB loss follows the tube.

That’s what I figured. 2db loss aside, could the tube be responsible for one being slightly brighter?

The voltage at the mic (in other words, the voltage in the circuit) is what matters, since that is "where the action happens".

makes sense! Is it safe to assume the loss from PSU to mic will be consistent (using the same cable)? That way I can log what the PSU should be set to if I ever need to calibrate w/o opening the mic…

 

[imo]

Been getting together a build that seems to be a bit out of step. Years ago I ordered a m49 body by one of the forum members, that burnt a lot of folks. That was the last DIY project I did for quite a while.

I visited a studio recently and my friend had a DIY M49 that was fantastic! I’ve had the pleasure of using many real M49s over the years. They work really well with my voice, and I was really blown away by how powerful the circuit sounded with the 5840 tube.

I got home and started trying to organize the pieces. I reached out to Chunger, but I think he is stepping back(I know there are no 49 style bodies to be had.) the only bodies I could find were the ‘Micandmod’ bodies. I asked Dan if his pcbs fit, and ordered both. I got back from tour and unfortunately the pcbs do not work with the mic body. Both of these ship for Europe, so returning them is really not worth it. I also learned, as I caught up on the threads, that the micandmod folks aren’t super loved here.

I though for a minute about trying a point to point but with time crunch, limitation with material access and experience, I think I’m gonna try to get the micandmod PCB. There version is rev C, which is a bit of a bummer, as I was pretty geared on building the earlier revision.

I’m gonna look into how challenging it would be to use their PCB for the B version. If anyone has any experience, let me know.

I’ve got one of Soliloqueens “flat” capsules, a Moby M11, and some nice 5840 that my friends at Royer sent me.

I’m putting power supply together first, waiting on a binder I had to special order, and hopefully a clear path on the mic build.

Onward

 

[Delta Sigma]

Been getting together a build that seems to be a bit out of step. Years ago I ordered a m49 body by one of the forum members, that burnt a lot of folks. That was the last DIY project I did for quite a while.

I visited a studio recently and my friend had a DIY M49 that was fantastic! I’ve had the pleasure of using many real M49s over the years. They work really well with my voice, and I was really blown away by how powerful the circuit sounded with the 5840 tube.

I got home and started trying to organize the pieces. I reached out to Chunger, but I think he is stepping back(I know there are no 49 style bodies to be had.) the only bodies I could find were the ‘Micandmod’ bodies. I asked Dan if his pcbs fit, and ordered both. I got back from tour and unfortunately the pcbs do not work with the mic body. Both of these ship for Europe, so returning them is really not worth it. I also learned, as I caught up on the threads, that the micandmod folks aren’t super loved here.

I though for a minute about trying a point to point but with time crunch, limitation with material access and experience, I think I’m gonna try to get the micandmod PCB. There version is rev C, which is a bit of a bummer, as I was pretty geared on building the earlier revision.

I’m gonna look into how challenging it would be to use their PCB for the B version. If anyone has any experience, let me know.

I’ve got one of Soliloqueens “flat” capsules, a Moby M11, and some nice 5840 that my friends at Royer sent me.

I’m putting power supply together first, waiting on a binder I had to special order, and hopefully a clear path on the mic build.

Onward

https://www.tab-funkenwerk.org/ami-parts/mic-kits/m49a-kits/
http://www.flea-microphones.com/parts.html
My M49 (AMI body, Moby BV11, 5840, Beesneez M7) sounds unbelievable.

 

[Delta Sigma]

That’s what I figured. 2db loss aside, could the tube be responsible for one being slightly brighter?

makes sense! Is it safe to assume the loss from PSU to mic will be consistent (using the same cable)? That way I can log what the PSU should be set to if I ever need to calibrate w/o opening the mic…

Brighter? I would guess the capsule over the tube but you never know. You'll have to swap one or the other to start troubleshooting.

 

[imo]

https://www.tab-funkenwerk.org/ami-parts/mic-kits/m49a-kits/
http://www.flea-microphones.com/parts.html
My M49 (AMI body, Moby BV11, 5840, Beesneez M7) sounds unbelievable.

Man, I'm glad you hipped me to that. So much more where I want to be. I'm gonna return the micandmod body. I can't build the right circuit in it anyway. Thanks. I talked to the guys at AMI(incidentally live really close to me) and get one of their B-stock.
I will have a similar mic to yours, though with a different capsule.

 

[Delta Sigma]

Man, I'm glad you hipped me to that. So much more where I want to be. I'm gonna return the micandmod body. I can't build the right circuit in it anyway. Thanks. I talked to the guys at AMI(incidentally live really close to me) and get one of their B-stock.
I will have a similar mic to yours, though with a different capsule.

AMI are absolutely great to deal with. I would recommend building with their acrylic boards. I had to skip a few components to work a layout on their boards so opted for using Dany's PCBs. I ended up removing those components anyway (C4, C6 and R3). Just don't use alcohol on acrylic.

I would also recommend buying an M7 and do your best to compare the two capsules. Whichever one you don't pick, you can use in your next build.

 

[EarthTone]

Man, I'm glad you hipped me to that. So much more where I want to be. I'm gonna return the micandmod body. I can't build the right circuit in it anyway. Thanks. I talked to the guys at AMI(incidentally live really close to me) and get one of their B-stock.
I will have a similar mic to yours, though with a different capsule.

You could make the Dany pcb's fit into that MicnMod body. The MicnMod body just comes from ShuaiYin. I ordered one thinking it would fit Dany's PCB and it doesn't. But to get it to fit would not be that hard. The internal chassis is 55mm, the mounting holes for the PCB chassis are 65mm apart (5mm arms on each side support it) and there is 70mm of clearance internally. Dany's boards are 60mm wide. The top PCB is only used to mount the capsule on so you could sub it out for something else that fits where it mounts to the headbasket. So what I plan to do with mine so I don't waste the ShuaiYin body (very nice) is just buy a circle of material either brass, steel, or PCB material around 65mm or 70mm wide, drill holes in it to mount at the 65mm points, and use standoff spacers to make the circuit fit between the top of the headbasket and the screw-on mic base. Should work fine. You can do that too if you want to save the trouble of buying something else and returning to EU.

It sucks AMI's body is out of stock. You are saying they will sell you B-stock parts? What's wrong with them? I may give them a call about m49 bodies... Chunger is still doing some business but it took about 6 weeks to receive my u47 body from him after ordering. And the m49 Chunger body is perpetually out of stock, indeed...

 

[imo]

AMI are absolutely great to deal with. I would recommend building with their acrylic boards. I had to skip a few components to work a layout on their boards so opted for using Dany's PCBs. I ended up removing those components anyway (C4, C6 and R3). Just don't use alcohol on acrylic.

I would also recommend buying an M7 and do your best to compare the two capsules. Whichever one you don't pick, you can use in your next build.

It's pretty cool to have someone local as well. I am going to build with this capsule, and compare to M49's around. Paul Allen's engineer still has a number of them. I'm curious to establish a somewhat more concrete sense of the mic. I've used them many times but it has been a while.
Which schematic are you referencing? If Olivers for the 5840, the only component I'm not seeing is C6

 

[Delta Sigma]

It's pretty cool to have someone local as well. I am going to build with this capsule, and compare to M49's around. Paul Allen's engineer still has a number of them. I'm curious to establish a somewhat more concrete sense of the mic. I've used them many times but it has been a while.
Which schematic are you referencing? If Olivers for the 5840, the only component I'm not seeing is C6

M49b: https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a05446.pdf

 

[imo]

M49b: https://cdn.groupbuilder.com/groupdiy/u/39511/58d1402a05446.pdf

Yeah, aren't those the components used for broadcast? I don't know enough about the design.

Also, was going to return the micandmod body, but it was almost as much to return it as it was to buy it. I think I may eventually build a C version in that one, and try to figure out how to make Dan's PCB's fit

 

[donivan]

Are the m49 pcb's still available from poctop?

 

[imo]

Blowing fuses on the HT side of power supply. I checked both transformers for output and they registered right where they should be. Im US, so using a .3 slow blow. Ive got the supply on a variac so see the B+ climbing and then something is pulling too much current. I have my ground reference from the 0v point to earth ground(where the IEC is grounded as well) . All electrolytics are mounted correctly. Resistors are all in spec. This is happening both "loaded" with a 47R and unloaded. The heater side works fine.
All components are well soldered, and there are no bridges or anything under the board
I just want to think this through before I start replacing components, especially the electrolytics as its hard to get those snap ins off.

The only thing I can think of is that I got the 4007 diodes from Amazon(I thought i had enough before i started the build) They have a lower forward voltage(.15 instead of the typical .45 of most 4007s). Either that, or one of the new electrolytics was faulty before install. I didn't check them, but i'm not seeing any unusual behavior when i check them in circuit with the meter.

https://www.amazon.com/BOJACK-Recti...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

[imo]

Found a failed diode, replaced it, ramped up voltage and another diode failed open.
I've never had a 4007 failure in a new circuit, and it seems particularly strange when i don't even have a load on it. Must be fake 4007's. Ive never encountered that before