C414 EB P48 build

[Spencerleehorton]

Just wondered what effect it would have on this circuit for changing the 15pf cap to 33pf?

 

[Gus]

Note how the pad works.

You would lower the gain when the pad is off

 

[Spencerleehorton]

I've not connected a switch for the pad yet so I'll change the values to 15pf as I only had 1 x 18pf and a few 33pf polystyrene caps.
Have ordered some new ones now

 

[Spencerleehorton]

Bit strange , bought some 2sk30 off ebay and used in both fet points and the circuit didnt work, replaced with one j201 and the pf5102 and seems to work but the capsule I'm using I think is shot but voltages look very close!
Must have bought a fake set of 2sk30?

 

[Spencerleehorton]

Think I made a mistake!!! Just found a bc560c in there instead of bc550c, works great now!!

 

[zephyrmic]

Instead of what? Your last post seems not to make sense.
Kindest regards,
zephyrmic

 

[Spencerleehorton]

Sorry corrected, should make sense now!!

 

[zephyrmic]

Thanks. Now it makes sense.
Kindest regards,
zephyrmic

 

[Spencerleehorton]

Gonna make some bodies for these now, they will be slightly wider than originals as I made the pcbs a touch wider.
I might try and mount the capsules on springs inside the headbasket.
Haven't decided what I'm going to do yet about the switching, need to find a few more choices on switches, seems to be a shortage of options with 2p4t in minature size, also with the 2p3t and 1p3t.
Also got to work out how I'm gonna mount to mic stand!!!

 

[Spencerleehorton]

Is there a way to configure two dpdt switches to get all 4 patterns?

The se 4400a seems to do it with a 3 way and a 2 way dpdt, I just cant seem to figure it out yet, could anyone help please?

 

[Tim Campbell]

Never, ever mount capsules on springs unless you want to hear the springs ringing in the capsule. It only worked well for carbon button microphones.

 

[zephyrmic]

Agree with Tim. Compare the use of springs in reverb units.  Springs are very reactive. Capsules need to be mounted in material that gives no room for resonance.
Kindest regards,
zephyrmic

 

[Spencerleehorton]

Fair point, I'll bin the spring idea, what about using the two switches anyone able to draw out anything for how to do the dpdt switches so to get all patterns please?

 

[Spencerleehorton]

Just got back off holiday and did this sketch but already it's not ideal for what I want, I think it will work but ideally want a 3 way switch to do the pattern switching, omni, fig 8 and cardioid, then the second switch to switch cardioid to hyper cardioid.
Will have to try and figure it out a bit better!!!

 

[Spencerleehorton]

This is first version

 

[Spencerleehorton]

If someone could be so kind as to suggest a good way of switching between at least the 3 main patterns I can finish testing now as I've got some edge terminated capsules and have some bodies I've made.

 

[Spencerleehorton]

Have done another version for the pattern switching and come up with a version using 2 x 3 way dpdt switches with the middle position as off so I can get all 4 patterns, dont know if that will work?
Will test and see what thumps I get!!

 

[Spencerleehorton]

I've done the hpf with a 3 way dpdt and the pad I'm just going to use -10db first of all and 2 way dpdt, if I need -20db I'll just change the wiring, -10db should be fine for what I want to use them for.

 

[Spencerleehorton]

Finally started on my first prototype of the c414 body.
It's going to be a bit bigger, more like my c12a bodies I did but with some switches hopefully if it all fits in!
Started to cut all pieces of brass for body then bandsaw drive belt snapped!!!
Finished first pieces off by hand and will braise body tomorrow.
Once I've played around with this one I can then see how I want to do the next two.

 

[Spencerleehorton]

First attempt is pretty ropey to say the least,  gonna wait till I get my bandsaw back on line and setup then try and make the body a bit smaller and better design.
Also gonna try and reduce the pcbs a little.