U47 with EF14 tube Build

[rock soderstrom]

just a quick question in case ive thought about this wrong, for the 7 pin connector into the mic body is it just a male 7 pin XLR?

if so where are you guys sourcing?

Yes, 7pin XLR male (or tuchel/binder but more $$$). I take Neutriks and order it from Thomann together with the matching connectors and 7 core cable from Sommer.

https://www.thomann.de/gb/sommer_cable_sc_octave_tube.htm

 

[Khron]

Look up Cliff UK connectors You can scavenge the insert from their old-style panel-mount connectors.

https://www.cliffuk.co.uk/products/xlr/metal.htm
TME in Poland usually have plenty in stock, and for pretty good prices too.

I take Neutriks and order it from Thomann

Too bad they don't make/sell NC7MP connectors anymore... Or were you implying using the male XLR insert from a second 7pin cable connector?

 

[Spencerleehorton]

yes i was thinking of taking one from a 7 pin XLR male connector but feared it wouldnt be the right size?

 

[Khron]

More importantly though, how would you fasten that in the mic's bottom "neck"?

The Cliff connector i mentioned has a normal M2.5-threaded hole, just like all 3pin XLR's you find in mics do.

Only caveat would be that you might need a longer-than-stock screw, if the mic "neck" is as thick as the SYT5's, for example.

Actually nevermind, the M2.5 thing only applies to the 5pin Cliff panel-mount XLR. The 7pin has a built-in left-hand-thread screw, so you can mount it anywhere with no extra tooling.

 

[nielsk]

I maintain you are much better off with an EF14 (the EXACT same tube as a VF14 with the sole difference of a separate heater according to Telefunken's data sheets).
You just need to find one that is quiet enough.
You need to get the low noise (k) version of the EF12 to go that route.
I tried and tried with an EF12k and Oliver's design and could not get it to sound "right" (comparing to several original intact U-47s). With the EF14 all is good.
The output transformer is at least 1/4 of the sound of this mic, I will be curious to find out how the Alibaba version works out!

 

[Spencerleehorton]

ive found a 7 pin male XLR insert on AliExpress for £4.50 so i will check it out as have to order ELAM 251 body as well.

 

[rock soderstrom]

Too bad they don't make/sell NC7MP connectors anymore... Or were you implying using the male XLR insert from a second 7pin cable connector?

That's a real shame, I had to check this first. I think your solution is the best one now. TME is a good supplier, I like to order from them. Unfortunately they don't have Sommer cables, I always try to buy everything from one supplier to save on shipping.

 

[Khron]

I always try to buy everything from one supplier to save on shipping.

I do that too, but on the other hand, TME's UPS Express Saver is 10eu and gets delivered sometimes even the next weekday Don't think i've ever had a Thomann order delivered in less than a week (and the UPS Express is 40eu extra)...

TME have good prices on passives too, though

 

[rock soderstrom]

I do that too, but on the other hand, TME's UPS Express Saver is 10eu and gets delivered sometimes even the next weekday Don't think i've ever had a Thomann order delivered in less than a week (and the UPS Express is 40eu extra)...

TME have good prices on passives too, though

TME is great and their delievering time is fast. But you can not beat Thomann here in Germany. Sometimes I have the suspicion that they are on my doorstep and already know what I will order. Thomann is really fast...incredible

 

[Khron]

I don't know, for my last two orders it seemed to take them 1-2 days just to pack the items i had ordered And it was all in-stock items, so that wasn't an issue. But oh well...

 

[rock soderstrom]

I tried and tried with an EF12k and Oliver's design and could not get it to sound "right" (comparing to several original intact U-47s). With the EF14 all is good.
The output transformer is at least 1/4 of the sound of this mic, I will be curious to find out how the Alibaba version works out!

Thanks for your experience.

If you have a direct comparison with the original, you can assess it more realistically. I have heard so many different opinions on this subject. Many compare their solution with a U47, which at best they heard somewhere years ago. A direct comparison with the same source is something else.

You just need to find one that is quiet enough.

The current price situation makes this point very unpleasant, even junk EF14s are offered for 100€...where do you buy such EF14s suitable for microphones? Just taking a chance on ebay etc. is a pure lottery. What do you spend on a suitable EF14?

Niels, have you ever compared an EF800, dual 408a or 5654/E95F against the original? I would be interested in your opinion. I like the price of these much better.

 

[Spencerleehorton]

First trial fit of the bits

 

[Spencerleehorton]

I had to put the base on the lathe and make the inside a bit bigger to accomodate the transformer, was 44mm opened it up to 46mm.
transformer sits in there nicely now.
just waiting for the 7 pin inner connector to arrive then i can test this.

 

[Spencerleehorton]

Just waiting for some 7 pin connectors so I can make the cable and test.
Will put in the capsule and reed relay once done the cable as well.

 

[Spencerleehorton]

Capsule and relay connected now, just the wait for the 7 pin connectors to make the cable!!!

 

[Spencerleehorton]

well first impression isnt good, all works, seems to lack bottom end? lovely clear top end, much clearer than my dany U47EF which im comparing it too as that seems to be my stand out U47 so far.
will change capsule and see if its the capsule
also will leave it on for a few hours for the EF14 to burn in and seem if it improves

 

[gyraf]

seems to lack bottom end?

..testing with headphones? then check polarity..

 

[ElSmurf]

When I first fired up my D-EF47 I also had a lack of low end. Ended up being the transformer not wired properly.

 

[Spencerleehorton]

well ive check the transformer and it seems to be conencted and wired correctly
Changed the capsule and the thin sound is exactly the same
the EF14 is a bit microphonic but not anymore than the EF80 ive used
will test all circuit to see where all voltages are, change the transformer for another to see if that is the problem and check the circuit for any errors or wrong voltages

a couple of other observations:

The Choke gets quite hot?
And when switched to omni the level goes down a lot?

 

[Spencerleehorton]

Here is how I have it connected.