D-EF47 Tribute To Oliver Archut U47 Build Thread.

[JMPGuitars]

Has anyone tried an ef184 in this build? Are they all microphonic or is it possible to find acceptable ones? Thanks.

I'm curious about that tube also. It replaced the EF80 and was claimed to be a superior tube, but that doesn't mean it's superior for our needs. Though I did read somewhere that the EF184s with mesh are supposedly less microphonic.

I'm using an EF80 right now, and it's only minimally microphonic while being handheld, I imagine it should be much better in a shock mount.

I bought a couple NOS RFT EF184s. IME RFT had the least microphonic EF86s, so hopefully it's true here too. It will probably be a while before they get here though.

Thanks,
Josh

 

[Purplenoise]

I'm curious about that tube also. It replaced the EF80 and was claimed to be a superior tube, but that doesn't mean it's superior for our needs. Though I did read somewhere that the EF184s with mesh are supposedly less microphonic.

I'm using an EF80 right now, and it's only minimally microphonic while being handheld, I imagine it should be much better in a shock mount.

I bought a couple NOS RFT EF184s. IME RFT had the least microphonic EF86s, so hopefully it's true here too. It will probably be a while before they get here though.

Thanks,
Josh

Thanks, I read about that as well somewhere as I was searching. I guess I should get a few and try them. Let us know of your findings when you give it a try please. I think I’ll get a couple of telefunken ones since so far they have been the most reliable and consistent.

 

[JMPGuitars]

Thanks, I read about that as well somewhere as I was searching. I guess I should get a few and try them. Let us know of your findings when you give it a try please. I think I’ll get a couple of telefunken ones since so far they have been the most reliable and consistent.

I haven't seen any telefunken with the mesh, but it would be interesting to compare and see if that really matters.

 

[Delta Sigma]

Oops. Looks like I was the gremlin. The mic I built before this was the M49b, and I made the mistake of wiring the transformer the same way for the EF47. Once I realized my mistake, I fixed the transformer wiring, and this thing is FANTASTIC. It's by far the best build so far regarding SNR and output level. This mic gets plenty loud in the mid 20s on my input gain knob, whereas my M49 has to go into the high 30s or 40s to compete. The U87 around 50.

This mic is dead quiet, no noise issues or anything. I'm looking forward to trying different tubes in it. Right now I have an NOS EF80, but I will also try some EF800 tubes and see if one is really favorable compared to the other.

I won't be experimenting with the voltages until I can convince my tube tracer to test these tubes.

Thanks,
Josh

What transformer did you use?

 

[JMPGuitars]

What transformer did you use?

I used the Triad VPT230-110.

 

[Delta Sigma]

I used the Triad VPT230-110.

Sorry, meant output transformer. Which BV.08?

 

[JMPGuitars]

Sorry, meant output transformer. Which BV.08?

Oh, no I used the AMI T47. It sounded great on my M49, so I got another one for this mic.

 

[Purplenoise]

I haven't seen any telefunken with the mesh, but it would be interesting to compare and see if that really matters.

Tried an amperex ef184. I got to say it sounds really good, less midforward around 2k and more extended highs and lows. That was a quick test but I think I prefer it. This particular ef184 is a little microphonic around 10/11k but not audible unless maybe I record drums. Vf14s were a little microphonic too so maybe it’s a good thing haha.
H+ at 5.05v

    ——a little update——

After using it in a couple of sessions and bringing up the h+ to 5.1v to achieve proper bias I got to say I really like the ef184. It works really well with the k47 capsule and it sounds really close to an original u47. Density, fullness yet really smooth. Smoother than ef800 with k47.
Now since I really liked the mic with ef800 and m7 and found it to be really smooth and big sounding I have a feeling that the ef184 might be a better match for k47 and ef800 a better match for m7 capsules. Just a feeling but I can’t say unless I try it.
Now the next thing is to figure out the way to calculate the best value for the 100k plate resistor in this build. If someone wants to school me on this it would be greatly appreciated.

 

[snaredrum]

hi  , i have a D47  (circuit board from vintagemicrophone) it work well , but i swich my own diy body for a pro body ,because  i had sometimes  a bad bug with gnd . i take the psu measure  and i have 153V B+ ( 105V normaly? ) the secondary of my triad power trasfo is 135V , normaly 115 V . is the power trasfo wrong ? or can i modify some value  for good B+ ?  and thanks for all yours infos tips , they made my dream possible . sorry for my english , may be i am  not in the best way all the time )

 

[Purplenoise]

hi  , i have a D47  (circuit board from vintagemicrophone) it work well , but i swich my own diy body for a pro body ,because  i had sometimes  a bad bug with gnd . i take the psu measure  and i have 153V B+ ( 105V normaly? ) the secondary of my triad power trasfo is 135V , normaly 115 V . is the power trasfo wrong ? or can i modify some value  for good B+ ?  and thanks for all yours infos tips , they made my dream possible . sorry for my english , may be i am  not in the best way all the time )

Don’t you have a trim pot in the psu to adjust B+? 153v is way too high indeed

 

[dasnevestheo]

Hey, haven't seen anyone mention this source for the tubes : https://www.reichelt.com/fr/fr/tube-lectronique-pentode-noval-9-broches-6-3-v-tube-ef800-p258429.html

Seems too good to be true ? I never had any bad experience with reichelt tho..

 

[rock soderstrom]

Hey, haven't seen anyone mention this source for the tubes : https://www.reichelt.com/fr/fr/tube-lectronique-pentode-noval-9-broches-6-3-v-tube-ef800-p258429.html

Seems too good to be true ? I never had any bad experience with reichelt tho..

On the German version of this site says Reichelt.com:
"Attention, images are for illustration purposes only! Under certain circumstances, the makes may differ from the manufacturers shown. They may be substitutes for the goods, some of which are no longer produced."

The question is what you really get.

 

[dasnevestheo]

Mmmh well catched, I'll just order one and see what I get

 

[rock soderstrom]

Mmmh well catched, I'll just order one and see what I get

Keep us posted! Good luck!

 

[dasnevestheo]

Is it possible to use neumann k47 get capsule for this ? It looks like backplate has no membrane so I guess no omni ? Also there's only one wire..

 

[Purplenoise]

Is it possible to use neumann k47 get capsule for this ? It looks like backplate has no membrane so I guess no omni ? Also there's only one wire..

Neumann has basically three versions of the k47 capsule.
-k49 or older k47 with both diaphragms very close in sound selected for their multi pattern mics
-k47fet has both diaphragms gold sputtered and functional but one of the diaphragms is “better” than the other so they use them in cardioid mics. Those come with no wire attached to the rear diaphragms but if you connect a wire they work perfectly.
-k49fet which has only one functional diaphragm ( rear is not gold sputtered) and they only work in cardioid.

All those capsules are a proper k47 sound. No difference in sound as far as I know.

Any of those capsules can be used for the u47. In your case it will be cardioid only of course. You will need to connect also a second wire to the backplate ( side) so two wires total.

 

[dasnevestheo]

Thanks a lot. Well I'm pretty sure it's a K47 FET so the back diaphragm should be sputtered.
Not sure if I'm better with this or some other brand capsule... Beesneez's been silent for a while and I'm not sure I'm a big Thiersch fan from the few demos I could hear. :/

 

[Purplenoise]

Thanks a lot. Well I'm pretty sure it's a K47 FET so the back diaphragm should be sputtered.
Not sure if I'm better with this or some other brand capsule... Beesneez's been silent for a while and I'm not sure I'm a big Thiersch fan from the few demos I could hear. :/

Check because at some point Neumann I believe called the cardioid only capsule k47fet too. In any case the Neumann capsules are the best k47s out there. I have found them thought to be a little bit “peaky” at around 2k with an ef800. An m7 capsule was a better pairing to my ears with ef800. I tried Danys m7 and 3u audio. Danys capsule is exceptional but the 3u audio isn’t far behind. I would totally use the 3u audio if I didn’t have Danys and I prefer it to the thiersch blue.
BeesNeez make awesome capsules too. I have a d87 with a BeesNeez k87 style and it sounds great, almost identical to a vintage u87 I compared it to. All manufacturers make a good product but they tune them a little differently according to their control sample and taste. It’s very subjective. For example I installed a BeesNeez ck12 style in a 251 build but I found it a little  “dull” and dense for the sound I was going for. I ended up selling the mic and the person that got it is raving about it’s sound...favorite mic in his collection.

 

[dasnevestheo]

Thanks a lot that's great info here I'm so pissed I waited too long to buy my capsule, a few months ago sennheiser was selling K49 for so much cheaper... Now I can't decide what to choose but good thing is those options all seem great

 

[Purplenoise]

Thanks a lot that's great info here I'm so pissed I waited too long to buy my capsule, a few months ago sennheiser was selling K49 for so much cheaper... Now I can't decide what to choose but good thing is those options all seem great

Very recently sennheiser stopped selling Neumann capsules. I would say get a more affordable capsule and when you make sure your mic works as it should then you get a better one down the road.