FS: DIY 47 body, PSU components, PCBs

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wstratton

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Hi all,

I had been building my own D-EF47, but I've become a bit squeamish about the high voltage involved in some of the final steps, including wiring and testing the PSU. So I've decided to opt for something with a pre-built PSU, and piece out most of the parts I have acquired to whoever wants them on this board (and is willing to pay a reasonably discounted amount for them). Here's what I've got:

An extremely lovely hand-machined 56mm body for a U-47 project built by board member Spencer Lee Horton with Amphenol connector

A mostly-completed D-EF47 PCB containing AMI's T47 transformer, with two NOS EF-80 tubes

A PSU case from Collective Cases, with mostly-completed D-EF47 PSU PCB and related components (not everything needed to complete the PSU, but most of it--I don't have the on-off switch or LED jewel, and BYO wiring)

Pictures attached and following--feel free to ask me questions about any of these items.
 

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wstratton

Active member
Joined
Apr 2, 2020
Messages
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Location
Beacon, NY
The board was rejecting my other images, so you can view or download them here: https://www.dropbox.com/sh/aztpsuykl0559xe/AACekVhDE5M39HBI2t5VB_SZa?dl=0
 

wstratton

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Messages
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Location
Beacon, NY
If it's for the lot, I'll do $750--that's about 25% or 30% off what I paid for the parts individually. And I'm in the states, so if I need to ship internationally I'd like to split the shipping cost.
 

rmburrow

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Oct 8, 2013
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Who ever made that mic body did a great job from what I see....I want to build a pair of M49's but I want bodies that are dimensionally accurate...was your D47 body dimensionally accurate to a real U47?

The purists always talk about the VF14 tube being the "sound" of the U47...it would be interesting if a EF14 tube sounds just as good, or the late Oliver Archut's circuit using a miniature glass tube... There is some truth the AC701 tube was the "solution" before a suitable solid state device (FET) was available...and a AC701 equipped mic like the KM56  or Schoeps M221 sounds real nice....but the capsule also "makes" the sound and I like the sound of submicron nickel membrane...
 

wstratton

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Messages
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Location
Beacon, NY
rmburrow said:
Who ever made that mic body did a great job from what I see....I want to build a pair of M49's but I want bodies that are dimensionally accurate...was your D47 body dimensionally accurate to a real U47?

Yes, he did do a great job. I don't believe that this body is dimensionally accurate to a U47--it fits the PCB just fine, but I wasn't particularly interested in getting a body with accurate dimensions. The body tube length is 15 cm without the headbasket on. With the basket on, the internal length minus the bottom bell is about 20.5 cm. The distance between struts is just a hair over 4.5 cm, with a mm or two of flex in either direction if necessary. The length of useable vertical space within the struts is about 13 cm.
 

rmburrow

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Oct 8, 2013
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177
The VF14 (or EF14) base is around 43 mm diameter.  45 mm inside diameter the case is tight for the original tube...but a EF800 should fit fine along with the caps and output transformer....The EF14 is the 6.3 v heater version of the VF14.... That mic body is a work of art....
 

wstratton

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Beacon, NY
A quick update: I'm waiting on word from AMI as to whether their power supply could be easily modified to work with the D-EF47 circuit. If so, I think I will end up holding onto the parts listed here except for the PSU components and PSU case.
 

wstratton

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Beacon, NY
Pip said:
Check out Hamptone PSUs

Their website appears to be down right now. But in any case, it looks like an AMI PSU will work well if I swap out a couple of the resistors on the mic's PCB. So that's the current plan. Thanks!
 

iturnknobs

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Aug 2, 2014
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Crystal Lake, IL
wstratton said:
A quick update: I'm waiting on word from AMI as to whether their power supply could be easily modified to work with the D-EF47 circuit. If so, I think I will end up holding onto the parts listed here except for the PSU components and PSU case.

AMI's can can be used for d-ef47 circuit. If you order one of the daughter boards for the pattern switching circuit and "insert" it into to d-ef47 circuit you can then have 11 patterns instead of 2(omni/cardioid). You must also fabricate a way(and have space) to fit it in and secure in inside the chassis. I did this for a friend who started with d-ef47 mic pcb, but bought a PSU through AMI... the answer is yes, regardless which PSU you have. I can help, if need be but will have to refresh my memory. It's been 2.5 years since I completed that project.
 

wstratton

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Messages
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Location
Beacon, NY
iturnknobs said:
AMI's can can be used for d-ef47 circuit. If you order one of the daughter boards for the pattern switching circuit and "insert" it into to d-ef47 circuit you can then have 11 patterns instead of 2(omni/cardioid). You must also fabricate a way(and have space) to fit it in and secure in inside the chassis. I did this for a friend who started with d-ef47 mic pcb, but bought a PSU through AMI... the answer is yes, regardless which PSU you have. I can help, if need be but will have to refresh my memory. It's been 2.5 years since I completed that project.

Thank you, I appreciate it! I ordered the AMI PSU with the pattern switching circuit built in--I'm assuming that I don't need to insert anything into the microphone circuit itself, with this choice? I'm fine with just the omni/cardioid. As I wrote in my last post in this thread, I'll be swapping a couple of resistors at AMI's recommendation.
 

iturnknobs

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Aug 2, 2014
Messages
547
Location
Crystal Lake, IL
wstratton said:
A quick update: I'm waiting on word from AMI as to whether their power supply could be easily modified to work with the D-EF47 circuit. If so, I think I will end up holding onto the parts listed here except for the PSU components and PSU case.

Check Duantro's post with schematic. The "remote pattern board" is what needs to be "inserted" into the mic circuit with the 11 pattern PSU. If you get the regular PSU, you will need to install a switch on the PSU for omni/card. If you need, PM me going forward so we don't keep posting in the Black Market.

https://groupdiy.com/index.php?topic=52022.260
 

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