D-EF47 Tribute To Oliver Archut U47 Build Thread.

[vinylwall]

Thank you Dany.  I was close!  hahaha.  I've updated the drawing to reflect the changes and changed it in my original post #58 to make sure there is no confusion for anyone else.  I don't know how to make it fit in the window though.  Maybe you could take it from there and adjust the size?  Thanks.  Jimi Ray

 

[soapfoot]

Hi there. Cool project, and thread!

I see you used a 27 ohm resistor in the filament/bias supply instead of the 29 ohm as Oliver spec'd.

Just curious if there is a (good) reason for this, and if I should do this in my own build?

Thanks!

 

[poctop]

Hi there. Cool project, and thread!

I see you used a 27 ohm resistor in the filament/bias supply instead of the 29 ohm as Oliver spec'd.

Just curious if there is a (good) reason for this, and if I should do this in my own build?

Thanks!

27 Ohm is a much more common value and with the tolerance It will get you there,
but you could use this as well

http://ca.mouser.com/ProductDetail/KOA-Speer/MF1-4DC28R7F/?qs=sGAEpiMZZMu61qfTUdNhG%252biW3YcKDP2vpCiYaw4hNOQ%3d

haven't found much difference between the 2
best,
Dan,

 

[soapfoot]

thank you!

 

[trans4funks1]

The illustration attached to post #58 with the power supply interconnections shows the exterior view of the IEC AC input panel mount connector but it shows the wire connections as they would appear from the rear.

It may be obvious to some people when they are wiring it up that they need to translate this by thinking backwards. If someone uses the illustration at face value it may create a circumstance where the the switch position is in "off", or the fuse may seemingly be open, while part of the circuit inside the chassis is still hot.

I just prepared a specific illustration of an IEC AC input connector with an integrated fuse in the hopes that it will helpful to someone.

 

[vinylwall]

Thanks trans4funks1.  I've updated the sketch in post #58 to include your input connector drawing.

 

[vinylwall]

I thought I'd throw some pics of my build so far up here.  AMI BV08 Classic transformer, NOS 1968 Telefunken EF800 tube, body ordered from Mic & Mod, Thiersch STW7 Red (shipped but not received yet).

Update: Theirsch Red is now installed and is a very nice sounding capsule!  I highly recommend Siegfried's work.

 

[vinylwall]

Inside

 

[vinylwall]

Inside / tube side.

 

[vinylwall]

PSU complete.  Binder type case from Dan at collectivecase.

 

[poctop]

PSU so far.  Still waiting for some parts from mouser.  Binder type case from Dan at collectivecase.

i Really like your solder dispensing tool   nice work place
DAn,

 

[vinylwall]

Hey Dany.  The Pot to adjust the H+ voltage gets warm to the touch in my PSU.  Is that normal?  I'm able to get 5.05v for H+ and 105v on B+ but I'm a little concerned the adjustment pot gets warm to the touch.  Thanks - Jimi Ray

(BTW - the mic fired up just fine!  Very quiet although I'm hearing some microphonics.  Gonna let the tube burn in and go from there.)

 

[poctop]

Hey Dany.  The Pot to adjust the H+ voltage gets warm to the touch in my PSU.  Is that normal?  I'm able to get 5.05v for H+ and 105v on B+ but I'm a little concerned the adjustment pot gets warm to the touch.  Thanks - Jimi Ray

(BTW - the mic fired up just fine!  Very quiet although I'm hearing some microphonics.  Gonna let the tube burn in and go from there.)

Glad you made it  , Do not hesitate to put up a nice picture of your build up on this thread if you like, it is always nice to see completed build ,

The Pot from the BOM is spec`d for 5W so it is normal that it will get warm those are made for that purpose , make sure it is firmly attached to a bracket or bolted in the PSU case somewhere so it can dissipate heat optimally.

Thanks for Sharing,
Let us know how you like it ,
Best,
Dan,

 

[vinylwall]

Hey Dany.  The Pot to adjust the H+ voltage gets warm to the touch in my PSU.  Is that normal?  I'm able to get 5.05v for H+ and 105v on B+ but I'm a little concerned the adjustment pot gets warm to the touch.  Thanks - Jimi Ray

(BTW - the mic fired up just fine!  Very quiet although I'm hearing some microphonics.  Gonna let the tube burn in and go from there.)

Glad you made it  , Do not hesitate to put up a nice picture of your build up on this thread if you like, it is always nice to see completed build ,

The Pot from the BOM is spec`d for 5W so it is normal that it will get warm those are made for that purpose , make sure it is firmly attached to a bracket or bolted in the PSU case somewhere so it can dissipate heat optimally.

Thanks for Sharing,
Let us know how you like it ,
Best,
Dan,

Thanks for the reply Dany.  Glad to know the warm pot is normal.  You'll see it is up high on a bracket in my photo.  Reply #66-69 have pictures of my build.  I'll post some recording samples soon.  Thanks.  Jimi Ray

 

[poctop]

Mic body for this project are now available here


http://store.studio939.com/category/microphones-and-parts

http://groupdiy.com/index.php?topic=50015.880

http://groupdiy.com/index.php?topic=58609.0

 

[vinylwall]

I thought I'd throw some pics of my build so far up here.  AMI BV08 Classic transformer, NOS 1968 Telefunken EF800 tube, body ordered from Mic & Mod, Thiersch STW7 Red (shipped but not received yet).

As I just posted in the U87 build thread, I want to apologize to the group.  I have only  just discovered the discord over "Mic & Mod" and the designs here on GroupDIY.  I did not know about this when I purchased this U47 mic body from Mic & Mod.  I feel horrible and have ordered 2 of Chunger's MK47 mic bodies to make up for it.  I'm really sorry guys  :-\

 

[jpsexton]

I got my body from Chunger and I'm finishing assembly of my Mic & PS. I have a newbie question though.

What are the 7 pin connections to the Mic PCB and also the 7 pin connections on the PSU?

I've tried to figure it out on the schematic but I don't guess I'm smart enough! :-\

Thanks,

John

 

[poctop]

I got my body from Chunger and I'm finishing assembly of my Mic & PS. I have a newbie question though.

What are the 7 pin connections to the Mic PCB and also the 7 pin connections on the PSU?

I've tried to figure it out on the schematic but I don't guess I'm smart enough! :-\

Thanks,

John

if you made it that far I am sure you are smart enough  ,
tomorrow morning I will try and prepare a little explanation as I have to go now ,
Best,
Dan,

 

[poctop]

Hope this will help,
Best,
Dan,

 

[jpsexton]

Perfect! That's exactly what I needed!

Thank You!

John