Redd 47 Mic Preamp

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Success! I replaced my JJ E88cc with a NOS Sylvania tube and the unit is silent. Tried the JJ tube again and the noise returns. Sylvania to the rescue. Thanks to all on the help on this one.
 
I'm looking for suggestions regarding the power transformer in this build. Is there a Sowter stock version? (I looked through the list but didn't spy it.)
 
Just switched it on and both sides work perfectly & sound very nice. Surprisingly posh!
Sowter R47 inputs & Carnhill outputs. I used the capi attenuators on the front & back for more driving options. I like em. Clean & so easy.
Original schematic all tube psu with Hammond power tranny - in a separate case so it’s dead quiet!
Found the Simpson meters on eBay for £10 each! Stoked!
Thank you to all the knowledge on this here thread. I’m so pumped!!!


 

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Not the neatest but it’s dead quiet so I’ll take it! Ha!
 

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Hello,

Has there ever been a full schematic and layout doc created and offered for this build? 

If not, does anyone have a schematic / layout doc for this build ( or any other REDD.47 point-to-point build ) that includes USA power input ( 120V ) and panel control information?  I found thread responses here for previous requests like this suggesting more or less to 'figure it out' which I suppose is a legitimate response in a DIY forum.  Hoping rather than spending time guessing on my part, maybe someone has a full set of docs that would be willing to share or even charge a resonable fee for?

Thanks in advance!
 
JW said:
Schematic here: https://groupdiy.com/index.php?topic=51980.msg661595#msg661595

Thanks for the response JW!

I have that manual already, though.  While the schematic in the manual does indicate FINE GAIN and PAD circuitry specifically, and polarity and rumble filter ( sorta? ), in a perfect world I'd like to have a schematic that also includes phantom power, input and output controls, and maybe even a meter.  The meter not necessarily a deal breaker along with maybe the input / output volume controls.  I understand that the real preamp didn't offer these 'extra' features as built in features hence why they are not present in the available schematics for the actual unit.  I'm guessing phantom power, for example, was provided by separate discrete stand alone mic power supplies used to power the tube mics in play in the studio, hence why the real preamp device didn't have built in phantom power? 

Maybe all of these features are easily added by someone with more electronics engineering skills than I, and... I have no problem trying to learn what I can, but at this point given my experience level short of someone with expert knowledge double checking whatever I might be able to add to the schematic, I'd be reluctant to spend the money for parts just to 'test' a guess on my part.  Finding threads of how to add volume controls, phantom power and other sub circuitry to circuits is easy enough on the InterWebs, I'm never sure how exactly any of that would be baked into an already proven circuit design without possibly making serious assumptions and / or errors.

At the end of the day, if I decide to actually embark on a build, I might just build the basic unit without any of the extra desired features just to have a working example in hand, then I can play with adding features one at a time making sure each addition works without affecting the overall performance in any detrimental manner.

Cheers!
 
The Orange86 project covers many of your wishes. For the VU meter get a driver board and for the output a pad. Voilà, your dream preamp is reality!

https://groupdiy.com/index.php?topic=33657.0
 
rock soderstrom said:
The Orange86 project covers many of your wishes. For the VU meter get a driver board and for the output a pad. Voilà, your dream preamp is reality!

https://groupdiy.com/index.php?topic=33657.0

Hi rock soderstrom!

Thanks for the response.

I'm aware of the Orange 86 PCB, thanks.  Really interested in a point-to-point build only because I enjoy that type of build over PCB builds.  I have built devices in the past using PCB's so not necessarily a deal breaker and all things being equal, I understand that sonically there's no difference. For me, I better understand the circuit after a build when building point-to-point rather than just plugging a PCB with components.  Sure, the same can be done with a PCB if desired, but much harder to dig through someone else's idea of a build since most of the circuit design is baked in. 

Cheers!

 
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