3u audio transformers or keep stock? A third option? (OEM mic mods to 47 & 251)

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Urskov

Well-known member
Joined
Jan 6, 2020
Messages
46
Location
Denmark
Hi there

I'm undertaking my first tube mic projects modding a T. Bone SCT-800 and a Nady TCM-1050 to an ELAM-251-ish (www.advancedaudio.ca • View topic - Modding a t.bone SCT-800) and U47ish (more like Advanced AUdio CM-47: www.advancedaudio.ca • View topic - nady 1050 mod) respectively.

Now, since it's my first and I don't want to screw up expensive Thiersch or Campbell capsules, I'm going with Maiku capsules for both.
I also want to keep it cheap on the transformers and am looking into 3U Audio transformers.

However, I read in another thread on the forums someone recommending just keeping the transformers in these stock as the 3U ones aren't neccesarily an upgrade.
For the Apex 480 mod, the good Dave of AA recommends a 14:1 transformer (though the original T14 was 12:1?) for the Apex and a BV8-style 6,5:1 in the U47.

Anyone have any experience doing similar mods and picking transformers? And does anyone know what the ratio is in the stock transformers?
 
hi urskov!
i built both with the same line up (maiku capsule, 3u audio transformers).
i‘m super happy with the elam clone, the u47 is ok, but i will still play a bit with the coupling cap ...
alternatively you can look into 797 capsules (bit cheaper but usable and i think cheaper). from the sound the maiku is better ( i only compared c12 style capsules, and taste is of course subjective).
nevertheless i spent like 300 euros in total on the elam 251 and by now it outruns all mics in my locker (c414, mkl2500, sm7) for vocals. also compared it with friends and their opinion was the same!
if you do it properly, you gonna have a lot of joy with the outcome,
wish you fun building,
all the best
mike
 
Hi there

I'm undertaking my first tube mic projects modding a T. Bone SCT-800 and a Nady TCM-1050 to an ELAM-251-ish (www.advancedaudio.ca • View topic - Modding a t.bone SCT-800) and U47ish (more like Advanced AUdio CM-47: www.advancedaudio.ca • View topic - nady 1050 mod) respectively.

Now, since it's my first and I don't want to screw up expensive Thiersch or Campbell capsules, I'm going with Maiku capsules for both.
I also want to keep it cheap on the transformers and am looking into 3U Audio transformers.

However, I read in another thread on the forums someone recommending just keeping the transformers in these stock as the 3U ones aren't neccesarily an upgrade.
For the Apex 480 mod, the good Dave of AA recommends a 14:1 transformer (though the original T14 was 12:1?) for the Apex and a BV8-style 6,5:1 in the U47.

Anyone have any experience doing similar mods and picking transformers? And does anyone know what the ratio is in the stock transfo
forgot - the stock transformers of my sct800 were all something like 7:1 ratios. i just used them in some bo hansen builds recently and they sound decent, so for the u47 you can try the stock. i think there the ratio should be 6.5:1, if i remember correctly ...

cheers
michi
 
Last edited:
I'll be using 3U Audio Tx for my 251 build also. HerbertR used one in his 251 build as well. Just waiting for OPR to make more capsules.
 
Back
Top