Help Building a High Output Passive Apex 205 Ribbon Mic?

Would it be a good idea to make a very high output passive ribbon mic using an Apex 205 with a high ratio transformer like the 1:54 FAB XL or 1:55 Samar RT55 (or maybe an even higher ratio?) and thin ribbon foil? I have some 1.8 micron ribbon already, but I'm not sure if it will cooperate with one of these transformers.

I would also like to open up and extend the high end some, which I’ve read that better transformers (Lundahls or Cinemags) in more typical ratios like 1:37 can help with. I don't really want to lose any of the thickness on the low end that I like on my voice either.

I enjoy using ribbons on my soft,  quiet vocals and finger-picked acoustic guitar. They sound very thick and natural. I have a True Systems P-Solo Ribbon pre already, I just still get some preamp noise recording these two soft sources, especially at a decent level. If I lift the high end with eq and add compression, it just adds more noise. There's only vocals, and acoustic guitar in my songs, so there isn't anything else in the mix to hide the noise. There's at least a little noise in basically every recording or video I've heard or seen on quiet sources similar to mine, whether they were using a dedicated ribbon pre or not.

Would the high output transformer dampen the thin ribbon too much and affect bass. mid, or high end response? I’ve found posts online where people talk about using high output transformers with thicker ribbon for impedance purposes to use with typical preamps. No one ever explains why thinner foil may not work with high output transformers or if the sound quality is just going to be subpar. I’m hoping something like this would work, since I already have a ribbon pre with a 10k ohm input impedance.

Maybe an active ribbon would be a better choice, but nice ones are more than I would like to spend right now. Is my idea a good alternative?

My first thought is maybe try a Beesneez Angus Preamp between your ribbon mic and preamp and see how that works. Should that work, at least your mod-choices can be based on tone and not gain/noise-issues for your application and you’ll have, you have a suedo-active ribbon mic on the cheap!

Recording Engineer said:

My first thought is maybe try a Beesneez Angus Preamp between your ribbon mic and preamp and see how that works. Should that work, at least your mod-choices can be based on tone and not gain/noise-issues for your application and you’ll have, you have a suedo-active ribbon mic on the cheap!

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I have a similar Cathedral Pipes Durham that I've tried between my ribbon and interface preamps, and it's slightly more noisy than the ribbon preamp. The P-Solo Ribbon preamp doesn't supply phantom power though.

I found a post where Marik gave the math for figuring out the mic's output impedance:

Some more on how winding DCRs affect noise. Any resistance is a noise and the problem with high step up transformers is the primary resistance gets multiplied by the turn ratio square.

Say, a typical Chinese ribbon transformer has Pri DCR=0.3 Ohm, Sec DCR=90 Ohm, and ratio 1:55. The primary translated into the output will be already 0.3 x 55^=907.5 Ohm. Add to this the secondary DCR and we get 997.5 Ohm of pure noise.
Another element of the noise increase is lower output due to the series losses (think of it as a resistive divider). You can see with 1.5K typical input impedance of preamp the losses can be quire considerable.

Now let's take a low DCR transformer with Pri DCR=0.002 Ohm, and Sec DCR=6 Ohm (for 1:55 ratio). 0.002 x 55^=6.05 Ohm+6=12.05 Ohm, which also adds very little to the series losses.

But we forgot that the ribbon itself also has resistance (noise). Typical DCR (or for practical purposes, impedance) of a large ribbon of 1.8 um is about 0.15 Ohm. Translated into output it becomes 0.15 x 55^=453.75 Ohm, which leaves us with total resistance in Chinese transformer 453.75+997.5=~1.45 KOhm, and with low DCR transformer 453.75+12.05=465.8 Ohm.

Another consideration is output impedance. In the modern equipment the rule of thumb is the input impedance of next stage should be 5 times highr the output impedance of preceding stage. Most of the preamps are 1.5K in, so the output stage should provide 300 Ohm.

My preamp has more than enough impedance if I used the FAB XL transformer. It comes out to about 760 Ohm.

Does anyone have any input about how the transformer would affect/sound with the thin ribbon?