Adding output transformer to Green Pre.....

[therecordingart]

I want to build a pair of mic pres that have a "sound" to them, but I don't have a lot of money to spend. I was in the process of building some 312 style pres, but the in/out iron and opamps are little out of budget so that idea is scratched for a while (I'm getting married and am on a budget).

Would it be a decent idea to add an output transformer to a Green pre or SSL9K?

 

[keefaz]

If you have the opamp and in/out irons, why not build a 312 preamp ?
You have nearly all the ingredients

You just add 2 diodes, 6 caps, 3 or 4 resistors and a pot and you are done

API Circuit

 

[therecordingart]

I don't have the opamps or iron for the API. That is the part that makes it out of reach for me.

 

[Handcrafted Tone]

I've built 312 circuits using an IC instead of a DOA. Works great. Easily upgradeable to DOA. Try the AD797. Its voltage and current noise are similar to the JH990, and both are perfect for 1:2 input transformers. You just have to make sure your IC can perform under the transformers load.

cinemag 1:2 input tx - $45
cinemag 1:1 output tx - $35
AD797 - $7
misc (home etch PCB, resistors, caps) - $13
total = $100/channel

This is probably $30 more than you'd spend/channel on a green with output tx, but if you want transformer color it's worth it.

 

[mhelin]

How about buiding a Neve 1272 using the Sowter/Carnhill or vintage Neve input & output transformers, the AD797 IC instead of the BA283AV and using the Jensen circuit (http://www.jensen-transformers.com/as/as018.pdf ) with the offset trim and without any caps in signal path? How much the DOA actually affects to the sound? It can't obviously drive very long cables, but sonically could anoybody really notice the difference? After all, isn't the sound in the iron?