Hodge-podge Mic Preamplifier

[fuzzedout]

Greetings,

I was recently given a couple of input transformers and monolithic TOA audio opamps salvaged from a TOA board. Is it possible to cobble these together and make an very primitive (lo-fi) API style mic preamplifier on the cheap? I have a 500 series lunch box with two open spaces and would love to have it fully loaded. The only problem is that I don't know where to begin. I know that Eisen Audio had a DIY 500 series kit a while ago but it was discontinued in 2010...

Any help would be highly appreciated!

Thanks,

fuzzedout

[kato]

It's definitely possible.  Since they were given to you, it can't hurt to try. Also since you already own a rack, the difficulty of the power supply is taken care of.

Do you know anything about the unit they were salvaged from?   A little backstory would go a long way to help you know if the transformers are line input 1:1 ratio or mic input - 1:8 / 1:10 or thereabouts.  In a best case scenario, the input transformer and opamp were made to go together to form a mic pre. If that's the case, you can probably follow the basic API 312 schematic and cobble something together.

You could use a API style breadboard, like the one from AML:
http://www.diyrecordingequipment.com/projects/aml-500-series-51x-alliance-breadboard/

Although that may not be economical given the current euro-to-dollar ratio and shipping from the UK. Perhaps just the edge card adapter and some other flat board would do. Like this one from Jeff:
http://classicapi.com/catalog/product_info.php?cPath=87_88&products_id=164
Along with an L-bracket:
http://classicapi.com/catalog/product_info.php?cPath=87_88&products_id=181

Are you still considering doing it? If so, post here, we'll walk you through it.