Originally Posted by TonyBelmont
Yes, the 312 circuit is fairly simple, which is why so many people try to copy it. Half of the preamps in the 500 series are a direct rip of this design.
You could build your own 312 type of preamp (or in a non-DIY'ers case, buy the parts and have them sit in a box for years). But, the end result wouldn't share any of the same parts as the BAE... The BAE uses the Avedis 1122 op amp and custom Jensen transformers. You can't buy those parts.
I've built my own with API op amps and API transformers... Was it worth my time based on the savings? Not even remotely. Let's face it... Unless you are somewhat experienced with soldering and assembling gear, this is a little too complicated for the average gear user.
What kit did you build your pre with Tony??
As far as knowing how to solder etc..the 312 is a very simple preamp in design. We're not talking building a tube rectifier.
The majority of the work with a kit for the 312 is stuffing the pcb, soldering, trimming legs, double checking that you didn't make any bone headed mistakes and good old fashion QC.
In no way am I implying it will be superior to what BAE does, there's quite a few closed shop parts that can drastically alter the sound of a product.
However, the old school API sound is what alot of people are chasing it seems versus the new and that site that Ben referenced is doing some great things by even existing, let alone trying to approximate the old school API sound.
I think moreso than anything, if you look at what you'd have to spend on modding a GAP73 with Carnhill transformers and upgrading the transistors, damn near gutting the thing, that puts us at almost 600 bucks!
This thing, the kit is 30 bucks with the Neutriks connectors, there's maybe 30 dollars in caps and resistors, the case is 60, the Cinemag transformers are about 70 bucks total and opamp is say 50 bucks. (I've seen different ones for much less though!)
If you buy a 5 fish PSU w/ the torroidal transformer, thats another $75.
That puts us at $315. If you hire a tech at $50 an hour, this is maybe 3 hours of work. (Stuffing and soldering the pcb is maybe an hour for an experienced handy tech, so 2 hours to drill two holes and connect a PSU is really pushing it)
Anyone seen an 312 style preamp for this much??
Plus with that same PSU and case, you can put 7 more modules in there over time and all you'd have to do is drill holes and connect the PCB via the ribbon connector, like an IDE hard drive. Basically a primitive lunchbox! Expandability. To be perfectly honest, you could have your case predrilled for 8 modules total and then all you'd have to do is pop in your new card, screw the connectors in and connect the ribbon yourself. This way your unit never has to leave your studio to get expanded!
Nevertheless, I still feel that the 312 itself regardless of kit or not, is a wonderful preamp, very simple, only a relatively small number of caps in the signal path = PURE SOUND. A design that definitely passes the test of time and regardless of what incarnation you hear it in, it just makes sense to have at least a pair in your studio. They have a very nice tone to them. I really dig the older stuff though.
The Five Fish Audio Kit, I really want to hear, the X12.