What parts are needed on each kit to finish? A12- no op amp

[redstudio]

What pieces are needed on each KIT, that don't come with the package. After reading the a12 bill of materials it shows no op amp and also L1, L2 Jensen pieces. Not sure what those are, but am concerned that I have to do some extra searching if I decide to go with any of the preamps...

Any more info on the site about that would help, I didn't notice this until someone from gearslutz.com let me know that it didn't.

So is there more components for each pre that I would have to purchase separate from the kit, or just on the A12?

Thanks,
C

[craigmorris74]

You need to get an opamp for the A12. It's $40 when you buy the kit (you get a discount). L1 and L2 are optional parts, only needed if you'll be driving long cable lengths. The kit includes jumpers in their place.

I believe the J99 is the only other kit that needs extra parts, and again, that's the opamps.
Craig

[redstudio]

Now, is there a forum with different parts in place of these op amps that can change or make the sound more "clean" or "warm" as opposed to the parts that come in the kit?

Anything you can change around as you want or need without hurting the pc boards??

Thanks,
C

[craigmorris74]

You can substitute different discrete opamps on the J99. With the included transformers, I'm guessing it's still going to be relatively clean (I'm building one right now). One thing I didn't make clear about the J99 is that it does come with IC's which can be used in place of the discrete opamps.

There's supposed to be an N72 kit coming out that allows the use of a Cinemag input tranformer, which I'm guessing will be cleaner sounding.

Also, I've read about a new version of the A12 being able to use different transformer for what I would think would be a cleaner sound.

I wouldn't mess with anything else in these builds if it weren't recommended by Tim, though.

[tpryan]

You can also substitute many different op-amps, input, and output transformers on the A12, but it's up to you to first make them work and then decide if they're an improvement. I'll be adding some information to the A12 assembly instructions soon on how to recalculate resistor values for different input transformers and load impedances.

[redstudio]

yeah that would be a great selling point. I'm glad you guys have this forum to help new builders get their hands dirty with alot of support

Thanks,
C