Op-Amps No longer needed for J99?

[wshaw]

I'm getting ready to buy two J99s, and I just want to make certain that I understand this correctly: separate op-amps are NOT required for these any more? Is there any sonic loss in not including them?

Thanks!

[john1056]

I'm getting ready to buy two J99s, and I just want to make certain that I understand this correctly: separate op-amps are NOT required for these any more? Is there any sonic loss in not including them?

Thanks!

see - AD797 vs. 990c

[wshaw]

Hi--

Thanks for that.

Not to sound dim or anything, but I gather that your point is that 1) op-amps are NOT needed, but 2) there is a loss of headroom.

Is that right?

Thanks!

[tele_player]

Without op amps, the J99 won't do anything at all. The point is, you have your choice of what op amps to use.

[wshaw]

Hi--

Thanks for that clarification!!!

What made me wonder about this was this sentence from the sticky posting in the J99 forum, titled "New Features--Must Read"--

"J99KFs are shipping with 8 pin DIP sockets and a pair of AD797 op-amps, so it's no longer necessary to purchase discrete op-amp modules in order to get a working J99."

OTOH, I now find this sentence hard to understand. But I'm not much of an electrician . . .

Thanks again.

[tpryan]

The J99s need a pair of op-amps in order to function. The kits include a pair of AD797 IC op-amps, so a separate purchase is not necessary. The boards will also accept discrete op-amp modules (like the JH990C) that conform to a 2520-style pinout. The discrete modules can provide more headroom and output current, but may not necessarily sound better for your application.

[Ken Schumacher]

OK, I think I understand the general Op amp situation with the J99. Would it be feasible to build up a kit with the Op amps provided, and later upgrade to discreet Op amps when finances allow? I've have poor results in desoldering components, but maybe the unnecessary items could just be cut off later, and the new ones added to solder free holes?

I'm asking because I am thinking about getting another pair of pres to go with the 2 C84s and 2 N72s now in my rack.

Ken Schumacher
www.livevibesrecording.com

[tpryan]

Would it be feasible to build up a kit with the Op amps provided, and later upgrade to discreet Op amps when finances allow?

Of course.

I've have poor results in desoldering components, but maybe the unnecessary items could just be cut off later, and the new ones added to solder free holes?

Exactly. You will have to remove the 8 pin DIP sockets, however, but you don't necessarily need to remove them in one piece. If you don't have the experience, tools, or time to get them out cleanly, just crunch the plastic with a pair of nippers and remove the pins one at a time.