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Using (and abusing) API pres Dual-Channel Preamps
Old 22nd August 2007
Lives for gear
Tubthumper's Avatar

Using (and abusing) API pres

I’ve just picked up an API A2D. Cue Mamas and Papas....... "it was all I hoped it would be".

Just hoping to get some advice from experienced users on how to get the most from this box.

I know that in order to attain a rich, more saturated sound, while still maintaining usable recording levels, some users like to crank the APIs gain, then insert an external attenuator between the APIs output and the recorder. It looks like the A2D can achieve this internally – only if you’re using digital output however - without the use of an external output attenuator. The A2D provides a means of attenuating the mic/line signal before it hits the converters. The plot thickens, however…….

The A2D also has a feature called “2:1” that applies to the analog signal path. When switched in, this option results in an attenuation of the signal by 10db at the output transformer. In order to bring the signal back to a usable level you need to increase the gain, presumably driving the opamp harder in the process. Just giving this some thought: this new 2:1 feature achieves a different result to the tried-and-true external attenuation method doesn't it??? That is, by driving the gain hard and using an outboard attenuator, the output trannie would be loaded differently, right??

I’m also thinking about the “pad” button. I’ve heard A Designs Pacifica users say that the Pacifica can be used clean or, by turning on the pad, driven harder for increased saturation. Just wondering whether the same can be achieved with API pres??? Can’t say I’ve ever heard anyone refer to this. Presumably the pad affects input levels, and has a different effect to using the 2:1 option or the external output attenuation method??

Regarding the (front panel-mounted) line input jack. The manual describes this as “direct input with high Z”. I’m a little confused here. I’ve been of the belief that line level input is physically different to DI input. After all, this is what DI boxes do, isn’t it???? That is, convert a low level signal to line level???? Anyways, just wondering whether this jack is for connecting line level devices or for direct-injecting guitars, synths, whatever. Or both?

OK, lastly, if DIing a bass guitar for example, would I be better off using an outboard DI box and patching it into a mic pre input on the A2D, or using the onboard “line input” jack?

Old 22nd August 2007
Lives for gear
lowfreq33's Avatar

The front panel jack is for an instrument, making the pre a D.I. You can also use a separate D.I. if you feel it colors the sound in a good way. Think about it, passive D.I.s use a transformer, right?
Old 22nd August 2007
Lives for gear

Yep - the back panel XLR i/o is low-z, and the front panel is your hi-z instrument input. Very nice.

I shouldn't think it would matter too much what means you use to drive the transformer into saturation. I expect the attenuation that follows is mainly just to get your output level right for the next stage (in this case the A/D). It would be the input to the transformer that saturates it.

I don't actually like it too saturated - seems a bit metallic to me. I guess that's typical of the 312 preamps?
Old 22nd August 2007
Lives for gear
OK, lastly, if DIing a bass guitar for example, would I be better off using an outboard DI box and patching it into a mic pre input on the A2D, or using the onboard “line input” jack?
Well, IMHO the using the A2D as a bass DI is one of it's best features! It's a big improvement in my mind over my old pre / di combo.
Old 28th August 2007
Here for the gear

Tubthumper? Do you think your'e in Chumbawumba or whatever?! That song blows. Please quit Gearslutz. Thank you and goodnight.
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