Expanding Pres on my present Audio Interface

[rone2him]

I presently use t.c. electronic's konnekt 24D interface which I'm pretty happy with now (Line 1 & 2 have dedicated pres), but was considering purchasing a better pre amp (like a AD2022 - Dual Mono Pure Class A Preamplifier);

sending it's outputs into the 3rd and 4th Line Inputs of the 'konnekt 24D'...

konnekt 24D

Line Inputs specs Ch. 1,2,3,4):

Connectors - 1/4” Phone Jack (balanced) Ground sensing design.

Impedance, Bal - 20 kOhm/25 kOhm

Full Scale Input Level @ 0 dBFS +13 dBu

THD+N <100>111 dB(A), >108 dB, 20 Hz to 20 kHz

Freq. Response +0/-0.5 dB, 20 Hz to 20 kHz

Crosstalk < -100 dB, 20 Hz to 20 kHz

A to D Conversion specs:

24 bit, 128 x oversampling bitstream

A to D Delay 0.68 ms / 0.63 ms @ 44.1 kHz / 48 kHz

Clock and Jitter

Internal/External Sample Rates 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz and 192 kHz / 43 to 193 kHz, jitter rejection at all rates

Jitter Rejection Engine - JET™ technology in TC DICE II

Jitter Rejection Filter <-3 dB @ 10 Hz, < -100 dB @ 600 Hz

DIO Interface Jitter < 1 ns peak, BW: 700 Hz to 100 kHz

AD/DA Conversion Jitter < 42 ps RMS, BW: 100 Hz to 40 kHz

Digital Output

Phase (stand alone and across network) < 0.5 % of sample period

Input Slip Sample Tolerance (all DIs) +50 % to -50 % of sample period

Processing Delay DIO @ 96/48 kHz 0.15/0.3 ms

Frequency Response DIO - DC to 23.9 kHz ± 0.01 dB @ 48 kHz

all going to my DAW through Firewire IEEE 1394a, S400, IEC 61883; seems to me that this would work ok, and be a fairly cheap up grade to my present I/O situation... the one gotcha I see is the Fixed Full Scale Range of +12 dBu on (Ch. 3,4); where the Balanced, high-current Class A output of +36dB would overdrive the konnekt 24D interface outputs?

 

Would this be a problem, or are there any other significant cons to using an audio signal chain with this type of a configuration?

[uhdinator]

I 'm guessing the +36db is the MAX capable output of the Pre with it cranked.....

 

If the line in on the interfaces says +12 db (max it can accept) and you track at -12 db peak into DAW you should have 24 db head room for the interface line in.

 

Think you will be fine. I know one of my condensers is around -30 output so I am maybe using 15-20 db of gain on my outboard pre running line in to a Motu.

[rone2him]

hey uhdinato,

 

Thanks for your response, it helped me put perspective into my thinking, on some of the biggest questions I had in my mind...

 

Your logic seems dead on to me, as far as to not being overly concerned about over-driving my present interface... just have to watch the level at each stage I remember seeing some spreadsheets for mic sensitivities and outputs now, and it's making more sense to me now (related to pre amp selection); need to go back and re-read those post & do the calculations to be absolutely sure, for the microphones that I have... I'm sure it will be ok like you said.

 

But it's still always good to get some confirmations from others, before following through on ones plans, and going out and making such a purchase, as it is a relatively big expenditure, and step in building up my setup. So thanks again 4 ur inputs!