Just starting out

Hi Devilboy-

I looked up the specs of the 700i and the DAC that I am interested in.

Integrated Amp Sim audio 700i 23,700 ohms Input impedance

Specs on Tube DAC-II-MK2 Accustic Arts are below
Digital inputs up to 192 kHz: 2 x S/P-DIF; unbalanced – 75 Ω (COAX)
1 x TOSLINK; optical
Digital input up to 96 kHz: 1 x USB 2.0
Digital inputs up to 48 kHz: 1 x AES/EBU; balanced – 110 Ω (XLR)
1 x S/P-DIF; unbalanced – 75 Ω (COAX)
1 x S/P-DIF; unbalanced – 75 Ω (BNC)
Digital outputs: 1 x S/P-DIF; unbalanced – 75 Ω (COAX)
1 x AES/EBU; balanced – 110 Ω (XLR)
Analog outputs: 1 x balanced – 2 x 33 Ω (XLR)
1 x unbalanced – 33 Ω (COAX)

Using your rule of thumb I should be OK. Correct?

Well, first of all, the input impedance of the sim is a VERY low 23,700 ohms. Personally, I wouldn't buy it based on just that spec alone. Even if your dac has a low output impedance, it kind of paints you into a corner acoustically. Meaning, if you keep the sim, you limit your dac choices to ones the MUST have a low output impedance. Apperently the dac you mention has a low output impedance of 33 ohms either from balanced or single ended, which would be ok with the sim. I think there are better amps (ss or tube), that would have a higher input impedance. Also, I don't see a mention of the output voltage of the dac. What is the input voltage sensitivity of the sim integrated?

Although I don't know the output voltage sensitivity of the dac, I think the main issue is the sim's input impedance. 23,700 is waaaaay low. Personally I would avoid it. YMMV.

Devilboy-

Here are the specs on the 700i
including the input sensitivity

Type Solid State
Configuration Dual-Mono / Balanced
Class of operation - Amplifier A/AB
Single Ended Inputs (RCA) 5 pairs
Balanced Inputs (XLR) 1 pair
Input Sensitivity 490mV - 6.0V RMS
Input Impedance 23,700 Ω
Monitor Loop 1
Preamplifier Output 1 pair @ 50 Ω (RCA)
Output Device Types - Amplifier Proprietary MOON BiPolars - 6 per channel
Output Binding Posts Gold-plated WBT
Output Power @ 8 Ω 175 Watts per channel
Output Power @ 4 Ω 350 Watts per channel
Output Impedance 0.02 Ω
Damping Factor > 400

Good news is the input voltage sensitivity of the sim is 490mv, so it only needs about a half of a volt to play at full power. If you get the dac and integrated you are interested in, you should be in good shape.....as long as you don't change the dac, since it has such a low output impedance.