Just starting out


Needing advice on digital sources:
I am new to this world of high-audio; I have been reading on the subject matter over the last 8 weeks. To be honest is really has captivated a lot of my attention.
I recently ordered the SA 710i along with Transmission Audio speakers. I have gone back and forth on the musical source options. I am leaning towards digital. I own -0- CD's.
Why not just invest in a high-end DAC with a great music server and download high rez music? I do not see the benefit of the CD transport option. Is there something I am not getting?

Thanks...
ddelisle911
Unless the integrated has a passive preamp section, incoming voltage, 2V,3V, etc, shouldn't be a factor since the preamp section usually would be active. You should note, however, the input impedance of the integrated. Incoming and outgoing impedance is important for EVERY component, regardless if it's cdp to preamp, dac to preamp, or preamp to amp. The general rule of thumb is that the output impedance of a component should be ten times LESS than the input impedance of the component it's going into. For example: if the output impedance of a cd player or dac (whichever your system has), is 5,000 ohms, the input impedance of the integrated amp should be 50,000 ohms or greater. 5,000 ohms is very high but they do exist. The industry standard for an amp's input impedance is 47,000 ohms.
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