2. speakers
  3. 1270447920

I think I've made up my mind

After having auditioned the following :

1. Avantgarde Uno G2 + Audio Note SET amp/Pathos Twin Towers integrated amp
2. Magico V2 + Soulution 720 pre + 710 power amps
3. Sonus Faber Elipsa/Wilson Sasha + ARC Ref 3 + Ref 110
4. Thiel CS3.7 + Parasound JC1 pre + JC2 power amps

...and after weighing all factors like room interaction, degree of difficulty of setting-up, value for money, magazine reviews, and comments posted here and AVguide.com....

...the winner is: Thiel CS3.7 + Parasound JC1/JC2!

Now for the cables. MF and JA of Stereophile noted that the specs of Parasound show ultra-wide bandwidth and high-current capability which reminds me of Spectral amps. Therefore, would MIT Magnum MA speaker cables and interconnects be a good match? Anyone has any other suggestion? Thanks.
jtein
pubul57
3,712 posts
 
Well, I guess we can say the ARC Ref3 may be dull and bland with Pass XA.4 amps, and that might very well be true with that combination. I've just heard the preamp sound anything but dull and bland which makes me think it is not an inherent quality, but like much else a question of matching components.
ack's avatar
ack
115 posts
 
Yes indeed you don't have to experiment with cables - it's done for you. What do you think we as consumers are doing by experimenting with cables? We try to find synergy. Well, synergy is also an electrical engineering science that can be calculated. It's that simple.
tvad
9,467 posts
 
The match may be within range but 30K ohm is still towards the low end of the SS amp input impedance range from what I've seen, which seems to be around 10K ohm.
Mapman (System | Reviews | Threads | Answers)
I don't understand this comment. In the case of the Pass XA-60.5, which is the only observation I am making in this thread, 30K ohms is well above the minimum required to match a preamp with an output impedance of 600 ohms.

John Atkinson's test measurements of the XA-30.5, which correlates to the 60.5, stated:
The input impedance of the balanced XLR jacks was 29k ohms, close to the specified 30k ohms; the input impedance of the single-ended RCA jacks was higher than specified, at 20k ohms. Both figures were constant across the audioband.
The important statement being "both figures were constant across the audioband".

Therefore, the 10K ohm input impedance figure you mentioned in your post is not applicable to my observation of the REF3/XA-60.5 impedance match.
mapman's avatar
mapman
15,679 posts
 
Tvad,

I think I recall you indicating in prior discussions that you believe higher amp input impedance generally leads to directly observable improved bass performance, or something to that effect, which technically sounds viable to me.

In that case, 30K ohms is a lot closer to the low end for SS amps I have seen (about 10K ohms) than it is the max I have seen (about 200K ohm balanced).

It would be more of a factor for higher output impedance tube pre-amps than lower impedance SS pre-amps.
tvad
9,467 posts
 
Mapman, what I have posted here are specifically the impedance numbers for the REF3 and XA-60.5, including test measurements from John Atkinson for the XA-30.5, which correlates to the XA-60.5 (comparing the specs on the Pass Labs website).

Atkinson measured an output impedance spike from the REF3 at of 1437 ohms at 20Hz in balanced mode. That spec still provides at 20:1 ratio into 30K ohms.

These numbers are well within the generally accepted range for impedance matching.

Nevertheless, if you have specific numbers that would suggest a non-optimal match, then I'd be interested in seeing them and learning more.

Certainly, my experience with the REF3/XA-60.5 match was that the sonic results were not the best I had heard.
More to discover