2. amps-preamps
  3. 178939-172731

Time to upgrade the pre-amp.

I am currently running and ARC SP-16l into an Art Audio PX-25 power amp which feeds a pair of Blumenhofer Genuin FS2s (94db). I listen to mostly vinyl atm, and I have an external phono stage (Icon PS1 mkii). I think at this point, the pre-amp is the weak link.

Although I am not wedded to buying another ARC preamp, I am leaning in that direction due to company reputation, longevity, accessibility of local dealers (Northern NJ) and resale value, though I am definitely looking for that full mid-range and "musicality" typically associated with all tube architectures.

I have an opportunity to buy an SP-11 for $4,000, and from what I am seeing, if I wait, I may be able to get an SP-10 in that same range. However, for ~$2,000 more, I could likely get a Ref 5SE, which would be the top of the budget, but has in addition to any sonic advantages, a remote and tube hour tracker.

My questions are: (1) is it worth holding out for the newer Ref series (~10 yrs old at this point) vs the SP10/11 which are 40 years old at this point; and (2) if it comes between the SP10 and SP11, What I have read here is that the SP10 is all tube, but while that unit’s phono stage is particularly strong, the rest of the line inputs are not up to the SP-11. If it turns out that they are close, I would likely choose the SP10 between those two.

Very interested in how folks think about this.

saulh
saulh OP
56 posts
 

This is the first time I am thinking about the gain from the preamp. So e.g. I see the Ref 6SE as having 6DB gain from its single-ended outputs vs 75db for the SP-11. @verdantaudio @ozzy62 is that more in line with what I should be looking for?

Specs for the PX25 are:

Power Output: 6 wpc
THD: less than 1%
S/N Ratio: >85 dB
Output Impedance taps: 4 and 8 Ohm
Input Sensitivity : 400mV
Input Impedance: 180 kOhm
Frequency Response: 10 Hz to 20 kHz +/- 0.5 dB

What am I trying to match in a pre-amp?

verdantaudio's avatar
verdantaudio
1,528 posts
 

Lower the better. 6dB is good.  You aren’t going to find many preamps in the market that are going to be active and have lower gain.  

ozzy62's avatar
ozzy62
3,375 posts
 

My take is that you need zero gain, and will be the better for it. YMMV...

cleeds
6,170 posts
 

saulh

I see the Ref 6SE as having 6DB gain from its single-ended outputs vs 75db for the SP-11.

Apples/oranges. The SP-11 gain figure includes its phono stage.

verdantaudio's avatar
verdantaudio
1,528 posts
 

There is no way SP-11 main preamp stage has 75dB of gain.  Not sure what its main preamp stage has.  I don't have a PX25 here but have a diavolo which is a very similar amp.  Just 300B instead of PX25.  

I have tried it with a myriad of preamps and it sounds best with no gain but is fine so long as gain levels are in single digits.  You are okay with 6dB.  0dB is better but the matching preamp is uncommon used and new is $8500.  I think above where you are looking in the used market. 

I have one arriving later this week or early next week and am in central jersey if you want to arrange a demo.  

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