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High Output Preamp for First Watt SIT-3?

I'm new to the audiophile world and recently purchased a First Watt SIT-3 with Magnepan .7s.  I have a Mytek Brooklyn Bridge for streaming, though I prefer to play vinyl with my Mofi Ultradeck.  The Mytek serves as the phono stage (69dB gain for MM?), and I don't use a preamp;  the Brooklyn is connected directly to the First Watt. 

I understand that the SIT-3 is only 11.5 dB of gain, and that's extremely low compared to most amps.  I like most everything about the system except for the fact that I have the Mytek maxed out volume-wise many days.  Certain LPs are cut quieter, and I wish I had more power.  There are times streaming where the Maggies aren't getting to their sweet spot.  I realize the Maggies are a lower sensitivity speaker. 

What should I look for in a preamp to fully drive the SIT-3?  Eventually, I'd like to replace the phono stage instead of relying on the Brooklyn.  Is there a tube preamp featuring a phono stage with sufficient output to drive my amp in the $4k range?  Otherwise, I'm eyeing the Modwright PH 9.0 and a linestage preamp, realizing that this will probably be costlier.  I'm looking for a warm sound, not analytical but engaging. 

Any help is greatly appreciated.  I'm a working musician with a basic understanding of related electronics but little experience in this world. 

murphbass

Showing 5 responses by joeinid

joeinid's avatar
joeinid
658 posts
 
@charles1dad 

Regarding the optimal ohm rating for the SIT3, the following is from Nelson Pass.

“The most popular impedance for the load is 4 to 8 ohms, which is the region where it measures best, and there is not a lot of difference between those two numbers. At lower, we see increased distortion, and at higher impedancethe distortion numbers don’t go up, but there is an increase in higher orderharmonics. It’s not a big deal, but you can play with this by putting some resistance across the speaker. Typically people play with resistor values from 8 to 25 ohms, and since resistors are cheap I recommend that you get several values to try. The type of resistor is not critical, but should be ratedat 5 watts or more.”


I have Avantgarde duo XD at 18 ohms. I use a Zu Audio 10 ohm resistor across my terminals to give the amp a resistance rating of 6.42 ohms calculated. 
Works wonderfully.

joeinid's avatar
joeinid
658 posts
 
With the appropriate speakers, the SIT3 is sublime. I’m sorry but the Magnepan speakers are not the right pairing. Everything said by the others is right on. Maggies need a lot more power to sing. The SIT3 may be difficult to replace in the future so I vote for a new, highly efficient speaker to mate with it.

 I have Avantgarde Duo XD which are 107db efficient. With a resistor across the terminals to bring down the resistance that the amp sees (the SIT3 prefers to see 4-8 ohms), its been a revelation. A wonderfully engaging amp. Keep it and get new speakers.
joeinid's avatar
joeinid
658 posts
 
@almarg

I totally agree with your assessment. Thank you for posting.

In my case, even 8 wpc is a lot for me.

It’s true that I’m wasting or throwing away power for the sake of keeping the SIT3 in its happy zone. So far the SIT3 is my favorite solid state amp on my Avantgarde although I enjoy others, just not as much.
joeinid's avatar
joeinid
658 posts
 
@oddiofyl 

Spot on about not selling the SIT3. With the proper speakers, OMG!
joeinid's avatar
joeinid
658 posts
 
@charles1dad 

Hi Charles,

 I don’t claim to have the best ears but I’m sensitive to too much or aggressive treble. Avantgardes beg to be driven by wonderful SET in my opinion. 
I’ve been told that the Avantgarde amps are especially wonderful for classical music but still have a bit of solid state sound. 
I do enjoy a Valvet E2se as a close second. Some of the less recent McIntosh amps like the 452 or 302 sound decent if a little bit flat. 
The Benchmark AHB2 is wonderful too for low to medium volume but it could need more break in. It’s very neutral but also very natural and dead quiet. Spooky details pop out of nowhere. 
The SIT3 is a warm, yet open and laid back presentation. The SIT3 is more mid hall perspective with beautiful vocals and piano. Because of its low gain, it’s also dead quiet and works superbly with various preamps. Best combo is CJ GAT2 with the SIT3. 

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