surprising comparison of tube preamps

I am wondering if people have an explanation for this but, more importantly, have been looking into getting a very simple tube pre to use for the phono part of the system. Mapletree audio sells a simple preamp that I believe is a SET OTL (are all preamps OTL?).

@arhgef 

’OTL’ means ’Output TransformerLess’ and there are preamps that use output transformers. They are often used for driving a balanced line, where the shield of the cable isn’t supposed to carry any signal current at all.

This property is useful to prevent the cable from imposing an artifact of its own. If you’ve ever heard differences between cables you know what I’m talking about.

There is a standard involved (and I’m talking about this because your amplifier has balanced inputs which if favors) for balanced operation, known as AES48. None of the ARC products support this standard. In fact there are only a few manufacturers of preamps in high end audio that do.

This might be worth looking into if you want additional transparency with a sound that is also engaging.

@atmasphere I'm reading with keen interest and hoping to learn.  So is your point leading to any reason to believe that integrated units have an  advantage?  Any, or would they need to be fully balanced from input to output?  I'll just sit back and learn now.   

@arhgef - I am not suprised at all. I have an OTL headphone amp that I also use as preamp in my office system. Between the DAC and the integrated amp to the speakers. Although one more gain stage is not ideal, the results are clear: The more of the total gain made by the OTL, the better the sound. It might even improve the sound in my main rig, but is not practical to use there (maybe, I should give it a try). I also agree that AR can be a bit lean and analytical, I have other tube gear with more bloom and warmth, which I like (to an extent). I think the great thing about OTL is relative simplicity. So I am sceptical about 'simulations' (but have not heard your example).

Great advice in this thread on several fronts.  Take some time to settle into the new sound.  Sometimes different sounds better at first but given time, you might start to notice you aren’t as in love with the new sound as you thought.  Synergy in your system is key, if your Mac is designed to operate best with balanced inputs, that will play a role in how well a pre integrated with your amp.  Simplicity, synergy and thoughtful design often win over price, great advice that you don’t need to brake the bank to get a sound you love from your system if you know what you like and are thoughtful about the components you buy. 
 

good luck!

This is exactly the question I've been researching. I put a $400 Schiit Valhalla 2 tube headphone amp in place of my SS preamp. It sounded good from the start but really opened up when I configured it differently. I run the Valhalla with no attenuation, bought a Schiit Kara, and use it in passive mode as a volume control. 

Now I'm looking at upgrading that config with an LTA Velo headphone amp/preamp. I'm also looking at some others. But I agree that the simplicity of the design is key.