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Allnic OTL/OCL Phono vs Allnic DHT

I’ve owned both the Allnic DHT phono stage and now the newer OTL/OCL phono, and to my ears, the OTL is simply on another level.

The DHT was impressive—open, natural, and full of that classic tube warmth. But the OTL not only brings greater transparency, speed, and clarity—it somehow retains the same warmth and richness of the DHT, but does it better. It feels more refined, more coherent, and more emotionally engaging without sacrificing any of that organic beauty.

I’m curious—has anyone else here made the comparison? Did you find the OTL to be a clear step forward, or did you prefer the DHT’s character?

Would love to hear your impressions.

phantom_av

Showing 1 response by atmasphere

atmasphere's avatar
atmasphere
12,180 posts
 

never heard the sound of OTL phono amps. 

@joeycastillo nearly all phono sections are OTL; OTL stands for 'Output TransformerLess'.

Since we have been making preamps with direct-coupled outputs (so OCL and OTL) for decades now, we had considered doing a phono stage as a stand-alone but kept running into the issue of doing the direct coupled output.

That requires an additional tube and a servo circuit. We patented a method of doing this balanced; when its done single-ended you usually have to have some kind of timer or protection circuit to be active until the output has warmed up and stabilized properly. David Berning made a very interesting preamp using this technique about 40 year ago called the TF-10. 

The tricky bit is making sure the servo does not affect the sound of the unit, for example if the opamp for the servo gets changed out for another. The design should be immune to that sort of thing.  

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