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

To do this, Allnic uses a “floating power supply circuit”, a design that deals with the issue by not creating any DC potential in the first place, or such a small potential that it is harmless.”

@kevalinaudio We have two patents concerning a method of using a Circlotron circuit for this purpose as @lewm  suggested. It indeed is

a “floating power supply circuit”, a design that deals with the issue by not creating any DC potential in the first place, or such a small potential that it is harmless.”

During warmup, the Circlotron circuit can produce small DC offsets less than 1 Volt. Once warmed up the DC Offset is typically less than a milliVolt. Its plug and play since no adjustment is required. 

However its pretty obvious such a circuit is not used here. 

On reading the documents at the links you provided, it appears an SEPP circuit is used. The SEPP is a push-pull circuit of the 'totem pole' variety not unlike what you see in Futterman OTLs. They are often used in headphone power amps. 

 

 

 

 

 

Was wondering how or even if the floating PS as used by Atmasphere in the circlotron could be implemented in a SE output.

Regardless of the design wizardry Allnic employed in the OTL/OCL phonostage, I find it to be noticeably quieter than the DHT — and far easier to live with in terms of maintenance, operation, and day-to-day running. Cartridge loading flexibility is effortless, and the noise floor is effectively nonexistent.

With the older DHT 8000, I often battled microphonics and an occasional quirk where the soundstage would lean subtly to one side. Achieving a rock-solid, dead-centre image could be frustrating, requiring constant fussing with tubes and fine adjustments. The H10,000 OTL series has been the complete opposite: it simply warms up and is ready to make music, no drama, no fiddling.

What really stands out is the leap in performance: transparency, microdetail retrieval, tonal accuracy, soundstage precision, and dynamic range all surpass the DHT 8000 — which I had always regarded as an exceptionally musical phono stage in its own right. The H10,000 series feels several levels higher on the ladder.

Bass is no longer a touch overripe; instead, it extends deeper with greater control. Vocals have gained refinement without losing body and presence, while the highs are sweeter, more polished, and free of any edge — delivering a presentation that’s both revealing and inviting.


 

For much less money, though I don’t know the current retail price, the Atmasphere MP1 will give you similar results. Two differences: the MP1 does not use a SUT to achieve high phono gain, and the Allnic affords 4 pairs of phono inputs vs one pair on the MP1. Important also, the MP1 is fully balanced with an OCL/OTL linestage built in

@lewm      As Phantom audio is an Atma-sphere dealer, I'm sure he can test your hypothesis for himself. I, for one, would love to hear the unbiased results of such a comparison.