I ran my ST-100 with Gold Lion tubes. Stock JJs don’t cut it as they sound plain and flat. I also had good experience with Brimar CV4003 from Upscale combined with the Gold Lions it was the right blend. The amp also sounded much better in Triode mode than it did in Ultralinear. It produced sweeter more vibrant and dimensional soundstage. Rogue customer service is also first rate.
The ST-100 is a great value in its own right but it isn’t Audio Research Ref75SE level. The degree of improvement will depend on the components chain and speakers. I don’t think it’s possible to quantify without taking all this into consideration.
Rogue Audio and Audio Research Comparisons
Recently I've purchased a Rogue ST-100 amp and enjoying quite a bit. My personal opinion is it punches way above its price point and in my opinion has a lot of the Audio Research sonic characteristics. Curious has anyone owned both Rogue and ARC and what are your thoughts? I'm not referring to the current Ref series but the older such as REF110, REF150 and REF75SE.