Hi group
I just wanted to give some feedback to Pier about his APP992 in my Sontec 250 clone from donclassics.com.
My background is that I do maintenance work in quite some studios, a bunch of mastering studios included, in my area. The latter ones all equipped with one or two Sontec EQs. From my first experience with a real Sontec on I was hooked on these. I consider them to be amongst the very finest EQs ever, if not the best at all (whatever best means...). So when Igors 8 channel kit became available I built them using 2604 opamps throughout. The first comparison the the real 250 was disappointing. While Igor´s kit is a fine EQ it has a totally different tonality and the HF band, which he unfortunately modified, couldn´t hold a candle compared to the original. In itself it´s a nice and versatile EQ, better than many if not most others. But still far away from the real deal.
Later on when the Donclassic came out I made one of these for myself. First I´ve been using OPA132 at the input/summing position for money and convenience reasons but it quickly turned out that it didn´t have the headroom a real Sontec has, as well as it didn´t sound like a real Sontec. The HF band sounds a lot closer to the original than Igor´s version, though. That gave me hope at least and I changed the OPA chips to APP992 DOAs running on +-24V. That solved the headroom problem and the tonality came a lot closer to the original 250 boxtone, closer than any other version before. It still isn´t exactly the same, but I haven´t heard anything better yet.
So there you have it, my opinion at least. Give the APP992 DOA a try in your Sontec builds.
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