What can you tell me about First Sound pre-amps?

Drubin, I agree. It's interesting to note that the steps in the FS Holcro
attenuator are not an issue when I run my VAC Phi 110/110 with
negative global feedback, but it does become an issue when I run the
amp with zero global feedback...especially at the lower volume steps (1-
3). I notice a big jump in volume between positions 2 and 3 on the
volume pot.

Kalan, regarding downsizing, I think if I had the dough, and the proper
motivation to take the plunge, I'd buy a VAC Phi Beta integrated amp. It
wouldn't be downsizing from a cost perspective, but it'd be downsizing
from a two to one box solution with the benefits of ideal synergy
betweeen preamp and amp, and the obvious elimination of a set of
interconnects and a power cord.

Rackon:

It's possible that the FS and the Valhalla aren't the best of friends, but in this system, it does show up regardless of the interconnects.
Trust me, Artg, I'd love nothing better than for the system to NOT sound a bit hard on brass crescendos. I just don't know what else I could change as every single components, tubes included, has been substituted into the system. It's a bit of a puzzle to me. I wondered if the OA 2 tubes could be going bad, as they're the only tubes I HAVEN'T changed in the preamp!
And, for those considering the First Sound, it is entirely possible that this may be an issue endemic only to MY particular preamp. Not this model, just, literally, the First Sound Presence that I own. And I've read the reviews and I've never noticed anyone mentioning this. Unfortunately, my First Sound hasn't read the reviews, and it seems not to know it shouldn't sound edgy on Forte-level brass!

Mphkns, Here is another hypothesis: is it possible that what you are hearing with FS on loud brass creschendo is what is sometimes called 'cuivre', or 'brassy', which can be heard live, when the metal body of the horn actually vibrates somewhat loosely under extreme FFF. If that were the case it may mean simply that FS is more revealing than other pres. But, if you do not like 'cuivre', you are not the only one. Cuivre sound is the bane of orchestras and conductors, unless it is specified explicitly in the score.

My understanding is that the OA2 tubes are either good or they are not, but they don't go bad over time. Also, as I recently discovered, the preamp works just fine even after they do go bad (or at least after one goes bad). The triode tube doesn't get properly biased is all that happens, so you may start to notice some sonic changes.

By the way, I bought 4 of them from New Sensor and it's a good thing because one of them failed pretty much right away. Apparently the failure rate is high, but if it happens, it's within a couple of days.

Guidocorona, thanks for the suggestion that this might be what I'm hearing.
I suppose it's possible. It's just that it seems unlikely that it would show up on nearly every cd in the collection, especially given that I've had some of these cds since 1991, and have never heard this particular sonic trait before, and I've had some very revealing equipment in the "good ol' days." If it only showed up on several of the CDs, I would just chalk it up to the CDs themselves, but it appears pretty frequently. The oddest trait is how it's ONLY brass that causes this effect. I suppose it's still possible that the First Sound is showing this, but over the course of 20 years, I wouldn't think that the First Sound is the first high resolution preamp to demonstrate this.
In any case, I'm more interested in doing the detective work to find out what's causing it than getting another preamp.