[SteveFord]

I got on a wild tear this morning when some new tubes showed up so I ended up comparing three preamps:
deHavilland UltraVerve 3
AVA AVAStar and
Sonic Frontiers SFL-2







The deHavilland is all Sylvanias except for the rectifier which is an RCA
The AVA has two Sylvanias in there and
The Sonic Frontiers is Russian Rocket Ships

I did this in the main system (20.7s, VTL 300s, etc.) and here's what it sounded like:

deHavilland sounds mushy until it warms up and then it has a great soundstage, very good detail retrieval, average dynamics, the tonal balance leans towards the warm side, it's also the least fatiguing to listen to

AVA has the highest gain and is the most forward sounding with really great detail retrieval, bass and highs - really good top end with very strong dynamics, deep soundstage but not as tall as the other units.  This isn't a problem with the 20.7s because they're such tall speakers but this was noticeable with the 1.7s.

Sonic Frontiers is a little bass shy compared to the other two units, strong mids and highs, very good soundstage, detail retrieval is not as good as the AVA or deHavilland, very strong dynamics, fairly forward sounding

I think what I'll do it use the AVA with the MMG/CC5 combo to perk it up a bit, use the SF with the 1.7s and the deHavilland with the 20.7s.
PartsConnexion has some upgraded caps available for the SFL-2 so that's a project for later on this Summer which I'm sure will yield dividends. 
At any rate, here's my 2 cents worth on how they perform in my system.  How these would work in somebody else's I have no idea.
There's not a loser in the lot and it was fun to hear how the different manufacturers voice their products. 
If I owned a stereo store I'd probably spend my working hours mixing and matching components to see what I'd end up with!

[medium jim]

I will bring the beer and chips....

Jim

[ArthurDent]

Nice write-up Steve. Thanks for taking the time to post it, and with pics to boot. 
JD

[SteveFord]

It was fun to do as I was curious as to how they would sound compared to one another.
I think a lot of it is amp dependent, too, so this is just how they sound with VTLs.
I was going to use the AVA in place of a modified Carver C1 unit but after looking at all of the connections that I hooked up to the C1  I think I'll save the AVA for a future project or wait until I get a little more ambitious... 

[JakeJ]

Cool comparo, Steve, thanks for doing it.

[MaxCast]

Thanks Steve. That was pretty cool and wish I could have been there. Not many of us have three nice preamps to cycle through.

[medium jim]

Steve:

I tend to agree that tube amps have their own signature. You favor VTL's and would imagine that they have a similar sound between the models.  I found that to be the case with older Marantz's, i.e., the model 8 sounds like the model 9 but with less wattage.  The Audio Research VS-115 sounds very much like my VS-110, even with different tubes. 

This makes the preamp a valuable tone weapon and the right one can really make a system come together.

Jim

[JakeJ]

Tone weapon, I like that.   Sounds like the name of a band.

[SteveFord]

Preamps are the most interesting part of the system to me - there are so many different approaches to them and they make such dramatic changes.  Tone weapons, indeed.
I mentioned the amps as one fellow has the same basic system as I do (more or less) aside from the amps.
We've been going back and forth with swapping tubes in the AVA and he's finding RCAs to be recessed but detailed and here it's in your face with too much bass so I need to contact Frank and see about dialing the gain back a fair amount. 
I'm sure that's what's making it a bit overbearing right now.  You can hear the greatness in it so I'll get there!

Medium jim's correct with the VTL house sound; I can't tell any difference between the MB250s and the 300 deLuxes as they sound identical to me which is a good thing. 

Before I croak I'd like to own preamps from Joule, Conrad-johnson, SAS and Manley but that's for another day.
The deHavilland Mercury looks like a winner, too!

P.S.
I heard from Frank this morning (thanks!) and will be doing a little soldering sometime next week and begin another round of tube rolling: RCA clear top, RCA black plate, GE and Sylvania to see which floats my boat.   

[Maritan]

I'm getting closer to my own "house" sound... Once I nail it down, I will have to experiment with the highly regarded TAD-150 Signature and pit it against the Ultaverve 3. Will be an interesting comparo.

[SteveFord]

Please post your impressions when you do so.
FWIW, I'm breaking in a Sylvania VT-231 which I got from a member here and it sounds really good.

[medium jim]

Please post your impressions when you do so.
FWIW, I'm breaking in a Sylvania VT-231 which I got from a member here and it sounds really good.

A great tube indeed!

Jim