Or this one. Gulp 5 times the price of the dehavilland
http://www.whatsbestforum.com/showthread.php?9844-New-tape-pre-amp-king!!
That's the sort of design I'd be looking at Graham. Fully balanced, pretty simple, open loop. The AT7 is obviously at the IP and ECC99 OP driver.
That's pretty much how I build my mic pre amps which is a pretty similar thing but without the required tape specific EQ (or bias trap where applic).
Also a fair bit of cost looks to be in the enclosure.
This fully balanced simple design approach can yield really great results but there is one possible caveat, it is usually on the -clean- side.
If you are a single ended triode fan, it may not be your cup of tea. The ECC99 OP drivers will help this, 12BH7 is another good
candidate.
B.B of Puget Studios is pretty clear about his preference here and wants his electronics to be as transparent as possible. Being
a mastering lab, probably not a bad thing.
I've got a lot of time for his opinions. He's been there and knows his stuff.
PS edit: I just read that the Doshi pre amp uses an IC at the front end. Looks like it will be banned from this forum
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