I'm busy building Allen's RTP3D. What is it about the line stage that you would change? I'm concerned about this lack of musicality that Allen's gear supposedly displays, that it is too neutral, that it is not sufficiently involving. Other criticisms I've seen are that the RIAA equalisation is out of whack and that the preamp has way too much gain.
Again, in which way would you modify the line stage? Keep in mind that Allen has modified it himself recently and that it differs somewhat from the public domain schematic published on the Vacuum State website.
Again, in which way would you modify the line stage? Keep in mind that Allen has modified it himself recently and that it differs somewhat from the public domain schematic published on the Vacuum State website.
Reinhard, I guess you want to copy a VK-P10
These BAT guys refer to 1mV input for 78dB S/N ratio.
A genuine cart will put out ~ 0,25mV and give 66dB S/N respectively.
A cascoded 6922 stage may do 59dB gain (more realistic is 50dB), but after RIAA there is no more left than 40dB total gain.
You need to go 2-stage for sure.
These BAT guys refer to 1mV input for 78dB S/N ratio.
A genuine cart will put out ~ 0,25mV and give 66dB S/N respectively.
A cascoded 6922 stage may do 59dB gain (more realistic is 50dB), but after RIAA there is no more left than 40dB total gain.
You need to go 2-stage for sure.
Brett said:
I'll keep it in mind. Right now the rational approach is to assume that Allen knows what he's doing and build the preamp exactly to spec. Then I'm at liberty to throw a brick at it if that's what I want to do.
Here's a question: how come whenever Allen's stuff gets mentioned everything gets strangely quiet? Seriously, it happens every time. There's a thread very similar to this one about balanced preamps dating from 2001 and the same pattern is discernible on that thread. Someone mentions Vacuum State and suddenly you can hear crickets chirping.
If you don't believe me, take a look at your own response. A few posts back you were rather voluble, even engaging in a bit of lighthearted badinage. Now you're a man of a few terse words.
So c'mon, Brett, you can tell me. Does Allen's stuff suck or what?
I'm pretty blunt in real life too. There are no long wooden handled, metal headed manual earth moving implements in my shed.Martin Hayes said:
I have enormous respect for Allen and his amps. I've built the FVP, RTP and both the published PP amps and modified all of them. I like them, but Allen and I have different approaches to some things, and prefer my own, and that's why I do it my own way. Until you've tried, then you won't know, will you?
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