Nati phono pre amp
This project came about as I was modyfing a jadis JA 40 pre amp , I'll post those pictures in the modification page.
The Jadis had a very simple phono stage , very std engineering , and I was absolutely not impressed with the sound.
So after carefull thinking I had this idea allready for a long time that the E180F or 6688 Penthode was also great as a triode high Gm so low noise and anough gain. Also after building many phono stages I have pretty high standards on how good it should sound.
And the most critical part to get right is the Riaa EQ part , as it also has time alignement issues and transients do suffer and then there is tonal balance which can also be a problem . And I'm not even mentioning ground loops and other hum sources which sometimes cost me weeks to solve.
Star grounding is close to the best solution , but with such small signals u need to be very clean with your input lay out and using step up transformers are really beneficial ground loop wise , as they break these apart.
The current top level Lundahl Moving Coil step up transformers are really amazing , the LL1943 is my fabourite , but the LL1933 is also delicious.
This circuit was immediatelmy loved by its new owner , he also compared it with my 6922 ref phono pre amp , and both are excellent .Hard to choose :)
This one has no semiconductors in it , no current sources , no cathode bypass either . In that respect it is quite unique.
A few pictures + complete schematic .
If u have questions just email me
, ALL PARTS IN STOCK
Here u can see what point to point cabling means
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