jwrosenthal
Super Member
Grettings all,
So I took delivery of my TF-10 last week and it really is an awesome preamp- won’t bash anything else I own, but I will say it’s the best preamp I have.
I reached out to David before I bought it and asked about the “H” modification which designated one of the 3 phono inputs as a high gain MC stage. He said all I have to do is drop a pair of film resistors in there to get the right loading.
At first I expects a small transistor board but he did a 12ax7/fet driven pre-pre in this thing (he mounted it vertically against the phono stage- very clever). I see where the 47k resistors are (right at the top) and he installed two sets of gold rings right in front of them for adding the loading resistors.
I am assuming I can slip resistors of the correct value in there and either bend the legs or solder if I want it semi-permanent. I have read the threads and see the calculations for adding resistors in a high gain 47k phono stage to get the correct loading, but I suck at math and got very confused. So can I ask someone to either make it really easy for me to figure out which resistors I need or tell me which to get.
I understand that an SUT (which is what I currently use for my cartridges) is different loading than an active stage which only confuses it more for me (its greater than 10x if I understand correctly).
The three cartridges I would like to play with on this preamp are the Denon DL103 which wants a >40ohm load, The DL103R which wants >14ohm, and the Ort SPU Classic GME MkII which wants >10ohms.
Obviously I would like to learn how to fish, but if someone can tell me which fish to buy to get me going that would be awesome.
Thanks,
James
So I took delivery of my TF-10 last week and it really is an awesome preamp- won’t bash anything else I own, but I will say it’s the best preamp I have.
I reached out to David before I bought it and asked about the “H” modification which designated one of the 3 phono inputs as a high gain MC stage. He said all I have to do is drop a pair of film resistors in there to get the right loading.
At first I expects a small transistor board but he did a 12ax7/fet driven pre-pre in this thing (he mounted it vertically against the phono stage- very clever). I see where the 47k resistors are (right at the top) and he installed two sets of gold rings right in front of them for adding the loading resistors.
I am assuming I can slip resistors of the correct value in there and either bend the legs or solder if I want it semi-permanent. I have read the threads and see the calculations for adding resistors in a high gain 47k phono stage to get the correct loading, but I suck at math and got very confused. So can I ask someone to either make it really easy for me to figure out which resistors I need or tell me which to get.
I understand that an SUT (which is what I currently use for my cartridges) is different loading than an active stage which only confuses it more for me (its greater than 10x if I understand correctly).
The three cartridges I would like to play with on this preamp are the Denon DL103 which wants a >40ohm load, The DL103R which wants >14ohm, and the Ort SPU Classic GME MkII which wants >10ohms.
Obviously I would like to learn how to fish, but if someone can tell me which fish to buy to get me going that would be awesome.
Thanks,
James