I dont know how to do that, but i am very very satisfied with the result!
By the way it suits (usfp) with the crimson.... And i have a pre above 4k€.
I have made a catastrophic attempt to alter value in the older sfsp (blue one) and i destroy everything. I order from mike 2 sk and a couple of blue one pcb's, but he has only one. I am waiting for the items and i am searching for one blue pcb.
By the way it suits (usfp) with the crimson.... And i have a pre above 4k€.
I have made a catastrophic attempt to alter value in the older sfsp (blue one) and i destroy everything. I order from mike 2 sk and a couple of blue one pcb's, but he has only one. I am waiting for the items and i am searching for one blue pcb.
You can do it with a test record that has anti-skating setup tracks and instructions. Or simply with music records trying to best center the stereo image you perceive when listening far enough and equidistant from the loudspeakers. Try much anti-skating trim both +/- to first discover which way it goes towards a better channels balance for the specific cartridge. Then fine tune.
Working on a folded RIAA. I'm having trouble setting the TP1-TP2 voltage to 3 to 4 volts (per the instructions?). Voltage low .7V. Instructions say to lower B+ (correct?) to raise this voltage. Anyway no matter what I set B+ (31V to 39V), I can only get .7V? Changed Q1, K369 (11mA and R2 3.9 ohm) and Q3, BC560c (also tried BC327) no change. Bias voltage at BC560c base is 7.9V
NJFET Folded Simplistic 2013. Yes point to point. Single K369 11mA. For my cartridge, I built the 56-57db gain version. For a 11ma fet, R2 3.9 ohm is recommended. You say raise this value? I also just noticed I have a 1.2K installed for R13 load resistor, notes say 2.2K...I'll change that. I have not yet measured cascode's bias yet, but will do. What should the voltage be at the FET drain/ BJT emitter?
From the FSP build guide:
C2Y treble trim. If you got a 0.5% or better LCR meter measure each C2 15nF 1% nominal cap and note its exact value. Measure to find a C2Y trim cap so C2+C2Y=15.2nF. Gives almost neutral RIAA curve. Use the most tonally balanced input load value for your cartridge in combination.
If you don't have such a meter, install random C2 1% and 200pF up to 5% C2Y.
By listening, if the treble is dull exchange for 100pF. If its bright exchange for 300pF.
You may use 50pF intermediate value piggyback on C2Y if you can hear differences. Its an opportunity to tune your phono preamp to the tonal balance of your TT and speakers. Verify VS listening to other audio sources.
C2Y treble trim. If you got a 0.5% or better LCR meter measure each C2 15nF 1% nominal cap and note its exact value. Measure to find a C2Y trim cap so C2+C2Y=15.2nF. Gives almost neutral RIAA curve. Use the most tonally balanced input load value for your cartridge in combination.
If you don't have such a meter, install random C2 1% and 200pF up to 5% C2Y.
By listening, if the treble is dull exchange for 100pF. If its bright exchange for 300pF.
You may use 50pF intermediate value piggyback on C2Y if you can hear differences. Its an opportunity to tune your phono preamp to the tonal balance of your TT and speakers. Verify VS listening to other audio sources.
No if you will feel that the treble amount is still balanced with the rest of spectrum. Most builders find the 220pF C2Y middle spot value adequate. So they have reported in this thread.
It's just an additional trim point to fine tune this phono to your needs. Beyond the many loading and sensitivity options.
Not common to meet fine treble curve user intervention possibility in other designs, thus not a familiar feature, but there's nothing to be much worried about it either.
If it sounds tonally correct with the same C2Y pF across your cartridges, fine. If not, you can tweak it a little between them.
It's just an additional trim point to fine tune this phono to your needs. Beyond the many loading and sensitivity options.
Not common to meet fine treble curve user intervention possibility in other designs, thus not a familiar feature, but there's nothing to be much worried about it either.
If it sounds tonally correct with the same C2Y pF across your cartridges, fine. If not, you can tweak it a little between them.