Final build will be inside the BA3 preamp. There will be a dirty box for transformers and raw supply for both the phono stage and preamp and control circuit. The clean box will have the phono boards, BIB regulators and BA3 board, as well as a relay based attenuator and source selector.
The speakers are rega RS3, nice sound!
The speakers are rega RS3, nice sound!
A rega P5/RB700 with the optional power supply and a goldring gx1012 MM. Amplifier until now was a rega brio, a small integrated amp. It will be replaced by the folded phono, and the BA3/ Cripled F4 amplification sistem. The control circuit will be the Relaixed passive.
No negative global feedback on the amplification chain, I had good result with no feedback with headphones.
No negative global feedback on the amplification chain, I had good result with no feedback with headphones.
Right now the preamp duties are with a headphone amp which doesn't have the horsepower to drive the cripled F4. It is also lacking in resolution probably as it uses automotive tubes and was meant to be a simple no frills project.
Do I need to have music playing or can I just leave the FSP burning all night long?
When I finish the preamp in a couple of weeks I'll see if I need to tune C2Y.
Do I need to have music playing or can I just leave the FSP burning all night long?
When I finish the preamp in a couple of weeks I'll see if I need to tune C2Y.
I've still got balance issues bugging me. Several posts ago I mentioned that one channel is muffled/rolled-off compared to the other. I have checked reference voltages through all stages of both channels - no significant variance, have also swapped channels (imbalance remains with bad board) and double checked wiring, input & output resistance, everything really. The TT & Cart are perfect, no imbalance, and the good channel sounds very good. When I play, I get the full range from LH channel and muffled/rolled-off sound from the RH channel, it's not blatant, as in the whole lot sounds great to my wife, but clearly there is a significant variance.
I've played around with CY2 - LH channel has 2X150pf polyester, I've tried same and also one single 150pf.
I suspect this to be an RIAA imbalance, I will replace the other small caps in the circuit to see if I can fish out what the issue is. I shouldn't be any of the semi's should it? certainly doesn't appear to be any issues at all with the power supply side.
AJ
I've played around with CY2 - LH channel has 2X150pf polyester, I've tried same and also one single 150pf.
I suspect this to be an RIAA imbalance, I will replace the other small caps in the circuit to see if I can fish out what the issue is. I shouldn't be any of the semi's should it? certainly doesn't appear to be any issues at all with the power supply side.
AJ
Only with curves measurement you can absolutely quantify their shapes and the effect of the tweaks. A bad part could also be the case. Like an interstage capacitor. Or a bad solder joint. Yesterday Santos had lost signal in a channel completely due to an oxidized wire for instance. Generally, bad semis bias wrong and/or make noises.
Finally againYou know what - major success. I had a small solder bridge I hadn't noticed in the RIAA circuit despite several checks. Perfect sound perfect balance my life is now completeit's a very impressive phono stage
