Hello Andrew
I am sure we are talking about different subjects.
Off course you know a lot more about balanced connections but I am trying to stress that if you use four amplifiers to make a stereo balanced amp, each pair of amps should produce at least the same freq response and phase shift.
As you know the simplistic dos dot have differential amps so the results might be very difficult to come with.
Anyway, I believe Merlin did it... maybe he could comment on the results compared to his latest SE build 🙂
I am sure we are talking about different subjects.
Off course you know a lot more about balanced connections but I am trying to stress that if you use four amplifiers to make a stereo balanced amp, each pair of amps should produce at least the same freq response and phase shift.
As you know the simplistic dos dot have differential amps so the results might be very difficult to come with.
Anyway, I believe Merlin did it... maybe he could comment on the results compared to his latest SE build 🙂
Well, you could improve your CMRR by connecting the RIAA network in between the two channels instead of just having one. Having said that the common mode gain will be very high still.
R-Core transformers
2x30 VA (30VA for each R-Core Transformer) is appropriate for your phono stage, please?
2x30 VA (30VA for each R-Core Transformer) is appropriate for your phono stage, please?
Selectronic 2X15 nominal are around 2X17 on Eurpean mains, so they are good also. At least they used to be over achieving ACV last time I bought some.
Gone went the 10000uF Mundorfs (with styroflex bypass) and in came the 4 pole Jensens..... Bliss....
I must stress the importance of the smoothing caps that seem to be as radical as the Vin Vout minimal difference specd for the shunts.
I do not know if it is due to the construction of these caps and if this effect is also possible with other manufacturers 4 poles but stage width and depth increases, high freq detail is much enhanced ..... Piano seems credible... there is a sense of space not easily felt with other solutions.
PS (Not related with the previous findings) : I am not so sure about zobels on the TX primaries.....
I must stress the importance of the smoothing caps that seem to be as radical as the Vin Vout minimal difference specd for the shunts.
I do not know if it is due to the construction of these caps and if this effect is also possible with other manufacturers 4 poles but stage width and depth increases, high freq detail is much enhanced ..... Piano seems credible... there is a sense of space not easily felt with other solutions.
PS (Not related with the previous findings) : I am not so sure about zobels on the TX primaries.....
OK
Hi,
Several weeks ago Salas answered, about transformers, 40-50 VA, for HMC and MM phono. Higher power avoid transformer non-linearity, distortion, however. Just a friendly comment.
Hi,
Several weeks ago Salas answered, about transformers, 40-50 VA, for HMC and MM phono. Higher power avoid transformer non-linearity, distortion, however. Just a friendly comment.
My experience has been that replacing a 40VA power transformer (2 x 25v secondaries) with a 160VA transformer (so vastly over-specced), delivered a better bass response from the phono stage.
Andy
I am sure about zobels on the TX primaries....., it's true, very useful. It worth every penny. Quasimodo it's very interesting, indeed. Thank you for Quasimodo. Linear Audio | your tech audio resource, and the classical paper: www.hagtech.com/pdf/snubber.pdf
Somehow I get the idea that damping ressonances in the secondaries reduces the ability for the psu to radiate hum into other circuits.
As I am using "soft" diodes, ringing might not be so evident and as I am using a separate PSU that is physically far from the amp, it might be really difficult for me to detect improvements.
I agree, but more important for SQ is the relative Vin Vout on the shunts.
I noticed great improvements going from Vin-Vout = 6 to Vin-Vout = 15