Salas changed the EI core 240V tx for two R-Core 230V 120VA but still the reg can gives max. aprox. 200mA, must be something wrong cinnected or burned at the SSHV2?
R-Core without SSHV2 gives 314VDC, when connected to SSHV2 I measure at the SSHV2 input 298VDC, In the PSU box I have R1 110 ohms instead 220 ohms and a bleeder resistor of 220K, have I to change for other values?
R-Core without SSHV2 gives 314VDC, when connected to SSHV2 I measure at the SSHV2 input 298VDC, In the PSU box I have R1 110 ohms instead 220 ohms and a bleeder resistor of 220K, have I to change for other values?
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Sorry this DMM is wrong, I measured with good DMM with 1uF 450V, max current 22mA, R-Core tx 230VAC 120VA
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Hi Salas
Yes I found a solution. I have a pair of Partridge 977 SUT's in an external box. Now the grids of the input stage are at zero volts with the SUT's connected and the balance is better.
I guess the Sowter SUT's did not like the small DC on the secondary windings.
I just have to experiment now to optimise the loading on the Ortofon MC25FL.
I still have 47K input/loading resistors which is giving me a reflected load of about 1500 ohms on the cartridge, which is a little high for the Ortofon, but it still sounds very good, very quiet background too, the best phono stage I have used so far.
If you lower the voltage current goes up? Try to put a bigger capacitor before the regulator to see what is happening. Also check voltage drop across the 110R to check current. Bypass the 110R.
This is what I would do to find the cause of your problem.
Voltage across 110R is 3.5V.
The thing I'm not clear is the voltage sag when I connect the PSU to the SSHV2: now I measured at the input of the SSHV2 301.5VDC, output PSU without SSHV2 conected 316,3V so I will take off the 110R to see what happens.
Hi Salas
Yes I found a solution. I have a pair of Partridge 977 SUT's in an external box. Now the grids of the input stage are at zero volts with the SUT's connected and the balance is better.
I guess the Sowter SUT's did not like the small DC on the secondary windings.
I just have to experiment now to optimise the loading on the Ortofon MC25FL.
I still have 47K input/loading resistors which is giving me a reflected load of about 1500 ohms on the cartridge, which is a little high for the Ortofon, but it still sounds very good, very quiet background too, the best phono stage I have used so far.
Could it have been some form of oscillation with the previous SUTs even? Does the new OK situation reflect to an uplift in perceived sound quality?
P.S. Try 18K-22K, it also gave me good square waves with the 977.
There must be some drop when the secondaries face constant current draw for the caps I would guess.
I use rule of thumb secondary x 1.33 for total Tx & rectification losses under load, not the theoretical x 1.414. That gives 306VDC for 230VAC. Most of the times falls between 1.30 to 1.35 in the end. Set the reg at 290 to see if it gives it new breath and to be more compatible with mains play.
Do the setting to lower first, to see what is the main holding factor.