Repairing old SSHV2 reg, first rearranged CCS now is OK, caps C1 & C2 don't touch pcb, 1K trimmer is OK, SK117GR is OK, Q4 is OK. Can't adjust Vout: is fixed 320VDC, can be IRF840? or KS1381? I have more IRF840 but I only have one used KS1381 that I don't know if is good or bad, could I use KSE350 or other semi?
KSE350 & MJE350 will work. Don't know what it can be still keeping it steady. Is the board perfectly OK if you will inspect with a magnifier? Maybe some HV incident could had damaged a track or created conductivity between adjacent lines? C1, C2 still OK for value?
Yes measured boths caps and are OK, I will change first the KS1381 for KSE350 to see what's happen, if still not fiex I will change IRF840, thanks for support Salas.
You can check your ks13981 for hfe and see if it' s good or bad. Did you measure Vbe in circuit to see that they are working ok or not?
Quote:
Originally Posted by king4joy
Salas...if you remember, with your help, I have added a SSHV2 to my CCS (C4S) loaded VT-25A line amp. Adding the SSHV2, all hums are gone....however, a light zzzzzssssszzzz....takes over....(which I can live with, although my friends cannot....)....I think this could be because of old tubes.....Salas, what you think??
And with the SSHV2 added, I feel that the music has become a bit restricted...less lively....less fluid.....what I think is I should get rid of the C4S, and instead going back to use resistors to load my tube with your SSHV2.....with a good quality resistor after your board, it should act like a CCS anyway, with the added avdvantage of setting the loading current (voltage across the resistor) easily with your board......
Your board opens up opportunities for me to fine tune my amp with much less fuss and more joys.
Will report back further later....thankyou....
zzzz means you gotta sort out some small ground loop somewhere or some tube problem that surfaced better after the hum blanket has gone.
Try the resistor indeed.
Salas....I have tried using resistors //12K to load the tubes instead of C4S, with your SSHV2....the music comes back to live again....with no hummmm at all....just a little bit of insect noise at the left channel....I am able to trace and find where that insect lives....it was in the filament transformer for the left channel.....the noise should be gone when I next change that transformer....
But the music has a ever so slightly muddy background to it....I think it is because I am using only one board to load the two channels.
Is there anything that I can do to improve channel seperation when using only one board??
Thankyou so very much, Salas, for your board.
Cheers,
King
Originally Posted by king4joy
Salas...if you remember, with your help, I have added a SSHV2 to my CCS (C4S) loaded VT-25A line amp. Adding the SSHV2, all hums are gone....however, a light zzzzzssssszzzz....takes over....(which I can live with, although my friends cannot....)....I think this could be because of old tubes.....Salas, what you think??
And with the SSHV2 added, I feel that the music has become a bit restricted...less lively....less fluid.....what I think is I should get rid of the C4S, and instead going back to use resistors to load my tube with your SSHV2.....with a good quality resistor after your board, it should act like a CCS anyway, with the added avdvantage of setting the loading current (voltage across the resistor) easily with your board......
Your board opens up opportunities for me to fine tune my amp with much less fuss and more joys.
Will report back further later....thankyou....
zzzz means you gotta sort out some small ground loop somewhere or some tube problem that surfaced better after the hum blanket has gone.
Try the resistor indeed.
Salas....I have tried using resistors //12K to load the tubes instead of C4S, with your SSHV2....the music comes back to live again....with no hummmm at all....just a little bit of insect noise at the left channel....I am able to trace and find where that insect lives....it was in the filament transformer for the left channel.....the noise should be gone when I next change that transformer....
But the music has a ever so slightly muddy background to it....I think it is because I am using only one board to load the two channels.
Is there anything that I can do to improve channel seperation when using only one board??
Thankyou so very much, Salas, for your board.
Cheers,
King
King,
are you saying that the C4s did not sound good enough?
And are you saying that the Salas Shunt reg improved the amplifier when reverting to a resistor feed?
are you saying that the C4s did not sound good enough?
And are you saying that the Salas Shunt reg improved the amplifier when reverting to a resistor feed?
We would need full schematic and total build photos to possibly say something constructive about your query.
AndrewT....with my situation....the amp sounded better with C4S than resistors, BEFORE using SSHV2.....and when I added SSHV2 in the beginning, I was using SSHV2 and C4S...then I found the music is a bit constricted....so I talked to Salas....and together we both think that I should try using resistors again with SSHV2 (I hope you can understand my English....if not, please ask again.
With SSHV2 no hummmmmms.....and should be dead quiet if not for that transformer I have.
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Salas....I will prepare schematic and build photos... it may take a couple of days....thanks in advance.
With SSHV2 no hummmmmms.....and should be dead quiet if not for that transformer I have.
***
Salas....I will prepare schematic and build photos... it may take a couple of days....thanks in advance.
AndrewT....a bit more about the amp I am talking about....it is a VT-25A cap out put line amp...PSU is 83 tube rectified, choke input....first resistors loaded....that changed to C4S loaded....then added Rod filament boards....and now added SSHV2 and go back to use resistors loading...