Valve Itch phono

[merlin el mago]

Yes, metal base hole plates.

 

[Salas]

As the MELZ seen in post #31. One of the best 6SN7 compatible realizations.

 

[merlin el mago]

What dampers are you using?

 

[Salas]

Oh, five years old photos as assembled by a friend. He possibly told me back then but I can't remember.

 

[merlin el mago]

Can the different heaters voltage dull the sound?

 

[Salas]

If they mean different bias current and gain difference between channels yes. But it can be irrelevant also. Measure the channel balance.

 

[stajo]

heaters not, one measured 6.5v and the other 6.2

Are you regulating? What type?

 

[merlin el mago]

Are you regulating? What type?

The same PSU Salas suggested, only difference4 I'm using SSHV2.

 

[merlin el mago]

If they mean different bias current and gain difference between channels yes. But it can be irrelevant also. Measure the channel balance.

There is a lot of difference in SQ, I didn't noticed by listening any difference of gain between channels.

 

[stajo]

The same PSU Salas suggested, only difference4 I'm using SSHV2.

Then you can set voltage with R2/R3

 

[nicoch58]

little mod
PS C3 is really big... maybe split the r1 un two 100r and put one before ?

 

[merlin el mago]

Then you can set voltage with R2/R3

Yes I use trimmers.

 

[Joshua_G]

little mod
PS C3 is really big... maybe split the r1 un two 100r and put one before ?

There is a mistake in your schematic, pins 5 & 8 of V3 & V4 are connected both to ground and to HT lift (R7, R8). Thus the HT lift is shorted to ground.

 

[stajo]

little mod
PS C3 is really big... maybe split the r1 un two 100r and put one before ?

Hazardous without a bleeder to C3. If you pull the umbilical cord and start working inside PSU you will have 220 uF of HV stored to kill you.

 

[stajo]

Yes I use trimmers.

So why on earth so you bother us with that you have forfotten to set apropriate voltage? I have a problem. I am to lazy to set my voltage right according to the build prescriptions. What shall I do about it? Do you have any suggestions?

No, we dont!

 

[nicoch58]

the schematic is merlin, no one note that is better have a caps on pre ,small caps first or resitor for more conduction angle...
sure bleeder is a good thing

 

[merlin el mago]

So why on earth so you bother us with that you have forfotten to set apropriate voltage? I have a problem. I am to lazy to set my voltage right according to the build prescriptions. What shall I do about it? Do you have any suggestions?

No, we dont!

It's only to notice other people that changing tubes needs adjust again the voltages.

the schematic is merlin, no one note that is better have a caps on pre ,small caps first or resitor for more conduction angle...
sure bleeder is a good thing

Not my schematic, Salas schematic.

 

[Salas]

If it is from #391 I don't see a C2 ground there and the bleeder is pictured in the first box so you must have kept some even earlier one before debugged for drawing mistakes. Go there to get it and replace with the good one.

 

[merlin el mago]

What's the correct, C2 grounded or without ground?

 

[Salas]

Without. #391 as linked from page one in year 2011 has it without.