Valves inc Russian for Phono2 and 3

[Richard]

The "ask or don't do" is more to cover myself Dave Not knowing what level folks are at on these jobs I'd hate to be responsible for a shorted heater supply etc Full pdf of the Russian valve is attached

[Dave999]

well Mathew kindly supplied, 1 phono3 circuit board and its now in my possession.

its a lot more complex than my series ii phono 2.

i'm sure i will have a couple of questions regarding variable capacitors and the numerous connections that could be heater or HT
i'll do some track tracing while i wait for the postman to bring a range of components.
some of those resistors are not commonly held stock from the big suppliers..."back order 6 weeks" was ignored and ebay came up with the goods.

content running russian valves and adapters with the lid off phono 2 at the mo. i'll wait till i have the full compliment of parts before a soldering session


dave

[bob orbell]

Dave, read the notes posted by Richard in the FAQ, if you are going to use ECC83 tubes then R19-20 needs to be 165K not 180k, the 180K changes the 75 uS time constant an it will sound too bright, you will need a scope, signal gen and revers RIAA network to adjust the variable trimmers to achieve a nice squire wave form, but I doubt you will hear any difference. Bob

[pre65]

Originally Posted by bob orbell

you will need a scope, signal gen and revers RIAA network to adjust the variable trimmers to achieve a nice squire wave form, but I doubt you will hear any difference. Bob

I seem to remember the advice was to set the variable trimmers mid way.

[Greg.]

Originally Posted by pre65

I seem to remember the advice was to set the variable trimmers mid way.

That is correct. It is stated in the build instructions.

Dave, do you have a copy of the instructions? If not, PM me your email address and I’ll forward a copy to you.

[Dave999]

crikey a year has passed

i spent a couple of months (lockdown and no Maplins) acquiring the range of easy to get parts for this project,then went through a protracted process trying to get some of the less common parts, with Covid degraded deliveries playing their part. 2 attempts in some cases, ripped empty envelopes arriving with no trimmers in etc

then i moved house .......which ridiculous as it sounds, has taken 6 months+

showers fixed
fridges and washing machines plumbed in
antennas installed
taps no longer drip
BT master socket moved to a sensible place where they wanted £150 to fit it...
walls and sheds reduced to rubble and taken to the tip....phew...

and of course the carefully laid out parts ended up bundled into a box and packed away

finally got the last of my "hobby" focused stuff out of storage this weekend and found my PCB and components, typical last box...

hopefully back on track...

dave