[rico]

Hi! What are the parameters for the relays in dual rectifier? Nothing is shown on the schematic

[TubeLeo]

Hi

I am not sure about the parameters of these "relays".

I use some kind of photocoupler which i made by myself. LDR - LED kombination. Did you see Guidos amp? There are some pictures of them.
But I think it should also work with other photocoupler relays.
Hmm  trial and error

[rico]

Oh, i see.. So i can use one of those VTL5C9 optoisolators from vactec?

[rico]

Someone? SOS

[Joachim]

Hi Rico,

They should work.  Also I think, Mesa use this parts in his amps. But it is a VTL5C1 not a VTL5C9. Unfortunately this parts are really expensive

Joachim

[rico]

Should i use it instead of relays or along with relays? Cause on 3-channel dual recto schematic only 2 optoisolators, but more than 10 relays. Someone knows what does it mean?

And i also need to ask about LM3914 chip. What is it for? What it does?? It's required or not?

Thanks!

[rico]

Someone, help! Need parameters for the relays

[TubeLeo]

Hi

I do not have the schematic for the 3-channel-dual-recto but I think that the LM Chip is for the stabilization of the DC-voltage -6,3V - you need to heat the preamp tubes. You do not really need to head all 12AX7 with DC. But most head V1 with DC to reduce interferences. So the chip is not really necessary.  

Did you see other (older) schematics from the 2-channel-version of the amp. There you will see other opportunities to create the direct voltage needed for V1.
There you will also see that mesa used for all switches LDR`s. So I would use some kind of optocoupler for all switches. For some MOSFET Transistors should also work.
I hope I could help you a little bit. In these Forum are some other cuys they are much more familar with these recto amp than me - but I think they are afraid to write in english.

Bye the way - sorry for my english  

Bye

[TubeLeo]