Channel relay, heater power??

[sonofmickel]

I have a Weber relay that I would like to use in my 102/183 build, for clean/OD switching. It is a TR99-6VDC-SB-CD prefab mounted on a board.
The powersupply is a prefab that has elevated heaters implemented.
The Weber switch needs 6.3 from the heaters for power.
Can I tap off elevated heaters for the relay or do I need to implement something else?

Thanks!

[DonMoose]

You _can_ tap off the heaters, BUT you MUST use an isolated jack that does NOT ground to chassis. Your wiring goes 6.3VAC1 -> Diode Anode::Diode Cathode -> Relay Coil +::Relay Coil - -> JackTip -FTSW- Jack Sleeve -> 6.3VAC2

You probably want to add a diode across the coil (cathode to +, anode to -) to help suppress pops.

Hope this helps!

[sonofmickel]

Thanks.
Got it working!
Using a Cliff jack, not grounded.
I have it hooked up per Weber diagram, Tip/Ground to the relay, nothing even comes close to chassis ground.

[titser_marco]

Hi! Does anyone have a schematic of the solution posted above? Thinking of doing the same thing for my recent build as my PT doesn't have a separate tap for the relay. Thanks!

[Stevem]

If you go to the mojotone site and search for relays you will see the 6.3 volt kit they offer and you can click on the instruction button for the info you seek.

[SilverFox]

I recently built the preamp portion of a Dumble and used relays. The power supply is isolated from the chassis but I have horrible hum in the signal path.

What I did was use the 6.3, (actually it is a 7 VAC filament supply), rectified and powering both the filaments and the relay circuit. Only one 4700 uf filter cap. The DC for the filaments and relay circuit is not grounded to the chassis. Really bad hum.

The Cliff Jack is grounded to the chassis at a star point with all the other relevant circuit grounds and the input lead to the first stage is shielded.

Personally I think I need another filter cap in the relay and filament circuit. Any ideas?

silverfox.

[Davidg]

I may be wrong cause I'm no expert by any means but I think u will still have to have a chassis ground for heater supply through either center tap or artificial center tap (2 100 ohm res to ground). But after u decouple, rectify, and filter relay supply THEN u do not want any chassis connection and DEF don't want to connect the relay supply to a star ground. I'm sure someone will chime in that knows more than I.

[Davidg]

I did not realize u were using dc filament but I would suggest using ac filament with center tap but keep dc supply for relay. maybe decouple with another cap before rectifier but with no ground connection and get rid of star ground connection. ground ac center tap to chassis or with main power ground

[JazzGuitarGimp]

Sonofmickel, how high are your filaments elevated? Some amps elevate by 70 or more volts. If the shield in the cable to your footswitch is tied to the footswitch enclosure, you may get a shock if you happen to be holding the guitar neck in one hand, and reach down to move the footswitch with the other hand. If you only have one footswitch in the enclosure, you may want to consider using a TRS jack / plug, using the tip and ring for the footswitch connections, and using the sleeve for grounding the enclosure.

[titser_marco]

If you go to the mojotone site and search for relays you will see the 6.3 volt kit they offer and you can click on the instruction button for the info you seek.

Nah, no schematic.

[SilverFox]

I used the Kustom circuit as found on this schematic for the filaments. I also used the existing Kustom PT and the filament voltage is 7.x volts since it was rectified with a bridge. Presumably that dropped the filament voltage to 6.x volts after rectification. In the Kustom there was no chassis connection so I did it the same way.

Ooops- Guess what I just saw? The filament supply is grounded on one side. What does NET Tie and NT1 mean in the schematic?

In any event, I can hear the preamp is working and it sounds great underneath all the hum...

silverfox.