Ampdoc style relay boards available

[grangeramp]

Hi all, and Happy Holidays.

I have a small quantity of Ampdoc's relay boards that I'm offering for sale. I originally contacted David about using his design as a replacement for another switching circuit in a couple of my own amps, and he gave me permission to use the design, and his PCB file (Thank you David!). I ordered 50 boards via ExpressPCB, since the more ordered the lower the cost per board. Since then I've used 4 of them, so I have an excess that I probably won't use for some time. I've also been designing my own PCBs using ExpressPCB, so I'll eventually be moving away from using this design and won't need these boards.

The boards have the main components installed, and I'm selling them for $45 + $7 SH in the 48 US. If for some reason anyone wants an unpopulated board, contact me thru my website.

http://www.grangeramp.com/3relay_switch_board.php

Hope this helps some of you guys!
Thanks,
Curt

[Drumslinger]

nice boards from Ampdoc. I bought a few some time back and still have a couple of extra. nice little buy with the components installed. thanks for the heads up Curt.

[gary sanders]

HEY Granger! I'll take a blank board!

[grangeramp]

Gary! Come on over man! Give me a ring.

[Structo]

First of all thanks for offering these.
This seems to be the part that is hard to fabricate when building these amps.

I'm curious, I see on the OD relay you are wiring it differently.

Does this work so that when the relay is not energized, the amp is in OD mode and when the relay is turned on, the clean channel is on?

Does this make the amp quieter in OD this way?

I just wanted to point this out in case somebody gets confused by the different ways these relays can be wired.

[grangeramp]

Hi Tom,

The wiring docs are not mine, and I'm just making them available as a courtesy. I've never built, or used the board in an OD Special, just for channel switching in my own amps. Hopefully someone can chime in and answer your question.

[Structo]

OK, that makes sense now.
I know that David had attempted wiring these in the manner I mentioned for lower noise.
Not sure if he got it going.

So just so guys know, you need to take a close look at how you wire them since it is at the heart of the amp and channel switching.

[guitardude57]

Tom I wired up my channel switching for OD in un-energized state. Works well.

[tictac]

The idea behind wiring the OD or any other switching job you're going for in the "un-energized" state is that what ever condition you want your footswitch LED to be on should be the unenergized state of the relay. Basically you're leaving the hot connected to one side of the relay and switching the [floating] ground on the other side. In between the relay and ground is your LED/current limiting resistor.

Unenergized the LED is lit, shorting the LED/resistor network to ground energizes the relay coil and turns the LED off.

TT

[guitardude57]

I only used a green LED on the foot switch, that turns on when energized to clean mode. ODS style build.

With a set of Jason's relay and relay PS boards, we had the feature of current limiting on the PS board for foot switch LEDs.

I also paralleled the LED so if it fails.......it will still switch.

One may also wire up things for a multi-color, or 2 different LEDs to show both status of N/O or N/C state of relay.

[Structo]

OK, it's a matter of preference.

I couldn't have the led on when the switch is off.

But, if you are using the generic Marshall foot switch from AES, couldn't you just move the two wires on the switches to the left?
Then wouldn't the led light when the switch is off?

[David Root]

I am still not 100% on the AES fsw box. If want the led ON when that position is selected eg OD is connected, how is that wired inside the box? I thought it was as Tom showed in the Brown note pic.

[martin manning]

I am still not 100% on the AES fsw box. If want the led ON when that position is selected eg OD is connected, how is that wired inside the box? I thought it was as Tom showed in the Brown note pic.

That's my take; I'm converting an AES 3-button box right now, using the BN scheme. As supplied the wiring isn't even close, so I just de-soldered everything. The cable has only 4-conductors, so I'm tossing that too. I'm also adding a Switchcraft DIN jack like the one on the amp and making up a cable with locking Switchcraft plugs on both ends. The stomp switches the box comes with don't look like they are the best quality but they'll work for a while, I guess, and can always be replaced later.

...couldn't you just move the two wires on the switches to the left? Then wouldn't the led light when the switch is off?

You would move the LED's to the unused switch lugs and add a jumper so the switch would ground the relay coil or the diode (LED or relay on) instead of both (LED and relay on). A common-anode multi-color LED would work fine in this arrangement too- green for on and red for off, say.

[David Root]

Thanx Martin. I think I have some 5-conductor cable, will take a look.

[martin manning]

Basically you're leaving the hot connected to one side of the relay and switching the [floating] ground on the other side. In between the relay and ground is your LED/current limiting resistor. Unenergized the LED is lit, shorting the LED/resistor network to ground energizes the relay coil and turns the LED off.

I guess this is the way the AES/Marshall wiring is designed to work. It eliminates the need for a dedicated wire carrying supply voltage for the LED.