Dynaco Stereo 400 Relay Replacement

Raccoon1400

Raccoon1400

Super Member
I just replaced the oddball relay in a Dynaco 400, I thought I'd share how.
The original relay is 48V, 15A contact rating. It is mounted to the underside of the plate that is the ground between the main caps.
I used this part, from mouser or digikey. It has a contact rating of 25A. I mounted it to the bottom panel between the main caps.
G7L-2A-TUBJ-CB-DC48

Here are some pictures.
 

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Basically the same relay I would like to use in my SAE amplifier. Need that configuration so you can mount it somewhere.
 
How the heck do I install this? I need to get some m4 screws but I have no idea how to read a relay schematic.

I’ve got two blacks, a red and a green to land. My guess is the black go to 0, 1 and the red , green go to any of the other 2,6.
 

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I’m guessing green & black to 2 & 4 or 6 & 8 and red & black to the two not used for green & black.

I think there should be two wires going to the bottom of the old relay that are for the coil (0 & 1).

Hard to tell from the pic.
 
hamrules said:
I’m guessing green & black to 2 & 4 or 6 & 8 and red & black to the two not used for green & black.

I think there should be two wires going to the bottom of the old relay that are for the coil (0 & 1).

Hard to tell from the pic.
Click to expand...

So you think there are 6 wires? I’ll need to pull out the schematic. I honest I thought I was done looking at that thing lol. This has been a long haul.
 
Looking at my notes I did something with a bridge rectifier and 47uf cap to make the relay shut off immediately on power off. I might have just powered the relay off that bridge rectifier instead of the main caps.
 
Raccoon1400 said:
Looking at my notes I did something with a bridge rectifier and 47uf cap to make the relay shut off immediately on power off. I might have just powered the relay off that bridge rectifier instead of the main caps.
Click to expand...
Please let me know if you get a chance or I’ll have to order the other part I guess.
 
pjrengineer said:
Please let me know if you get a chance or I’ll have to order the other part I guess.
Click to expand...
Here's what my notes say

The relay takes a couple seconds to shut off on power down because it is powered off the main caps.
Use a bridge rectifier, and a 47uf cap. The rectifier is run to the AC side of the main bridge.
Cap goes from negative of the bridge to ground, negative side to the bridge.
Use a 100V cap for #$%@'s sake

So a new rectifier in parallel with the main one, and I think I just ran the wire to the relay from the negative of the new rectifier. But double check that makes sense. My memory of what I did to a piece of gear years ago is not that great>
My note about the 100V cap is there because I originally used a 50V cap and exploded it.

Basically this just uses a much smaller smoothing cap so it will discharge instantly instead of waiting for the mains to bleed down
 
Did this in some SAE amps. Went from bridge rectifier AC (used double terminal thingy) that’s there already then to diode then to cap and finally to relay coil. This is just a quick overview. Works nice though.
 
What does this added rectifier and cap prevent? Audio from playing for a few seconds before the filter caps have drained or something worse? I’m fine with the audio playing for a few seconds.

What rectifier part? Maybe I can draw a sketch and you tell me if I’m right.
 
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