Mod Allen & Heath for direct outs?

wpaldridge

New member
Hey, guys (are there gals on here?).

An Allen & Heath SR 424 (allen-heath.com/veterans/sr.htm) mixer has recently come into my possession. It has great pre's/EQ and I really wanted to use it in my computer set-up (16 channels), but the damn thing has no direct outs.

Is it possible to modify the board and put in my own direct outs? Is it as simple as finding where the signal goes from the individual channel to the main out?

I'm reasonably competent when it comes to electronics and soldering and such, but would it be worth my time?

Any tips/tricks from any of you experienced mod'ers? What's a good brand of jacks to use? What kind of wire for the internal connections?

Or should I just bite the bullet and get a new mixer?

Thanks!
 

wpaldridge

New member
That's what I was intending. I just want some input as to whether it'd be more trouble than it's worth. Also, what materials (jacks, wires, etc.) I should be looking at.
 

mshilarious

Banned
Check the manual or email A&H, because a lot of their boards have internal options that could make that mod quite easy. I'm not familiar with that board though.
 

theobvioustroll

New member
Check the manual or email A&H, because a lot of their boards have internal options that could make that mod quite easy. I'm not familiar with that board though.


It's from the Mid 80's - it's a good board, but it is really kind of barebones; a friend had one... I think that model sold for around $1,500 in say... 1985 or 1986.... I remember thinking that was a small fortune for a mixingboard considering we paid $2,500 for a huge (used) 24-channel Peavey soundsystem with 6 CS800 and 2 CS400 amplifiers. LOL
 

dementedchord

Psychotic State alumni ch
you want the outputs to be pre-fader... either pre/post eq... alotta ahb boards have internal jumpers so you can config the sub groups or sends pre/post... that's where i'ld be looking to tap in... what kind of convertor are you useing??? does it want balanced outputs feeding it???
 

theobvioustroll

New member
Well, if you wanted them prefader, you could just install a patch point using a 1/4" TRS Jack (IIRC it's a closed circuit jack - you'd have to look at the jack - the one you'd need has an extra piece on it that makes contact when there is no jack present in the return section of it - so that teh signal will continue through the channel like a normalled patchbay.) Your option would be to either go pre or post EQ, or I guess if you really wantedto get into it, you could make it switched so you could flip back and forth between the two.


Tim
 

dementedchord

Psychotic State alumni ch
what the troll is not taking into account is the points he's suggesting you use may not be able to drive the output... muchless the output and whatever it is already driving... do your homework... unless you think screwing up a good old board is fun.... ymmv..
 

MrBluesMan

New member
I would agree its not worth screwing it up just to obtain a quick fix for your direct out problem. At the very least you can use the inserts as Direct outs just so you can utilise the pre-amps.

I would buy a new mixer personally.
 

Tedward

New member
I Want the Exact Same Thing

I know this is quite an old thread I'm bumping, but I'm really curious how this situation was resolved. Wondering if the OP ever actually tried to mod the board. I'd like to do the exact same thing to an SR8, and I could use guidance. Thank you!
 

Maddy

New member
Sorry for waking the poseidon, but new thread is a waste.
It can be done and is quite easy, except for the output attaching part.

see this: ww<remove this>w.youtube.co<remove this>m/watch?v=mwYExS4QKMk&feature=emb_logo

It needs some creative approach, so I used jacks from an old british console, that was not really worth saving for its poor build quality. Maybe will use the preamps in the future.



I used microphone cable for the direct outs. Seems noiseless, but makes the jack DIY jack module more difficult to force in place. The shield lugs were connected together with a rod. I did precision measurements to get them side by side and it was a tight fit because of FET radiator of the power supply.

Oh, and this is all post EQ, pre fader! I suggest this one if you want to simultaneously record and track through.. let's say PA system.
 

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Maddy

New member
In case the video gets removed in the future: Red-hot; Green-shield; Blue-neutral

If You're gonna do it the same way, I'd suggest to have the mount points of the socket plate on the corners, not on sides. This wasted at least a cm of space.
 
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Do not use flashlight battery knowledge on a device like this. Tapping on the fader is wrong as the load impedance will affect the signal and make a mess of it from that point on.
The correct way and Engineer would do it is find out what signal you are looking for and then tap off the driving Op amp to the direct out using a 100 ohm resistor for isolation. The driving op amp specs can be checked as to output impedance and then it normally being very low less than 100 ohms will deliver signal without a problem. IF the op amp is not powered by a bipolar supply and is like given 24Vdc then it's output will be 1/2 of that dc voltage requiring a 100uFd 25V electrolytic to stop the DC from going into your direct out. If done correctly the job can be done with degrading the console. I try and avoid mods usually as then you need to write up schematic and what was done to the board so that the next repair guy can see what was done and it is also the competent way to do a mod. This may require PCB or schematic computer programs such as Eagle to do this neatly.
 

Papanate

Active member
Hey, guys (are there gals on here?).

An Allen & Heath SR 424 (allen-heath.com/veterans/sr.htm) mixer has recently come into my possession. It has great pre's/EQ and I really wanted to use it in my computer set-up (16 channels), but the damn thing has no direct outs.

Is it possible to modify the board and put in my own direct outs? Is it as simple as finding where the signal goes from the individual channel to the main out?

I'm reasonably competent when it comes to electronics and soldering and such, but would it be worth my time?

Any tips/tricks from any of you experienced mod'ers? What's a good brand of jacks to use? What kind of wire for the internal connections?

Or should I just bite the bullet and get a new mixer?

Thanks!
Doesn't the ST424 send direct off the Inserts?
 
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