Geekslutz DIY Summing Mixer

[nerogtr]

i'm still in!

[Tibbon]

Would having it electronically balanced on the Monitor out, and Transformer balanced on the main out mean that you'd be hearing something slightly different in the monitors than is hitting tape? I realize that this is done for cost considerations however. I guess it's best to monitor from the tape playback heads anyways.

[Tim Farrant]

Originally Posted by Tibbon

Would having it electronically balanced on the Monitor out, and Transformer balanced on the main out mean that you'd be hearing something slightly different in the monitors than is hitting tape? I realize that this is done for cost considerations however. I guess it's best to monitor from the tape playback heads anyways.

Well you can feed the mix from your DAW back into the Stereo Aux in and monitor the whole chain that way. A patch bay of some sort would certainly help implement this unit.

[Jam]

Good to see this is getting moving again.

Many thanks to all the people - especially Tim - who put time and effort in.

Jam

[AMIEL]

TIM...Any idea when this project can happen?
THANKS!

[filthyrich]

Still interested here depending on the cost. Thanks for all the hard work that everyone is doing.

[heathen]

I'm keen too, just interested in cost also. This is a good idea Tim. Farout Buzz gear will be dominating my studio soon. Not a bad thing by any means, actually great.

Heath

[filthyrich]

Are there any pcb boards available? I've seen sumthing cases at prodigy. I can't post there because there's no contact info for the site and I can't sign up for some reason.

I'm up for a kit, but I could likely get someone to put together a box if I had the the boards at least.

[RedSun]

I'm still in too!

[delasoul]

its been a couple months.. i dont think its gonna happen.. :(

[Mihaly]

Definitely want to register an interest too. The wait so far hasn't been so bad the way the A$ has been going......

[WidgetNinja]

Originally Posted by Analogue Vanity

glad this project finally grew wings. I'm in depending on price point. passive might be ok too for me. Thanks for your work on this

Sum Bull... it gives your project wings! (that's a joke about Red Bull energy drinks for you foreigners to the US) So what do you mix through? Oh, just Sum Bull in my rack.


Tim, I think the final thoughts you posted are right on... especially having the cascade/monitor pair. So now we just need a price, before the dollar gets any weaker.

[delasoul]

wow thanks. coming from you tim that means alot.

[Damian Taylor]

I'm in for one Tim....

[mlange]

Count me in, too - gotta build Sum Bull Buzz

[ind]

...taps on the mic, this thing still on?

Hey if it happens I'm in, so the kit would be most of the parts and pcb's? I dont know what I'm doing but I can solder well and half read schems. And I cant afford some 2500$ summing mixer (as cool as they all look).

[trevvahhh]

count me in if this goes down!

[jkrummri]

I am still in

[seppa]

Well ! there is a project on prodigy :

the sumthing pcb Prodigy Professional :: View topic - Sumthing Rev. 2 - Passive Summing PCBs for Sale
the sumthing case by parusha...
Prodigy Professional :: View topic - SUMTHING CASES - BATCH PRODUCTION - ROUND 2


the rest seems very simple.....

I'd be interested in another project if its ever materialized

[crimelab]

I am In if this thing goes Down!

Where do i sign?

Stu

[George Necola]

we need to kick some newzealand based balls

TIM

don't sleep, work on the summingbox

count me in.. I have no time either


+1

cheeers

[Tim Farrant]

Hi all,

I must apologize for the lack of communication in this thread. I'll be perfectly honest and admit I just have not been able to find the time to go further on this - we are flat out here!

The thought of putting this kit together and providing support for it is somewhat daunting given my current work load, and I wonder if I will really have the time to do it justice. Given that there are published designs and stuff at Prodigy, perhaps those still keen should follow up along that route.

If over the next 6 months things ease off a bit, I could take another look at it, but right now I'll have to put the idea to one side. I am truly feeling a little guilty over this, but I must be practical and sensible and not promise something I cannot deliver. I hope you understand.

Best regards
Tim.

[supaheef]

Hey Tim,

All understood, and don't feel bad! Judging by the amazing gear you have released in the last 6 months, I'm surprised you even took the lead on this at all. The SUMTHANG project seems to be well supported at the Prodigy Pro forum, as you mentioned. And I'm just thinking of buying a nice little mixer (A&H, probably) and gain a little flexibility too.

Keep up the good antipodean work,

heath.

[tonymite]

I'm in - so are a few of my mob.

[JAY X]

Dear Friends!

I am building Tim Farrant's summing mixer.

But without output trafos by now. I supose this will make output unbalanced. So the 0v pin 1 of the XLR output should be bridged to pin 2 (negative) because of the inverted polarity.

As i will not use trafos ¿should i use the 470p condenser and 2k7 resistor?

thank you for your help!

JAY X

[AMIEL]

Originally Posted by JAY X

Dear Friends!

I am building Tim Farrant's summing mixer.

But without output trafos by now. I supose this will make output unbalanced. So the 0v pin 1 of the XLR output should be bridged to pin 2 (negative) because of the inverted polarity.

As i will not use trafos ¿should i use the 470p condenser and 2k7 resistor?

thank you for your help!

JAY X

good luck!

[JAY X]

Originally Posted by AMIEL

good luck!

Thanks Amiel,

I think i will go for an unbalanced output. It's easier to do.

I have a picture of the card with resistors and condensers, ¿may i post it here?

JAY X

[Tim Farrant]

Hi Jay X

I know you sent me an email and I did not reply yet, we have been moving premises and things are very busy!!!

The transformer is an intergral part of the design, and should not be omitted. It performs the input common mode rejection and re-balances the output. You do not need to use the Sowter, any good 1:1 ratio transformer will work.

Tim.

[JAY X]

Hi Tim!

I think by March i will end the summing mixer based on your drawings.

My question is if there are other options for volume control than stepped attenuators. ¿ maybe a dual ganged pot?

I suppose that the attenuator should go after the transformers. Or ¿can they go between the board an the trafos?.

I have the intention to put it as an insert in Cubase mix bus.

Thank you for your help.

JAY X

[Tim Farrant]

Originally Posted by JAY X

Hi Tim!

I think by March i will end the summing mixer based on your drawings.

My question is if there are other options for volume control than stepped attenuators. ¿ maybe a dual ganged pot?

I suppose that the attenuator should go after the transformers. Or ¿can they go between the board an the trafos?.

I have the intention to put it as an insert in Cubase mix bus.

Thank you for your help.

JAY X

For gain you could put a pot between the 2 -ve inputs of the opamps to create gain. Less than x1 gain is how it is drawn. With a pot and limiting resistor between the opamp -ve inputs this becomes the traditional instrumentation input with the transfomer doing the summing/difference passively. Our Elixir mic preamp has the same design idea except it's only 1 input with a lot more gain, but still the siganal is re-balanced by the transformer..