DIY Summing mixer - Doability?

[eman kayker]

Hi there,
My old A&H just passed out, and I have been reading a lot of threads on line mixers without finding the one for me. Here is my plan, I'd like to have a 24 lines summer, with pan and faders, out to 2 bus. I would also like to have 4 aux send on each track. That's it!
I'd like to know if the idea of building something like that is already ¨way out¨. maybe I'd finish it after a few years to find there's some unstoppable hum loop everywhere?
I would like to get something under the price of another A&H or ... a Toft

I can solder, have done a few diy things but can't design. I think I have a friend that have a very good understanding of audio and I'm hoping he'd help me... : ) and also, I am hoping to get help on forums, like here.
For budget I am thinking of $2-3k with transformers everywhere.
I would use it in my home studio, hooked up to my 96IO plus extra 8 analog outputs, leaving some extra channels for rev returns and computer monitoring.

What do you think?

Please answer in a non-too-technical, non-itb-vs-otb language... well just ¨yeah¨ or ¨neh¨ would do it. : ) I am not looking for other ways to summ, maybe if you know of one mixer that does EXACTLY that, this would save me some sanity, but please stay on the subjet.
Thanks a lot and amitiés
Emmanuel

[meteor]

Originally Posted by eman kayker

Please answer in a non-too-technical, non-itb-vs-otb language... well just ¨yeah¨ or ¨neh¨ would do it.

Buy a console... Don't build one... Spend that time making music... and money (to pay for said console).

What you are describing is a long, expensive process that is not a summing bus... it is much more than that.


cheers,

[eman kayker]

ok thanks

[Tim Farrant]

I under stand your concept, standby....

[Geoff_T]

Originally Posted by eman kayker

Hi there,
My old A&H just passed out, and I have been reading a lot of threads on line mixers without finding the one for me. Here is my plan, I'd like to have a 24 lines summer, with pan and faders, out to 2 bus. I would also like to have 4 aux send on each track. That's it!
I'd like to know if the idea of building something like that is already ¨way out¨. maybe I'd finish it after a few years to find there's some unstoppable hum loop everywhere?
I would like to get something under the price of another A&H or ... a Toft

I can solder, have done a few diy things but can't design. I think I have a friend that have a very good understanding of audio and I'm hoping he'd help me... : ) and also, I am hoping to get help on forums, like here.
For budget I am thinking of $2-3k with transformers everywhere.
I would use it in my home studio, hooked up to my 96IO plus extra 8 analog outputs, leaving some extra channels for rev returns and computer monitoring.

What do you think?

Please answer in a non-too-technical, non-itb-vs-otb language... well just ¨yeah¨ or ¨neh¨ would do it. : ) I am not looking for other ways to summ, maybe if you know of one mixer that does EXACTLY that, this would save me some sanity, but please stay on the subjet.
Thanks a lot and amitiés
Emmanuel

Hi

I would wave a warning flag that you are expecting too much of a passive design.

You are hanging an awful lot of devices on your input signal and each device's impedances will affect the law/performance of neighbouring components. A proper mixer will have buffering between stages to provide isolation but you are hanging this all on your input signal and/or fader.

It's a compromise and you could spend a lot of time and money producing a built in crosstalk box with crummy fader laws.

[eman kayker]

So it must be active.
What does it imply?

[TRW]

Originally Posted by Tim Farrant

I under stand your concept, standby....

Oi oi, whats cracking Tim?!

-T

[Geoff_T]

Originally Posted by eman kayker

So it must be active.
What does it imply?

Hi

The problem is that the pan pot needs slugging resistors to achieve the -3dB down in the centre. You also need one or two pots to perform the pan, then there's the bus resistors hanging off it. You also mentioned four aux sends which are four pots, plus the bus resistor, all either hanging on the fader wiper or the input source.

You have to go from low impedance to high impedance to minimise the loading effect of the pan and aux pots on the fader, but then you'd be presenting a very low impedance to the source and still have a relatively high source impedance to the following circuitry.

Honestly, by the time you bought the transformers, the faders, the pots, the metalwork, the knobs, etc., you could have bought the Toft console and have more features than you originally proposed.

There's a reason why folk don't build a big passive console like you described... too many performance compromises.

[666666]

I'm also a DIY guy, I can solder well but don't know too much about electronics.

A ways back I had also entertained the idea of building a custom fader pack / mixer thing... seemed simple enough initially... but after doing a certain amount of research, I quickly came to the conclusion that it would be way more complicated to do it RIGHT than I had thought.

The final analysis is that it's way easier and wiser in the long run to just purchase an existing production unit that does what you need it to do.

Originally Posted by Geoff_T

...you could spend a lot of time and money producing a built in crosstalk box with crummy fader laws.

This pretty much sums it up

[Lupo]

Originally Posted by eman kayker

So it must be active.
What does it imply?

A Short Discussion on Summing Busses and Summing Amplifiers
By Fred Forssell

[Wavebourn]

In order to build a "summing mixer", or "summing summer", or "mixing mixer", or "mixing summer", whatelse, I would take a console that does that already and used insert jacks to feed signals. Another way is to disconnect all stages in every chain before faders/switches/pots you need and wire them directly to input sockets, to reduce heat and power consumption. But the last approach will involve the necessity to learn a technical language... So take some console from ePay or from BeroutofGerman and use it.

[JohnRoberts]

Originally Posted by Lupo

A Short Discussion on Summing Busses and Summing Amplifiers
By Fred Forssell

Among other things, it's properly spelled "bus".

"Buss" is a verb.

JR

[Wavebourn]

Originally Posted by JohnRoberts

Among other things, it's proprly spelled "bus".

"Buss" is a verb.

A buss station is where a buss stops;
a workstation is where a work stops.

Back in 70'th when I once needed to record some band I used very straight approach: one rotary pot for sensitivity (10K) and 3 sliding 100K potentiometers per channel: left, right, reverb. Summing amps (all 3 of them) were made on one nuvistor and couple of PNP transistors each. It was very cheap and clean sounding device made of aluminium angles; I even did not cover sliding pots bolting them open to angles, tightly to each other. The band had a vocal amp, but I did not use it, instead I made mic pres with medium power input transistors; instrumental inputs I took from preamps of their instrumental amps. Since I had 4 mic pres only I've recorded drums and instruments a first, adding vocal later...

It's funny to remember that days, but the result was great per a rouble spent!

[Mushy]

The Prodigy Professional Forum

Hit the link for the Meta-Meta on top and scroll down to mixers. This is a good place to start your research. Others have posted similar projects here as well so you can see the pain and anguish others have gone through to help you decide if DIY is worth it.

The one thing I will say about this project is that if your goal is saving money, forget DIY. Your costs in parts and time will far outweigh the 12 months of no interest from Sweetwater.

Good luck in whatever you decide.

[eman kayker]

Quite a lot of thinking, learning and some nice reading here for me...
Is there something in common with all those summing boxes here that could inspiring?
Summing Mixer Shootout
Thank you all,
and please go on!

: )

[Geoff_T]

Originally Posted by eman kayker

Quite a lot of thinking, learning and some nice reading here for me...
Is there something in common with all those summing boxes here that could inspiring?
Summing Mixer Shootout
Thank you all,
and please go on!

: )

Hi

The common thing in your link is that none of the summing devices would meet your original specification... that speaks volumes in itself...

Plus most, if not all, are active summers and many would cost less than the money you would expend on building your own device... and then finding "issues" in its performance.

That's the best advice I can give!