Building a Small, High Quality Mixer

Help Support GroupDIY:

cpsmusic

Well-known member
Joined
Dec 3, 2013
Messages
210
Location
Melbourne, Australia
Hi All,

I'm interested in building a small (say, four channel), high-quality mixer for location recording. As this is a small, one-off project for my personal use, I don't mind going the extra mile in terms of quality for both the design and construction.

With respect to the design, I'm curious about the shortcomings of common off-the-shelf units such as the Yamaha MG series of mixers. Where are compromises made in units such as this? If you were building something similar to this (say with four channels) where could it be improved?

And what about the construction?

At this stage, I'm leaning towards a solid-state design.

Also, I'm aware of Ian Thompson-Bell's designs at Custom Tube Consoles so no need to mention those.

Cheers,

Chris
 

Bo Deadly

Well-known member
Joined
Dec 22, 2015
Messages
2,448
Location
New Jersey, USA
cpsmusic said:
With respect to the design, I'm curious about the shortcomings of common off-the-shelf units such as the Yamaha MG series of mixers. Where are compromises made in units such as this? If you were building something similar to this (say with four channels) where could it be improved?
All modern mixers use the same circuits pretty much. It's doubtful that you could build something that would really improve on it. In a pro environment the headroom might be an issue. But most stuff ends up going to a digital recorder so it really wouldn't matter. You would only pick up a few db in noise / headroom whatever the case. The difference these days is all about features like different kinds of routing and maybe parts like the kind of pots used and such.

So IMO the only reason to build something custom would be if you do it differently. Just brainstorming here but if I wanted to create a small format mixer, I would do a 20dB pad for line level input impedance into Jensen mic transformers with individual phantom switches for each channel (something the cheaper small format mixers almost never do) into THAT 1510 but switched gain and NKK ON-OFF-ON 3pdt toggle for 2 frequency low cut + out (gotta have low cut). Then an impedance balanced bantam jack direct output and bantam jack return tapping the output. Then 2 aux controls with bantam jack I/O, the usual pan, mute, PFL and mix but 4 bus select switches.

But I guess this would be more of a personal mixer. Especially with all downstream connections being bantam jacks. Meaning someone has a rig with a patchbay to / from a bunch of sources and output gear, keyboard, multi-effects or whatever and you want a personal monitor mix while sending dry to the digital recorder.
 

abbey road d enfer

Well-known member
Moderator
Joined
Jan 22, 2008
Messages
12,366
Location
Marcelland
cpsmusic said:
With respect to the design, I'm curious about the shortcomings of common off-the-shelf units such as the Yamaha MG series of mixers. Where are compromises made in units such as this?
The main compromise is serviceability. Most use a single PCB and SMD's. If you need to replace one component, you have to dismantle the whole damn thing, which means dozens of screws and pot nuts, just to gain access. After that, you need dedicated equipment (hot air and magnifier) and a good dose of steady hands and acute vision.
For the rest the balance of performance vs. cost is unmatchable by DIY.
If I was in your shoes, I would start by making a thoroughly thought out block diagram, look at what it would look like in terms of physical layout, then put schematics in the boxes.
 

wlinart

Well-known member
Joined
Jan 19, 2012
Messages
165
Location
Belgium
Why don't you start the other way around? What do you miss in a unit like the ones you mentioned?

Maybe it's a bit blasphemous to say in a DIY forum, but if you can buy something that does exactly what you want for a very good price, and there's nothing you can find that's wrong with it, maybe you should just buy the thing. Instead of building something which may or may not be better, but will definitely be more expensive.

But if you can't find a mixer which has the exact features you need, or it's way too expensive, or you want it a bit different (bigger or smaller for example), or... So think about the why, and if you find the reason, you can ask how to improve the part that you think is missing.
 

ruffrecords

Well-known member
Joined
Nov 10, 2006
Messages
13,409
Location
Norfolk - UK
I think one good reason to build your own mixer, especially for location recording, is you can choose to use decent quality faders, pots and switches instead of the cheap rubbish they fit to most small off the shelf mixers.

Cheers

Ian
 

wlinart

Well-known member
Joined
Jan 19, 2012
Messages
165
Location
Belgium
ruffrecords said:
I think one good reason to build your own mixer, especially for location recording, is you can choose to use decent quality faders, pots and switches instead of the cheap rubbish they fit to most small off the shelf mixers.

Cheers

Ian

That is indeed a good reason, the question is, is this a good enough reason for the topic starter to spend a lot more money? That’s why I asked that question
 

ruffrecords

Well-known member
Joined
Nov 10, 2006
Messages
13,409
Location
Norfolk - UK
wlinart said:
That is indeed a good reason, the question is, is this a good enough reason for the topic starter to spend a lot more money? That’s why I asked that question
If you ask, what does it cost you if your cheap off the shelf mixer breaks down mid session I expect you will have your answer.

Another important property of a decent mixer is switched mic gain instead of on a pot; switched EQ is also a boon for location recording as is a decent HPF to remove rumble.  None of these on your cheapo mixer.

Cheers

Ian
 

wlinart

Well-known member
Joined
Jan 19, 2012
Messages
165
Location
Belgium
ruffrecords said:
If you ask, what does it cost you if your cheap off the shelf mixer breaks down mid session I expect you will have your answer.

Another important property of a decent mixer is switched mic gain instead of on a pot; switched EQ is also a boon for location recording as is a decent HPF to remove rumble.  None of these on your cheapo mixer.

Cheers

Ian

All very good reasons, and now the topic starter needs to decide what’s worth it to him/her. We can’t judge that for any other person than ourselves.
 

cpsmusic

Well-known member
Joined
Dec 3, 2013
Messages
210
Location
Melbourne, Australia
ruffrecords said:
Another important property of a decent mixer is switched mic gain instead of on a pot; switched EQ is also a boon for location recording as is a decent HPF to remove rumble.  None of these on your cheapo mixer.

Could you go into a bit more detail about these things? Why is switched mic gain better than using a pot? Same for switched EQ? And when you say "a decent HPF" what are you referring too?

Cheers,

Chris
 

JohnRoberts

Well-known member
Staff member
Moderator
Joined
Nov 30, 2006
Messages
20,245
Location
Hickory, MS
cpsmusic said:
Hi All,

I'm interested in building a small (say, four channel), high-quality mixer for location recording. As this is a small, one-off project for my personal use, I don't mind going the extra mile in terms of quality for both the design and construction.

With respect to the design, I'm curious about the shortcomings of common off-the-shelf units such as the Yamaha MG series of mixers. Where are compromises made in units such as this? If you were building something similar to this (say with four channels) where could it be improved?

And what about the construction?

At this stage, I'm leaning towards a solid-state design.

Also, I'm aware of Ian Thompson-Bell's designs at Custom Tube Consoles so no need to mention those.

Cheers,

Chris
That sounds nice but is probably a lot harder and more expensive to even match the performance of a value mixer, let alone improve upon it.

For combining only 4 channels, sum bus noise will not be an issue so that makes the design easier.

Back last century I designed a small mixer (Peavey RQ200) that could even be powered from 9V batteries but I am unsure how often you will be completely without power during location reporting.

===

Start working on a list of features you want to include. Then work on panel layouts. Study existing designs (for inspiration).

JR 
 

ruffrecords

Well-known member
Joined
Nov 10, 2006
Messages
13,409
Location
Norfolk - UK
cpsmusic said:
Could you go into a bit more detail about these things? Why is switched mic gain better than using a pot? Same for switched EQ? And when you say "a decent HPF" what are you referring too?

Cheers,

Chris
If you have a stereo pair of mics you want to be reasonably certain the gain of both mic pres used is the same. Easy to do with switched gain. Hard with a pot. Similar arguments apply to switched EQ. Also, a session may last over several days with gaps between. Accurate recall of settings then becomes important.

It is amazing how much very low frequency rumble is present in many venues - from distant street noise to nearby kitchens and local A/C. A steep slope HPF is very useful at reducing this.

Cheers

Ian
 

H713

Member
Joined
Apr 3, 2019
Messages
8
IMO, it isn't just one thing. It's everything in those cheap off-the-shelf mixers. The EQ isn't great, the preamps are OK (but not great), and the build quality isn't great.

A good HPF (preferably with a sweepable frequency) is really useful.

I've been playing with the idea of building a good 8-channel console for a while. Something with good mic preamps, a decent EQ (probably a lot like the Harrison EQ) and a quasi-inline design would be kind of nice to have for all sorts of recording applications.
 

Newmarket

Well-known member
Joined
Oct 10, 2016
Messages
583
Location
Brighton Sussex UK
wrt 'Location Recording' - of what eg are we talking documentary / wildlife/ dialogue or music / bands / rehearsals etc ?
Apart from that I'd like to add that all the contributions to this thread have been excellent and well thought through.
 

audiosway

Active member
Joined
Jul 21, 2014
Messages
43
IMO, it isn't just one thing. It's everything in those cheap off-the-shelf mixers. The EQ isn't great, the preamps are OK (but not great), and the build quality isn't great.

A good HPF (preferably with a sweepable frequency) is really useful.

I've been playing with the idea of building a good 8-channel console for a while. Something with good mic preamps, a decent EQ (probably a lot like the Harrison EQ) and a quasi-inline design would be kind of nice to have for all sorts of recording applications.
I totally agree with you there. The current off the shelf mixers just have many things about them I'm not fond of. So, in a studio setting working with a DAW especially you end up with a ton of pieced together equipment. Not necessarily a problem, just not ideal. The Harrison EQ is my favorite EQ of all time. To me you get just enough of the color and just surgical enough. Best of both worlds.

I would love to build out something with a class A mic/line pre, Harrison style EQ, and a VCA compressor on each channel. I would also like to build in a VCA mix buss compressor. That's my ideal mixer. I love the SSL 4k mixers but they are getting harder to find (not even counting parts being harder to find) and the mic pres aren't all that.

I'm such a fan of the Harrison EQs that I've just moved over from pro tools to Harrison Mixbus32C. Just wish I could have that in a new console.
 

jacomart

Well-known member
Joined
Sep 13, 2017
Messages
161
Location
Tuscany, Italy
I would say (for me) the most three important points:
1. high quality of components (as already written by @ruffrecords in particular connectors, faders, switches and potentiometers)
2. ease of intervention for small repairs (so if possible no SMD components) as mentioned by @abbey road d enfer
3. care of all the screenings to avoid unwanted external electromagnetic interferences
... and fourth: robustness... oh.. fifth: build two (one for backup!)

Cheers
JM
 

Newmarket

Well-known member
Joined
Oct 10, 2016
Messages
583
Location
Brighton Sussex UK
I would say (for me) the most three important points:
1. high quality of components (as already written by @ruffrecords in particular connectors, faders, switches and potentiometers)
2. ease of intervention for small repairs (so if possible no SMD components) as mentioned by @abbey road d enfer
3. care of all the screenings to avoid unwanted external electromagnetic interferences
... and fourth: robustness... oh.. fifth: build two (one for backup!)

Cheers
JM
Totally get the benefits of what you are saying and Ian also.
And this is "DIY" so someone wanting to put some high quality kit together is great.
My concern is that the effort , risk, financial cost and (possibly most of all) time costs may not be worth it above a commercial solution that fulfils the required functionality to a useable degree in a much faster timeframe.
 

neil.johnson

Active member
Joined
Aug 14, 2012
Messages
27
So you want something better than, say, this: Mystere ENG Mixer | ENG Portable Location/Field Mixer | Mystère Mélangeur Portable | For Sale London, UK

Because if the answer is "same as" then you might as well go and buy that thing now, rather than spend a year of your life designing, building, testing, modifying, testing, redesigning, testing, etc etc etc until you reach either a point of completion (congratulations) or a point of despair (commiserations).

Building high-quality (whatever that means - it needs defining) takes experience and time and money. Throwing Grayhill or Elma switches, Neutrik or Switchcraft connectors, a custom machined enclosure, a robust and safe power system, will get you some way as long as you know how to use them effectively.
 

Winston OBoogie

Well-known member
Joined
Jun 3, 2004
Messages
2,476
Location
UK.
It doesn't look like the OP has checked in since the thread was started but, notwithstanding everything written above, I'll throw into the ring:

He did mention Ian's mixers so, if it's something along the lines of a small high quality valve mixer, that does change things as far as what's available as a product vs what he could build.

How much is a 4 channel valve mixer? Who else makes and sells them?
 

ruffrecords

Well-known member
Joined
Nov 10, 2006
Messages
13,409
Location
Norfolk - UK
It doesn't look like the OP has checked in since the thread was started but, notwithstanding everything written above, I'll throw into the ring:

He did mention Ian's mixers so, if it's something along the lines of a small high quality valve mixer, that does change things as far as what's available as a product vs what he could build.

How much is a 4 channel valve mixer? Who else makes and sells them?
For a fully featured 4 channel mixer (expandable to six channels) with three Band EQ with stepped controls etc etc from me it is £6000. As fa as I know, nobody else makes one. Over the years I have seen a couple of promotions for smallish valve mixers but none that are still around. It may sound strange to say this but I would love some competition.

Cheers

ian
 

Latest posts

Top