DIY SUMMING BUSS - Tube preamps - OPA & NEC Opamps - NEVE EQ & many routings.

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Active member
Jun 27, 2012
Hey Guys, I have a crazy idea!

About me:

Just wanted to share and maybe inspire other people too, ideas and suggestions are very welcome.
Can be I overlooked something and I think some help to get all volumes even when I bypass a lot stuff will be a pain in the ***

Usually I don't write a lot here so I do now  :p
I am someone that is very creative daily, for example I made my own VST 32bit Master plugin. Have had a chance to be in Musicradar with it, if you are interested download it for free here:
Also I run a webdesign agency (My job) and do a lot "FREE" for artist promotion behind the scenes.

My Setup:

So, to keep things "short" I have been brainstorming with myself for about 3 years now how to route my gear.
Took me so long to find out this idea because of trial and error => Expensive gear that I sold because it was not what I wanted.
How I placed my gear (order) to get it noise free. I have builded a lot DIY gear in last 7 years. Sold some API EQ's, liked them but not used them very much. I'm also building a Neve Buss Compressor and a MS76 Stereo Comp.

TIP:  You will think uhm? But I have replaced a lot XLR cables with Coax and have a much better stereo representation.
I could not pay the expensive cables from musicstore in my first years, so I found a better solution for it.  :-X 
In my pultec EQ's I used 60% Coax, more work after all but my tests have made me a better sounding unit. Very Fat Bottom!
The nice part, all noise is gone! Really

See the GREEN Coax in the Background?  8)

My current setup to produce electronic music is a computer > DAW > older M-Audio Profire 2626 and then
external to DIY builded Pultecs (2) , tape saturator (skulptor), DAOC (THX to [silent:arts]) and lastly a new DIY NEVE stereo SSL 4000E EQ (Not yet finished).
I also have a Thermionic Phoenix for 3 months now (The only mastering gear I actually bought from a store, I'm in love with it).

All these toys get my audio from my DA (Benchmark Converter) and then I record some audio back thru my gear in the computer with AD converter.
Simple and powerfull setup, and this way totally noise free. My DAOC feeds the Thermionic and they can be bypassed manually but I mostly use them together, sounds very fat and warm => Me likes!

It all may sound crazy what I write down but I wanted to give everyone a good insight in how I work.
I run two labels and do all masters myself, want the best for my artists and listeners.
Stab  Recordings (Germany)
Nyon Records (USA - New York)



Now to share my IDEA, it's a bit complicated so I put the sketches below.

I will build a custom Mixbuss with enough headroom and drive on the channels to have more analog color (Noise free).
My goal is to get anything digital really sounding like a vinyl, hihats that are polished but not crisp to the ears and a really fat but focused sub. Not that I cannot reach it digitally but I'm sure it will sound better in the end.
After all I will not use a lot external and have a lot analog color in one box. 
Maybe I include the soundskulptor Tape Saturator when there is space left in this mixbuss.

4 Channels with nice small 12V tube preamps that I trim on the output into
NEC, OPA (burrbrown) selectable opamps -> Maybe I add an API style 2500 as well.
The 4 Channels will be used to glue some groups coming from my computer.
Drums, Bass, mids, highs for example...  In the mixing stage I can use Kick, snares, percussion on the same 4 channels as well.
A very flexible approuch and easy to use unit I guess.

The whole idea is to have bypass over almost everything so I can have a clean or more colored sound.
All opamps can be trimmed but the NEC and OPA's will be fixed on the output of all channels.

Then every channel goes summed to the DIY NEVE SSL 4000E EQ (BUILD from this forum).
PIC PCB -> Need two for stereo Mix:
from this post =>

The reason I will use this EQ is for it's sound, I have had a Riverside (API 500 series) that had a really nice bottom to it.
People that have used an API2500 and the riverside know what I'm talking about. To be honost I miss my Riverside EQ but for the price I will build this unit I have a way more possibilities.

Every channel can bypass the EQ and also has a double output.
This way I can record audio back in the computer (mixdown).

The summing part after the EQ goes External.
External I will use it to glue it in a series flow over SSL, DAOC, PHOENIX back in the Summing Mixer.
Then we have some volume knobs to give the final result back at: Speakers, Headphones, AD Converter and Effects.

Audio will go into it in this flow:
Input switch on Channels (8 Stereo ins) -> tube preamps (I made 4 from these here: -> Switch for OPA or NEC/API opamps -> SSL EQ -> EXT COMPRESSORS -> INPUT VOL TRIM -> FINAL SOUND.

I placed a video on instagram when testing the Oatley preamp:


- The 12V Tube preamps sounds very warm and punchy in the low end  ;) -> The tubes are used in 800$ gear as well...
- The preamps, OPAMPS, SSL EQ can all be bypassed and I have old capacitors that I will use for AIR to add with volume.
- Just before the last chain I will have a dry DA converted sound that I can insert as parallel (original + extras is better)
- Phase problems and huge volume differences will be my most frustrating part in the design process.

**** All help is welcome, for switches I would like to have click buttons if not too expensive.
Think the unit will cost me around: 1600$. 160$ preamps, 800$ PCB SSL EQ and parts + CASE and Knobs.

**** Important to know, I have read an interesting article online somewhere about the 5$ preamp.
Link article:
They tested it soundwise against UAD gear and they have done a blind test with sound voting.. It seemed that people rated the unknown preamp from 5$
as the best sounded preamp. The whole and most inspiring fact here is => Low voltage is key to it's success. Therefore I gave the 40$ tube preamps a go and guess what. I love the sound they produce. If I push the volume I almost get the bottom to ring in some way = Giving the sounds some special something to it. For me sounds like something worth the money.

To close my long writing, is the low voltage (VINYL NEEDLE) the reason that it sounds so fat?
Think about it, maybe a lot people are building it wrong with their massive transfo' s.

Hope I'm not overwhelming you  ::)  :eek:  ;D

Grtz, Frederick



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Active member
Jun 27, 2012
New parts for the RIAA opamps have been collected (4 PCB's from Hong Kong).
NEC, Burr Brown (OPA) will be used after the tube preamps to give all channels some extra color and life ;)