REDD EQ, Helios 69 and Dick Swettenham

[Cyril Jones]

 

[Cyril Jones]

View attachment 103606

This is the Helios amplifier referred to above, my version compressed to a half size board also containing the voltage follower used in the Helios modules to drive subsequent stage of the Helios modules.. The pre-set potentiometer sets the gain when used as a stand alone amplifier rather than the microphone stage. Useful when used as the second post EQ stage. It is stable.
Cyril

 

[HerbertR]

Hi, I am also very happy with Ian's provided TL072 based Makeup circuit. Instead of the Fet TL072 I am using Burr Browns OPA2604 AP as direct replacement. These Burr Brown Opamps draw compared to the 072 a few more mA's - but these guys also sound in my opinion better - audible more detail. After the Opamp Makup circuit the signal passes in my build 10K/10K Edcors that gives an extra nice coloriziation.
At the Input I use an electronical debalancing board. I love this EQ, it is really fantastic, very powerful, gentle to play around. I also tried other R35 values what results in different Q Factors. Might be an option for a couple of engineers to trim the piece with broader Q and less gain to the ultimative cool mastering EQ. All pots/switches are stepped, perfectly ....Btw my unit shows a really good flat frequency response curve with about a decreasement of <1dB upper 14kHz to 20kHz (at neutral settings ), very happy with it. And the build did not break my bank....

 

[ruffrecords]

My latest REDD EQ design which I call REDDPLUS, uses a single string of resistors to set the boost and cut levels of all bands. You can add as many bands as you like just by adding a rotary switch and the appropriate R, L and C components for shelving or peaking responses. You can also design the resistor string for different boost/cut ranges. I recently designed and built a custom stereo mastering version with six bands of boost only in 0.5db steps up to 2.5dB.

Cheers

Ian

 

[bleachboy]

Wow, I’d be very interested in that one Ian ! I have only downloaded your previous Redd EQ design files, is this new mastering version available ?

Many thanks,

Louis

 

[ruffrecords]

Wow, I’d be very interested in that one Ian ! I have only downloaded your previous Redd EQ design files, is this new mastering version available ?

Many thanks,

Louis

Nothing is available yet. There is a long thread about the design here:

Passive Mastering EQ

Bear in mind this began in 2017. There was much discussion about what is should do and a lot of hurdles to overcome in its implementation but it basically works. I got distracted onto other things untill I was asked to build for a specific boost only stereo mastering EQ which I have built and delivered.. If I rememeber correctly it had six or seven bands; one high shelving and one low shelving plus four or five peaking mid bands. The boost range was just 0 to 3dB in 0.5dB steps but each band was stereo.

Cheers

Ian

 

[bleachboy]

Thank you Ian.

The more I look at all of you guys’ gorgeous builds on the last few pages of this thread, which I’ve read many times over the years, the more I realize with great sadness that I absolutely don’t have the skills to assemble a pair of these Redd Eq´s…
I use the plug-in version all the time, it started becoming a sort of secret sauce for me. I absolutely need those in my studio !

 

[TwentyTrees]

I absolutely don’t have the skills to assemble a pair of these Redd Eq´s…

...Yet! Everyone starts from that same place. If it's something you want to do, it's absolutely possible to work up to a build like this. The usual advice is to get your soldering skills honed in by starting on low-cost, low-risk builds like cables and guitar pedals, then try a preamp kit or two, and work up from there to a PCB-only project like this.

Believe me, if I can do it then you certainly can!

 

[ruffrecords]

...Yet! Everyone starts from that same place. If it's something you want to do, it's absolutely possible to work up to a build like this. The usual advice is to get your soldering skills honed in by starting on low-cost, low-risk builds like cables and guitar pedals, then try a preamp kit or two, and work up from there to a PCB-only project like this.

Believe me, if I can do it then you certainly can!

+1

You will find plenty of help here to get you started on your DIY adventure.

Cheers

Ian

 

[bleachboy]

Well I do a lot of cable soldering (big pedal board…), a couple of pedal mods and and I have (semi successfully, that’s for another thread) repaired a vintage mixing console, but that’s about it.

Is there an up to date BOM available for this build ? Also, can I just send the .png file of the circuit board to a company that builds them ? Or do I have to order the circuit boards from you directly ?

Thanks a lot !

 

[ruffrecords]

The boards are available to buy from me via my website:

Custom Tube Consoles - Ruff Records PCB Emporium

Documentation including BOM can also be found there:

Custom Tube Consoles - DIY

just scroll down and click on the REDDEQ folder. I have attached the assembly instructions to this post for you.

Cheers

Ian

 

[bleachboy]

Fantastic ! I hadn’t seen your new website.

 

[ruffrecords]

.Fantastic ! I hadn’t seen your new website.

Unfortunately I cannot access the old site to edit it to include a pointer to the new one

Cheers

Ian

 

[Silas]

Hi Grandmaster Ian, for sure!
It is also a good thing to share the .fpd with everyone who needs it. It is simple to modify it with the free FP Designer Software. Change the initials, change the drillholes for the used rotary switches like Grayhill 71ADF or 71BDF....Lorlin or Elma..and go..its a durable UV Print on anodisised Alu. You can calculate less than 100 Bucks for this FP. Perfectly for Studio usage. Frank from Frontpanels.de or Schaeffer AG do a real great job.

Hi Herbert,
Beautiful front panel design, do you still have the design? I would be interested in modifying it to build a pair of these
I hope that's what you were suggesting in this post,
Thanks