REDD EQ, Helios 69 and Dick Swettenham

ruffrecords said:

left and right have separate controls? Is that an advantage for mastering or is it simply to simplify the switching.

Cheers

ian

Click to expand...

Yes, there is a copy of this left and right.
I do track (as well as master) through my 1-2 so I want independence. But the switches (and my resistor tolerances) give me left right matching. 

Assuming it all works. I've got my makeup amps burning in.  Time to test over the weekend.

Sleeper said:

ruffrecords said:

left and right have separate controls? Is that an advantage for mastering or is it simply to simplify the switching.

Cheers

ian

Click to expand...

Yes, there is a copy of this left and right.
I do track (as well as master) through my 1-2 so I want independence. But the switches (and my resistor tolerances) give me left right matching. 

Assuming it all works. I've got my makeup amps burning in.  Time to test over the weekend.

Click to expand...

That's handy, so you can use it as two mono channels for tracking and as a close matching pair for mastering. Neat.

Cheers

Ian

Hey Ian,

I have a few bucks for a the REDDEQ boards now. Since my REDD47/orange86 parts have mostly been acquired I think I should get on top of implementing this. Man I'm so excited! 8) How should I go about paying (if they are available)? I might pick up a Poor Man's Gain make up stage PCB too.

Thanks.

buildafriend said:

Hey Ian,

I have a few bucks for a the REDDEQ boards now. Since my REDD47/orange86 parts have mostly been acquired I think I should get on top of implementing this. Man I'm so excited! 8) How should I go about paying (if they are available)? I might pick up a Poor Man's Gain make up stage PCB too.

Thanks.

Click to expand...

Go here:

http://www.ianbell.ukfsn.org/EzTubeMixer/

and follow the instructions at the top.

Cheers

Ian

Thanks Sleeper, but I should have mentioned; I'm referring to the REDD EQ.

Here are my thoughts so far... I'm thinking of taking inspiration from EMI/Abbey Road and housing this EQ in one of BUD's portacabs or whatever they're called (à la RS127). Will be like having my own little "Presence Box". Of course these boards go way beyond just a RS127 though since they also include the Treble and Bass from the REDD Console.
In fact, The REDD Console EQ part of this project tempted me to integrate it somehow into the REDD47 preamp that I'll be building soon, but I'm pretty sure I've ruled that out. Doing it that way requires a lot more thought, because in a way one is pretty much creating a "REDD Channel Strip". I've already spent lots of time on my REDD47 panel and to include this amazing little EQ would mean a complete (or close to it) re-design. Pretty sure I'm gonna use the BUD boxes. I'm interested in hearing from anyone else who bought the REDD EQ. What do you plan?

Sleeper said:

Here's one side of a helios Mastering version - all stepped controls.
Although I normally like my high-end on the right and my low on the left, I prefer not to mount my boards from the roof.
Not sure about the redd, but the Helios also presents the dilemma of having a midrange control that steps over the high boost/cut - but for me the mid is the most important feature.

I don't find that a polar array of the text elements ever really looks right.  you have to nudge things around a bit to get it to look proper.  I use the array in the center to mark my switch steps and to give me a drilling center, it's not in the final print.

Click to expand...

So starting to build the REDD EQ stereo mono pair. Newbie at this type of build so will be asking lots of questions and ask for advice. Here is the front panel design for the project.

Daniel

Nice panel layout.Love the logo - somehow it reminds me of Popeye - no idea why.

Cheers

Ian

I'm certain popeye goes to a pirate island...
It's the logo off of Wimpy's tricorner hat

I had success with the Helios all stepped EQ.
It sat for a while because my scope was on the fritzz.
It's burning in with 2520 make up gain amplifiers. 
So far so good. Can't wait to crank it through my real monitors.  8)

Thanks again Ian.

BTW
I just put a couple of extra grayhill 2deck switches on blackmarket.

Studio is named after my son who is called stinky monkey.

We have Stinky Monkey Records

and

Monkey Dungeon Studios - our moto "You don't get out till the music is right!"

Sleeper said:

I'm certain popeye goes to a pirate island...
It's the logo off of Wimpy's tricorner hat

I had success with the Helios all stepped EQ.
It sat for a while because my scope was on the fritzz.
It's burning in with 2520 make up gain amplifiers. 
So far so good. Can't wait to crank it through my real monitors.  8)

Thanks again Ian.

BTW
I just put a couple of extra grayhill 2deck switches on blackmarket.

Click to expand...

Can you email me some pics for the gallery. Pierre is running this. We can also put a link to your studio website if you wish.

Cheers

Ian

Ian, I sent you some pics directly. Hope you got them.
Here's one for your listeners ;D
2 channels of Ruff Helios EQ mastering version all stepped controls. 
Solid State Pultec output circuit- 2520 opamp with a quadfilar transformer.
Run a few mixes with it.
Beautiful
Recycled rack case - decals mounted on 12 gauge aluminium front panel.
good enuf.
Thanks for the great project.
Kelly

Sleeper said:

Ian, I sent you some pics directly. Hope you got them.

Click to expand...

Yes, thanks, they arrived safely. I will be forwarding them to Pierre to add to the gallery. Do you want us to include a link to your studio?

Cheers

Ian

Ok I just got the transformers from Sowter and wired everything up. A nubbie questions. Can you tell me the procedure to setup the trip pots on the PAD and direct signals? Also I have a dual mono version and want to know how to match these trim settings. Any info would be appreciated.

Bonsaimaster

Bonsaimaster said:

Ok I just got the transformers from Sowter and wired everything up. A nubbie questions. Can you tell me the procedure to setup the trip pots on the PAD and direct signals? Also I have a dual mono version and want to know how to match these trim settings. Any info would be appreciated.

Bonsaimaster

Click to expand...

The procedure is quite simple and applies to just about all of my passive EQs:

1. Set the EQ controls to lfat - no boost or cut
2. Set the EQ in/out swtich to EQ in.
3. Feed a 0dBu signal into the EQ and adjust the gain of the gain make up amp for 0dBu output.
4. Set the EQ in/out switch to out.
5. With the same input signal. adjust the pad pot for 0dBu at the output

If you adjust both channel of a dual mono system they should be quite closely matched.

Cheers

Ian

Finally got the transformers and finished the project. Sounds great! Thanks Ian for all the help and tolerating the stupid questions.

Hey there those in the know,

As a quick (and highly subjective question)to answer primarily aimed for those who have used both.
If you were choosing one option re the REDD or Helios 69 EQ which would you go for and why?
How do people compare things like e.g. -
Mid range similarities/differences
Applicability to particular styles or instruments
Anything else that they think might be relevant to consider...
Also for the REDD EQ, any particular recommended make up amps over any others? (i.e. suitability, cost effectiveness etc) e.g. Poor mans tube make up, REDD Pre etc (or should I just use one of my e.g. 1950's style tube line amps, Neve, manley, API etc)

Any info/wisdom much appreciated

As I mentioned right at the beginning of this thread, Dick Swettenham, who designed the Helios 69, previously worked at EMI where the REDD EQ was developed. it is clear there are a lot of topological similarities between the two EQs and my guess is Dick saw his own EQ as an improvement on the REDD. The top boost/cut are identical. The Helios bass cut is a HPF whereas the REDD is shelving. The Helios bass boost is peaking whereas the REDD is shelving (but both use inductors for bass boost). The Helios uses the same inductor for mid  boost as for  mid cut which makes its cut curves much sharper than its boost curves. The REDD EQ uses different inductors for cut to keep the overall curve shape for cut the same as for boost.

Those are the technical differences. You will see many references on the net the the 'musicality' of the Helios EQ, not just by recording engineers but by musicians. I don't think there are any hardware versions of the REDD EQ except for mine and a few originals secreted away somewhere so most of the net based comments you see on the REDD EQ are based on the software plug ins.

I did a test recording of my REDD EQ in action which you can listen to here:

http://www.ianbell.ukfsn.org/EzTubeMixer/docs/sounds/REDDEQ/reddeqtest%2005.wav

To me the inductor based bass boost is nicely fat despite being a shelving type. The mid frequency peaks and shapes seem well chose to bring out individual instruments without distorting them. The treble is capable of adding a nice 'air'.

I am biased but I would recommend using my Twin Line Amp for gain make up.

Cheers

Ian

Cool thanks Ian

what did everyone do for the 18uf and 68uf caps in the helios eq? seems like i cant find anything that small with that rating, at least not at mouser, also couldnt find n56 and 4n3  maybe not standard values in the US?

I got all my stuff at mouser or from my parts bin. If you look at my post on the previous page you can see I mixed it up a little bit... They aren't all exactly the same style.  I couldn't get one value, so I just used 2 caps in parallel. this won't necessarily work with the WIMA box type caps, you need a bit longer leg because the parallel caps have to sit up off of the board somewhat...  you could always make a longer leg from resistor off-cuts.

I feel like 68uf seems a little big. be careful that you are reading it right...
maybe that's correct.
I'm pretty sure that a couple of the largest caps in the project did require a little bit of lead forming, in other words, shaping the legs like hockey sticks so they would fit the hole spacing on the pcb. nothing extreme.
Good luck