Helios thread

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He played a gig in town, bumed into him walking out the door (good timing) and had a drink, pretty casual. Perhaps it was refreshing for the guy to try to remember some esoteric detail about an old console compared to the questions he must be hit with everynight...

dave
 
Piccie of the innards of the EQ modules from reconrding consoles.net

http://www.4sync.com/rc/picdisplay.asp?itemkey=1010
 
From a friend of mine....
BTW the schamtic he is talking about is the dan alexander one with the missing value for the inductor...

I quote

"
I've just had a long, very long, chat with a friend of mine about this. I was on the phone to him when I spotted your question. He was a senior tech at Olympic and one of the people who designed, built, modified and looked after the original Helios (and other) console(s) at the studios. He's a bit tied up at the moment but he'll have a look at the circuit diagram later and come back with some info. He did say "if it's the drawing off that american site, it's bollocks, that's not the original Helios design its some bastardised ripoff". He didn't expand on that but he's never a man to mince words

He told me that the *only* completely original Helios EQ modules are in the UK and there are only about 4 of them. He has a couple and one of the other ex-Olympic techs has the others. (Apparently the original Helios console currently for sale in the US for rather a lot of money had a number of it's sections, including the EQs modified during it's life at Olympic.)

For anyone thinking of trying to copying them, two of the orignal EQs are currently with Raindirk (Cyril Jones was also involved in the early consoles at Olympic, and later supplied some Raindirks there) and Cyril has disassembled the units down to taking apart the inductors and other parts to enable him to produce a proper copy that'll be "as close as it can get; and miles better than the bollocks other people are passing off as real Helios bits". There are some Helios "recreations" around at the moment but these apparently are not as close as they could be.

I'll post more when I find it out.

Incidentally, if you're looking for a nice old console and have about £7.5K to spend, there's a Raindirk Series 3 on eBay at the moment. We also talked about this as the seller says it's ex-Olympic in "Richmond". Since Olympic were never in Richmond I was a bit confused but my friend was able to confirm that it was one he worked on quite extensively from Olympic Studio 2 in Barnes! He described it "as a very nice little console and if you want a really simple recording console with a nice short signal path you could do a lot worse - not worth the price though. Might be a bit noisy but it's full of 5532s so if you want to make it quieter it'd be easy"
 
[quote author="Tekay"]Since Sowter is making the input tx (8666) maybe they're making the inductor too? Has anyone asked Brian about that?[/quote]
Yes I have asked the question and no is the answer
 
I have some decent pictures of what I believe are amp cards from a Helios preamp/eq. I did not see anyone post these pics yet.


They have OLYMPIC SOUND STUDIOS M.M.C. 1 printed on them.

I do not have any way to post them. Maybe I can email them to someone and they can post them.

Maybe this can help with the components.[/img]
 
I don't use it but there is photobucket which is free, or email them to me at smilinfu"at"earthlink.net and I'll pop them up tonight.
 
I emailed the pics to buttachunk.

I am pretty sure these are from the Helios that was originally built for Olympic.

I had inquired about cloning these some time ago. some info is under the rec.audio.pro newsgroup under the heading "helios discrete" or something like that. Thats where I first inquired about the Helios design. Thats also where Fletcher had brought up the germanium transistor thing. The problem is in obtaining germanium NPN transistors. Germanium PNP are used in a lot in DIY guitar fuzz boxes. See smallbear electronics.

Anyway, the 2N3707 is available by the assload from Mouser. And the 2N4058 can be replaced with the NTE234 for $1.25 each from Mouser. Or you could possibly find a suitable germanium replacement for the 2N4058 and maybe, just maybe for the 2N3707 if your heart desires.

Specs for the 2N3707:
Hfe min 100 max 400
Specs for the NTE234
Hfe min 350 max 700
 
I have a big handful of toshiba germanium pnp's that arent too leaky to use in a fuzz box, hfe's around 130, if they are any use on this project...

dave
 
I've been behind this project due to an operation. I'll read up and get back. I haven't had any time to do any practical experiements though, sorry.

uk, any luck sourcing that inductor at Sowter?
 
Sowter doesn't have the inductors but read on...
Passed onto me from somebody who definately knows what they are talking about on Helios' - inc;uding the original Veroboard prototypes....
D'oh! I just typed out a long post, then managed to crash my pc and lost it all!

Anyway - in short, from a phone chat I had this afternoon:

The inductor value is 12H (12 Henrys) and it's the bass control so it's a good idea to get a good one. For such a high value you'll probably need to go with a ferrite cored unit. (The originals were ferrite cored.) The original inductors were hand made and the ones used in the first full production modules were produced by a company that no longer exists. As far as my friend knows, Sowter made some of these for fitting in the modern copies sold by Vintage King in the US (for rather a lot of money!) and they might be able to help you out with them.

Ther might be some more info on this as the question prompted some rummaging in the "junk" cupboard which yielded one of the two original-original prototypes of these units, made on veroboard! My friend describes it as the Mk 0 design that never went into production whereas the Mk1 production unit is the Mk2 design. The two Mk0 design/Mk1 production units that my friend has are what's with Raindirk and there shoufl be commercially available copies available very soon - at a price.

A few further comments to pass on about the circuit and Helios console in general:

What goes before and after the EQ circuit is critical in getting it to sound right.
If you build any of this Helios stuff you need to use germanium transistors and get the right transformers as without these you have no hope of getting it to sound right.
The original console was noisy, had "crosstalk like you wouldn't believe, way up into RF", had little headroom and ran very low levels internally.
The famed sound of the console and EQ came from these problems and the fact that they lead to the circuits distorting very easily. Distortion in the EQ, and most of the other circuits, is "badly asymmetrical" and the settling time from saturation to full recovery after removal of the signal is "about a weekend"! The engineers using the console frequently (almost routinely) drove it into (and kept it in) distortion by keeping the gain high and the fader low to get a warm sound and use the natural compression of the circuit saturation.


OK, I thought I'd left a bit out so I was just checking what I wrote and that fourth paragraph is gibberish! I got my Mk0/Mk1/Mk2 mixed up. I wrote it off the notes I made during the phone call but somewhere it all went wrong. It seemed so lucid at the time! I've called and checked this morning that what I now have makes sense. So here's a new version, now that I'm awake and with coffee ! There's a bit added that I forgot yesterday too.


Quote:
--------------------------------------------------------------------------------

Me, in my last post above:
Ther might be some more info on this as the question prompted some rummaging in the "junk" cupboard which yielded one of the two original-original prototypes of these units, made on veroboard! My friend describes it as the Mk 0 design that never went into production whereas the Mk1 production unit is the Mk2 design. The two Mk0 design/Mk1 production units that my friend has are what's with Raindirk and there shoufl be commercially available copies available very soon - at a price.



--------------------------------------------------------------------------------



This makes no sense; it should've read:

There might be some more info coming later on this as the question prompted some rummaging in the "junk" cupboard which yielded one of two original-original prototypes of these units, made on veroboard! My friend describes it as the Mk0 design that sounded best but never went into production; the Mk1 production unit is apparently a small revision of this design. The two production units that my friend has are what's with Raindirk and there should be a commercially available modern version very soon - but at a price." He's also got a couple of the further slightly modified EQs from the console in Olympic Studio 2. These he describes as "technically a bit better; much more stable; almost identical to the first production units but not quite as warm sounding - not enough distortion".
 
Nice work uk! :thumb:

I did try out a breadboard version with that 10H inductor I mentioned earlier. I use a big ass choke, it did work, but I didn't finish it up before I went to the hospital :roll:

I'll try a 12H then..
 
Here is the stuff that Raindirk are going to put out
http://www.lntech.nildram.co.uk/helios.html
I quote:
"EQ capacitors are either polystyrene or polyester. Rotary switches are Elma types - just as the originals."
heliospassiveeqmi.gif

item4a.gif
 
Yeah well, I don't care about the pissing match. Every Helios mfg seems to say that the competitors product is inferior and not 'real Helios'. Hmm, where have we heard this before? Neve, Vintech, BA, Aurora, whatever...

It's just advertising bullshit. The vast majority of the buyers have never heard an original Helios module anyway :roll:

Looking at original Helios modules, they look kinda messy, with cheap standard components. Also, Swettenham made so many different modules, that the sound is all over the place (I guess, I haven't listened to the lot). No module is gonna make me sound like Rolling Stones anyway :green:

Everybody uses Elma switchec and 'polystyrene & polyester caps' could mean anything. From junk to NASA/audiophool parts. Me thinks they're standard Philips stuff or whatever.

I mostly concerned about how the Sowter replacement will sound compared to the Lustraphone and that inductor as well. At 10/12H with an iron core it certainly will have it's effect on the sound. The actual amps will be the easiest part to recreate. All components are standard and exact types can be had today. Hope the schematics indeed are true to the originals :?

The distortion part is interesting too. The overload characteristics of an amp/product is one of the first thing I check out. It's very telling about the sound quality in general :wink:
 
So the amps are no problem? Are there commonly available Germaniums of the right type? Is it best to do like the original with the negative supply?

Bear
 
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