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General Discussions => The Lab => Topic started by: Igor on November 10, 2009, 07:59:46 PM

Title: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on November 10, 2009, 07:59:46 PM
As far as I know, there's no any legal issues with it :)

Sooo....I will have some time this weekend to start PCB design.

Need some input from you, lady's and gents.

My guess is:

Choice of input transformers for mic pre;

Same mic input amplification stage like used in older consoles (3-transistor's circuit);

Optional DI (HI-Z buffer) before input transformer;

RM-8 or RM-10 layout for HF inductor;

AFAIK the LF inductor originally done on iron or nickel lamination, small size core like EI-24...
if someone can put lite on this?

As line out amp, I'd used prooven second half of BA-283....fat, Class A, etc...
This will make actually a bit different thing, not like already commercially available
and will reduce headache caused copy-paste-righters....etc.

Insert after micpre? Line input option?

And, replacement for Elma switch to something cheaper, as well as (maybe) use of Lorlin switches+resistors
instead of potentiometers?

Your input wellcome. I think this can be really nice project.

Ah, yes....just a thought....Lunchbox format card wit EQ only????


(http://i251.photobucket.com/albums/gg291/diy33609/schem_V69-1973-1-Var-1.jpg)
Title: Re: DIY Helios EQ? Let's do it!
Post by: SSLtech on November 10, 2009, 08:24:22 PM
I think this might be a little too contentious.

Helios gear IS in current production, and Tony Arnold (in Europe) is known to visit forums such as this and voice his opinions.

If a version was attempted, I'd suggest some considerable changes and a COMPLETE avoidance of the term 'Helios'. It is a registered trademark and will bring down quite a lot of trouble, I've little doubt.

Keith
Title: Re: DIY Helios EQ? Let's do it!
Post by: Igor on November 10, 2009, 08:32:04 PM
Aha, will change the topic name...to avoid debats :)
Thanx Keith!
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Biasrocks on November 10, 2009, 08:39:49 PM
Would love to have a couple of these guys.

An Olympic studio Helios opened up.


Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 10, 2009, 08:46:08 PM
It can be good to know material and core size for LF inductor.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: hobiesound on November 10, 2009, 08:57:19 PM
LOL, I'm very interested. I've got a pcb layout for those amp cards and two sowter lustraphone copies waiting to be used. i even bought a small coil winding machine and i was just about to order some formers and core to try winding that low freq inductor. 

Greetings,

Thomas
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: desol on November 10, 2009, 09:11:36 PM
Ditch the mic pre. Keep the switches and pots.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Biasrocks on November 10, 2009, 09:45:05 PM
Ditch the mic pre. Keep the switches and pots.

Nooooooo, don't do it.

It's not like that mic input stage/transformer has anything to do with the sound of these modules.   ::)

Mark
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: gyraf on November 11, 2009, 01:10:53 AM
What value is the LF-inductor?
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: hobiesound on November 11, 2009, 04:39:30 AM
i simulated the schematic a few months back with the values from various schematics and i got a value of 10H (this was confirmed in one of the posts here IIRC). I can't run the sim right now coz i'm at work so i don't know what the value is for the mid-band. But IIRC the mid-band inductor got varied in quite a few versions so there's no telling what the actual values were but i remember the values for the 2 tap inductor in one of the versions was more or less correct but i was planning on winding an inductor with more than 2 taps to match the values of the styroflex i have lying around.  

for people that want more info i suggest searching the B-B-B-Big helios picture thread on Pro Sound Web. I'm still looking for the schematic that was posted on vintageking for the 2004 helios reissue, i found the first page, but if anyone has the other 2 pages could they be so kind and email it to sureshotstudio -AT- gmail -dot- com .

greetings,

Thomas
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 11, 2009, 07:14:32 AM
Yap. Every additional info wellcome.
Title: Re: DIY Helios EQ? Let's do it!
Post by: desol on November 11, 2009, 10:47:08 AM
I think this might be a little too contentious.

Helios gear IS in current production, and Tony Arnold (in Europe) is known to visit forums such as this and voice his opinions.

If a version was attempted, I'd suggest some considerable changes and a COMPLETE avoidance of the term 'Helios'. It is a registered trademark and will bring down quite a lot of trouble, I've little doubt.

Hmm. I agree about the name and i don't think the schematic should be posted. 

But, there are many in-production projects going on here. What's different about this? Why can't Igor do a H*** type? Others do other type's? The only reason there would be a problem is if TA had a fit (uh oh, being such a small project and totally modified) and that would be a real downer.. Sheesh. Besides, this would be a great addition to the 51x release! :)

Let's party!! Champagne?

I think Tony should helping us out!? He can have some champagne too?  :D

Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: okgb on November 11, 2009, 10:59:17 AM
I'm in for two of any version
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: skal1 on November 11, 2009, 11:10:16 AM
I am in, depend on  how much those inductors are going to cost, i was waiting for someone to do this.

skkal1
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 11, 2009, 12:11:56 PM
In case you wound inductors youself, $20 max for pair.
In case someone else do it....$40-50 maximum for pair of inductors.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Freddy G on November 11, 2009, 02:22:07 PM
I'm in for a pair!
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: mata_haze on November 11, 2009, 06:02:32 PM
WERE IS THE KIT???
 ;D ;D ;D ;D ;D

M.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 11, 2009, 06:37:29 PM
Ahem. Little by little. For now, I just have incomplete PCB design on my laptop
and waiting for oppinions etc.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Joechris on November 11, 2009, 07:15:35 PM
Mabye Carnhill inductors from Audio Maintenance would be a good option. VTB 9043 for the bass, and VTB 9048 for the midrange. ca. 34€
Its hard to get the Bass cut/boost done without a expensive rotary, unless you limit the choice to two cut and three boost steps (read lorlin 6x2)
j
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: desol on November 11, 2009, 08:24:02 PM
Some info: http://cms.orphanaudio.com/forums/viewtopic.php?t=136&sid=d4fd1c008b499f33f5c201d359597575
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: hobiesound on November 12, 2009, 04:23:56 AM
oh yeah on the dan alexander schematic it says L2= 680mH with a 220mH Tap. That one more or less works.

greetings,

thomas
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 12, 2009, 08:13:37 AM
Carenhill can be good option. The .pdf file have detailed pinout for most inductors, but does not have the exact pinout for VTB9048.
I guess, for low frequency inductor we will need good shielding (it may pick up some inductive noise and 50/60Hz hum).
For example, RM10 core can fit inside A262CAN, which can be used with nickel EI24 core as well.
Pinout for both Carnhill and RM10 inductors can be done on PCB.
As Keith pointed, we don't want any mess with manufacturers, etc, so it should be bit different then commercial product.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: MikoKensington on November 12, 2009, 01:27:39 PM
Is the idea of mic/line/DI switching on the table? 
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: tommypiper on November 12, 2009, 01:35:11 PM
Is the idea of mic/line/DI switching on the table?  

I second that.  I hope so.  An EQ's utility is only fully utilized if you can use it both during tracking (with mic input) and mixing or downstream from another mic pre (line input).  Having a DI input also, would increase the utility!

Carenhill can be good option. The .pdf file have detailed pinout for most inductors, but does not have the exact pinout for VTB9048.

Igor, the VTB9048 is a good choice, as it's also used in the Neeve 1081.  The pinout info should be easy to find because of that, if not directly from Carnhill.  Just look at a 1081 schemo.  The Neeve and other part numbers are: vt22675, L1, IN2012.  (All are the same part = VTB9048.)

8 pin package (5 connected), core material not specified
Shielded can

Mid-Hi :  L1, (VTB9048) inductance taps at   767mH,  504mH,   296mH, 205mH
            resistance at taps      105R,       57R,       46R,   24R

Mid-Lo : L2, (VTB9047) inductance taps at 5.11H,   3.56H, 2.06H, 1.43H
            resistance at taps  1036R,    804R,  611R,   500R

Source : Carnhill part # VTB9048, VTB9047 measured resistance, inductance specification.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Biasrocks on November 12, 2009, 02:05:28 PM
Is the idea of mic/line/DI switching on the table?  

I second that.  I hope so.  An EQ's utility is only fully utilized if you can use it both during tracking (with mic input) and mixing or downstream from another mic pre (line input).  Having a DI input also, would increase the utility!

Third. :)

Mark
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 12, 2009, 02:56:53 PM
OK. Pad before input transformer gives us "line" option.
Active buffer before input transformer for DI. When jack inserted, relay takes care of this.
Insert after micpre, right before the EQ will give us "only EQ" option.

Insert can be done with relay and active line receiver/driver....
This complicates a bit and requires +/- audio power supply instead of single + or - 24V
(depending on how old the Hel**s model is...)
Just a thought. Older Hel**s modules were using -24V supply. We need +24V for makeup stage (second half of BA283).
So, why not use +/-24V power supply and power from here switchable insert's balancing driver/receiver?
This way we have (if insert is "on") balanced micpre out and balanced input into EQ.
When insert is off, relay takes care of insert and sound does not passing thru balanced driver/receiver.

Carenhills can be easy sourced, but I will try to fit here standard RM10 inductors for folks
who want to save some money and wound inductors by themselves.

Regarding the Elma switch. The easy and cheap solution is next.
One Lorlin takes care of low cut, second takes care of low boost.
We can have even more settings with single 12-pos switches which is allways wellcome (more OPTIONZZ!!!!)
With use of dual on-on-on toggle, we can apply boost, cut, or both-oops, new feature!!! :)
For those who can't find on-on-on dual toggle, with use of dual on-on toggle (on same pcb) there will be boost or cut only option.

So, than, the thing will be not exactly original Hel**s, BUT this is what we want.

Ahemmmm....Thoughts????? Oppinions?
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Joechris on November 12, 2009, 03:16:36 PM
From wikipedia: "The best known story involving Helios is that of his son Phaëton, who attempted to drive his father's chariot but lost control and set the earth on fire."
Maby PHAETON could be a cool name for this project  :D
j
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 12, 2009, 03:30:05 PM
What-so-ever. Ideas about naming the busstard are wellcome as well as ideas about functionality/desigh.
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: phishman13 on November 12, 2009, 04:47:05 PM
I 4th the inclusion of the mic pre section.

And 2nd the name Phaeton. That sounds bad ass. Especially as this could be considered offspring of h*lios. And from the way things are shaping up, it will set audio on FIRE!
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Joechris on November 12, 2009, 05:19:48 PM
ok,ideas about functionality/design..The switch between bass cut/boost/both is unnessesery because if you use two 12 steps all those options can be obtained just by using the rotarys. (placing the low cut infront)
12 possisions seems a bit overkill for cut, since its just a 6 db slope anyway. You would´n  hear much differece beetween the steps, unless you take the range all the way up to something like 500hz. But the boost would be nice since its a peak thing, and with a multitap like the vtb9043, a lot of different curves and frq could be obtained. Out of normal range is of cause a good thing.
j
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: Igor on November 12, 2009, 08:17:06 PM
@joechris: yes, when lo cut is shorted, it is OK.
Ahemm...Phaeton....FIRE?????? My DOB is 8th Dec, and I am almost 33.
FFFFFIIIIIRRRRREEEEE!!!!!!!!!!!!!!!!!!!!
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on November 12, 2009, 08:37:02 PM
Next: why can't we use the rest of LF inductor's peaking values for different freq's?
All I actually needed from lo-cut circuit is...50 or 120, 2nd order, bit peaking=always prefereable,
in any circuit, in studio or PA across.. some small arreas at this world.
No more, it is...maybe just my bad taste.
But......MAYBE.... 11 positions for lowcut from "off" to 500 can be usefull?
VTB9043 gives us a lot of midrange options as well to increase lo-range switch to some fun positionZZZ...
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: desol on November 12, 2009, 08:42:22 PM
Is the idea of mic/line/DI switching on the table?  

I second that.  I hope so.  An EQ's utility is only fully utilized if you can use it both during tracking (with mic input) and mixing or downstream from another mic pre (line input).  Having a DI input also, would increase the utility!

Third. :)

Mark


Well, that's cool i guess. I have 16 nice preamps, don't need anymore, don't want anymore, don't need to spend $100 per input transformer(which i would rather put into other parts for the eq), that will never sound like the original transformer anyway, etc. I think it's a waste of money, most everyont has tons of pre's...and what about 51x? If we go that way, will everything fit?
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: audiovisceral on November 12, 2009, 08:59:25 PM
2 Phaetons please. I also would appreciate a line/DI/mic function. To be honest I don't even need more pres but as long as the eq can still be used independently I think this should be great. Looking forward to it.  Good choice. :)
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: desol on November 12, 2009, 09:20:46 PM
From wikipedia: "The best known story involving Helios is that of his son Phaëton, who attempted to drive his father's chariot but lost control and set the earth on fire."
Maby PHAETON could be a cool name for this project  :D
j

Phaeton...curiously similiar to Photon?? Who knows..
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: hitchhiker on November 12, 2009, 10:20:41 PM
I agree with Keith, Why find trouble? it's a current product.
 Besides, much of the great vibe of this fella may likely have be the amps/console/transformers themselves. And sadly that's not a well covered subject.  Why not look at the passive eq design and go from there? Get the inductors, Q's freq'"s etc. Go for neve, helios amps or whatever? And yes a new name too.
cheers, Lance
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on November 12, 2009, 11:04:35 PM
I'm all for the preamp.  Sowter makes a Lustraphone-style 1:10.  That appears to be what the current Type 69 is employing.  I think the input transformer and preamp are part of the magic.  The new and originals are unbalanced out.  So there's some savings there.

There are plenty of EQ only projects around here, between the 5003, two 1084's, Pultecs, Calrec 1549, S800, W492 and the NYD Passive.  So you want EQ only, build one of those and let us have our preamp! 

(http://www.vintageking.com/core/media/media.nl?id=71246&c=360669&h=fe2988026bf9fe06e1e7)
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: tommypiper on November 13, 2009, 12:19:44 AM
I'm all for the preamp.  Sowter makes a Lustraphone-style 1:10.  That appears to be what the current Type 69 is employing.  I think the input transformer and preamp are part of the magic.  The new and originals are unbalanced out.  So there's some savings there.

I second Miko.  Yes, there's lots of pres out there.  This is a pre AND an EQ!  We don't see those that often.  And as Miko points out, maybe we can have an optional unbalanced out that doesn't require output iron.  However, if Igor puts in the Neeve 283 output, those Carnhill and other output iron options are not expensive.  Cinemag has some.  And Miko, weren't you doing a group buy of some other Neeve outs that were inexpensive?  In any case, even the 283 circuit has an unbalanced out built in, for those who wish to avoid output iron.  (I personally always favor using output iron!)

I'm not a fan of the 500 or 51x series module sizes.  Too small. 
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on November 13, 2009, 08:16:29 AM
Ok...Where can I find PCB footprint for Sowter Lustraphone-style 1:10?
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Kingston on November 13, 2009, 08:26:41 AM
http://www.sowter.co.uk/vintage-audio-transformers.php

model 7490

http://www.sowter.co.uk/mech.php

"eE" Mumetal,
Mumetal can
Threaded boss

In other words, it doesn't have a PCB layout, but mounts in a hole with a bolt (M10 I think) and you solder the wires.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on November 13, 2009, 08:32:46 AM
Thanx. If someone have VTB9048 drawings with measures, can be great.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Rob Flinn on November 13, 2009, 08:41:18 AM
Colin at Audio Maintenance is normally pretty useful for supplying drawings for the Carnhill stuff !
Title: Re: DIY Hell-I-OS EQ? Let's do it!
Post by: hobiesound on November 13, 2009, 09:19:42 AM

Insert can be done with relay and active line receiver/driver....
This complicates a bit and requires +/- audio power supply instead of single + or - 24V
(depending on how old the Hel**s model is...)
Just a thought. Older Hel**s modules were using -24V supply. We need +24V for makeup stage (second half of BA283).
So, why not use +/-24V power supply and power from here switchable insert's balancing driver/receiver?
This way we have (if insert is "on") balanced micpre out and balanced input into EQ.
When insert is off, relay takes care of insert and sound does not passing thru balanced driver/receiver.


i might be the odd one out, but if you run the amp card on +24 you have a PNP on input which theoretically should be lower noise than a NPN. Not sure if that is still the case with modern transistors. I'm gonna be building 2 old skool style, i've got enough info/parts to build it more or less as authentic as possible. only difference with mine is probably gonna be the output amp which i'll be making balanced out. (still deciding on the options out there, so i'm watching this thread closely :) .

Still hoping to find some info that i don't already know. i was kind of disappointed when this thread turned into a ordering thread instead of a sharing info and learning thread... but then again that's the way this forum is heading lately.....

greetings,

thomas
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: audiovisceral on November 13, 2009, 09:20:59 AM
I agree with Keith, Why find trouble? it's a current product.

It's decades old. The patents for the original designs are long expired. The trademark still applies, but this is a Phaeton project, not Helios. This is no different from the UA 1176, LA2A, and G-SSL clones which are also  of current products.

And I agree with the others - mic and eq (plus di) in one is great, but only if we can also use the eq alone with line levels.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: hobiesound on November 13, 2009, 09:36:44 AM
i don't understand the discussion whether to include a line input the original already had a line input.... although unbalanced but that can be solved in a number of different ways if need be.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: audiovisceral on November 13, 2009, 10:27:15 AM
i don't understand the discussion whether to include a line input the original already had a line input.... although unbalanced but that can be solved in a number of different ways if need be.

Could we incorporate a little circuit we can switch in  to electronically (or transformer) balance this line input when the mic in is not being used?

Could be a nice modern upgrade.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: tommypiper on November 13, 2009, 11:00:20 AM
...the original already had a line input.... although unbalanced but that can be solved in a number of different ways if need be.

I prefer to have unbalanced options when possible.  I suggest we have OPTIONZZZ  :D  for unbalanced input and unbalanced output. 
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on November 13, 2009, 12:24:11 PM
Could we incorporate a little circuit we can switch in  to electronically (or transformer) balance this line input when the mic in is not being used?

Could be a nice modern upgrade.

The idea mentioned a little while back was to pad the signal before the input transformer for line level. 

Perhaps Igor can layout the board in a way that can leave it up to the builder how far they want to go.  Like leaving off the preamp or keeping it and having solder points for an optional unbalanced in.  Which ain't my bag, but I can see how people may want it for mixer inserts.


Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: audiovisceral on November 13, 2009, 03:53:56 PM
The idea mentioned a little while back was to pad the signal before the input transformer for line level. 

Perhaps Igor can layout the board in a way that can leave it up to the builder how far they want to go.  Like leaving off the preamp or keeping it and having solder points for an optional unbalanced in.  Which ain't my bag, but I can see how people may want it for mixer inserts.

The only problem with padding if I understand is to get a balanced line input, we're essentially having to run signals through the preamp a whole second time (40 dB pad to mic level, 40 dB gain back up to line), which might add coloration we don't always want.

I doubt Igor will be able to find a design that works for everyone, but I hope he will be able to develop a bit more elegant of a line/mic/DI in solution.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on November 13, 2009, 04:18:46 PM
...we're essentially having to run signals through the preamp a whole second time (40 dB pad to mic level, 40 dB gain back up to line), which might add coloration we don't always want.

Isn't color kind of the point of this unit?  If you want cleaner EQ, I'd elect to build something else.  There are plenty around.  

Going without the input stage of this is kind of like getting an old sports car, taking out the engine, having a tow truck pull you around everywhere, and telling everyone you drive a sports car wherever you go.  It sort of kills the point of the old sports car, doesn't it?

On the other hand... I love flexibility as much as the next guy, I'm just worried that adding too much could eventually take this so far way from it's origin it may not be worth the cost and effort.  

Igor, you're a smart fella.  I'm sure you'll do a wonderful job putting together something we can use with pride.  Cheers.

BTW.  I sent Colin at Audio Maintenance an email about the inductor dimensions. 
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: drpat on November 13, 2009, 06:10:22 PM
...
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on November 13, 2009, 06:27:38 PM
Is that anything like putting a huge wing on the back of a front wheel drive Honda?  ;)

I'm demo-ing the 500 series Helios in a couple weeks.  I'm curious to see what they sound like.  They're priced pretty well.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 06:41:51 PM
I'm demo-ing the 500 series Helios in a couple weeks.  I'm curious to see what they sound like.  
Ah yes, those are pretty. What's the selling price on those Mike?

And there's the Realios Mic Pre's as well.

http://www.realios.com/

Mark
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: strangeandbouncy on November 13, 2009, 06:44:01 PM
Hi,


  as a current owner of several original helios modules, and a former owner od several other types of Helios modules, both active and passive eq's, I suggest that going in and out un-balanced is a good idea. I have tried several different trannies in and out, and I can honestly say that they sound best un-transform(er)ed. They sound loads better imho going unbalanced Line-in than Mic in padded. Just give it a try if you don't believe me. Strange, since the mic pres are pure sex! I only have modules with the tiny Beyer trannies at the mo, but I have had Lustraphone, and also some big Sowter inputs on my stolen Active 3 band eq's.(If it was you that stole them, I am coming to get you, and it is going to hurt quite a lot when I find you . . . . ) My life is NOT the same without them.

    Let me know if I can help!


       ANdyP
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 06:54:15 PM
And there's this beauty.

Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on November 13, 2009, 07:08:02 PM
Thanks for chiming-in Andy.  Good to know the EQ does have its "own" thing.  Have you ever seen the green Helios console made for Apple Records?  I was at VK the other day and they had a repair in from someone famous.  They looked like Helios modules but they were bright green anodized faceplates.  

Mark, any idea what those Realios are going for?  Vintage King is selling the 500 Type 69's for $1375.  Which is a lot for any 500 module, but perhaps these might be worth it.  
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: audiovisceral on November 13, 2009, 07:28:43 PM
 as a current owner of several original helios modules, and a former owner od several other types of Helios modules, both active and passive eq's, I suggest that going in and out un-balanced is a good idea. I have tried several different trannies in and out, and I can honestly say that they sound best un-transform(er)ed. They sound loads better imho going unbalanced Line-in than Mic in padded.

From your post I will skip the trannies. I feel uncertain about how good an idea it is to have unbalanced gear in an otherwise balanced studio, but if we want  balanced line input without using transformers it would be fairly easy.

All we need is a little circuit like this on the line input jack:

(http://sound.westhost.com/p51-f2.gif)

If people don't want the line input balanced, they could just bypass the circuit and wire the jack in to a given point directly after it. Simply as can be.

Then for the output, we could similarly have a simple balancing circuit like:

(http://sound.westhost.com/p51-f1.gif)

Those that want unbalanced out or transformer balanced out would again skip this little bit and take their output from a given point before it.

(figures from http://sound.westhost.com/project51.htm)

I don't design gear though and I don't know the Helios so I don't know if this would work. But it seems to make sense to me and seems simple enough.

It would only take up a tiny spot on the PCB if integrated. If it's not an integrated option, I think it would be easy enough to breadboard in.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 08:33:36 PM
Isn't there a provision for a line input on the original schematic?

I'm certain I saw it there.

Ah yes, it looks like it bypasses the input transformer and goes into Pin 1 on Card 1.

Unbalanced isn't a big deal, you lose 6db but it's not like I need to run a signal to Cleveland and back. :)

Here's the first gain stage from the Olympic modules.

Mark
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 08:41:16 PM
1973 V69 schemo #1

Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 08:46:03 PM
2003, V69 schemo #1
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 08:51:06 PM
2003, V69 schemo #2
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 08:51:37 PM
2003, V69 schemo #3
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 08:56:54 PM
1973, V69 Line Output schemo

Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: hobiesound on November 13, 2009, 09:16:54 PM
thanx for the 2 missing files of the 2003 schematic! Way back can sometime only get you so far......  ;)

greetings,

Thomas
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: desol on November 13, 2009, 09:51:01 PM
...more like building a fake sports car and modifying it to something different before it even leaves the drawing board.

Yes, which was the suggested idea. To make it something different, to avoid pissing off someone who could possibly get pissed off about it. To be somewhat considerate i guess.

So...

...if it were to be 'different', I would rather have more of the eq's in a smaller format, because i have lots of preamps. This seemed to offer more at a lesser cost while trying to adhere to the idea of making something different. Also, it seemed to come at the right time for the 500 series cases, of which there are plenty of other folks projects and eq's involved.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Biasrocks on November 13, 2009, 10:04:28 PM
...if it were to be 'different', I would rather have more of the eq's in a smaller format, because i have lots of preamps.

If you look at the schematic, you'll see that the line input bypasses the transformer and goes directly into the first gain stage.

Leave the transformer and the gain set switch out, set up the first gain stage for unity with a single resistor.

Viola, EQ only. :)

Mark
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Baltimore on November 14, 2009, 12:43:50 AM
I'd love to see a 500 series version, with or without mic pre.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: desol on November 14, 2009, 09:32:42 AM
...if it were to be 'different', I would rather have more of the eq's in a smaller format, because i have lots of preamps.

If you look at the schematic, you'll see that the line input bypasses the transformer and goes directly into the first gain stage.

Mark


Exactly, and i had noted this earlier, but then erased it...silly me. Line goes straight into a switch, then bounces over to the pad switch and into 1 on the 51c1 card...i believe. So yeah, no lustraphone involved. Also, i read that Dick Swettenham kept all the cards seperate in the original modules because of problems with oscillations at high levels. The reissue card(that's pictured on the first page) bears no resemblence to this tho...obviously TA had no problems with this.

Gotta go for now...two emergency calls just came in...7:30 am yay.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on November 16, 2009, 12:20:09 PM
OK!  Colin was kind enough to revise the inductor measurements for us.

http://www.audiomaintenance.com/downloads/carnhill_design_guide.pdf
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on November 16, 2009, 08:19:37 PM
Yes, I see...From both old and new .pdf's, like from a mystery puzzle, it is possible to
figure out pinouts for most inductors. In new file, for example, missing footprints for VTB9043/44/50/54/55.
Well...Thanx. And, hopefully, the file with all footprints fixed will be there! :)

I working on two PCB versions: Lunchbox format and 1RU. In 1RU version, there will be separate low cut and low boost switches instead of Elma.

What about placing the power supply on-board?
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on November 16, 2009, 08:36:14 PM
Two versions?  Wow, you like being busy.  ;) 

I don't know if I'd put the PSU on board.  Is the 1RU version two channels?  It might be nice to have them as individual boards per channel.  That way you could configure them vertically if desired.  To fit a few in a tall rack case, or to make a small sidecar mixer. 
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: tommypiper on November 16, 2009, 11:34:28 PM
I don't know if I'd put the PSU on board.  Is the 1RU version two channels?  It might be nice to have them as individual boards per channel.  That way you could configure them vertically if desired.  To fit a few in a tall rack case, or to make a small sidecar mixer. 

I second Miko.  PSU off board is better, as separate board.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: hobiesound on November 17, 2009, 06:02:38 PM
Hi,


  as a current owner of several original helios modules, and a former owner od several other types of Helios modules, both active and passive eq's, I suggest that going in and out un-balanced is a good idea. I have tried several different trannies in and out, and I can honestly say that they sound best un-transform(er)ed. They sound loads better imho going unbalanced Line-in than Mic in padded. Just give it a try if you don't believe me. Strange, since the mic pres are pure sex! I only have modules with the tiny Beyer trannies at the mo, but I have had Lustraphone, and also some big Sowter inputs on my stolen Active 3 band eq's.(If it was you that stole them, I am coming to get you, and it is going to hurt quite a lot when I find you . . . . ) My life is NOT the same without them.

    Let me know if I can help!


       ANdyP

hi Andy,

do you own a passive eq module? if so would it be too much to ask if you could measure the inductors and get a inductance and DCR values for both inductors? measurements of size (lams, former etc) and maybe a few pics would be even better! i'm wondering since i'm winding a 10H inductor for the low band right this moment.

greetings,

Thomas
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on November 18, 2009, 07:28:36 AM
Yes. This info is wellcome.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: desol on December 10, 2009, 08:53:53 PM
Bump. Can't forget this one.  :)

Be nice to have the lustraphone. The sowter is probably pretty good...

Mic pre is nice. Couple anyway...and some 500 series.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: strangeandbouncy on December 11, 2009, 05:25:16 AM
Hi,


   sorry guys, I haven't had time to follow everything!


   I have 2 different types of passive. I would suggest the ones from MCA Hllywood cansole would be the ones you want to copy - and that's just because they are TURQUOISE in colour . . . I don't know how to measure inductance . . . Help?


       I will take piccies when I can. ie they are in permanent use . . .



     ANdyP ;D
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: SSLtech on December 11, 2009, 05:07:48 PM
Anyone had a look here lately?

http://recforums.prosoundweb.com/index.php/mv/msg/16023/0/1856/2172/

 ;D

Keef
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Mark Burnley on December 11, 2009, 05:57:23 PM
Yum!

...now that's a way to spend and evening...

 :o

Mark
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: SSLtech on December 11, 2009, 07:29:04 PM
An evening???[/u]

-You speed-reader stud, you!

Keef
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Mark Burnley on December 11, 2009, 07:44:22 PM
...yea,

....must've spent too much time with our baby's books-

I only look at the pictures now!

 ;)

Mark
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: SSLtech on December 11, 2009, 07:47:29 PM
Well, you'll be pleased to know that you're personally referred to at the foot of page 6... and it's now at almost 150 pages!

You star you!!!

Keith
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Mark Burnley on December 11, 2009, 08:48:22 PM
...oh yes,

I like a bit of Heelyoss Tompfoolery me!

 :P

Mark
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on December 12, 2009, 07:54:41 PM
If someone can give us more info about core material used in original modules or
close-up pictures, it is more than wellcome. The rest is more or less layed out on PCB....including
two options for input amp (Ne/He) and two options for output amp (Ne/He)....relay's switching of course...
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: SSLtech on December 12, 2009, 08:19:57 PM
or close-up pictures, it is more than wellcome. T
There are a few in the other thread...

Although it's so long that it may take a while to find them.

-I suggest a couple of hours right-clicking... "save-as"

Keith
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on December 13, 2009, 01:39:53 PM
I found the way to get same functionality on LOW freq. switch just using...one Lorlin 2x6!!!!
It is simple, just open it and take off one wiper. In case it is stopped to 12 positions,
we can have 2 new Low Boost frequencies as free gift from Carenhill. VTB9043 has 10 and 7Hy taps....
More later, freakin' on lining up 4 nice amps and relays switching on main board......
HeNe. I like this :)
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on December 13, 2009, 08:59:41 PM
Well....

EQ board.

Still have to fix some stuff, but mostly done.

Schemo:

http://i251.photobucket.com/albums/gg291/diy33609/hene_sch_prelim.jpg

Layed out to fit 2 channels in 1RU if only EQ used,
or can be connected to BA-283 based Ne*ve pre-amp,
or can be used with HeNe motherboard....


(http://i251.photobucket.com/albums/gg291/diy33609/hene_eq_prelim.jpg)
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: MikoKensington on December 13, 2009, 09:27:45 PM
Ooooooooh.
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Junction on December 13, 2009, 10:05:37 PM
Nice work Igor.

Any chance someone could rework this with the mic pre in a 500 format, i want some!!
Michael
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: haima on December 14, 2009, 02:53:07 AM
very nice igor! thumbs up
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on December 14, 2009, 04:30:31 AM
Yes, as promised, there will be 500 format PCB's. But later.
For now, I want to complete rack PCB's. Ideas/thoughts are welcome. 
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Moses on January 09, 2010, 02:29:18 PM
Any more news on this? I ask merely to bump this thread!!

Very excited to get a couple of the 500 series version, should that happen!!

Mo
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Igor on March 10, 2010, 08:52:18 PM
http://www.groupdiy.com/index.php?topic=38176
Title: Re: DIY Hell..S.... EQ? Phaeton Son Of Hellios! FIRE!!!Let's do it!
Post by: Whoops on October 20, 2012, 05:18:37 AM
This is a really cool project, but what happened to the Mic Pre?