Helios thread

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Whoops

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Those look like Lustraphone transformers, nice.

I can't see what cards are fitted on the mic amplifier. Can you take some pictures of the cards at the top?
 

J0hanne5

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Whoops said:
Well if you know a source for more modules and dont want them all for yourself please let me know, I would buy a few.

Thanks

I am not sure if the modules are for sale but a copy of the manual would be nice...


Whoops said:
Those look like Lustraphone transformers, nice.

I can't see what cards are fitted on the mic amplifier. Can you take some pictures of the cards at the top?

There is no any text on the trannies and Lustraphones are new to me so I cannot say anything about them.
I can try to measure them also if it reveals something.

I will take more and better pics soon!

Edit. Pics of the PCBs added https://drive.google.com/drive/folders/0B53QfYJWE3UVUUczOFo4bGxfSm8

"line amp" is a line amp for sure and "5252" seems to be a level meter circuit which drives an LED.  "5349" is the first PCB in the signal path and "5054" has two identical circuits on it.
 

Whoops

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I searched my Helios docs,
I don't find any info, pics, or schematics of the 5359, 5054.

I have the schematics for the 22113 that are posted in this thread.

As for the Lustraphone transformers those are the most regarded transformers that Helios used.
you can see this pictures of the original Lustraphone transformer

Helios%20MMC1.jpg



Heliossilver2.jpg

 

skidmorebay

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I've put together a mostly point-to-point version of the Helios eq, based on Ruff Record's schematic. Make up gain is via CAPI-Gear's 2-stage booster board, basically one 2520 as a receiver and another as a booster amp. Since I took the photo I've installed 990's in place of the GAR2520's. There's a Cinemag CMOB-2S, 1:1 transformer on the output.

Has anyone found that the lowest frequencies of the mid range boost have a very broad Q? I noticed that in RuffRecord's documentation also, but it seems a bit exaggerated in mine.

 

ruffrecords

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Just because they look broader at lower frequencies does not necessarily mean the Q is lower. The frequency scale is logarithmic  so the low frequencies spread out s lot more. Try measuring the Q from the curves.

Cheers

Ian
 

Squeaky

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I know there has been some interest about Helios consoles and output transformers and whether they were ever used or not (interest in the very least from me). There are currently some Sowter output transformers for sale and the sales blurbs include some interesting photos and comments. The transformers were apparently used in a small Helios console (special order in 1976). Furthermore, these same (or similar?) type of Sowter transformers were also apparently used in a couple of large format recording consoles.
 

Whoops

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Squeaky said:
There are currently some Sowter output transformers for sale and the sales blurbs include some interesting photos and comments. The transformers were apparently used in a small Helios console (special order in 1976). Furthermore, these same (or similar?) type of Sowter transformers were also apparently used in a couple of large format recording consoles.

Do you have links?

I have yet to see any Helios schematic, or photo with an output transformer.
Even if there's a particular model that had output transformers the original ones would not be Sowter for sure.

 

ruffrecords

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Whoops said:
Do you have links?

I have yet to see any Helios schematic, or photo with an output transformer.
Even if there's a particular model that had output transformers the original ones would not be Sowter for sure.

I have definitely seen photos of Helios consoles showing output transformers but I agree they are unlikely to have been Sowter ones.

Cheers

Ian
 

Squeaky

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https://www.ebay.com.au/itm/Helios-Sowter-3865-transformers-LOT-of-seven-6-1/264302853643?hash=item3d89ad7e0b:g:2MQAAOSwwRBc0rAx

https://reverb.com/nz/item/22309576-7-x-sowter-3865-transformers-from-helios-broadcast-mixer-plug-play-6-pack-2ru-panel-1-spare-unit
 

Squeaky

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Apart from the 3865 the other model mentioned is the 4231.

https://reverb.com/item/21802872-9-x-talent-studio-helios-sowter-transformers-1-boxed-8-unmounted-split-sales-at-150-piece-ok
 

ruffrecords

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There is a serious amount of hype surrounding  those ads and the prices are ridiculous when you consider you can get a brand new Carnhill for £25.

Cheers

Ian
 

Squeaky

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From my perspective, I was mainly interested in the information (if it were true) that accompanied the advertisements. Gleaning becomes a pass-time.
 

Whoops

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Thank you so much for the video Ian, and thank Squeaky for the links.

I really don't think any of those transformers have anything to do with Helios or Helios consoles.
Those were probably post-installation transformers that clients asked to be installed to have balanced outputs.

All of those are externally mounted, and don't feel like they were part of any original console.
Neither were any of them made for Helios specifically. They are balancing transformers that a contractor "Benum" ordered for their custom installation.

Some clients, like broadcast companies felt the need for Balanced outputs and they would contract a  post-installation of balancing output transformers, that would be mounted on the patchbay, the back of the console or wherever it was practical.

I never seen an Helios Schematic with an output transformer, neither I have ever seen an Helios console picture with factory installed output transformers.
Maybe there is, but I still have to see one

 

snigglepit

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Hi,

I'm wondering if anyone might be able to help out with information about some modules from an old radio console.  The forum software won't let me attach a photo, but there are some pix here:

www.themorningpeople.com/helios/

They're being restored and racked at the moment but I am struggling to piece together their history because they were not part of a Helios console. They were actually built into a mixer by Tweed Audio that was installed at Capital Radio in London. What seems to have happened is that Helios were in the middle of a big job for Capital when they went out of business, and after this happened, the Capital engineers went to the Helios factory and took away a lot of parts, presumably including these modules.

I've talked to Cyril Jones and a couple of ex-Helios engineers and none of them has a clear memory of these modules, even though they are unusual. Were they originally intended for Capital, or for some other job? Why do they have a compressor built in when no other Helios channels do? Does anyone have any schematics that might be relevant to these? They are the later style with active rather than inductor-based EQ, and the compressor uses a dBx 202 VCA.
 

Winston OBoogie

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When Dave Amels was helping restore and modify Lenny Kravitz's Helios desk and external modules, he added a push-pull transistor buffer to the outputs so a transformer and lower load could be driven comfortably.
On pretty much all the Helios amp stages I've seen, I think this is necessary.
 

Winston OBoogie

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Neat looking modules and story Snigglepit 👍

I think the issue may be the pics are a bit too large to upload, gives us more resolution to zoom in though so thanks 😊
 

Whoops

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Winston O'Boogie said:
he added a push-pull transistor buffer to the outputs so a transformer and lower load could be driven comfortably.
On pretty much all the Helios amp stages I've seen, I think this is necessary.

Do you have idea of what circuit was that?
Any schematic available for that circuit?

thank you so much
 

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