EMI RS124

[Rob Flinn]

I think this one was the transformer you once linked to:
https://www.audiophonics.fr/en/r-co...Cr2-NRgF4h9Ugi11VJVDFSJlAhfjTFL7qKPZRLgUml6t8

But this one also seems even more appropiate (less voltage to drop) when you're ok with using AC heaters:
https://www.tubetown.net/ttstore/de/ringkern-netztrafo-30va-8808.html

Either should work.

 

[thomasdf]

Anybody familiar with this brand ? https://www.ebay.fr/itm/163446639404

The 180V secondary is spot on. I'd prefer doing without a dropper resistor

 

[Rob Flinn]

Anybody familiar with this brand ? https://www.ebay.fr/itm/163446639404

The 180V secondary is spot on. I'd prefer doing without a dropper resistor

The heater current is not enough. If you add it up the valves draw 1.3A (6bc8 0.4A, 6cg7 0.6A, 6al5 0.3A).

 

[thomasdf]

There's two taps for the heater, for some reason. But yeah, that's more wiring for sure... still on the lookout for the perfect power transformer... The toroidal from Tube Town is cheap and powerful enough for sure ... but a 180V must exist somewhere
Hiwatt transformer are often 178V, but they are more expensive.

 

[rock soderstrom]

The heater current is not enough. If you add it up the valves draw 1.3A (6bc8 0.4A, 6cg7 0.6A, 6al5 0.3A).

+1

 

[rock soderstrom]

The toroidal from Tube Town is cheap and powerful enough for sure ... but a 180V must exist somewhere

I cannibalize (tube) tape recorders for this purpose. Some Grundig TK models are in the right range depending on the load. I am preparing an additional RC-filter stage on my PCB so that different transformers can be adapted.

 

[rock soderstrom]

The 180V secondary is spot on. I'd prefer doing without a dropper resistor

Me too. You can of course adjust B+, but I am also interested in the "original" voltage to compare everything that follows with this reference. The closer you get to it, the closer you are to the original design.

 

[thomasdf]

There's this one, but I am scared : https://www.ebay.fr/itm/272830258688

And the original one is a joke :

 

[C.B. - Boudio]

I cannibalize (tube) tape recorders for this purpose. Some Grundig TK models are in the right range depending on the load.

I have done it myself as well, but please do not exaggerate with cannibalizing, they are sometimes just too neat for it - or there must be some broken zamac in it or something ;-)

 

[rock soderstrom]

I have done it myself as well, but please do not exaggerate with cannibalizing, they are sometimes just too neat for it - or there must be some broken zamac in it or something ;-)

No, I'm not overdoing it with the cannibalization of such devices. I only take them from the recycling yard, usually with significant casing defects. I have four of them in the cellar in excellent working condition, otherwise there are very many of these in defective or poor condition. I think it's better to give such devices a new life, at least in parts, and I believe in upcycling and prefer it over a thermal "treatment".

I try really hard to make the right decisions here, but I can also understand if someone sees it differently.

 

[Rob Flinn]

There's this one, but I am scared : https://www.ebay.fr/itm/272830258688

That looks usable although it doesn't tell you what the current is for the 180-0-180 winding. I would use the spare 6.3v winding to power an "on" lamp.

 

[C.B. - Boudio]

No, I'm not overdoing it with the cannibalization of such devices. I only take them from the recycling yard, usually with significant casing defects. I have four of them in the cellar in excellent working condition, otherwise there are very many of these in defective or poor condition. I think it's better to give such devices a new life, at least in parts, and I believe in upcycling and prefer it over a thermal "treatment".

I try really hard to make the right decisions here, but I can also understand if someone sees it differently.

I did expect that you are quite careful. But we all know that there are others that do it... differently....

 

[rock soderstrom]

I did expect that you are quite careful. But we all know that there are others that do it... differently....

I still don't quite understand what you want from me and what this has to do with the topic of the thread?

Let's get back to talking about the actual topic.

I managed to find some 110v bayonet fitting neons on ebay which work great & are easy to replace if one dies on me.

I like the idea of making the neon lamp socketed. I don't have any Bayonet sockets but I do have some solder-able E12 sockets.

There are suitable 110V glow lamps on ebay that should also work?

https://www.ebay.de/itm/13418509388...abOHt0UrFHtkZPOAZzWqSW6w==|tkp:Bk9SR_aFsb7kYw

 

[rock soderstrom]

For all those who are wondering (like me) how the balance process works and, above all, what it sounds like , here is a video.

 

[berret]

I have used this one for several projects:
https://a.aliexpress.com/_EIhkfdD

 

[Murdock]

This one would be perfect for a stereo version. Two times all the needed windings.
The two 6,3V windings have 2A each.
And even a 9V 1A winding for DC heater for the first tube if needed.


https://www.don-audio.com/Audio-Toroidal-Transformer-Pri-115/230V-Sek-2x-180V-2-x-63V-9V

 

[thomasdf]

I have used this one for several projects:
https://a.aliexpress.com/_EIhkfdD

I bought a pair ! Thanks for the reco

 

[rock soderstrom]

This video explains the balance circuit with the neon lamp - it is called a relaxation oscillator.

 

[rock soderstrom]

Hey guys, I think there were gutshots of original RS124s in this thread? Could it be that they were deleted (by Winston?) Does anyone still have them on their hard drive and would post them or send them to me via PM? That would be super nice, I'm interested in the build and component selection.

 

[thomasdf]

Interested too, though I have some gut shots taken from various Reverb sales, let me check