Thanks I will look out for spare one original trannies meanwhile I try your method
More progress. I have done more testing both with music (vinyl) and also frequency responce with good result. You can see the responce from before refurb and here comes after. Im most happy about the almost mirror like diff between speakers. Also some assembling at the new EHT-boars.
And also a test video when playing real music. Just for the feeling
https://drive.google.com/file/d/1XK4S8pFIJUKQtKpQxQaSX0pP7LUNG8Mg/view?usp=sharing
And also a test video when playing real music. Just for the feeling
https://drive.google.com/file/d/1XK4S8pFIJUKQtKpQxQaSX0pP7LUNG8Mg/view?usp=sharing
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For simple checks, you can use a very low voltage transformer, and reduce risks being hurt. Example attached: 28VAC that give 280VDC.
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@ForsbackaKalle Is this what you are looking for?
Set of power transformers and set of step-up transformers for sale in The Netherlands
https://www.marktplaats.nl/v/audio-tv-en-foto/luidsprekers/m1826243730-qua-esl-57-set-audiotrafo
Set of power transformers and set of step-up transformers for sale in The Netherlands
https://www.marktplaats.nl/v/audio-tv-en-foto/luidsprekers/m1826243730-qua-esl-57-set-audiotrafo
Im currently working on another pair of ESLs. They got arced treble cell. A early pair form 1960 and 61. Will be ready soon for some new music.
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First testrun of the reworked panels. Done with 3micron Mylar C. After a night of charge works just fine.
https://youtu.be/CFvCiluVolU
https://youtu.be/CFvCiluVolU
I did some testing with different caps in EHT unit. And it did not work well with the small ceramic disc caps (the bigger ones were okej) i had on hand. But my question was if they were to small to hold charge in the multiplier. Was not able to meaure them, the gigaohm-probe did load them too much. So I set it with paralell and series to get same capacitance and better voltage handling and then now they seem to work just fine.
Result is alot of caps but I have a big bag of them at hand.
I also see a lot of EHT-DIY boards out there. With separate multiliers for bass and treble and also flashing neon bulbs. Good handy gadgets but do any of them really inprove the performance? Separate multipliers will get you advantage not to load the other panels but you still got a problem and flashing bulb to decouple from EHT and flashing to point out performance seems nice but if something is wrong and load the speaker membranes you still need to deal with it. Any thoutgts?
Result is alot of caps but I have a big bag of them at hand.
I also see a lot of EHT-DIY boards out there. With separate multiliers for bass and treble and also flashing neon bulbs. Good handy gadgets but do any of them really inprove the performance? Separate multipliers will get you advantage not to load the other panels but you still got a problem and flashing bulb to decouple from EHT and flashing to point out performance seems nice but if something is wrong and load the speaker membranes you still need to deal with it. Any thoutgts?
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This item came receantly.
https://www.amazon.com/dp/B07BWFRY8C?psc=1&ref=ppx_yo2ov_dt_b_product_details
Great to use as a probe together with multimeter. Provides 10Gohm together with multimeters internal resistance 10Mohm. Get a result in volt corresponding KVolt
https://www.amazon.com/dp/B07BWFRY8C?psc=1&ref=ppx_yo2ov_dt_b_product_details
Great to use as a probe together with multimeter. Provides 10Gohm together with multimeters internal resistance 10Mohm. Get a result in volt corresponding KVolt
The voltage tolerance is not spcified, and I am afraid the 2.9cm body size is too small. I use a 9Gohm 100mm long resistor built in a plastic tube.
But it works. On your own risk of cource.... And I get a reading corresponding to what I predicted. Just above 6volts and also above 1,5volts for treble tap. But if you want a reading with measurement uncertainty its the wrong way. If you just want to see the circuit is working properly you are ok. I have also a isolation meter with Gohm meter function and have measured the resistor.
Had some luck tresure hunting around Stockholm this week. Look what I found. Some really early ones. First serial number is 587.Probably from 1958. This one have lightly darker grilles. The last one in picture. Really lovley colour. Hope to find something to match up with it. Would be a really hot pair
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I will be busy with other refurbish for a while. I just came over this pare of Quad IIs and I cant resist getting them up to drive my ESLs. Someone have done a massive rebuild earlier and I will try getting them back in shape, Tubes are weak and I hate those polycaps incerted.. Back to "gunsmoke" and new Quad logos and so on... This pair have served at Swedish Govermental Radio in the beginning. All trannies measures well. A good start.
