Crown Macro Reference Monster amp rework.

WOPL Sniffer said:
The specs for an average EL panel has a wide operating range so finding an inverter should be easy enough.


  • Glow Size: 10 cm x 10 cm (3.95" x 3.95")
  • Plastic Size: 10.4 cm x 10.4 cm (4.1" x 4.1"), about 0.5mm thick
  • Panel lifetime: >25000 hours
  • Operating voltage: 60-250VAC
  • Operating Frequency: 50-5000HZ
  • Current Draw: 0.14mA/cm2 (max) @ 110V / 400Hz
  • Initial Brightness: 85 cd/m2
  • Operating Temperature: -50 C / 65 C
  • 45 nF per panel
Click to expand...
Shame on Crown putting a switching PSU inside an audio amp of this caliber
 
Hi,

I have no clue, but I did my share of reading about EL foils. They fade with time, inverters are rarely the culprit. I likely am wrong, but hey...my Revox B285 receiver is iluminated from behind with an EL foil...there are but a few of these around. So, if I pulled it of , you most definitely can. On the other hand, I suggest you use a LED ilumination panel instead.

Revox B285 LCD + EL-foil inverter (1).jpgRevox B285 LCD + EL-foil red (1).jpgRevox B285 LCD + EL-foil red inverted (2).jpgRevox B285 LCD + EL-foil blue (1).jpg
 
borchee said:
Hi,

I have no clue, but I did my share of reading about EL foils. They fade with time, inverters are rarely the culprit. I likely am wrong, but hey...my Revox B285 receiver is iluminated from behind with an EL foil...there are but a few of these around. So, if I pulled it of , you most definitely can. On the other hand, I suggest you use a LED ilumination panel instead.

View attachment 74595View attachment 74596View attachment 74597View attachment 74598
Click to expand...



Yep, I'll verify what is causing the issue later. I am preparing for any of the items being bad. I don't see both EL panels going tits-up at the same time but I could be wrong. If you look at the skimo I posted above, it has 2 panels driven in parallel so I doubt both would fail at the exact same time. But, you never know.
 
They don't fail/die in the sense of a lightbulb or LED for example, they just fade away with time - the filament (or something like that) wears out with use and time...I guess simmilar to vacuum fluorescent displays. So, it's plausable that both are equaly worn out. It can be the inverter's fault of course.

Good luck...not that you need any.

BTW, this realy is a monster - at the first glence it stroke me like a boombox for the Hulk.

Edit...forgot to mention it. There are a few lines exchanged regarding the foil/inverter with this amp: https://www.audioheritage.org/vbulletin/archive/index.php/t-39601.html
 
Last edited:
borchee said:
They don't fail/die in the sense of a lightbulb or LED for example, they just fade away with time - the filament (or something like that) wears out with use and time...I guess simmilar to vaccum fluorescent displays. So, it's plausable that both are equaly worn out. It can be the inverter's fault of course.

Good luck...not that you need any.

BTW, this realy is a monster - at the first glence it stroke me like a boombox for the Hulk.
Click to expand...

I see they make the new EL foil pieces too just in case. Good to know it can all be built/rebuilt. And yes, I DO need a bit of luck at times. But it's nice to surround ourselves with brainiacs. :)
 
If the precut foil is to expensive (Revox, for example, demands an arm and a leg...100 ++ smackaroones and others still 60-70-80) you buy a larger one, cut it accordingly and isolate/seal the edges or laminate it. You may look out for foils with multiple contacts - it may be even cheaper, depending on how many you need and how many you can cut out.

If I recall it correctly, inverters are rated by the area/surface they should, or can reasonably, illuminate...for example up to 25 square inches.

...and the manuals from elektrotanya are safe - they are Magyars, not Ruskys. ;) The SMs for the monster are of good quality.
 
Last edited:
Sorry for the late reply, Perry, but I have never inquirie for this amp schematics. If that a foil related issue, then, that explains it. All Revox B 200's series has the same problem, like my B 215S and B 226.
 
I have +6.5vdc on one side of the inverter and 3 vac on the other. I don't think that's enough to drive the EL panels. I think the inverter is bad. I don't know what the circuitry looks like inside in but I think part of it may not be working. The pot is still in it's original position with the red spooge marking it's factory setting and I believe the inverter will work at 6.5vdc but should be putting out MUCH more than that.


EL PS.jpg
 
WOPL Sniffer said:
I have +6.5vdc on one side of the inverter and 3 vac on the other. I don't think that's enough to drive the EL panels. I think the inverter is bad. I don't know what the circuitry looks like inside in but I think part of it may not be working. The pot is still in it's original position with the red spooge marking it's factory setting and I believe the inverter will work at 6.5vdc but should be putting out MUCH more than that.


View attachment 74616
Click to expand...
You should lift the red wire from the inverter and then measure the unloaded voltage of the input regulator (emitter of Q5) to see if the broken inverter was dragging down the input source.
 
Gepetto said:
You should lift the red wire from the inverter and then measure the unloaded voltage of the input regulator (emitter of Q5) to see if the broken inverter was dragging down the input source.
Click to expand...

To do that, I'd have to pull the whole control board since the board is mounted solder side down. It would be quite the job. If you look at the pic, you'll see that the board is IN there good. I will if I have to (and change Q5 if I have to) but I think the 6.5VDC is correct for it's input. Most of the EL Panels use that exact voltage for operation.


crown_macro_reference_power_amplifier_02jpg.image.600x450.jpg
 
WOPL Sniffer said:
To do that, I'd have to pull the whole control board since the board is mounted solder side down. It would be quite the job. If you look at the pic, you'll see that the board is IN there good. I will if I have to (and change Q5 if I have to) but I think the 6.5VDC is correct for it's input. Most of the EL Panels use that exact voltage for operation.


View attachment 74621
Click to expand...
Is it sitting on top of a toroid? (the big bolt)
 
I hooked up my Variac (Good Call George) to the top EL panel and brought it up to 120VAC. Looks great. Maybe I'll just hook it up to switched power.


EL.jpg
 
WOPL Sniffer said:
I think the 6.5VDC is correct for it's input. Most of the EL Panels use that exact voltage for operation
Click to expand...
I believe EL foils in general start to wake up at about 20VAC. My inverter works with 5VDC and puts out 110 VAC, I tend to remember...no clue about frequency anymore. A good read for a layman like myself, particulary the "hum" notice...yep, should have come across this earlier...although it was't humming, but rather screaming at an annoying frequency: https://www.el-licht.de/elektrolumineszenz/

Edit
Never mind my babbling...looks great!
 
borchee said:
I believe EL foils in general start to wake up at about 20VAC. My inverter works with 5VDC and puts out 110 VAC, I tend to remember...no clue about frequency anymore. A good read for a layman like myself, particulary the "hum" notice...yep, should have come across this earlier...although it was't humming, but rather screaming at an annoying frequency: https://www.el-licht.de/elektrolumineszenz/

Edit
Never mind my babbling...looks great!
Click to expand...


It appears that the higher the freq, the brighter they get. I see some that will go to 400hz. Mine is not that bright as the pics I posted show at 120VAC but I can't vary the freq.
 
Yes, brightness increases with frequency as well as with voltage...lifetime is shortened, though. Decrease voltage to test.
 
This is with the shop lights off so it's not too bright but I'm looking at inverters with a higher freq since I can only simulate 120VAC @60hz. It needs to be brighter. But I have the 2 EL panels hooked up in parallel like the skizmo. I got the Harmon Engineer looking into what the original was since he said, Take it to the Service Center and I said they can't do anything with it, they are in the same boat as me not knowing what to use for a replacement inverter. At least he's being helpful. He used the proverbial "Rabbit Hole" which I hate, but help is help. Otherwise I'll have to do some experiments with replacement 6 volt inverters which they do make in a couple different freqs.

EL2.jpg
 
I don't know how bright it originally was, but I'm sure even if you get an original inverter, or one with same specs, it won't reach original brightness - foils are old/original, probably. Their brightness halves in the ballpark of 5.000 hours.

I understood you are fixed on frequency, but voltage you can de-/increase to see how it changes...if I got it what a variac is.
 
borchee said:
I don't know how bright it originally was, but I'm sure even if you get an original inverter, or one with same specs, it won't reach original brightness - foils are old/original, probably. Their brightness halves in the ballpark of 5.000 hours.

I understood you are fixed on frequency, but voltage you can de-/increase to see how it changes...if I got it what a variac is.
Click to expand...


Who knows how long the inverter was burned out. It could have happened early in it's life and never got 5000 hours. Either way, the higher freq is needed. I see they like 400-800 hz to brighten. The voltage won't do it alone. Even if the foils are old and not at peak glow, I can put new ones on but need a 6VDC 400HZ inverter which I have found. I'm trying to get one here in the US but I will order from the UK if I need to.
 
You must log in or register to reply here.
Back
Top