Forum Replies Created
The plugging/unplugging topic has been beaten to death on pg. 1 and in a number previous posts for that matter.
The bias circuit has been generally reliable over the years, panel issues are another story, at least for some pre PX panels, also mentioned on pg. 1.
At the end of the day do what makes you feel comfortable, you wanna leave them powered 24/7, do it. You feel more comfortable unplugging/ turning them off when not in use, do it.
The one instance when I would certainly unplug them is when severe weather (lighting) is forecast/imminent.
BTW, TWB’s comments about pre and post PX panels are accurate, had my share of factory returns due to pre PX panel failures.
Now, let me go turn my panels on and listen to some music.;))
Check the older threads, another member uses wireless lamp switches, RF not Wifi, to turn his Majestics On/Off.
Might be easier than bending over to flip the switch.
I also unplug my U890’s when not in use. I have a short male-female extension with inline switch (https://www.amazon.com/gp/product/B01HGNN30M/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1).
As D10 mentioned above, the panels bias up in seconds as per Roger West.
That’s great, glad to hear it!
Been there, done that.
I’d much rather feel like an idiot than:
1. Have a bad panel/supply that needed to be returned and repaired.
2. Return the panel/supply only to find out there was no problem
My rule of thumb, check the simplest most obvious items first
even though I think, “NAH, it can’t be that” ;))
Enjoy your system!
By your description you could have some dust or other contaminant that is causing a discharge. If so it should subside over time.
I’ve had variations of random noises caused by contaminants over the years with the various SL panels I’ve owned. The noise, with no music playing, can take the form of crackling, sizzling, whistling, ticking, etc..
At times I have been able to change the characteristic of the noise, or even eliminate it, by standing close to the panel and blowing hard into the area where the noise emanates. You might be able to use “Dust Off” canned air to provide the same effect, just don’t point the nozzle too close to the membrane.
The PX panels are very reliable, Roger has mentioned in the past the only issues they’ve had are due to shipping damage.
That’s correct, you can see that it is connected to the AC receptacle
and line fuse holder. Output of the supply, red wire, plugs into the HV mixer.
Correct, directly from the SL factory, speak to Connie and she’ll be able to fix you up.
Replacement is not difficult although it does entail soldering a few connections. Take a look at the pix. below, that should give you a pretty good idea. You’ll need to replace the bias control, included with the bias supply, also.
AFAIK the brilliance control (L Pad) has a linear taper, but that said, the only way to know for sure is to measure it.
As to mounting the resistor, why not just remove the brilliance control and mount your resistor to the backplate with a screw/washer passed through the controls mounting hole in the backplate? Add some thermal paste for heat transfer and away you go.
Looks like that is the earlier input circuit. There was a revision to increase the impedance of that circuit to make it easier for tube amplifiers to drive the speaker. At one time there was an upgrade kit which included a new circuit board.
I would call the factory and speak to Connie to see what is currently available.
How are you going to mount them as they need to be heatsinked to meet their power rating?
Is this as a replacement for only the brilliance control or also the 8
resistors on the input side of the Toroid?
You could try replacing both bias supplies with the newer version to see if that resolves the issue.
Also, the new bias supplies are regulated so line voltage variations no longer affect the bias level.
How old are your A1’s?
I’ve attached a wiring pictorial for you to peruse. The diagram may not match the wiring of your Pristines so I would suggest you contact the factory to obtain the correct one for your speakers.
It would help if you posted a few pictures of your backplates to give us a better idea of what your describing.
I’m unclear as to what you mean by “bias taps”. The bias level is set via a variable resistor. To set proper bias the shaft on the resistor is rotated clockwise to increase the bias to the point where the panel starts to crackle and then backed off to the point where the crackling just ceases.
A number of people have replaced the brilliance control with a fixed value resistor by setting the brilliance to a level that gives a proper high frequency balance, measuring the resistors value and then replacing the control with the measured fixed value. I would use a 50W non inductive style resistor.
Good Luck with your restoration, I hope the panels themselves are functional and in proper order.
- This reply was modified 4 months, 2 weeks ago by John V.
Good to hear from you!
The Herbie’s I use are the stud gliders and they have no point/base.
Below are a few pix. of the modified frames along with one
shot of a stud glider.
Roger had his metal fabricator make up the extensions and then shipped them unfinished to me where I had a local auto body shop
paint them. I supplied the shop with one of the metal caps from the frames so they could get a good color match. I had a few issues with fitment at first but was ultimately able to get them installed.
I used a bright flashlight to illuminate the membrane through the Spandex and it was quite easy to see the wrinkles/ripples in the membrane.
Have another person hold the flashlight while you manage the heat gun. I tried doing both at once and it got quite confusing at times as to which hand had the heat gun vis a vis the flashlight. ;))
You will easily see the wrinkles disappear as the membrane tightens up as the heat is applied, just don’t overdo it.