have to decide if I gonna coat the EHT with isulation lacquer or just close it with the wax so next generations/ or even I could remove and disolder this work.
Hope to finish the EHT boards and try them on one bass plate with music.
still have to make the protect board
Replaced the screw
Decide to do the forbiden thing and repaint the front covers.
too bright to my oppinion but identical to the original.
applied without primmer.
covered with cheap spray can.
(all the parts washed last month with water and metal parts covered with trempantine once, wood part covered with Teak oil before paint of the black parts with cheap spray. as I said)
*Teak oil + any spray applied twice (woods and metal).
Hope to finish the EHT boards and try them on one bass plate with music.
still have to make the protect board
Replaced the screw
Decide to do the forbiden thing and repaint the front covers.
too bright to my oppinion but identical to the original.
applied without primmer.
covered with cheap spray can.
(all the parts washed last month with water and metal parts covered with trempantine once, wood part covered with Teak oil before paint of the black parts with cheap spray. as I said)
*Teak oil + any spray applied twice (woods and metal).
Last edited:
Couldn't be patient and done "Test nomber1"
resolts:
- the pannel really quite, used 100% of the amp SONY STR-DN1080 (first tested on a cheap one)
-sound little bit distorted/harsh/and scretchy on high tones (+ it resonate with house furniture)
What things I added in addition to regular instruction:
- Bass panel Bias/EHT added 20Mohm resistor (20Mohm*2 to Treble bias) like Sheldon soggested
- added 2.2Ohms resister to sound input ("Crossover"), to stablize the inpidence, protect the amp and protect the panels from over load.
-Bias voltage values not tested, I do everything righ and I not having skills to do so.
-added 32mA 250v Fast Fuse to input voltage line (230v)
-not full day tested.
Issues:
- the bass panels is tilted/bent and not restored
- no treble panels
- no back wool / felt on the back side
video of the testing (sorry for bad quality and the mess)
YouTube
resolts:
- the pannel really quite, used 100% of the amp SONY STR-DN1080 (first tested on a cheap one)
-sound little bit distorted/harsh/and scretchy on high tones (+ it resonate with house furniture)
What things I added in addition to regular instruction:
- Bass panel Bias/EHT added 20Mohm resistor (20Mohm*2 to Treble bias) like Sheldon soggested
- added 2.2Ohms resister to sound input ("Crossover"), to stablize the inpidence, protect the amp and protect the panels from over load.
-Bias voltage values not tested, I do everything righ and I not having skills to do so.
-added 32mA 250v Fast Fuse to input voltage line (230v)
-not full day tested.
Issues:
- the bass panels is tilted/bent and not restored
- no treble panels
- no back wool / felt on the back side
video of the testing (sorry for bad quality and the mess)
YouTube
Last edited:
Hi Guys,
I know this is a mixed bag posting but I don’t want to start a new thread. I found out what the thumping noise was at high bass. The screws on the rebuilt bass panels have thread sticking out. The dust covers were punctured by them in a couple of places. I think at big bass excursions the dust cover is getting caught on the screw ends.
Now for something much worse. One speaker is quieter than the other. Has been for a while. While I had everything apart I thought I would trouble shoot. Here’s what I did after swapping speaker left and right and amps.
1) Swapped psu. No change.
2) Swapped audio transformer. No change.
3) Disconnected bass panels. The treble panel on one is at least double the volume of the other which sounds dull in comparison.
There’s no indication of arcing. I’m thinking I might have to rebuild as depressing as that is as I paid a small fortune to do it the first time. Are there any external checks I can do to the tweeter without power that could tell me what’s wrong?
I know this is a mixed bag posting but I don’t want to start a new thread. I found out what the thumping noise was at high bass. The screws on the rebuilt bass panels have thread sticking out. The dust covers were punctured by them in a couple of places. I think at big bass excursions the dust cover is getting caught on the screw ends.
Now for something much worse. One speaker is quieter than the other. Has been for a while. While I had everything apart I thought I would trouble shoot. Here’s what I did after swapping speaker left and right and amps.
1) Swapped psu. No change.
2) Swapped audio transformer. No change.
3) Disconnected bass panels. The treble panel on one is at least double the volume of the other which sounds dull in comparison.
There’s no indication of arcing. I’m thinking I might have to rebuild as depressing as that is as I paid a small fortune to do it the first time. Are there any external checks I can do to the tweeter without power that could tell me what’s wrong?
this thread is moor like my fixing bloog.
you can actually open a new one.
but if it can help you somehow I will not post here new posts ubtill you will get your answare
If there is some punched hole on dust cover then put on it some tape to cover this hole
do you tried to switch between the speakers on the amp connection?
also can be the EHT or the crossover board.
if you have some skills to work with top level voltage (6000v) then try to switch between working parts.
if not then dont open the speaker
you can actually open a new one.
but if it can help you somehow I will not post here new posts ubtill you will get your answare
If there is some punched hole on dust cover then put on it some tape to cover this hole
do you tried to switch between the speakers on the amp connection?
also can be the EHT or the crossover board.
if you have some skills to work with top level voltage (6000v) then try to switch between working parts.
if not then dont open the speaker
Sounds like you did everything I'd suggest to do. Swapping the power supply and input transformer with no change eliminates them. So now it's pretty obvious that the treble panel is bad.
Sorry to hear you spent a fortune on that rebuild.
Sheldon
Thanks Sheldon. Just for the record this was not a Sheldon rebuild and there’s no reason to think it failed due to construction...that being said I decided to take it apart as it’s a write-off anyway.
Is it me or should these not have two membranes???? One seems to be fairly intact. The other is a total mess. Big hole in the middle.
Is there something I’m missing here?
Is it me or should these not have two membranes???? One seems to be fairly intact. The other is a total mess. Big hole in the middle.
Is there something I’m missing here?
Attachments
That is really weird, I've never seen anything like it. That's certainly not normal for a panel rebuild. The only thing I can think is that if Wayne used the same crappy nylon coating that quad used, and put it on REALLY thick, the "second" diaphragm you see could just be the coating that pealed off in a unit.
In your picture, you can see the real diaphragm glued to the bottom stator, and the mystery sheet is not really glued to anything. I suspect that is his conductive coating, but anything is possible.
Sheldon
quadesl.com
In your picture, you can see the real diaphragm glued to the bottom stator, and the mystery sheet is not really glued to anything. I suspect that is his conductive coating, but anything is possible.
Sheldon
quadesl.com
It’s pretty damn weird.
It’s not Mylar as it’s quite stretchy and you can roll it into a tight ball like wax. I think you’re right about it being the coating. On the side with the membrane the membrane is stuck to the stator pretty much along the length and width of the panel. I think when I split the panel it pulled off the coating as it came away with the free stator.
It’s a miracle it made any noise at all!
It’s not Mylar as it’s quite stretchy and you can roll it into a tight ball like wax. I think you’re right about it being the coating. On the side with the membrane the membrane is stuck to the stator pretty much along the length and width of the panel. I think when I split the panel it pulled off the coating as it came away with the free stator.
It’s a miracle it made any noise at all!
Ok, little bit about me.
I decided to take some measurments from EHT
It took some time until I found how to do that correctly.
first I dont know the resistence of the DC Voltmetter, so I checked and checge the resolts:
actually is ~10Mohm (-5%)
The test used 1Gohm5% + 20Mohm1%
The fues replaced with 240v 1A fast (instead 240v 32mA fast that "blowed")
6000v Used build in soldered resistors of 20Mohm
1500v Used build in soldered resistors of 40Mohm
The m is:
6000v is 31.4v 31.3v for 20Mohm(||10Mohm Voltmetter) :: 1000+20 (+20) Mohm
1500v for 8.61v 8.62v for 20Mohm(||10Mohm Voltmetter) :: 1000+20+20 (+20) Mohm
not correctly but closed resolts after my math I got:
4835v
1350v
not going to check again.
build the protection board by my decision.
Stupiedly again used too much from the laquer that I forgot to throw before
each hole instead the soldered one drilled through and checked twice.
half CM mistake (from the planned but still ok).
I decided to take some measurments from EHT
It took some time until I found how to do that correctly.
first I dont know the resistence of the DC Voltmetter, so I checked and checge the resolts:
actually is ~10Mohm (-5%)
The test used 1Gohm5% + 20Mohm1%
The fues replaced with 240v 1A fast (instead 240v 32mA fast that "blowed")
6000v Used build in soldered resistors of 20Mohm
1500v Used build in soldered resistors of 40Mohm
The m is:
6000v is 31.4v 31.3v for 20Mohm(||10Mohm Voltmetter) :: 1000+20 (+20) Mohm
1500v for 8.61v 8.62v for 20Mohm(||10Mohm Voltmetter) :: 1000+20+20 (+20) Mohm
not correctly but closed resolts after my math I got:
4835v
1350v
not going to check again.
build the protection board by my decision.
Stupiedly again used too much from the laquer that I forgot to throw before
each hole instead the soldered one drilled through and checked twice.
half CM mistake (from the planned but still ok).
Last edited:
Receive today the treble panels,
not have any time to issue with this speaker this week
received with one of them some note that I have to heat this panels to stretch them before using.
*still no felt behind them
Remind that bass panels got some spark on first use,
I ordered the restore kit (and read a lot about how to fix this speakers and the restoring kit guide from ERAudio).
in addition bought some umik1 for recording and measurement.
Still without felt or wool for this speakers
*still want somehow to fix the old treble panels.
only the panels (bass+treble) remained to restore.
not have any time to issue with this speaker this week
received with one of them some note that I have to heat this panels to stretch them before using.
*still no felt behind them
Remind that bass panels got some spark on first use,
I ordered the restore kit (and read a lot about how to fix this speakers and the restoring kit guide from ERAudio).
in addition bought some umik1 for recording and measurement.
Still without felt or wool for this speakers
*still want somehow to fix the old treble panels.
only the panels (bass+treble) remained to restore.
Last edited:
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