Go Back   Home > Forums > >

Planars & Exotics ESL's, planars, and alternative technologies

Acoustat Answer Man is here
Acoustat Answer Man is here
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 6th October 2021, 12:02 PM   #2771
Deepblackjoe is offline Deepblackjoe
diyAudio Member
 
Join Date: Oct 2021
I responded to the person who posted the ad above, but then the ad was turned off a couple days later. I am trying to get a replacement bias transformer for one of the 1+1 interfaces on this pair of speakers I just got. Before firing them up, I opened both interfaces and saw one of the bias transformers has evidence of arcing damage - two wires were pressed up against it. I pulled them away, the insulation seems intact, but there is an obvious burnt spot. If anyone knows where I could purchase one of these, I'd be thrilled. They both power up and sound clean, but would like to be able to leave them on all the time with no worries, and get them sounding as good as possible. Thanks for any leads
Attached Images
File Type: jpg IMG_20210928_121650935.jpg (578.1 KB, 87 views)
  Reply With Quote
Old 6th October 2021, 12:52 PM   #2772
tyu is offline tyu  United States
diyAudio Member
 
Join Date: Jul 2009
Hi...thats not the bias trans....that the bass trans ....i cant see a bias trans on your pic, but if you can play the speakers an sound good the bad spot my just be on the out side of your bass trans..... in this pic the smaller trans up front brown paper is bias,you my also ck besure about the 1ohm 30watt res. is still 1ohm if not replace it........good luck
Attached Images
File Type: jpg DSCF0934.JPG (739.5 KB, 85 views)

Last edited by tyu; 6th October 2021 at 01:14 PM.
  Reply With Quote
Old 6th October 2021, 02:42 PM   #2773
Deepblackjoe is offline Deepblackjoe
diyAudio Member
 
Join Date: Oct 2021
Thanks for the reply, tyu. I should have looked at the wire colors closer. I'd assumed the two smaller ones were the medallions, whoops. I will check that resistor when I open it back up. Would it be beneficial to put some HV silicone on the exposed damaged spot to prevent further arcing? The main fuse on the outside was blown when I got them, replaced that and they're making music. I'm not sure what they've been thru.
  Reply With Quote
Old 6th October 2021, 03:14 PM   #2774
tyu is offline tyu  United States
diyAudio Member
 
Join Date: Jul 2009
Dont ever run the speaker with out the 1ohm res in the bass trans Negative input wire!!
Attached Images
File Type: jpg MK-121C_schematic.jpg (63.9 KB, 74 views)
  Reply With Quote
Old 6th October 2021, 06:38 PM   #2775
AcoustatAnswerMan is offline AcoustatAnswerMan  United States
diyAudio Member
 
AcoustatAnswerMan's Avatar
 
Join Date: Feb 2011
Location: Chandler Arizona
Quote:
Originally Posted by Deepblackjoe View Post
I responded to the person who posted the ad above, but then the ad was turned off a couple days later. I am trying to get a replacement bias transformer for one of the 1+1 interfaces on this pair of speakers I just got. Before firing them up, I opened both interfaces and saw one of the bias transformers has evidence of arcing damage - two wires were pressed up against it. I pulled them away, the insulation seems intact, but there is an obvious burnt spot. If anyone knows where I could purchase one of these, I'd be thrilled. They both power up and sound clean, but would like to be able to leave them on all the time with no worries, and get them sounding as good as possible. Thanks for any leads
That black spot on the transformer typically indicates internal arcing. It doesn't absolutely indicate a problem, but there's a good chance you need to replace the LF transformer.

The speaker may still play OK at lower levels if you have an internal high-voltage breakdown in the transformer. But at higher levels, the insulation may break down and arcing will resume. Of course this is a problem that will always get worse over time, not better. Putting silicon on the burnt spot won't hurt, but it may not help, either.

Unfortunately this is a common symptom on the LF transformers when driven too hard.

Last edited by AcoustatAnswerMan; 6th October 2021 at 06:41 PM. Reason: add info
  Reply With Quote
Old Yesterday, 05:48 PM   #2776
Deepblackjoe is offline Deepblackjoe
diyAudio Member
 
Join Date: Oct 2021
Thanks for responding AAM. I've purchased some Super Corona Dope and applied it to the burned area of the LF transformer, but the speaker is cutting out after about ten minutes, the music so faint it is near silent. I tested the bias with the speaker not connected with a non-HV meter and measure 70v at the red pin, so that seems in the ballpark. I guess I'm looking at getting the LF rewound, I really want to get these going. Is there a xfrmr rewind service that you know of who can do these? Or does anyone out there have an extra one of these to sell to me, or even a lead on one? I was hoping the corona dope would do the trick. Are there other things I should check? The other speaker sounds awesome.
  Reply With Quote
Old Today, 02:57 PM   #2777
mraudioguru is offline mraudioguru  United States
diyAudio Member
 
Join Date: Apr 2014
Maybe try Russ here:

ESL Repair - Home

Not sure what he has in stock, but I've sent quite a few people to him.

Good Luck!
  Reply to this post

Reply


Acoustat Answer Man is hereHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
No answer Antoni D The Lounge 2 13th February 2011 06:19 AM
need a tech to answer this one pks71 Car Audio 1 19th November 2004 11:50 AM


New To Site? Need Help?

All times are GMT. The time now is 06:09 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki