Hot Glue Let Go On My SDA2Bs

PreCd

I have noticed lately that the left channel of SDA2Bs was sound less that stellar. I noticed a very low raspy static at times and decided to start troubleshooting. Narrowed it down through the process of elimination and found that the hot glue had let loose on the components that I had upgraded my board with. the small inductor was flopping loose as well as all the new capacitors. That is a loser! Will be getting some double sided tape tomorrow to secure the components down to the board after checking the solder joints.

Toolfan66

Up grade the boards to a set of gimpods, and wire tie them down, problem solved, plus you have a cleaner look..

westmassguy

I'd recommend 3M VHB Tape, not just any double sided tape, nylon wire ties, and judicious use of some brush-on Cyanoacrylate between components. Hot glue should be reserved for Martha Stuart craft projects.

PreCd

Toolfan: Thought of that and I might just go that route.

westmassguy: Thanks for the material list. It helps to know which direction to travel.

Conradicles

Hot glue can fail at high temps. Not the best choice.

westmassguy

Conradicles wrote: »

Hot glue can fail at high temps. Not the best choice.

And with age. I've yet to service a vintage Polk crossover that doesn't have loose or hanging components due to hot glue failure. At some point, it just stops sticking due to heat or shrinkage.

PreCd

There is no telling what effect this was having on my listening experience! It has been frustrating when listening critically hearing noise that should not be there. I did my mods about 2 years ago and the speakers were sitting idle for about 6 months of this year. I am just glad that I pulled the board and found it. Will pull the right channel board as soon as I get the components on this board secured.

Again I wonder what effect these loose components had on the listening experience. I am sure it was not a positive.

westmassguy

Micro vibrations, resonances were probable blurring everything. That's why all the components should be immobile, and tied down where possible. Your 2B boards can easily be modified for additional wire ties, or gimpods boards as your alternative.

leftwinger57

Talk about flopping in the wind ,when I first opened up my 2Bs the entire left x-over was off the plastic stantions or stand offs and just hanging.Since I had to pull them to replace the polyswitches w/ the Mills 0.5 as a minmal fix I stuffed it back under the polyfill and closed it up.Now since I've gone much further w/ my mods but not the x-overs themselves I secured the loose one w/ ty-raps in the holes where the stantions were and when I send them out to Trey he said he would provide new stantions to secure them the right and correct way.

westmassguy

leftwinger57 wrote: »

Talk about flopping in the wind ,when I first opened up my 2Bs the entire left x-over was off the plastic stantions or stand offs and just hanging.Since I had to pull them to replace the polyswitches w/ the Mills 0.5 as a minmal fix I stuffed it back under the polyfill and closed it up.Now since I've gone much further w/ my mods but not the x-overs themselves I secured the loose one w/ ty-raps in the holes where the stantions were and when I send them out to Trey he said he would provide new stantions to secure them the right and correct way.

Lew, I can send you a bunch to get you through. I put new Threaded Nylon Standoffs on most of my crossovers, so I always keep the old ones as spares.

PreCd

I took a look at the board and it seems that I can wire tie most of the components down without modification. Will probably have to drill a hole or two but nothing major. Checked the foil on the board and Polk drilled it to tie down the large inductors so I cannot see it hurting anything to drill a small hole for a tie.

westmassguy wrote: »

Micro vibrations, resonances were probable blurring everything. That's why all the components should be immobile, and tied down where possible. Your 2B boards can easily be modified for additional wire ties, or gimpods boards as your alternative.

westmassguy

Correct, just be very careful, and double check the traces underneath

PreCd

I picked up some 3M auto trim tape today from Autozone. The stuff was so sticky I almost had to leave a finger on each board just to get the tape on. Very good stuff. Secured each component with the tape, wire tied them down, and closed her up. Sounds much better now. Every capacitor and the small inductor was loose from the board. Now at higher listening levels the music is detailed and not muddled. That was a symptom of the problem. The more volume I gave it the worse is sounded and I have a good room for higher listening levels. Also seemed to have a low raspy almost staticy tone to the music. Glad that problem is solved. Thanks for everyone's advice.

westmassguy

Excellent, the Auto trim tape is the same stuff from what I remember.

F1nut

I've yet to service a vintage Polk crossover that doesn't have loose or hanging components due to hot glue failure.

Interesting. I've never seen one with the glue that Polk used have an issue. Whatever they used isn't the same as the hot glue used these days, Polk's glue sticks way better.

westmassguy

I've done enough Polk crossovers, that I see them in my sleep. At least one of the inductors is always loose, and the only thing holding it on is the nylon wire tie, and the ties weren't that good back then either. Even the glue on the back of the Binding Posts is separated half the time, and no longer sealing the rivets or posts.

F1nut

I'm not doubting your word, but like I said, I've never seen that issue.

Even the glue on the back of the Binding Posts is separated half the time, and no longer sealing the rivets or posts.

That one is really surprising as that glue Polk used has a tenacious grip on the plate, in my experience.

westmassguy

Jesse, you'd be surprised at the condition some of these crossovers are in when they're sent to me, and not just Polks either.

PreCd

I cannot believe how much difference it made to tie those components down on the board. I have my speakers back and I have the sound I have been searching for. Crisp. Clear. Well defined bass and highs. Large sound stage. NO ear fatigue. Very musical. Before I found the problem I was getting discouraged with the speakers to be honest. I had bought a new power amp and tube preamp hoping it would give me the sound I was searching for. Securing everything to the board made all the difference.

westmassguy

PreCd wrote: »

I cannot believe how much difference it made to tie those components down on the board. I have my speakers back and I have the sound I have been searching for. Crisp. Clear. Well defined bass and highs. Large sound stage. NO ear fatigue. Very musical. Before I found the problem I was getting discouraged with the speakers to be honest. I had bought a new power amp and tube preamp hoping it would give me the sound I was searching for. Securing everything to the board made all the difference.

Awesome, enjoy you babies again.