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Issue with channel cutting out at high volume
https://www.canuckaudiomart.com/forum/viewtopic.php?f=9&t=49452
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Author:  outfire [ Sun Feb 25, 2018 2:03 pm ]
Post subject:  Issue with channel cutting out at high volume

Hi everyone,

Dont know if this question should be post on this or the ht section since this is a 5 channels parasound hca1205a.

Bought this from the pawnshop for $300. Upon hooking it up i noticed there is crackling sound when adjusting the volume pot so i opened and cleaned. Right after that i tested and the issue is gone. Fast forwarded a month and today while playing transformer 1 . the channel 2 cuts out. Turned it off. powered on and cutted out again. Turned back on and no sound. Adjust the volume knob and sound came back on and play fine for the whole movie.

This is my setup
Samsung tv arc out to marant sr5005 as pre only and powering the center and main and one surround with the 4 channels. The 2 other surround is powered by parasound hca750a.

My center speaker are.
C-martin logan encore
Rest is - martin logan mlt-1 5.1 set

Please some who had this happened to them before. Could you please point me to where could the issue be.

Thanks all
Mike

Author:  Nakamichel [ Sun Feb 25, 2018 2:19 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

This sounds like a cold joint solder somewhere.
It needs servicing. Better to not use it until then.

Author:  outfire [ Sun Feb 25, 2018 2:56 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

Nakamichel wrote:
This sounds like a cold joint solder somewhere.
It needs servicing. Better to not use it until then.



should i trace only channel 2 wiring? will look for cold solder when i have the time

Author:  outfire [ Sun Feb 25, 2018 7:20 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

Just got a reply from Richard at Parasound. the advise is to service the relay and also recommend the rest of relays to be serviced.

anyone know if this can be done by myself? when Richard says serviced, does he meant cleaning it?

please help me out.

Author:  Teo Audio [ Sun Feb 25, 2018 7:35 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

sounds like an easy fix. Maybe.

You can test this by tapping the relay (with a toothbrush or whatnot, as long as it is non conductive). bad contacts will show via scratchy sound happening --ie cutting in and out.

If it is as old as I think it is the relays may have removable covers so the contacts can be cleaned with 2000 grit sand paper that is available from the automotive finishing/painting section at your local Canadian tire.

if the relay cover cannot be removed then it is time for a relay replacement.


If you have no electronics experience, it is best to stay out of the amplifier's innards. Dangerous voltages are floating around in there.

-- 25 Feb 2018 23:43 --

channel two 1205a problem...

http://www.hometheatershack.com/forums/ ... lem-2.html

Author:  Che Cavolo [ Sun Feb 25, 2018 8:30 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

The link is telling.

You're running it into clipping and because it's been, no doubt, 'rode hard and put away wet', it's going into protection mode. It needs to be serviced, recapped, etc, meanwhile you need to avoid 'high volume'. That's a, what, 15 year old amp?, and you did buy it from a pawn shop for peanuts so expect to spend a few bucks bringing it up to spec.

Author:  outfire [ Sun Feb 25, 2018 9:00 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

Teo Audio wrote:
sounds like an easy fix. Maybe.

You can test this by tapping the relay (with a toothbrush or whatnot, as long as it is non conductive). bad contacts will show via scratchy sound happening --ie cutting in and out.

If it is as old as I think it is the relays may have removable covers so the contacts can be cleaned with 2000 grit sand paper that is available from the automotive finishing/painting section at your local Canadian tire.

if the relay cover cannot be removed then it is time for a relay replacement.


If you have no electronics experience, it is best to stay out of the amplifier's innards. Dangerous voltages are floating around in there.

-- 25 Feb 2018 23:43 --

channel two 1205a problem...

http://www.hometheatershack.com/forums/ ... lem-2.html



will try tapping it. I dont have extensive electricity base but we did learn basic electricity for fire alarm in fire protection classes.

I was reading and had read that link before i bought that hca1205a. i went over the amp with my phone flash light and see no bulging sign.

there is one thing that i do not know is how the relay looks like on the parasound. if some can help me to identify it, very appreciated it.

-- 26 Feb 2018 05:03 --

i don't mind spending the money to get it fix but if it is a easy fix. i want to learn.

Author:  Takira71A [ Mon Feb 26, 2018 6:41 am ]
Post subject:  Re: Issue with channel cutting out at high volume

Teo Audio wrote:
... If you have no electronics experience, it is best to stay out of the amplifier's innards. Dangerous voltages are floating around in there...

outfire wrote:
... there is one thing that i do not know is how the relay looks like on the parasound...

Agreed! If you do not know what a Relay Switch looks like...
You would be best advised to follow the above, cited advice and have the unit 'Properly' Serviced.
--
The HCA-1205A is not the correct place to begin learning 'Basic' Electronics.
Thank-you!

Author:  outfire [ Mon Feb 26, 2018 5:03 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

I spot two relay and search online. There are store that sells it. I also opened up mu hca750a and notice two relay with from same company. But the hca750 is japanese made and the other is china made.

Can i buy the japanese part and how much in labor do you think.

What techs you guys recommened

Author:  Nakamichel [ Mon Feb 26, 2018 5:41 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

You don't absolutely need the exact same relay.
Just respect those points:

-1 need to be sure of the ratings
-2 need to be sure same pinout
-3 need to be sure same function
-4 on very rare cases, the size (physically) could matter

Ratings are most of the time written on the relay, but if not, easy to find out online.
And by function I mean, is it normally close, open, momentarily ?

Once you are sure, you are good to go.

I can't be sure about the time to do it, I never worked on that component
but for a tech, one hour max and the job is done.

Author:  outfire [ Mon Feb 26, 2018 5:58 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

how much do you think for the labor.

this is the part-
omron made in china.
g4w-2214p-us-hp

contact
15a250vac
15a24vdc
coil:12vdc

pn:1319ys

Author:  brownslane [ Mon Feb 26, 2018 6:06 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

...you are not qualified to do this work yourself. If you don't understand what is going on inside your amp, well you know the rest. You might kill yourself. More likely is that you destroy the amp.

Dan Santoni is a great tech (in Hamilton area)

Drago Fucec is another great guy (in Mississauga)

Nobody can tell you in advance what is needed or how long it will take. Either of the above guys will do the job correctly and will not overcharge. Whether the caps are swollen or not, if they are 15 years old they are nowhere nowhere near their sonic best. Spend the money and get if fixed correctly. This might cost you a few hundred bucks. If you do not fix it, it WILL fry. Only a matter of time.

15-year-old electronics are due for maintenance ....Maintenance means replacing parts (resistors, relays, capacitors) that are out of spec. Your amp is sending you this message.

Author:  Che Cavolo [ Mon Feb 26, 2018 9:10 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

brownslane wrote:
...you are not qualified to do this work yourself. If you don't understand what is going on inside your amp, well you know the rest. You might kill yourself. More likely is that you destroy the amp.

Dan Santoni is a great tech (in Hamilton area)

Drago Fucec is another great guy (in Mississauga)

Nobody can tell you in advance what is needed or how long it will take. Either of the above guys will do the job correctly and will not overcharge. Whether the caps are swollen or not, if they are 15 years old they are nowhere nowhere near their sonic best. Spend the money and get if fixed correctly. This might cost you a few hundred bucks. If you do not fix it, it WILL fry. Only a matter of time.

15-year-old electronics are due for maintenance ....Maintenance means replacing parts (resistors, relays, capacitors) that are out of spec. Your amp is sending you this message.


+1 again. Unless it looks like it has been dragged behind a car down the 401, you picked up a nice deal. info@dtsaudioelectronics.com is Dan's email. That was, what, a 3 or $4000 piece new designed by John Curl? Nice catch, make it perfect again, and don't blow yourself or your speakers up by trying to diy something based on dubious forum advice.....

Author:  anatech [ Wed Feb 28, 2018 9:14 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

Hi,
I'm sorry, but I have to reply to correct some information.

Quote:
If it is as old as I think it is the relays may have removable covers so the contacts can be cleaned with 2000 grit sand paper that is available from the automotive finishing/painting section at your local Canadian tire.

It is absolutely never okay to use any abrasive on the contacts of speaker relays!!! The contact is a thin plating and you'll go through that pretty easily.

Relay contacts are cleaned. You can use WD-40 on a folded business card to clean the contacts. However, you must clean the WD-40 off with a cleaner that leaves zero residue. Look carefully at the contacts under a good light. If you see burned or pitted contacts, the relay is done. You need to replace it.

Having said that, I have to add that unless you are experienced in working on electronic equipment, you may well damage your equipment while soldering or desoldering parts. Then there is a puzzle for you to put back together. Take pictures as you take something apart. Draw pictures or write notes, whatever it takes so that you don't have any questions when it comes time to put it together. If you have really good equipment, take it to a good technician.

-Chris

Author:  outfire [ Fri Mar 02, 2018 6:19 pm ]
Post subject:  Re: Issue with channel cutting out at high volume

Thank for the help. I dont know how many ps3 I have soldered. I will leave it to the technician. I don't have the tool for soldering anymore beside the iron I used for solder cars' wires.

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