NEED DC OUTPUT PROTECTION FOR ADCOM GFA-565

MOJO1227

Yes, we all know the history of the 565 dc output. Looking for a suitable safe guard. Don't want to destroy my newly modded SDA SRS 2.3's (low impedance inductors, 4 ohm, not 6.5). Excellent job done by David at DHS SPEAKERS!

Original owner had amps repaired for leaky caps/boards cleaned, etc ....

Local repair guy suggested an inline fuse on the speaker outputs. Could be mounted on back of amp. Suggested a 2-2.5 amp fuse (doesnt sound right to me???). seems awfully small. Easy enough but is it adequate?

Another outfit (EBC ELECTRONICS) offers a 30 amp relay module that should trip if any dc voltage becomes present at output. Sounds like the way to go, but cost $100 each plus shipment of amps. Thats like $300 ... would like a cheaper option if possible.

Any thoughts/opinions would be greatly appreciated!!

heiney9

If they have been repaired then their is no need to worry. Are you using the AI-1 cable when running your SDA's?

Putting protection in after the fact could influence the sonic signature negatively. I wouldn't do it.

H9

MOJO1227

Check on the A1-1 dreadnaught. It is in the system.
So far as repairs go, I do not know of the extint to which it was done. If it were me I would have sent in for complete refurbish, but I just aquired them. Did check the DC output off spkr terminals and was very low .... around 2-3mV.
I just heard that when they go, they go quick.

littlewoodboats

My reworked GFA-585 has been hanging tough for going on four years with no issues. If the tech who did the overhauls did their work correctly you will have no issues. H9 gave you great advice.

heiney9

MOJO1227 wrote: »

Check on the A1-1 dreadnaught. It is in the system.
So far as repairs go, I do not know of the extint to which it was done. If it were me I would have sent in for complete refurbish, but I just aquired them. Did check the DC output off spkr terminals and was very low .... around 2-3mV.
I just heard that when they go, they go quick.

You said leaky caps and boards...........do you know what parts? I would guess it's the typical repair for these because of the run of defective caps from new. Not sure there are any other "leaky caps and boards" it could be.

I understand your concerns, maybe spend the money to have them checked.

H9

MOJO1227

"IF" .... That's what worries me. All I know is that prior owner said boards were cleaned and repaired .... no reciepts and do not know the time frame of repairs. Guess I could just monitor them for a while and maybe next year send them to "BIG SKY" for complete refurbishment and upgrades about $750 each. Lot of money for a poor boy to sleep well at night.
Sounds like it may be the only way to go.

MOJO1227

Ok .... I'll by-pass the protection output idea. Hopefully I'll get fair warning if things go south. Send them in for complete refurb next year .... Ran across one guy that actually had new pc boards made and uses new top grade components when re-populating the problematic board, among many other things. Not cheap .... but, is what it is.

littlewoodboats

Rick at Big Sky did my 585. His current pricing lists the 565's at $749.00 for the pair not each.

If you can do high res photography for us it will be easy to see if service work was done and to what extent.

MOJO1227

Sorry, my bad .... there is somebody else that does the rework and up grades. They actually made replacement pc boards for the 565 and 585. Think I got the two confused price wise. They replace all caps/resistors with T.O.L. replacements.

OK ... Will take high resolution photos and post.

THANKS for your help!

I work avionics for a living but these babies don't have wings!!! Not to mention that I am out of date regarding component level repairs. Once upon a time I worked the Nav./Comm. back shop for Eastern Airlines. I've forgotten much since then.

I am a FIRM believer that if something is worth doing, then it is worth doing RIGHT/RITE/WRITE .... just kidding, y'all know what I mean.

littlewoodboats

Rick had to replace the output driver board in my 585 which was extra. Any 585/565 series that has not had the basic factory service bulletin work done will need board replacement. If yours work they have been serviced at least once in their lives.

motorstereo

I had a 555 a few years back that went dc (6volts at the speaker terminals) on me one day with no warning what so ever. The day before it did this it was driving my refurbed Ohm Walsh 4's and sounding great. Having seen the effects dc has on a voice coil I wouldn't use the amp until there's something to stop dc from ruining your 2.3s.

MOJO1227

Tried taking pics but they didnt come out worth a hoot .... Previous owner did say they were serviced SEVERAL times. Hmmmmm .... Think I'll call EBC Electronics and find out more info on their 30Amp relay module upgraded board. Dont know if it will affect the sonic signiture or not. I'll see what they say and report.

Thanks for the info. guys.

machone

I would call John Hillig at Musical Concepts 636-272-0040 and get his input. He upgrades Adcoms all the time.