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'81 DR504 Powered but No Sound

Posted: Tue Dec 03, 2013 9:12 pm
by pjking81
I was setting up to playing a gig with my 1981 2 hole Hiwatt Dr-504 and after a little warm up and flick of the standby no sound was coming out of cab.

Everything was plugged in and set properly I knew that for sho.

My quess is the master volume pot went out?

Any quess as to what happen- before it went out I heard a little fizzle not sure what that was.

The long and skinny of it is that it remained power so I am guessing its not fuses.

Re: '81 DR504 Powered but No Sound

Posted: Tue Dec 03, 2013 9:51 pm
by Dr.HI-TONE
it is most likely a tube that died.
I would guess the phase inverter first, but it could be any of them.

Not likely a pot.

Re: '81 DR504 Powered but No Sound

Posted: Tue Dec 03, 2013 10:25 pm
by pjking81
Nope changed all tube EL34's and all pre-amp tube still no luck or sound.

Re: '81 DR504 Powered but No Sound

Posted: Tue Dec 03, 2013 10:59 pm
by OldSchoolDave
pjking81 wrote:Nope changed all tube EL34's and all pre-amp tube still no luck or sound.
Speaker fuse go bad? Need a meter to verify continuity.

Dave

Re: '81 DR504 Powered but No Sound

Posted: Wed Dec 04, 2013 7:05 pm
by mhuss
If you haven't already, check the HT fuse. If it is blown, the pilot light will come on, but no sound will come out.

http://hiwatt.org/tech.html

--mark

Re: '81 DR504 Powered but No Sound

Posted: Fri Dec 20, 2013 4:09 pm
by pjking81
I changed the V1 (HT) fuse and no luck.

Re: '81 DR504 Powered but No Sound

Posted: Fri Dec 20, 2013 10:18 pm
by OldSchoolDave
pjking81 wrote:I changed the V1 (HT) fuse and no luck.
Hmmmm. Pull the impedance selector out and check for corroded contacts. I've had those short out due to oxidation.

Have you checked the Phase Inverter (middle of the 3 preamp tubes), as Dr.HI-TONE suggested?

Dave

Re: '81 DR504 Powered but No Sound

Posted: Tue Apr 29, 2014 1:04 am
by pjking81
Turns out the fuse I was originally given to replace the one that burnt out was faulty.

I went back to the store and got another and like magic my Hiwatt lives again!

Well it wasn't just that, I went through two fuses after the first went I had a pair of Winged 'C" in there, threw in the fuse and bang it works, and then I swapped the tubes for a pair of JJ's and the it blew the fuse. I got another fuse and a fresh pair of tubes (wait don't crinch) Mesa Boogie EL34's, threw in the second fuse and it works again and still has.

And to think I had it up for sale at a $1,000 (originally paid $1,350 plus shipping) and a tech wanted to buy it and so he looked it over and told me that I just need a fuse.

He knew that if it was repaired that my asking price would go up, so he saved me from selling.

Phew that was close!