Amp hum normal?

Orange Amps Technical Q&A's

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Jayco
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Post by Jayco » Wed Oct 26, 2005 4:29 am

Already contacted the dealer I bought it from :)

I'll let you know what I find out.

Jim

VintageJon
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Post by VintageJon » Wed Oct 26, 2005 5:57 am

Yes, please do...

May The Tone Be With You,
Jon

Jayco
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Post by Jayco » Sat Nov 12, 2005 6:15 am

Ok... so here's the update...

I got a replacement AD30HTC... actually the store I got it from (I used to be one of their vice presidents) let me take the new head home, so I have both here to A/B.

Here's the story... the first head DEFINITELY has a hum that is not there under normal circumstances on the second head... HOWEVER, if I throw the power and standby right away on the second head (so I can hear it warm up), I hear the exact same hum as the amp warms up, but then it quickly goes away as the amp turns on.

So... now I'm wondering if its seeming more like a tube problem, since they both make the EXACT same hum, but one keeps doing it while the other stops doing it just a few seconds after the amp heats up at initial power on.

Any thoughts?

If it is a tube, which tube might it be?

Clueless..

Jim

irish_admiral
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Post by irish_admiral » Sat Nov 12, 2005 6:16 pm

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Any thoughts?<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">Keep the one that doesn't hum...

If it was a valve, i'd have suggested preamp valves being subject to electrical interference somewhere. But i'm still not sure it is...
Joe

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Orange AD15, Matamp 1224, Fender 'JD' Tele, G&L ASAT, Duesenberg Starplayer TV, Eggle Kanuga, Avalon D25, Warwick FNA Jazzman, Eden Nemesis / Bergantino EX112S, Eastman MD305 & other stuff...

Jayco
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Post by Jayco » Sat Nov 12, 2005 6:38 pm

There are a few other reasons for liking the first amp... besides the tone, the casing and face plate are in better shape (the other one must have been on the floor, as it shows significant wear on the tolex and some scratches on the faceplate).

What I'm most curious about is why they both make the same noise, but one stops and the other doesn't.

Anyone have any ideas as to why that would be?

Jim

irish_admiral
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Post by irish_admiral » Sun Nov 13, 2005 12:58 am

I really don't know. My AD30 does the same thing when I switch it on, but like your second amp, the hum dies down.

I think we're back to your original question, and any answer I can give beyond what i've already said would just be guessing.

If you can't get the first one repaired (maybe keep the 2nd one in the meantime?), then keep the 2nd one, and swap the actual amp out of the casing so it looks prettier if that's what you want.
Joe

G(sus) saves

Orange AD15, Matamp 1224, Fender 'JD' Tele, G&L ASAT, Duesenberg Starplayer TV, Eggle Kanuga, Avalon D25, Warwick FNA Jazzman, Eden Nemesis / Bergantino EX112S, Eastman MD305 & other stuff...

Jayco
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Post by Jayco » Sun Nov 13, 2005 1:14 am

I think I'm gonna switch the tubes between both amps... I'm really curious to know what causes the hum... with all of the volumes down, it makes me wonder if it could be the rectifier tube that makes the sound...

I'll let you know what I find when I tear them apart :)

Jim

mpisarcik
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Post by mpisarcik » Sun Nov 13, 2005 8:57 am

or just take out the physical amplifer from the wooden housing and swap them...

Jayco
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Post by Jayco » Sun Nov 13, 2005 10:05 pm

Ok... so here is the story... I took the tube covers off of both amps and initially switched the last two power amp tubes (two closest to rectifier between the amps). I noticed while doing so that one of the two tubes from the humming amp had an orange sticker on it while the other one didn't. Anyhow, switched those tubes and the hum was there, but was less. So I decided to switch the remaining two power amp tubes and I discovered again that one of the two had an orange sticker on it.

Fired up the original amp (now with four 'new' power amp tubes) and it hummed loudly (actually louder than before) for a brief moment and then got quiet... there is still the SLIGHTEST hum, but I can only hear it if I basically put my ear down right next to the grill on the cabinet, so I consider that normal.

Fired up the 'new' amp (now with the four tubes from the amp that was bad) and it hums badly, just like the other amp was doing while it had those 4 tubes in it.

So.. bottom line.. switched tubes between the amps, hum followed the tubes and not the amp.. must have a bad set of tubes.

Does anyone know what the orange dot (its literally an orange sticker) signifies on the 'humming' tubes?

I think I'm going to order a nice new set of quality tubes for the amp (even though its new) since I now know that the problems were tube related.

Jim

irish_admiral
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Post by irish_admiral » Mon Nov 14, 2005 11:20 pm

No idea what an orange sticker on the valve means. Don't buy a set of valves just yet. Call Orange and tell them what happened, and that you'd like some replacement valves.
Joe

G(sus) saves

Orange AD15, Matamp 1224, Fender 'JD' Tele, G&L ASAT, Duesenberg Starplayer TV, Eggle Kanuga, Avalon D25, Warwick FNA Jazzman, Eden Nemesis / Bergantino EX112S, Eastman MD305 & other stuff...

larry.R
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Post by larry.R » Tue Nov 15, 2005 12:26 am

Does it hum without gain?
Now go home and get your shine box.

Jayco
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Post by Jayco » Tue Nov 15, 2005 4:42 pm

Irish... I will do that. Thanks for the idea.

Larry... yes, it hummed without any gain... hummed with ALL dials at zero. Once I swapped out the power amp tubes however, it stopped humming.

Jim

VintageJon
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Post by VintageJon » Wed Nov 16, 2005 5:14 am

Well, your hum is the power amp or power supply.

Check all filter caps and connections. Power tubes good?

-Jon

Jayco
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Post by Jayco » Wed Nov 16, 2005 3:44 pm

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jayco</i>
<br />... Once I swapped out the power amp tubes however, it stopped humming.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

No, the power amps tubes weren't good ;)

I'm contacting Orange about having a new set sent to me.

Jim

beole
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Re: Amp hum normal?

Post by beole » Wed Mar 14, 2018 10:11 pm

I don't know if anyone solved the problem with the hum the ad 30 makes but I found that the heater wires also attached to the light on my ad 30. The connection on the light on the light was loose. I soldered that spot and the hum went away after 1-2 days.

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