My Aragon 8008bb Amp is making thud sounds thru speakers

[headrott]

OK, this is 2 for 2 on screwed up amps for me buying used (at least as far as I can tell). I hooked up the Aragon 8008bb amp using the RCA inputs and my usual Goertz python MI2 speaker cables for the output. I hooked everything up correctly and turned on the amp. It was OK until the output came on, then the amp makes a consistant thud thud sound (thru both speakers), then pauses, thud thud, pauses, thud thud......You get the idea. I can hear something clicking inside the amp when thud occurs. Also, when I turned on the pre-amp and switched to the output selction the thud stopped for a minute, then started again. I tried to play some music to see if it would output something besides the thud. The amp does output sound, but only when the thud happens, you can hear the music combined with the thud.

I need peoples' help to figure out why it would be doing this please. I am thinking it's not grounded correctly, but am not sure. I will try switching power cables and see if that helps at all. That clicking sound inside the amp must be a clue to what's wrong. Thanks for everyones' help with this.

[heiney9]

Do you have SDA's? I believe the Aragon is a dual mono design and is NOT common ground. Disconnect the umbilical cord and see if that fixes it. Hopefully you haven't damaged anything inside the amp or speakers . If you don't have SDA's not sure what to tell you.

H9

[headrott]

I do have SDAs (3.1TLs), and the Aragon 8008bb is dual mono, but from what I understood it is common ground. I will disconnect the interconnect cable and see if that fixes it though. If that does fix the problem, where can I get the AI-1 interconnect from?

[heiney9]

I do have SDAs (3.1TLs), and the Aragon 8008bb is dual mono, but from what I understood it is common ground. I will disconnect the interconnect cable and see if that fixes it though. If that does fix the problem, where can I get the AI-1 interconnect from?

Build one. Call Aragon on Monday and see if the negative speaker terminals can be "strapped". DO NOT do that unless you know for sure.

Since you have 3.1TL you can use an AI-1 but you'd have to build one or pay someone to build you one. I'd guess about $200

[headrott]

Yep, that's it. It's obviously NOT common ground, and it's my fault for thinking it was a problem with the amp. I know I read reviews that said that it was, but that goes to show you that what mis-information there is on the internet. The amp and the SDAs are fine, they make "normal stereo sound" fine still. I will try to call Aragon on Monday, or i will try searching the Klipsch web site to see if you can strap the negative terminals on the amp. Why so much for the AI-1 cable? What does it consist of? How difficult is it to build? I've done a normal SDA cable, but never an AI-1.

[headrott]

Ooops, I meant I will contact Indy Audio Labs on monday. Hopefully they will be able to tell me if the 8008bb can be strapped.

[hearingimpared]

The AI-1 has a transformer in it. If you do a search here, there are some very good threads on building one. They sometimes pop up on ebay.

[headrott]

Thanks for the info. I was looking at DarqueKnight's AI-1 Dreadnought project and will try to duplicate that. It doesn't seem too hard to do, but it requires more money. Do you know if there is any sonic difference between "strapping" the negative binding posts (if I can with the Aragon) and building the AI-1 cable? The AI-1 seems like the way it was designed to be done, but I am not sure if there is a sonic difference or not.

[hearingimpared]

Thanks for the info. I was looking at DarqueKnight's AI-1 Dreadnought project and will try to duplicate that. It doesn't seem too hard to do, but it requires more money. Do you know if there is any sonic difference between "strapping" the negative binding posts (if I can with the Aragon) and building the AI-1 cable? The AI-1 seems like the way it was designed to be done, but I am not sure if there is a sonic difference or not.

If the manufacturer says you can strap the grounds then you are better off doing that. Not that the AI-1 is bad but why bother if you don't need it.

[F1nut]

Didn't someone say that strapping was sonically inferior verses the AI-1?

[hearingimpared]

I don't recall. I don't see how it could be.

[headrott]

Didn't someone say that strapping was sonically inferior verses the AI-1?

Where did you hear this from? I'd be interested in finding out.

[hearingimpared]

Didn't someone say that strapping was sonically inferior verses the AI-1?

I don't recall. I don't see how it could be.

headrott, I was just reminded that I made the statement a while ago that strapping the grounds together was inferior to using an AI-1. What I was referring to was that I had two Adcom 565 mono blocks strapped together to use on my Polk 1.2TLs. I then purchased a TriVista 300 which couldn't be strapped together because of its design and I had to use an AI-1. The TriVista being a much more superior amplifier than the Adcoms lead me to make the statement. Sorry for the confusion.

[headrott]

Never mind Jesse, I found where it was you read it. It was in the Dreadnought post. DarqueKnight was the one that said the sound quality is diminished strapping the negative binding posts (you get the amps noise added to the output sound) where as the AI-1 is isolated from the amp and therefore is a cleaner signal. Makes sense.

[headrott]

headrott, I was just reminded that I made the statement a while ago that strapping the grounds together was inferior to using an AI-1. What I was referring to was that I had two Adcom 565 mono blocks strapped together to use on my Polk 1.2TLs. I then purchased a TriVista 300 which couldn't be strapped together because of its design. The TriVista being a much more superior amplifier than the Adcoms lead me to make the statement. Sorry for the confusion.

No problem, see my post above.

[F1nut]

Never mind Jesse, I found where it was you read it. It was in the Dreadnought post. DarqueKnight was the one that said the sound quality is diminished strapping the negative binding posts (you get the amps noise added to the output sound) where as the AI-1 is isolated from the amp and therefore is a cleaner signal. Makes sense.

I'm glad you found that info. As I said to Joe, I knew one of the people was Raife and thought Joe was the other, so either his or my memory is slipping concerning his rig.

[headrott]

Can anyone recommend a good place to get a black colored aluminum enclosure that is measured between 8" and 10" W X 8" to 10" deep X 4" or 5" high? I have checked mouser and farnell and a few independant companies, but can't seem to find a good one. If anyone could help me out in locating one I'd appreciate it. Thanks.

Greg

[hearingimpared]

I'm glad you found that info. As I said to Joe, I knew one of the people was Raife and thought Joe was the other, so either his or my memory is slipping concerning his rig.

It's probably my memory in question as I can't remember what I did yesterday.

[headrott]

I'm glad you found that info. As I said to Joe, I knew one of the people was Raife and thought Joe was the other, so either his or my memory is slipping concerning his rig.

Or maybe BOTH.:)

[F1nut]

Or maybe BOTH.:)

LOL....yeah, that too.

[hearingimpared]

Or maybe BOTH.:)

Listen ya young whipper snapper . . . :D

[xj4094dg]

It's probably my memory in question as I can't remember what I did yesterday.

Sounds like you have headrott. ;)

[hearingimpared]

Sounds like you have headrott. ;)

Ha ha ha more like burn out!:D

[Schurkey]

1. The "classic" Aragon amps are common ground, HOWEVER, the resistance between the channels is higher than the SDAs like. I measured two of my BBs, and they each have ~20 ohms between the channels. A jumper connecting the negative posts eliminated a TRULY UGLY phasy/midrangey coloration from my 1Bs. Thousands and thousands of years ago, I had a jumper connecting the negative terminals of my 4004; I never did test the resistance between negative terminals--but after awhile I removed the jumper and I don't recall hearing any difference.

2. Even with ~20 ohms of "un-common-groundedness" of my 8008BBs, the amps DO NOT "thud thud thud".

3. The clicking you hear inside the amp is the protection relay. Don't piss it off. The fact that it's activating is telling you that it's unhappy for some reason.

4. The 8008s (and the 004 series before them) were unusually dependable. The first thing I'd be doing is looking for defects ahead of the amplifier; perhaps passing DC to the amp. Next, I'd be looking for a dead short downstream from the amp; perhaps starting with disconnecting the SDA cable. Any chance of a stray strand of speaker wire going from + to - ?

5. If nothing else, there's a fuse on the back panel; and four fuses under the "long" top cover. Might be worth a look, although the fact that you're getting sound "sometimes" probably means the fuses are good. I had an 8008BB delivered to me with one of four internal fuses dead; it took out that channel. Fuses required are (1) 12 amp SLOW-BLOW for the back panel such as a Bussman MDA-12; and (4) 10 amp FAST-BLOW for "under the hood" such as Bussman AGC-10. (yes, the Aragon will throw ~20 amps continuous per channel!) These fuses (especially the AGC series) are ordinary automotive-style glass units 1/4" X 1 1/4"; dirt cheap at any auto parts store or hardware store.
http://www.hbassociates.us/AragonFuses5May08.pdf

http://hbassociates.us/Aragon_FanPage.html

[Schurkey]

OOoops. The MDA-series of fuses are ceramic, not glass. They'll be harder to find. I'm thinking yours couldn't be blown or the amp would be totally dead.

Please do me a favor and measure the DC resistance between your channels. I really did not expect to find ~20 ohms resistance in there...

OH, yeah! One more thing. Do you have a jumper installed in each of the XLR connectors on the back panel? Gotta have them when using the RCA inputs rather than the XLR (balanced) inputs. It's a simple, un-insulated copper wire; perhaps 12 or 14 gauge, and extremely short. Kinda like a very heavy-gauge staple. It connects two of the three pin openings. I'll try to come up with a photo...

[heiney9]

^^ good idea's Skurkey..............but when he removed the SDA cable the issue went away so it sounds like it's the SDA's.

H9

[Schurkey]

http://www.klipsch.com/images/download/86.aspx

Not a photo, but the three-page owner's manual. Has a wonderful diagram. The jumper connects "ground" to the "negative signal". (connects pin 1 to pin 3)

I had to "build" one of these jumpers; I just used an inch (or less) of plain household solid-copper wiring, formed into a "U" shape. Might have been 12 or 14 gauge; although probably 12 gauge. Poke it in as shown in the owner's manual; pin 2 stays open.

[heiney9]

Did your amp come with the shorting pins for balanced inputs? If not, you'll need them if you run single ended. I have bought from here and these Cardas are very nice.

http://www.dedicatedaudio.com/inc/sdetail/5158

Be aware there is a min. order $$$. I bought extra's in case.

H9

[Schurkey]

Did your amp come with the shorting pins for balanced inputs? If not, you'll need them if you run single ended. I have bought from here and these Cardas are very nice.

http://www.dedicatedaudio.com/inc/sdetail/5158

Be aware there is a min. order $$$. I bought extra's in case.

H9

Yep, same as what I'm talking about. About an inch of copper wire...

[heiney9]

Yep, same as what I'm talking about. About an inch of copper wire...

I'm anal. My Aleph came with the "romex remedy" and I had to get regular shorting pins :p:). Not because the "romex" didn't work.........simply because I'm anal. :)

H9