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Evening, Nad 533 with Marantz 6007 amp and Monitor audio bx2 speakers. So here is my problem, there are 4 speaker outlets on the amp and a hi and low connection on the speakers. I had just connected the cables from the amp to the speakers through the hi connectors on the speakers. I had the bright idea of connecting 4 cables to both high and low/ left right. The amp didn’t like that and turned itself off as soon as I turned it on. So; disconnected the low settings and cables running just to the hi on the speakers…but no sound. The amp still works as my headphones work, so what have I done?
The amp still works as my headphones work, so what have I done?
Well the headphone amp part of it does. You've blown something in the main power amp. No idea what, sorry.
You have an amp that can run 2 sets of speakers. You have speakers that can be bi- wired. Unfortunately (but totally understandably) you have connected both outputs to one set of speakers and doubled something or halved something. Whatever it may well have fried something.
luckily 6007 can be taken apart and fixed. Your problem will be finding someone in 2023 who can do this. I’d start by contacting Marrantz they are a fantastic company.
What you have tried to do is effectively bi-wire the speakers, which the amp should be able to do.
https://manuals.marantz.com/PM6007/NA/EN/DNTXSYjvpbupqb.php
Did you remove the links first and connect everything in the right polarity with no shorts or stray wires touching?
It sounds like maybe you didn't and the amp went into protect mode.
Re check all cables and put it back to how it was before.
Turn the amp off and unplug it for a few minutes.
If it then doesn't come back, hopefully you have blown an internal fuse.
It's unlikely you've damaged the speakers, unless a loud bang was heard.
internal fuse blown - might even be accessible from the back. Look for a little knurled bit on the back that unscrews and a fuse will pop out - or you might have to take the cover off the amp to find the fuses. I've had amps with both types. the fuses are on the power stage so headphones will still work but the power amp for the speakers will not
thats my guess anyway
Have you tried turning it off and back on again?
If not try that, but leave it off for quite a while, maybe 30 mins as it's possible an overload switch has tripped and needs to reset.
I don't know this specific equipment but have had this on other amps in the past.
Was going to say, it'll be to do with Bi-Amping, so instead of stereo (L-/L+) & (R-/R+) cables found on cheaper systems, they are saperated for bass and trebble
So on the left channel you have
Hi+ cable
Hi- cable
For the treble ON EACH speaker
And for the Bass on EACH speaker, another two wires
Low+ cable
Low- cable
So you'd have 8 seperate audio cables feeding two cabinates ( 4 each)
https://www.audioadvice.com/videos-reviews/speaker-bi-wiring-bi-amping-explained
Drat. That is all. Thanks everybody, the power switch flashed for a few seconds then turned itself off. No sound for the connected Bluetooth either so I guess I will have to get it looked at.
Like on seriously expensive stuff, you'll have a pre-amp, and two, or four, seperate powerful mono amps.
Matty, the speakers didn’t have bridge plates, will that have caused the short? The reason I fitted all 4 was because the source was sounding dull and bass heavy.
Just looked at the manual myself (hadn’t seen others posts at first).
you shouldn’t have done anything wrong with the 4 leads:
Suggests you simply have a 2 channel amp with 4 output terminals. So as above, something else must have gone wrong.
Matty, the speakers didn’t have bridge plates, will that have caused the short?
They should have had plates when wired previously, these should have been removed when bi-wiring. None of this would damage the amp mind, would just sound pants in 2 wire with no plates, would be fine with bi-wire no plates. So the damage is so far a mystery.
Were the speakers bought recently and if so were they s/h?
If the connection plates were not in, you’ve not been using the tweeters, so no wonder it sounded pants. <br /><br />And if s/h, maybe the previous owner blew the tweeters through clipping, which has now damaged your amp when you connected them.
They were second hand, I have bought generic connectors this morning.
Bi-wiring is a waste of time. Unless you’re missing the bridging wires/plates for the low-high terminals. Then it is easier to put a bridge wire in than bi-wire.
Provided your wiring was correct and there were no inadvertent shorts from stray wires then from the amp shutdown and the prior dull sound it would not surprise me if @twonks has identified a potential problem - the tweeters or tweeter filters are blown and present no load to the amp - acting like a short circuit.
You could see what resistance you get for the low and high using a multimeter. This might show a difference and help diagnosis.
Hope the amp is merely stunned and not broken and you’re back up and listening soon.
IT LIVES!!! 
Pgparrot, they didn’t have plates when I bought them, checked the auction and there weren’t any in the pics. So, connected like that it is too bass heavy so would that be because there are no connectors? Doesn’t work in the high setting on the speakers at all.
Not as neat, but you dont need the original terminal connectors on the speakers. A small loop of speaker wire between each +ve,+ve -ve,-ve achieves the same and will bring the tweeter into play.
Ie. Make your own bridge connectors
Are the tweeters producing sound?
I suspect they are not and are the root cause of your issues.
No Twonks, but would that be because there are no interconnects?
CSB, I will give that a go, it will let me eliminate at least one factor.
As others have mentioned above if you're running a single pair of cables to the speakers you need to bridge the bass and treble binding posts on the speakers.
You could do this by cutting a small length of speaker cable, trimming the ends and connecting the two + and - binding posts together.
If you run wires from the amp to each pair of binding posts (bi wiried) on the speaker you don't want any link cables or link plates. That could cause a short and do damage to the amp.
Oh and you can test the tweeters by connecting the speaker wires to the upper binding posts rather than the lower ones. Obviously the bass/mid drivers won't be driven, but it'll let you know if the tweeters are working.
If you're going to test the mid high input on the speaker, make sure you do it from the mid-high output from the amp. Don't want to be sending low freqs into the tweeters.
If you’re going to test the mid high input on the speaker, make sure you do it from the mid-high output from the amp. Don’t want to be sending low freqs into the tweeters.
I don't think that's applicable on this amp.
It looks like it supports two pairs of speakers wired conventionally, or one pair of speakers bi-wired. So I believe both speaker outputs deliver the same signal to the speakers. The speakers themselves will contain a crossover which will send the high frequency signals to the tweeters and the lower frequencies to the mid/bass divers.
That shouldn't be necessary Jordan, as the speakers are designed for Bi-wiring / amping.
I'd create jumper wires as mentioned above and see what happens.
Fully expect the amp to go into protect again.
I think, to be safe, you best buy a new amp and speakers, carefully reconnect them.
The images above from the amp manual appear to show seperate high and low outputs unless I'm missunderstanding. I just had a look at the speaker manual and it is a bit short of wiring instructions but one of the images does show a jumper plate between high and low inputs so a jumper wire would definately do the job if nothing is blown.
Edit: Just had a look at the amp manual, yes it's sending two lots of full range signals so could use either set if both are working.
I think what the back of the amp shows is A or B speakers. So two outputs doing the same. Presumably there is a switch on the front for either or both.
Edit. To bi-wire you'd choose the 'both' setting and two cables would run to each speaker, using both pairs of outputs for that channel, one into the tweeter and one into the woofer.
Jerry rigged connects and everything works, including the speakers. I am currently listening to King Creosotes latest brilliant album and drinking coffee which I am raising a mug of to the wonderful people of singletrack. Thanks everybody!
Great news. I can go out on my bike now!
Winner!
KramerFree Member
I think, to be safe, you best buy a new amp and speakers, carefully reconnect them.
This. And you’ll be needing a new bicycle too, because reasons
See you say that, but this all started 2 months ago with me buying a second hand turntable from a colleague to access the 200 albums that have been in the loft for 25 years. After that came a new cartridge, amp with phono stage and well…the old speakers had had the tweeters pressed in when my kids were wee…I was about to type cycling was cheaper but was pricing XT cassettes yesterday.