As others correctly say, this is an impedance issue. However it goes deeper than that because impedance isn't a constant figure but one that varies according to the frequency of the applied signal. A nominal four ohm speaker may well have a minimum impedance lower than the stated nominal figure. perhaps as low as 3 ohm (or lower). For example the B&W 703 is a nominal 8 ohm design with an impedance minima of 3 ohm.
The bottom line is that you need an amplifier capable of far more substantial current delivery.
The Marantz PM6004 is a fairly low powered budget amp. I'm not suprised you couldn't use it to play many speakers with the low impedance.
I would suggest you look at getting an amplifier with a pre out and then get a power amp separately (Rotel or NAD).
HiFi- Cambridge Audio 340C- Pioneer A30- Dali Lektor 2 speakers. Denon FM/AM. Pure DAB.
Marantz CD6004 - Beyerdynamic DT250
Your speakers are 4 ohm impedance and your amplifier will only take one pair of 4 ohm speakers. Two pairs give a load of 2 ohms as the A and B outputs on the amplifier are in parallel. It probably says on the back of the amplifier speaker A + B 8-16 ohms meaning the minimum impedance for both outputs is 8 ohms.
Thanks, just seen your post. That would explain it, I only wish this had come to light before we bought the amplifier. We thought we had covered all the bases with checking the amp and speakers and checking with the shop prior to purchase and even testing the speakers. Looks like I should have downloaded the instructions manual before purchase.
Any suggestions for how we managed to get the unit to cut out with just one pair of speakers on?
The information is written on the back of the PM6004 amp.
Just as you should see this on the back of your Yamaha amp(where the swich for the impedance is).
When testing just one pair of Dali 505, you did remove the other spare pair of speaker cable right? Since the speakers are single wired.
If left connected and the other end touches something conductive or each other, the protection circuit will activate too.
And you did disengage one of the speaker output by pressing the speaker A or B button on the front of the PM6004?
If not, it is still rated as 8 to 16ohms per output.
Anyway, you have returned the PM6004.
Try to look for an amp with higher output (the PM6004 is 45W, your current Yamaha is 60W) and higher current delivery.
Many thanks for your help
We just tested it via the A and B switch. Both sets on via the A+B together. One set on, say A set, then B set on its own, then both sets etc. We left both sets connected, didn't test by actually removing a set phyiscally both were left on the system. Didn't think to actually take a set off the actual amp, wouldn't have just taken the speakers off and left the wires on, like you say, that would have activated the protection system if it touched anything.
The amp sounded great, the cd player was great too, mind you we already have a Marantz CD player on another system and that's great as well. We had to fit a new CD tray gear but still going strong and wouldn't change it.
The PM6004 sounded brilliant just what we were looking for it really was, hubby won't give up a pair of the Dali's though, he likes running four speakers. I wish we had tried just running two speaker now (by actually removing the other pair physically including the cables rather than just hitting the A and B) Mind you, that would have been pointless, parting him from the dali's is impossible (I've tried lol)
We will make sure to actually physically check the back of an amp before we buy another amp now. All our current amps are high powered, our Yamaha at 60 watts is the lowest powered amp we currently have.
Thanks very much for your help
Cheers, seems that way
Now beginning the search for an amplifier that can handle the four speakers. Thanks.
I am realy enjoying this album I should have put it on ages ago to busy listening to the black keys yes black country communion roger chapman led zep the answer richard thompson the eels etc I hope some one will give you a suggestion as to which amp to go for you could try the m6i but its a bit expensive compaired to the marantz I have just bought my son a marantz 6003 cdp and an audiolab 8000a amp to go with my old mission 752 speakers you might find an amp on the bay another member Record Spot is always buying amps that may be up to the job I am sure when he see's your post he will make some suggestions
Musical fidelity M6i Roksan caspian M2 cdp Atc scm 40s Tellurium Q black speaker cable chord chamelian xlr graham slee novo sennheiser hd598
Great advice many thanks. I don't understand what you mean lol, Hubby does though. Sounds expensive though lol, I think we really do need to do some further research. Currently even though our Yamaha amp 60 watts runs these two sets of speakers without any problems even louder than we can listen to it lol, it isn't cutting it with sound quality, not crisp/detailed enough for us. Our current budget is only £600 so we are limited. Unless we buy secondhand gear, or don't buy outright and buy on credit say.
Lol, you've got varied music taste like us. Most people laugh at my music taste, one minute I'm classical next clubbing, bit of this bit of that...........ELO super, PM6004 loved ELO in our lounge. Then trance......................you name it I'll listen to it lol.
I'm hoping someone will come up with a replacement suggestion as well, Hubby wanted to by-wire two amps one for each set of speakers! I wasn't keen on that Idea. We have various amps, so no shortage to try. He wanted to run our Pioneer A400 with the Yamaha, I wasn't up for that idea, I still didn't think it would be good enough for my ears, mind you, I like my music quite loud, too much clubbing in my pre 40 years lol..
We don't mind buying second hand, all our current gear is second hand.
Thanks everyone All is clear now.
So, as much as we liked the PM6004 it wouldn't run our two sets of Dali 505's and I now understand why, thanks So because Hubby won't part with his Dalis at this point in time, we need a more powerful amp.
You guessed it, has anyone got any suggestions please? We don't mind 2nd hand, or new but our budget is not very big at the mo, £600 ish, can change but not at the moment.
We have other amps, a high powered Sansui, but I'm not overly keen on it, a Pioneer A400 amp again, I'm not keen because you cannot change the bass and trebble and it doesn't match the Dalis very much in my opinion. A Denon, but that is on another system in one of our bedrooms at the moment and that sounds better with the Mordaunt Shorts and Keffs and even the Sansui speakers, doesn't seem to like the Dalis. Seems we have trouble trying to match an amp to the Dalis we have, the PM6004 did sound great though, shame. I suggested getting rid of the Dalis, divorce would probably follow though lol.
Should I start a new thread for suggestions? Thanks.
Yes that might be a good idea
It looks like you need to work out the exact impedance characteristic of your Dali's. It obviously they are hard for the amplifier. However out of 4 one may exhibit very bas impedance causing the amp to go into protection. So maybe be there is a case of fixing the culprit speaker. If hopefully all exhibit good impedance then you cheapest bet to go for two amp configuration with the Dali's impedance not droping anywhere below 3ohms. If you want one amp configuration you will need to go for some essoteric amplifiers that are far to expensive. Your current yamaha appears to drive the Dal's because it may not have a protection circuit that is effective. However, when you drive the Dali's hard the amplifier will most likely sound stressed. Then you could try to connect your speaker in series then you would not have any issues with protection.
Thanks, I wanted to just buy a new system along with a new set of speakers (far easier) hubby doesn't want to do that, hence this problem.
The Yamaha does have a protection system on it, but it hasn't been triggered by these speakers, maybe it just isn't as sensitive or isn't working. None of our amps have had a problem running these speakers, not even a lower powered amp. Although, the Yamaha is the lowest powered amp we have at the moment.
I don't think it is a faulty speaker, but we could be wrong, they all sound the same and never distort etc. The Yamaha can take the speakers higher than our ears will allow and the system or speakers don't sound stressed. Mind you, that could just be that our ears don't allow really loud music. The most my ears can managed out of the Yamaha with the Dalis is the 12 oclock position and that is only for a very short time and I think the whole street would hear it as well. I think I killed my ears years ago, too much loud music. I good level for our room is around the 8-o'clock to 10-o'clock at the highest on nearly all the amps we've tried.
Would you loose sound quality wiring speakers in series? Thanks.
Speakers in series is a no no for quality as they interact electrically.
I don't know what it would be like in practice but the Marantz Pearl Lite squeaks in at £20 over the 600 mark and is reputed to be a sonic bargain. I have the Pearl Lite SACD and its stunning in every way.
You see, with the greatest respect, no amplifier in your price range is going to say that it will drive two pairs of 4 ohm speakers but, in real terms many amps will. You need a dealer that will let you try at home.
Thanks very much for your input. I think we need to find a dealer that will let us try something at home, I didn't know anyone would let you do that. We have never bothered in the past and yesterday was the first time we've actually taken any speakers into a store to demo an amp with.
The budget isn't fixed, it is just something that we would like to try and keep to but it can move. Having said that, if we heard something that would make these speakers sound out of this world (if that is possible with the Dali 505's that is) The budget could shoot up! Just listening to the Yamaha now and it isn't as nice as the Marantz was.
Yesterday I did some measures with Mara 6004 :CD Dark Side otm - absolutely high volumes (there were no neighbors!) with 15 o'clock knob , ( the max is 17 hours) in the peaks had (average) : Vmax = 14 V/ch and Imax = 1.7 A, for a maximum power of almost 25 pot W/ch; I generally listen to 9:30 hours max, with my wife who's coming asking me for lower volumes.... I've to say that while the Quad 34 + 306 , that I owned before, with the same B&W 603 towers , and at a little lower volume, was going in protection (I had to unlock it using the back button) and also warmed up a bit on the smart front radiator, the Marantz instead was almost cold and never gone in protection.The Quad was also sounding a little harsh and with harder highs, at these levels, while the Pm 6004 has retained a good liquidity on the highs, which were still confortable...; Anyway in everydays normal cd listening, at 9:30, I get only 1 W/ch max on peaks!For your new amp: Yam AS 500, with 85 W and impedance settings on the back; I think it will meet your taste for a detailed and brigth sound (not for my taste, anyway...) - Just a few thoughts.
MARANTZ PM6004 amp - B&W DM603 S2 - B&W 610 sub - DUAL TT - SHURE M97XE - PHILIPS cd - Florence, Italy
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