My Advent Baby IIs are misbehaving

Discussion in 'Speakers' started by mike_drop, Mar 13, 2018.

  1. mike_drop

    mike_drop Member

    Messages:
    51
    Hi all,

    My name is Mike. Very new to hifi and and brand new to AK and I’ve been told I’m long winded(apologies on all accounts). I’ve tried to research this myself, but a lack of available info and anxiety has me running to you for help. I will do my best to be more DIY in the future. To be fair, I’m doing pretty good IMO for being only 3 months in with this stuff(see pics!)

    I was fortunate enough to pick up a Marantz 2245 from a very nice guy who had more vintage amps/receivers in his basement than a girl has shoes. $325 and he threw in some Advent Baby IIs with it(the center piece of my problem). I figured out how to refoam them(yep, used a test tone while refoaming). I even replaced the boring black covers with some neat vintage Fender grills(have a feeling I’ll get mixed reviews on those).

    The setup had been working great for about two months- added a iFi NANO DAC and a AT LP120 to the rig in that time as well. I was really starting to enjoy everything and even found another pair of Baby IIs for $35 on FB(with stands!) to encompass myself in delicious hifi sound.

    That’s when the shit doth rained on my listening parade... something appears to be up with the left channel. Sounds faded, dropping in and out? It’s like it can’t handle any bass and it gets distorted or fuzzy sounding.

    At first I thought it was the speakers themselves(heck they were used with surrounds that were on life support), but after swapping the wires, the other speakers sound bad on the left now and the original ones sound fine on the right channel.

    To me, it seems like the receiver or DAC is the problem. It’s the bluetooth iFi DAC model- anyone have experience with the iFi Nano and an issue with one channel due to poor Bluetooth reception?

    My other theory is that my ignorance when it pertains to speaker and receiver power ratings and how to pair the two is probably the problem here... even worse, my Baby IIs don’t have a label on them with the power ratings and I’m getting mixed opinions on what they rate online. Can anyone tell me if the four speakers is too much for the 2245? Or is it maybe something internally on the Marantz causing the problem?

    If anyone can provide me with info and/or suggestions, I’d really appreciate it.

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  2. ivandezande

    ivandezande Super Member

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    Hi and welcome to AK! I'll toss out a couple thoughts; power rating on speakers doesn't mean anything, your amp and speaker combo is fine. Sounds like the Marantz is having an issue, which isn't super surprising assuming it hasn't been serviced at all. To be sure it's not your Bluetooth receiver, play some radio. Are you handy at all with electrical things? Otherwise probably want a tech.
     
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  3. spark1

    spark1 Super Member

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    I too suspect your Marantz as the problem. First step is to confirm this.

    To do that, choose a source other than the DAC (which I assume is plugged into your AUX input on the Marantz). Does the left channel still have problems when using the tuner (the radio portion of the receiver). How about when using the turntable?

    And does it happen ONLY when running the two pairs of speakers at the same time? Run just A, then just B. Does the problem occur in both cases?

    If the problem persists on different sources, and when running just A, just B, and then A/B together, it's definitely the receiver causing the problem.

    As an aside....while speaker power ratings are not very useful, impedance ratings are. The Baby IIs have a nominal impedance of 6 ohms, and can drop down to nearly 4 ohms at some frequencies. Without getting into the details, your Marantz is not really designed to accommodate a load much below 4 ohms for extended operation. Two pairs of 6 ohm speakers = 3 ohms, and that's at their nominal rating. Actual impedance will go below that at some points. Personally, I would not run both pairs simultaneously....others may feel otherwise.

    Once you confirm it is the receiver, you can decide which way to go (that is, try to address the problem yourself, with help from AK experts, or take it/send it to be repaired). AK folks can probably help steer you to a good repair resource in your area. Where are you?
     
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  4. F1nut

    F1nut Super Member

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    Spark1 hit the nail on the head, you can't run both pair of those speakers at the same time with that receiver, which is likely the cause of its demise. In addition, that thing on top of your receiver appears to be restricting the air flow. You should never place anything on top of a piece of gear with vents for cooling. Lastly, your speakers will sound a lot better when upright.
     
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  5. BigElCat

    BigElCat AK Subscriber Subscriber

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    You can run two pair of Baby Advents off that receiver, no problem.

    You need to start with Deoxit cleaner on the Volume pot, Balance pot, tone controls and all switches and selectors.

    This will probably fix it. If not let us know.

    You have cool system. I like the way the iFi DAC looks with the Marantz.
     
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  6. nfafan

    nfafan Well-Known Member

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    Just don't go crazy with volume using those 4 speakers.
    Heck, if Ohms law was a real law, I'd be in prison for life for what I run together.
     
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  7. spark1

    spark1 Super Member

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    Heck yeah....run three pairs, even four. Fun will ensue.:)
     
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  8. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

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    Let's not get overly exuberant. :cool:

    The Baby II is a 6 ohm nominal speaker. Very possible that running two pairs in parallel can stress the amp and cause distortion. Does the Marantz require at least 8 ohms per pair if running both? It will say on the rear panel and in the manual. If so there's your answer. Especially if you're running any bass boost, loudness, or just on heavy bass tracks.

    All that is assuming you don't have dirty controls or switches.
     
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  9. nfafan

    nfafan Well-Known Member

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    Location:
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    Problem appeared on left chan of Marantz 2245. Problem stayed on left channel after swapping speakers.

    I have same issue with my Marantz 2240, one side "went bad" - have to screw aound with left/right balance and volume to get sound on that side.

    Get receiver serviced.
     
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  10. J English

    J English Super Member

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    1,087
    That 4-speaker load may have stressed the channel, particularly if you run at higher volume level. Do uncover the top of the amp - it needs to be able to let heat out! The one other "cheap" thing to try would be to lightly de-ox the volume pot and the tape monitor switch. Many older receivers get a little channel drop out off the tape monitor switch dirt - my HK 430 is like that. Good luck! The 2245 was my first receiver back in 1974, I have a soft spot for them.
     
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  11. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

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    Classic dirty controls which are fairly easy, a DIY job for some people, and even shop doesn't have to diagnose electronics and change out parts so it's about the cheapest repair job you can ask for.

    Not just the volume pot and tape monitor. I've had receivers drop channels because of the source selector and speaker selector switches too. Signals go through all of those.
     
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  12. spark1

    spark1 Super Member

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    At best it is rated for a 4 ohm load. Two pairs of those advents = 3 ohms nominal, 2.5 at some frequencies. Not good. Doing dangerous things does not always result in disaster...but it makes such an outcome much more likely.
     
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  13. Old Guy8

    Old Guy8 AK Subscriber Subscriber

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    Find the General Audio Discussion secton. One the threads with red thumbtack is titled "Idiots guide to useing Deoxit." It would show you how to clean switches and pots in your receiver with contact cleaner. Try it, if you are comfortable DIY on your receiver.
     
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  14. Ramseybella

    Ramseybella AK Member

    Messages:
    642
    Location:
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    Nice amp cool lamp take it off the amp stop giving it the heat gun it's not good for the magic components inside it.
    Don't ask me how i know this is bad,,:rolleyes: I still have a bag of tube lights for that bad boy someplace in my parts box..
     
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  15. spark1

    spark1 Super Member

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    Excellent advice. The current draw from two pairs of 6 ohm speakers is already working that amp pretty hard, resulting in higher internal temps. Heat is the enemy of the magic components. Stacking stuff on top of the amp holds the heat in.
     
  16. tubed

    tubed Lunatic Member

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  17. spark1

    spark1 Super Member

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    Won't hurt, but I'm betting against it in this case.

    Still, the OP would benefit from trying to determine if any pots (volume, balance, etc) or switches are causing the problem, once he confirms that is not the DAC.

    He could do this by giving them a very rigorous workout (with power OFF), the power up the receiver and see if the problem gets even momentarily resolved by turning/pressing any knobs/switches. Press tape monitor in/out/in/out, etc...same for all other switches. Move the balance and tone controls back and forth. Turn volume up and down, up and down.

    If no change, it's probably not a pot or switch. If there is even momentary relief, then buying a can of Deoxit and reading the Deoxit for Idiots thread are certainly the next steps. .

    OP should also pull out the preamp out/main amp in jumpers and clean them, then work them in and out a few times before putting them back in place.

    Once he does all this, we can take the next steps in isolating the problem.
     
    Last edited: Mar 15, 2018
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  18. BigElCat

    BigElCat AK Subscriber Subscriber

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    The receiver was made in 1971.

    I don't think we're out of line suggesting it's time to use some contact cleaner. We luv our deoxit here.

    Once it's working again, wire the Baby Advents in series and use one set of speaker outputs (main OR remote).

    The 2245 has a recommended load range of 4 to 16 ohms. Wiring them in series would bring you to 12 ohms nominally.

    I seriously doubt you damaged the Marantz. The spaceman probably needs to find something else to warm his butt, though.

    :D
     
    Last edited: Mar 15, 2018
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  19. BigElCat

    BigElCat AK Subscriber Subscriber

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    Last edited: Mar 15, 2018
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  20. mike_drop

    mike_drop Member

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    51
    Hi all,

    Thank you all for your attention and solid advice. Re: the space man everyone is so concerned about ... he’s on the wood casing. Cmon I know better! The amp gets warm after prolonged use, but never hot. If you walk feel I shouldn’t have the album stand on there ill find a new spot, but it’s elevated by three legs with about 2-3cm clearance. It’s certainly not covering much square “inchage”, but I’m not married to it being there either if you insist.

    Back to the issue... I decided to rule out the DAC first. Seemed easiest to rule out. Hooked up a small Dayton 2x75w amp I’d bought for a separate speaker trunk project I’m working on. Ran the DAC through that and to two of the BA2’s. Certainly didn’t sound as pretty as the Marantz BUT the issue DID disappear. So then I went back to the Marantz and listened carefully using other channels/devices(it doesn’t happen all the time- the issue has always come and gone- not sure if I mentioned that from the start). Eventually The issue did return when using the phono.

    So, maybe cleaning is a good place to start. I’ve actually been meaning to clean the contacts and I’ve already purchased the cleaner recommended in the thread. What’s everyone’s opinions on the “preserver” by the way? See pic. Was thinking about picking it up also. Want this Marantz to last so I can hand it down some day...

    Running the speakers in a series could be an option whether or not the ratings are the cause of this issue- had to look running speakes in a series up(noob!). If that will allow me to use all four without damaging the amp, I’m all-four it(badumcha)! I don’t mind the volume taking a hit- I can’t blast it where I live anyways(le sigh), but I do want to have the sound coming from all sides. I just want this rig to last a long time and still sound good for years to come, so I’m not above being careful vs. blowing the roof off haha.

    That’s all I can write right now- on lunch break. There’s a few other suggestions you all have made that I have thoughts/questions on thought that I’ll get to tonight. To be continued...
     
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