Polk 7A's, Are these Frankenpolks?

milesaway
milesaway Posts: 14
in Vintage Speakers
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  • xschop
    xschop Posts: 5,000
    I vote museum relics.
    Don't take experimental gene therapies from known eugenicists.
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  • pitdogg2
    pitdogg2 Posts: 25,440
    Nope look legit to me
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  • aprazer402
    aprazer402 Posts: 3,147
    edited March 2019
    Appear to be a very clean first iteration of Monitor or "Model" 7'A's. Double fuses, one for the MW "bass" the middle driver, one for the tweeter. The bottom driver is not wired, it is a passive radiator. I believe fuses should be one amp slo-blow. These were probably made in the late 70's or very early 80's. These are keepers. :)
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  • F1nut
    F1nut Posts: 50,543
    ^ Nailed it ^
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • delkal
    delkal Posts: 764
    Did the 7's use slow blow fuses and was that the same with the early 10's?

    I have some 10As with the peerless tweeter (with only one fuse). It had 1 amp fast blow fuses but who know where they came from. Anyone know if I can safely use slow blow?
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  • F1nut
    F1nut Posts: 50,543
    You want fast blow.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • boston1450
    boston1450 Posts: 7,636
    edited March 2019
    MilesAway have you listened to the speakers & what do you think ? Ive had that same model & i had them hooked to a Marantz 2252b with a 6300 turntable & wow they sounded great
    ..
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  • mhardy6647
    mhardy6647 Posts: 33,799
    edited March 2019
    they look exactly like my 7As (which have been with me since 1978):

    11208642076_3f7f8db8b1_b.jpgPolkmonitor7Asn4900 by Mark Hardy, on Flickr

    The two-fuse models are relatively uncommon; mine also have two fuses per speaker unit FWIW.

    From the factory, fuses were thus:
    1A fast blow tweeter
    1.5 A fast blow system
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  • xschop
    xschop Posts: 5,000
    xschop wrote: »
    I vote museum relics.

    Meant that as a compliment. It looks like your Peerless tweets may have been installed with a viscous putty?
    Don't take experimental gene therapies from known eugenicists.
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  • pitdogg2
    pitdogg2 Posts: 25,440
    edited March 2019
    xschop wrote: »
    xschop wrote: »
    I vote museum relics.
    Peerless tweets may have been installed with a viscous putty?

    Rope caulk was modus operandi in those days
    Moretite.
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  • milesaway
    milesaway Posts: 14
    The 2 fuses is where i got confused about whether they had been altered or not. Haven't had a chance to hook them up yet to listen but will have a chance tomorrow.
    Wonder how they'll sound with an HH Scott LK-72 powering them.
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  • mhardy6647
    mhardy6647 Posts: 33,799
    edited March 2019
    Well, it's kind of hard to say, actually.
    The LK-72 you have is push-pull 7591, yes?

    I will say that my venerable :) 7As did not sound great driven by an EICO HF-81 (pp EL84). While there's no doubt that pp EL84 is a bit underpowered for them the issue was tonal. The pairing was just not great sounding -- and the HF-81 is (IMO) a great sounding amplifier on many different flavors of loudspeakers. :)

    The LK-72 is no slouch, either; well worth a try.

    I kind of inferred from the HF-81 experience that the 7A was just one of those loudspeakers that sounds better with soiled solid state amplification -- but, truth be told, I didn't really pursue vacuum tube amplification with them much further after the HF-81.

    Full disclosure: I do have an LK-72 here (early, chocolate-faced version), but it has an issue with low output volume from one channel which I've never managed to suss out (although I know the issue's upstream from the phase splitters). :p
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  • Mr_Q
    Mr_Q Posts: 1
    I have & love my pair of 7Bs and have 2 comments.

    1. Using something like the inner cardboard tube from a spent roll of paper towels to gently pull out the tweeter dent by setting onto the front of the tweeter face creating the best seal possible and creating mild suction seems to have worked for me on several occasions for both tweeter domes and pushed in center dustcaps.
    2. I love my Monitor 7Bs and have tried a Marantz 2250B, 2270 & 2275 as well as a Threshold FET-10/ Nikko Alpha 440 combo and prefer my Sherwood S-7200 and S-9400 better.
    These early-mid '70s receivers/ integrated rigs are a wonderful musical match for those 7Bs.
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  • Polkaguy58
    Polkaguy58 Posts: 352
    I have a tiny plastic 1" funnel that I attached a piece of surgical tubing to the stem and I find that placing the funnel over the dome and using a little gentle suction (I just use my mouth) almost always pulls those dents out.
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