Plate amp repairs for vintage speakers

neils
neils Posts: 26
edited March 2014 in Vintage Speakers
(mod, up to you if you want to make this a sticky or not)

Hey guys,

Thought I would share some valuable information with you, if you are stuck with a faulty plate amp (for sub drivers) on one of your vintage speakers. In my case, I had a plate amp go on me on my RT3000p. My heart sank cause I knew I would not be able to find another replacement plate amp (I was wrong). Being in Canada, my options were limited, call the Polk rep, who then referred me to an electronics repair company in Ontario. After looking over my plate amp (was making a loud buzzing sound), they concluded that the amp was not repairable (it is see below), but surprisingly, they had rebuilt plate amps lying in inventory, and cheap too. So a day later, I had a rebuilt unit sitting at my house, working perfectly. If you are in Canada, you can contact Walter Moser, or contact me as well, to put you in touch with that repair company.

As for the rest, after looking around on the net, I found the Holy Grail of repair companies, who bring vintage plate amps back to life. Their eBay handle is "electronetix", and they currently have a few auctions up for plate amp repairs. The way it works, you buy the auction on eBay, which covers parts and man-hours to repair your plate amp. Their prices are extremely reasonable. They ensured me that, minus the power supply, all other parts are repairable with over-the-shelf parts, which I believe.

If you cannot find the auctions, you can contact me, but here are some search examples:
Polk RTi100, RT1000i or RT1000p Powered Subwoofer Amplifier Plate Repair Service
Polk RT3000p Powered Subwoofer Amplifier Plate Repair Service

So if your plate amp blows, don't sweat it...

Neil
Post edited by neils on

Comments

  • jmcguire51
    jmcguire51 Posts: 25
    edited March 2014
    I was just telling a guy on here about that very company online that I have used for various RT plate amps and they give a 1 yr warranty too!...great and fast and reasonable! I believe they are based out of Chicago
    Polk audio RT3000p's
    Velodyne CHT15's x2 subwoofers! one for each tower
    RT2000i's as surrounds
    CS1000p
    FX500i's

    Looking for RT2000i's or RT3000p's...PM me...or click on profile and respond to my WTB ads...thanks!!!
  • Hi, I have a pair of RTi 100 tower speakers in great shape, both have built-in subwoofer amplifier system. One of the tower speaker is generating humming noise when it is switched to "Auto" that kicks in the subwoofer function. (Both the towers are hooked up to the AC outlet). Also, when I move the volume knob for increasing the sound, the humming noise also increases. I called Polk Audio and they provided me with Canadian Ontario Technician's contact but most of the times it is difficult to communicate him and get info from him as he is travelling most of the times, plus I do not know if he provides with a warranty after repair of the amplifier circuit plate and do they replace the plate or repair it. The postal charge is about $21for sending this plate to Ontario from Newfoundland and one of the local technicians told me its all digital switching plate so has to be replaced as they are difficult to repair.
    Now any one of you knows about this or have any experience, I do not want to junk them as they are absolutely wonderful speaker set.
    Thank you in advance.
  • dpowell
    dpowell Posts: 3,050
    Buzzing from an RT series plate amp is almost always the power caps going bad. You can either order the replacement parts from Polk Customer Service and do the repair yourself or take it to a repair shop to have done. Unless the amp has been severely damaged by a power spike, it is likely not beyond repair.
    ____________________________________________________________ polkaudio Fully Modded SDA SRS 1.2TLs + Dreadnaught, LSiM706c, 4 X Polk Surrounds + 4 X ATMOS SVS PB13 Ultra x 2Pass Labs X1, Marantz 7704, Sunfire Signature Cinema Grande 400, ADCOM 7807, Panasonic UB420, Sony SCD-C333ES, EPSON Pro Cinema 6050
  • i have two plate amps that burnt not completely burnt but overheated till discolored r 32 just need colors for replacement knowledge
  • RT1000i i believe
  • WLDock
    WLDock Posts: 3,073
    Here's the thread with all the vintage schematics and wire diagrams.
    http://forum.polkaudio.com/discussion/38755/polk-audio-speaker-wiring-schematics-more-all-models-except-sda

    Not sure of the differences between the RT1000P & the RT1000i in terms of the amps.

    RT1000p Wire Diagram
    https://us.v-cdn.net/5021930/uploads/attachments/4/6/7/2/8/18718.pdf

    RT1000p Amplifier Schematic
    https://us.v-cdn.net/5021930/uploads/attachments/4/6/7/2/8/18862.pdf

    RT1000p Crossover Schematic
    https://us.v-cdn.net/5021930/uploads/attachments/4/6/7/2/8/18719.pdf
    2.2 Office Setup | LG 29UB55 21:9 UltraWide | HP Probook 630 G8 | Dell Latitude | Cabasse Stream Amp 100 | Boston Acoustics VS 240 | AUDIORAX Desk Stands | Mirage Omni S8 sub1 | Mirage Omni S8 Sub2
  • fez34
    fez34 Posts: 1
    edited August 2018
    dpowell wrote: »
    Buzzing from an RT series plate amp is almost always the power caps going bad. You can either order the replacement parts from Polk Customer Service and do the repair yourself or take it to a repair shop to have done. Unless the amp has been severely damaged by a power spike, it is likely not beyond repair.

    Thanks "dpowell"... You gave me the key to the problem and confidence to tackle the problem. I took apart my RT1000P amp and noticed the Paper caps leaking and loose. The amp has 4700uF 25V capacitors. I was not able to find that same one locally, but I was able to find 4700uF 35V and installed them. From both speakers I found 3 out of the 4 capacitors (4700uF 25V) leaking and loose. I went ahead and purchased and replaced all four of the capacitors. I can report that my subs are no longer humming and sound amazing. Cost for the capacitors for me was $1.50 each. Since I purchased the speakers used and with the humming sounds, I never experienced them or their amazing bass. I disconnected my Velodyne sub and now have both the subs connected for bass. Using a Yamaha RX-V773WA.
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  • Tony M
    Tony M Posts: 11,009
    Interesting! ;)
    Most people just listen to music and watch movies. I EXPERIENCE them.
  • dpowell
    dpowell Posts: 3,050
    @fez34 glad that worked for you and welcome to club Polk!
    ____________________________________________________________ polkaudio Fully Modded SDA SRS 1.2TLs + Dreadnaught, LSiM706c, 4 X Polk Surrounds + 4 X ATMOS SVS PB13 Ultra x 2Pass Labs X1, Marantz 7704, Sunfire Signature Cinema Grande 400, ADCOM 7807, Panasonic UB420, Sony SCD-C333ES, EPSON Pro Cinema 6050
  • BiiigV
    BiiigV Posts: 4
    i have two plate amps that burnt not completely burnt but overheated till discolored r 32 just need colors for replacement knowledge

    On my plate amps r33 is burnt.
    Schematics showing R33 as 220/0.5W ???
    Anyone knows how to read it?
  • F1nut
    F1nut Posts: 49,704
    220 ohm, 1/2 watt.
    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

  • BiiigV
    BiiigV Posts: 4
    F1nut wrote: »
    220 ohm, 1/2 watt.

    Thank you
  • F1nut
    F1nut Posts: 49,704
    Be aware that replacing the resistor is no guarantee it'll fix the amp.
    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

  • BiiigV
    BiiigV Posts: 4
    F1nut wrote: »
    Be aware that replacing the resistor is no guarantee it'll fix the amp.

    I agree, but it worth to try
  • Here I am in 2022 looking to fix my plate amp and here’s my info, great!
  • Here I am in September 2022. I am already the happy owner of Polk Signature S60, S10 and s35 speakers. I recently acquired a set of RT1000i towers for free. One had a bad tweeter, the other no sound from the sub. A replacement tweeter is on it way to me. I took apart the plate amp and guess what. It's the same capacitor problem. I just ordered new caps and hoping to bring these towers back to their glory. Thank You, Thank you for this great info!!!