RTA 12B XO rebuild

FastGame
FastGame Posts: 67
edited September 2012 in Vintage Speakers
Hello all :smile:

I think it's time for my RTA's to be refreshed. I don't know anything about this so is there some where I can send them out for the work ? I want them to sound as good or better than new, guess I would like the best job for the $...oh and anyone know what the cost should be (ballpark figure). My drivers & tweeters are good as far as I know.

Thanks.
Samsung PN64F8500, Parasound 2100 pre amp, Parasound 2250 v.2 amp, Parasound Zdac, OPPO 103D, Monitor Audio Silver RX8, Dual SVS PB 2000
Post edited by FastGame on
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  • VR3
    VR3 Posts: 28,647
    edited August 2012
    I would love to help you out...

    Vr3Mods@GMail.com :)

    Thanks
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited August 2012
    VR3 wrote: »
    I would love to help you out...

    Vr3Mods@GMail.com :)

    Thanks

    He's your man!
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  • FastGame
    FastGame Posts: 67
    edited August 2012
    audiocr381ve wrote: »
    He's your man!

    Yes I think so, already made contact. Need to tear down speakers and get the show on the road.

    Thanks.
    Samsung PN64F8500, Parasound 2100 pre amp, Parasound 2250 v.2 amp, Parasound Zdac, OPPO 103D, Monitor Audio Silver RX8, Dual SVS PB 2000
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  • factorz
    factorz Posts: 353
    edited August 2012
    I had him do my RTA-12C and I can say it made a huge difference! Just make sure that if you get a new connector put on that it will fit the existing hole. I had to drill mine out a little to fit.
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  • VR3
    VR3 Posts: 28,647
    edited August 2012
    Hey Chris

    I think the future RTA12 I will use the NL4 connection like we used on your SDA... I think it might work better... hmm
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • FastGame
    FastGame Posts: 67
    edited August 2012
    VR3 wrote: »
    Hey Chris

    I think the future RTA12 I will use the NL4 connection like we used on your SDA... I think it might work better... hmm

    So I'm the guinea pig :eek:
    Samsung PN64F8500, Parasound 2100 pre amp, Parasound 2250 v.2 amp, Parasound Zdac, OPPO 103D, Monitor Audio Silver RX8, Dual SVS PB 2000
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  • factorz
    factorz Posts: 353
    edited August 2012
    FastGame wrote: »
    So I'm the guinea pig :eek:

    Acutally since my RTA's were his first I was the guinea pig. You get to benefit from the lessons learned! Trust me you won't regret doing it.
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  • VR3
    VR3 Posts: 28,647
    edited August 2012
    Trust me - I got this down pat now :)

    I have only modified like 100+++ speakers since I did your RTA12C ;)
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • cwsmith68
    cwsmith68 Posts: 434
    edited August 2012
    I have a question about my RTA 12B xovers. I am replacing the caps and in the process of trying to make room and the board, I bent one of the 750 pF Silver Micas and broke one leg of it. My question is where to get a replacement and should I replace them all?

    Thanks,
    Coley
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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  • pitdogg2
    pitdogg2 Posts: 25,446
    edited August 2012
    cwsmith68 wrote: »
    I have a question about my RTA 12B xovers. I am replacing the caps and in the process of trying to make room and the board, I bent one of the 750 pF Silver Micas and broke one leg of it. My question is where to get a replacement and should I replace them all?

    Thanks,
    Coley

    throw them away there no longer needed when quality caps are used.
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  • cwsmith68
    cwsmith68 Posts: 434
    edited August 2012
    pitdogg2 wrote: »
    throw them away there no longer needed when quality caps are used.
    So, I can just remove them all from the board?
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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  • pitdogg2
    pitdogg2 Posts: 25,446
    edited August 2012
    cwsmith68 wrote: »
    So, I can just remove them all from the board?

    yes you do not need them. They're only used with inferior caps to help them sound better. With better caps a bypass cap is not needed.
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  • cwsmith68
    cwsmith68 Posts: 434
    edited September 2012
    cool. Thanks Pittdogg
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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  • cwsmith68
    cwsmith68 Posts: 434
    edited September 2012
    I have another question about caps for my RTA 12b xover rebuild. When searching for replacement caps and cannot find the exact stock cap value, is it better to go with a lower value or higher? how far to either side is acceptable? For instance. I need a 55uF but cannot seem to find one. Would I be ok with say a 51uF or should I add a smaller value in parallel to get closerto factory specs? Or how about a 56uF?

    Thanks
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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  • TennMan
    TennMan Posts: 1,266
    edited September 2012
    If you have to use two caps to replace one due to lack of availability you should get two that are as close as possible to the same size. For instance if you need to caps to replace a 56uF you should use two 28uF caps if they are available.
    • SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
    • Crossover upgrades by westmassguy
    • Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
    • Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
    • Pioneer DV-610AV DVD/CD player
    • SDA CRS+ · Hidden away in the closet
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  • cwsmith68
    cwsmith68 Posts: 434
    edited September 2012
    TennMan wrote: »
    If you have to use two caps to replace one due to lack of availability you should get two that are as close as possible to the same size. For instance if you need to caps to replace a 56uF you should use two 28uF caps if they are available.

    ok. But what if i replaced a 55uF with a 51uF? I want to go with the same brand if possible and that is as close as that brand comes with the space I have to use on the pcb.

    Another thing I am not sure on. Does a higher value allow more of the freq band through or is it the other way around?
    does a 55uF allow more through that a 51?
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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  • TennMan
    TennMan Posts: 1,266
    edited September 2012
    I gave you a standard recommendation about how caps should be replaced when you need to use 2 instead of one. As for the "what ifs" you will need to talk to an electrical engineer to get the proper answer. Maybe someone a Polk would be willing to help.
    • SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
    • Crossover upgrades by westmassguy
    • Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
    • Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
    • Pioneer DV-610AV DVD/CD player
    • SDA CRS+ · Hidden away in the closet
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  • VR3
    VR3 Posts: 28,647
    edited September 2012
    56uf is fine.
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • Schurkey
    Schurkey Posts: 2,101
    edited September 2012
    cwsmith68 wrote: »
    ok. But what if i replaced a 55uF with a 51uF? I want to go with the same brand if possible and that is as close as that brand comes with the space I have to use on the pcb.
    Rule of thumb is that if the cap you purchase is nominally withing 5% you're fine.
    55 X .95 = 52.25. I would not install a 51uF cap in that application.
    cwsmith68 wrote: »
    Another thing I am not sure on. Does a higher value allow more of the freq band through or is it the other way around?
    does a 55uF allow more through that a 51?
    Higher-value cap lowers the crossover point.
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  • cwsmith68
    cwsmith68 Posts: 434
    edited September 2012
    Thanks guys!
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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