Problems with Dual Mono amp and 1000VA A-L AI-1

24

Comments

  • drumminman
    drumminman Posts: 3,396
    edited March 2013
    F1nut wrote: »
    I concur.

    drumminman, do you still have the 800V transformer?

    I don't.
    headrott wrote: »
    Confirmed. I get a 0 ohm reading between the left and right binding posts on my AI-1 Dreadnought (both positive and negative). You don't have a cold solder joint on one of the binding posts (or both) do you Fred? If you do not, it it is most likely a miswiring of the transformer primaries and secondaries. Very very low chance of occurance but not impossible of course. I would check you solder joints first though; especially since you said everything was working correctly when you first started using the AI-1.

    That's one of the first things I checked. All the wire pairs are firmly attached (as in no wiggle at all) to the BP's. I'm usually pretty good at soldering, but I can re-do it all. It's worth a shot since this issue is so bizarre.

    What I don't get is why the hum disappears with only one channel powered up, and I still get the SDA effect in the opposite speaker. The AI-1 is still passing the SDA signal.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • SCompRacer
    SCompRacer Posts: 8,507
    edited March 2013
    Since you followed color code, the possibilities are; 1) internal short of primary to secondary windings, or 2) like Fred mentioned, during construction they mixed up colors to primary/secondary wiring.

    I'd desolder all wires and start measuring between all wires following your color code below. Continuity or complete circuit means a primary or secondary winding. If correct, and you can't come up with an open circuit or no reading between R and L, you have a shorted tranny. If no reading occurs between any colors paired below, they screwed up.



    Left channel + : grey/brown
    Left channel - : blue/violet

    Right channel + : red/yellow
    Right channel - : black/orange
    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 *
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  • drumminman
    drumminman Posts: 3,396
    edited March 2013
    SCompRacer wrote: »
    Since you followed color code, the possibilities are; 1) internal short of primary to secondary windings, or 2) like Fred mentioned, during construction they mixed up colors to primary/secondary wiring.

    I'd desolder all wires and start measuring between all wires following your color code below. Continuity or complete circuit means a primary or secondary winding. If correct, and you can't come up with an open circuit or no reading between R and L, you have a shorted tranny. If no reading occurs between any colors paired below, they screwed up.



    Left channel + : grey/brown
    Left channel - : blue/violet

    Right channel + : red/yellow
    Right channel - : black/orange

    Good idea! It may take me a few days to find a block of time to do this, but I'll post results.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    drumminman wrote: »
    Per SComp's suggestion I got out my DMM, set it to 200 ohms and got the following readings taken at the binding posts:

    Left channel: pos to neg - 0.03 Right channel: pos to neg - 0.03

    Left pos to Right neg - 1.00
    Left neg to Right pos - 1.00
    Left pos to Right pos - 1.00
    Left neg to Right neg - 1.00

    I noticed that when I got ready to do the measurements below that the DMM (when set to 200 ohms) reads 1 ohm when the leads are not connected to anything including each other. I'm guessing that this means an open circuit, i.e. no continuity? If this is the case then the readings above do not indicate an issue. Comments?

    I proceeded to desolder all the tranny wires from the BP's and took the following bare wire measurements, all in ohms.

    Left channel:

    grey to brown: 1 (open circuit no continuity)
    grey to blue: 0.6
    grey to violet: 1
    brown to blue: 1
    brown to violet: 0.6
    violet to blue: 1

    Correct wiring is Left channel + : grey/brown
    Left channel - : blue/violet


    Right channel:

    red to yellow: 1
    red to orange: 1
    red to black: 0.6
    orange to black: 1
    yellow to orange: 0.6
    yellow to black: 1

    Correct wiring is Right channel + : red/yellow
    Right channel - : black/orange


    I found no continuity or resistance measurements between any combination of right and left channel wires. The way I'm interpreting this is that the tranny is correctly wired internally, so no issues there.

    Appreciate any feedback, criticism, questions, insight.

    Thanks!
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited April 2013
    drumminman wrote: »
    I sent my Odyssey Stratos stereo amp in to be converted to Dual Mono last summer. When I received it I connected it to my HT for 16 hour per day burn in, and then back into the big rig. After the conversion it ran warm to hot in the HT which has no SDA speakers.

    I am inclined to think that something was done in the Odyssey Stratos stereo to mono conversion that is causing some type of short condition. Can you find out what exactly was done to the amp in the conversion process?
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • headrott
    headrott Posts: 5,496
    edited April 2013
    I am thinking it has something to do with the amp as well. At least that was my initial thought.
    Relayer-Big-O-Poster.jpg
    Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
    "I'm yet to hear a Polk speaker that merits more than a sentence and 60 seconds discussion." :\
    My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....

    "Green leaves reveal the heart spoken Khatru"- Jon Anderson

    "Have A Little Faith! And Everything You'll Face, Will Jump From Out Right On Into Place! Yeah! Take A Little Time! And Everything You'll Find, Will Move From Gloom Right On Into Shine!"- Arthur Lee
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    DarqueKnight wrote: »
    I am inclined to think that something was done in the Odyssey Stratos stereo to mono conversion that is causing some type of short condition. Can you find out what exactly was done to the amp in the conversion process?

    headrott wrote: »
    I am thinking it has something to do with the amp as well. At least that was my initial thought.

    Based on these comments I'm assuming that there's nothing wrong with the transformer or the way I had it wired. I thought that going into this, but had to be confirmed. As I stated earlier. when I first connected and powered up the amp with the AI-1 connected everything worked fine. Then the amp slowly got hot, and then the hum started. However, if only one channel is powered up there are no issues; problems only occur when both are powered up.

    I emailed the schematics of the 2.3TL's to Klaus last week along with some pertinent info about the concept of using the AI-1 with Dual Mono or non common ground amps. I'll contact him tonight and see where we're at. I'm hoping it's something simple, but I have a feeling it's going to involve sending the amp back.

    I've never listened to these SDA's without the IC connected and, with the amp upgrades, they're phenomenal stereo only speakers. Must say I'm impressed, though I do miss the SDA effect.

    Thanks to all who have offered their input: F1nut, headrott, FTGV, SCompRacer, DarqueKnight. I'll keep posting to this thread as this problem moves along in case it's useful to someone at some point.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • FTGV
    FTGV Posts: 3,649
    edited April 2013
    These things usully take some trouble shooting to get to the source of the problem but atleast looks like you have eliminated the tranny and all else on your end.Hopefully your amp guy will have some insight .
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  • FTGV
    FTGV Posts: 3,649
    edited April 2013
    .....double post
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    DarqueKnight wrote: »
    I am inclined to think that something was done in the Odyssey Stratos stereo to mono conversion that is causing some type of short condition. Can you find out what exactly was done to the amp in the conversion process?


    Klaus reports that the dual mono is literally two mono amps in one chassis. There is no connection between the two other than being physically close together. The odd thing to me is this whole set up (AI-1, dual mono, 2.3TL's) functioned normally for 6 months before the left channel blew. Unfortunately I don't have the technical knowledge to get into amplifier design and how he did the conversion, changes made from stereo, etc.

    I've had numerous conversations with Klaus at Odyssey over the last two weeks, and the upshot is neither he nor his technical guy, Alex, understand why this problem exists. I sent them MSP's description of how the SDA signal is derived and how the AI-1 functions, schematics of the 2.3TL's and schematics and a wiring diagram of the AI-1.

    At his suggestion last night I tied the negative speaker binding posts together (AI-1 out of the mix). On power up I got a howl from the speakers so I immediately shut everything down and removed the connecting wire. Also at his suggestion I tried connecting the SDA IC (again no AI-1). This didn't work either as I got a loud mid range to low end growl through the speakers.

    At that point I gave up and called him back. The only other option at this point (other than selling the amp and going a different route), is to have Klaus build another stereo amp. He suggested he would build one that is essentially what I have now, but in stereo with common ground as before. He'd put their top tier boards in and replace the transformers just to be safe, all at no additional cost to me.


    The amp in its present configuration functions flawlessly with the speakers connected in stereo only (no sda). After all the experimentation I ran the system in stereo only mod and it sounded really good. Just no SDA. Very frustrating.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • Drenis
    Drenis Posts: 2,871
    edited April 2013
    Could a Cap or component in the crossover cause something like this? It's the only thing that hasn't been troubleshooted if I read correctly.
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  • nspindel
    nspindel Posts: 5,343
    edited April 2013
    Possible that the binding posts of the Dreadnaught aren't properly insulated from the enclosure, causing a short?
    Good music, a good source, and good power can make SDA's sing. Tubes make them dance.
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    Drenis wrote: »
    Could a Cap or component in the crossover cause something like this? It's the only thing that hasn't been troubleshooted if I read correctly.

    I ruled this out as the speakers sound quite good when the amp is connected without the SDA IC in place.
    nspindel wrote: »
    Possible that the binding posts of the Dreadnaught aren't properly insulated from the enclosure, causing a short?

    I used the insulators that came with the cardas BP's and there appears to be no connection between them and the case. I'll get out the dmm and check it out though just to be sure.

    Thanks for the suggestions
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • F1nut
    F1nut Posts: 50,649
    edited April 2013
    Do you have anyone that could bring over a pair of mono blocks to test in your rig?
    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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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    F1nut wrote: »
    Do you have anyone that could bring over a pair of mono blocks to test in your rig?

    No, don't know of anyone around here who has them.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    My Dual Mono is to be shipped back to Odyssey to be re-converted to Stereo with most of the same upgrades in place, plus one or two additional ones. Klaus has conferred with his technical guy and they can not understand why I'm having the issues I have, which are:

    a terrible hum with the AI-1 in place and the amp runs way too hot.

    Then, per Klaus' suggestion I ran the SDA IC without the AI-1 and it was even worse.

    Much head scratching at Odyssey headquarters, but Klaus is going to do all this work with no out of pocket expense to me except shipping. I'm disappointed but hopeful that I'll finally get things working properly again.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • headrott
    headrott Posts: 5,496
    edited April 2013
    drumminman wrote: »
    My Dual Mono is to be shipped back to Odyssey to be re-converted to Stereo with most of the same upgrades in place, plus one or two additional ones. Klaus has conferred with his technical guy and they can not understand why I'm having the issues I have, which are:

    a terrible hum with the AI-1 in place and the amp runs way too hot.

    Then, per Klaus' suggestion I ran the SDA IC without the AI-1 and it was even worse.

    Much head scratching at Odyssey headquarters, but Klaus is going to do all this work with no out of pocket expense to me except shipping. I'm disappointed but hopeful that I'll finally get things working properly again.

    Fred, I'm sorry for your woes. Very nice of Klaus to conver the amp back to stereo on his dime. Did you think of sending the AI-1 with the amp to Klaus to see if he can get it working correctly before converting back to stereo? Just a thought. Either way, I hope you are able to listen to your stereo without hassle after getting the amp back.
    Relayer-Big-O-Poster.jpg
    Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
    "I'm yet to hear a Polk speaker that merits more than a sentence and 60 seconds discussion." :\
    My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....

    "Green leaves reveal the heart spoken Khatru"- Jon Anderson

    "Have A Little Faith! And Everything You'll Face, Will Jump From Out Right On Into Place! Yeah! Take A Little Time! And Everything You'll Find, Will Move From Gloom Right On Into Shine!"- Arthur Lee
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  • nspindel
    nspindel Posts: 5,343
    edited April 2013
    headrott wrote: »
    Did you think of sending the AI-1 with the amp to Klaus to see if he can get it working correctly before converting back to stereo?

    How would he do that? Wouldn't he need a pair of SDA's to test that with?
    Good music, a good source, and good power can make SDA's sing. Tubes make them dance.
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    nspindel wrote: »
    How would he do that? Wouldn't he need a pair of SDA's to test that with?

    Yes, he would need a pair of SDA's. The whole thing is very weird, but he's putting forth a good faith effort which is all I can ask for. He thinks that with the AI-1 in place the amp is seeing an impedance so low it can't handle it, and his amps are rated for 2 ohms.

    Just don't get why it worked for 6 months.

    HR, I haven't forgotten the pics. I'll try to get them to you this weekend.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • headrott
    headrott Posts: 5,496
    edited April 2013
    Well, yeah. There is that little technicality.:wink: Well Fred, looks like you have to ship him you 2.3TL's too.:razz:
    Relayer-Big-O-Poster.jpg
    Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
    "I'm yet to hear a Polk speaker that merits more than a sentence and 60 seconds discussion." :\
    My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....

    "Green leaves reveal the heart spoken Khatru"- Jon Anderson

    "Have A Little Faith! And Everything You'll Face, Will Jump From Out Right On Into Place! Yeah! Take A Little Time! And Everything You'll Find, Will Move From Gloom Right On Into Shine!"- Arthur Lee
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  • F1nut
    F1nut Posts: 50,649
    edited April 2013
    He thinks that with the AI-1 in place the amp is seeing an impedance so low it can't handle it,

    That's not it. The problem is ground related.
    Just don't get why it worked for 6 months.

    That is a weird one.
    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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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    That's not it. The problem is ground related.



    That's my gut feeling. Something occurred inside the amp that caused the problem, some type of component failure I'm guessing. If it was design related it would have had the problem immediately on power up, it wouldn't develop it.

    Could the transformers inside the amp some how have gone bad? I don't have the knowledge to do much other than guess.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • Leftplumma
    Leftplumma Posts: 88
    edited April 2013
    Hey Fred,
    I am having the same problem with a 1000 va transformer as you.
    Well, pretty close anyways.
    I bought a new to me Krell FPB 600 fully balanced amp, and used it on my 1.2tl's for awhile without any sda cable whatsoever.
    http://www.polkaudio.com/forums/showthread.php?145210-New-Krell(to-me)-amp-amp-1000VA-drednaught&highlight=krell+fpb+600
    After hooking up the Dreadnought it played for awhile although I didn''t like the sound at all.
    I thought the stereo sound without SDA was much better.
    So after awhile I heard a pop, and that's the last I've heard from my Krell amp.
    I haven't had the funds to return the amp to Krell for service yet, but I plan on bringing the Dreadnought and the 1.2 schematic with me for Krell to review.
    I also measured with a DMM and had zero readings between all left and right connections as you have.
    I'm afraid to ever hook my krell back up to the 1.2's in this way again until I find the problem.
    Best of luck in finding this, and if I learn anything more I'll be sure to let you know.
    Best,
    Jeff
    Polk SDA 1.2 TL
    Infinity SSW-210
    Integra DTR 7.1
    Pioneer SC-57 Elite
    Sony X777ES
    Sansui BA-5000
    Hafler XL 600's in mono w/ George Kay Audio Tube upgrades
    Hafler xl 600 stock
    Krell FPB 600
    Avel 1000VA Dreadnought
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  • Leftplumma
    Leftplumma Posts: 88
    edited April 2013
    Also I've been running the Dreadnought since then with my BA 5000 amp. with absolutely no problems whatsoever.......
    The difference seems to be in the two amps.
    Polk SDA 1.2 TL
    Infinity SSW-210
    Integra DTR 7.1
    Pioneer SC-57 Elite
    Sony X777ES
    Sansui BA-5000
    Hafler XL 600's in mono w/ George Kay Audio Tube upgrades
    Hafler xl 600 stock
    Krell FPB 600
    Avel 1000VA Dreadnought
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    Leftplumma wrote: »
    Hey Fred,
    I am having the same problem with a 1000 va transformer as you.
    Well, pretty close anyways.
    I bought a new to me Krell FPB 600 fully balanced amp, and used it on my 1.2tl's for awhile without any sda cable whatsoever.
    http://www.polkaudio.com/forums/showthread.php?145210-New-Krell(to-me)-amp-amp-1000VA-drednaught&highlight=krell+fpb+600
    After hooking up the Dreadnought it played for awhile although I didn''t like the sound at all.
    I thought the stereo sound without SDA was much better.
    So after awhile I heard a pop, and that's the last I've heard from my Krell amp.
    I haven't had the funds to return the amp to Krell for service yet, but I plan on bringing the Dreadnought and the 1.2 schematic with me for Krell to review.
    I also measured with a DMM and had zero readings between all left and right connections as you have.
    I'm afraid to ever hook my krell back up to the 1.2's in this way again until I find the problem.
    Best of luck in finding this, and if I learn anything more I'll be sure to let you know.
    Best,
    Jeff

    Man that's interesting. When you find out what the issue is please post. I plan to do the same - could help others in the future. Is your Krell dual mono?

    Re: stereo image, my rig sounds absolutely great with the Odyssey in stereo mode without the SDA IC connected. But that's only 70% of what it could sound like.

    I was discussing the situation with my wife and we talked about some options: either sell the amp and get another, or sell the speakers. She was adamant that there's no way we're getting rid of the speakers !:cool::cheesygrin: She likes the way they look :lol:
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • nspindel
    nspindel Posts: 5,343
    edited April 2013
    Leftplumma wrote: »
    Hey Fred,
    I am having the same problem with a 1000 va transformer as you.
    Well, pretty close anyways.
    I bought a new to me Krell FPB 600 fully balanced amp, and used it on my 1.2tl's for awhile without any sda cable whatsoever.
    http://www.polkaudio.com/forums/showthread.php?145210-New-Krell(to-me)-amp-amp-1000VA-drednaught&highlight=krell+fpb+600
    After hooking up the Dreadnought it played for awhile although I didn''t like the sound at all.
    I thought the stereo sound without SDA was much better.
    So after awhile I heard a pop, and that's the last I've heard from my Krell amp.
    I haven't had the funds to return the amp to Krell for service yet, but I plan on bringing the Dreadnought and the 1.2 schematic with me for Krell to review.
    I also measured with a DMM and had zero readings between all left and right connections as you have.
    I'm afraid to ever hook my krell back up to the 1.2's in this way again until I find the problem.
    Best of luck in finding this, and if I learn anything more I'll be sure to let you know.
    Best,
    Jeff

    Ouch. FWIW, I use my Dreadnaught with a Krell KAV-2250, and it's perfect. I've had my 1000VA hooked up since we did the group buy, and I had an 800VA before that for at least a year.
    Good music, a good source, and good power can make SDA's sing. Tubes make them dance.
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  • Leftplumma
    Leftplumma Posts: 88
    edited April 2013
    No the Krell is not dual Mono, but it is fully balanced meaning the left and right channels cannot be connected in any way.
    I'm wondering if certain designs of amplifiers simply are not compatible with this system???
    It's interesting to hear your observations on running the SDA's without the cable......
    I'm thinking I'm never getting rid of the Krell, and certainly love my Polk's so.......
    I've been toying with the idea to give up on the SDA altogether and rewire all the midbass drivers as just a left and right channel.
    I'm thinking these big boys would really kick some serious butt.
    But I'm still going to look for a solution first.
    Also for the record I have a pair of FrankenHafler mono amps that were damaged by running them on the original A-1a cable as well.
    Polk SDA 1.2 TL
    Infinity SSW-210
    Integra DTR 7.1
    Pioneer SC-57 Elite
    Sony X777ES
    Sansui BA-5000
    Hafler XL 600's in mono w/ George Kay Audio Tube upgrades
    Hafler xl 600 stock
    Krell FPB 600
    Avel 1000VA Dreadnought
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  • drumminman
    drumminman Posts: 3,396
    edited April 2013
    Leftplumma wrote: »
    Hey Fred,
    I am having the same problem with a 1000 va transformer as you.
    Well, pretty close anyways.
    I bought a new to me Krell FPB 600 fully balanced amp, and used it on my 1.2tl's for awhile without any sda cable whatsoever.
    http://www.polkaudio.com/forums/showthread.php?145210-New-Krell(to-me)-amp-amp-1000VA-drednaught&highlight=krell+fpb+600
    After hooking up the Dreadnought it played for awhile although I didn''t like the sound at all.
    I thought the stereo sound without SDA was much better.
    So after awhile I heard a pop, and that's the last I've heard from my Krell amp.
    I haven't had the funds to return the amp to Krell for service yet, but I plan on bringing the Dreadnought and the 1.2 schematic with me for Krell to review.
    I also measured with a DMM and had zero readings between all left and right connections as you have.
    I'm afraid to ever hook my krell back up to the 1.2's in this way again until I find the problem.
    Best of luck in finding this, and if I learn anything more I'll be sure to let you know.
    Best,
    Jeff

    Found this in as Stereophile review:

    Latest and largest in Krell's current range of power amplifiers, the 600Wpc, $12,500 Full Power Balanced 600 joins the 300Wpc FPB 300 ($9000) and the 200Wpc (originally 150Wpc) FPB 200 ($5900). All are single-box stereo chassis and are specified as "Full Power Balanced"—I think to distinguish the essence of these designs from ordinary stereo amplifiers operated in balanced-bridged mode, usually with impaired performance. The FPB 600's speaker output is balanced; ie, neither "positive" or negative" terminals are connected to ground or the amplifier chassis. (Note that no speaker switches or headphone adaptors, which often have joined channel grounds, may be used, as they will short the outputs.) The output terminals are electrically at 0V, but float above the chassis ground.

    As F1 wrote I believe the issue with my Odyssey Dual Mono has something to do with the grounding scheme. Could it be with your Krell too?
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • Leftplumma
    Leftplumma Posts: 88
    edited April 2013
    nspindel wrote: »
    Ouch. FWIW, I use my Dreadnaught with a Krell KAV-2250, and it's perfect. I've had my 1000VA hooked up since we did the group buy, and I had an 800VA before that for at least a year.

    Yes, I think I remember you telling me that....
    I wonder if Fred and I are making the same mistakes????
    After all we're both drummers.... I think
    Polk SDA 1.2 TL
    Infinity SSW-210
    Integra DTR 7.1
    Pioneer SC-57 Elite
    Sony X777ES
    Sansui BA-5000
    Hafler XL 600's in mono w/ George Kay Audio Tube upgrades
    Hafler xl 600 stock
    Krell FPB 600
    Avel 1000VA Dreadnought
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  • Leftplumma
    Leftplumma Posts: 88
    edited April 2013
    As F1 wrote I believe the issue with my Odyssey Dual Mono has something to do with the grounding scheme. Could it be with your Krell too?[/QUOTE]


    I suppose that it could.
    But the Drednought is supposed to take care of that problem, and I believe it does.
    But then there is the operator error factor........
    We might just be doing one little thing wrong somewhere.
    Are you hooking the negative terminals on the Dreadnought to the negative terminals on the SDA??
    I am doing that, and read somewhere on here that that was fine.
    But that is my most suspicious connection in the system.
    Polk SDA 1.2 TL
    Infinity SSW-210
    Integra DTR 7.1
    Pioneer SC-57 Elite
    Sony X777ES
    Sansui BA-5000
    Hafler XL 600's in mono w/ George Kay Audio Tube upgrades
    Hafler xl 600 stock
    Krell FPB 600
    Avel 1000VA Dreadnought
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