Building the AI-1 dreadnought

I'm considering building a dreadnought. I've spent many hours reading countless threads and since I'm not an electrical engineer my head has started spinning. The original DIY instructions (from Ken Swauger at Polk) suggested a usage of three small and cheap transformers. In most of the more recent threads people seem to bee mostly using big and expensive Avel Lindberg transformers in projects costing hundreds of dollars. Being a cheap person I wonder why. Why didn't Polk suggest these huge AV transformers in the first place if there is a world of difference in sound quality? According to the 1000VA group buy thread it's even a whole lot of difference between the 800VA and 1000VA. I have a hard time figuring out what specs are important and what impact each has on sound quality. Is bigger automatically better? When do you start overspeccing? Is really more copper the better, one would assume that in many ways that less stuff put in the signal path would be better.

So, if I was to build an AI-1 interface and wasn't willing to spend $300-$400, what are my options? Are there lesser (cheaper) Avel Lindberg transformers I can use? Should I just try to find an original AI-1 cable for sale, or build one from one of the suggested transformers (if I can find their discontinued replacements)?

At the moment I have my SRS 1.2TL biamped using two NAD C272 power amps (2x150W @ 8ohms ). I'm planning to bridge them (400W@8ohms) since I think I would gain more from the added power than from biamping.

So for a cheap guy, what's the sensible thing to do?
1. Do nothing - keep the biamp setup
2. Build a "sensibly" priced AI-1 interface
3. Sell a kidney to build (or buy) a 1000VA dreadnought

SRS 1.2 TL | SDA 2B Studio TL | NAD M51 preamp/dac | DIY SET 300B tube amplifier | Cambridge Audio Azur 851W | Chromecast Audio | RoPieee Roon Raspberry Pi endpoint

Comments

  • pitdogg2
    pitdogg2 Posts: 24,474
    just buy it already. This is from our last go around and may not ever be another.

    https://forum.polkaudio.com/discussion/187437/dreadnaught-1000va-complete-package#latest
  • hauxon
    hauxon Posts: 161
    pitdogg2 wrote: »
    just buy it already. This is from our last go around and may not ever be another.

    https://forum.polkaudio.com/discussion/187437/dreadnaught-1000va-complete-package#latest

    ...probably around $700 to my door in Iceland.
    SRS 1.2 TL | SDA 2B Studio TL | NAD M51 preamp/dac | DIY SET 300B tube amplifier | Cambridge Audio Azur 851W | Chromecast Audio | RoPieee Roon Raspberry Pi endpoint
  • motorstereo
    motorstereo Posts: 2,042
    My thought is buy that 1000va dreadnaught listed in the for sale section. It's also far less money than a kidney or any body part for that matter and it's a substantial upgrade in the sound over the A1 interface. The A1 will get the job done but the dreadnaught is special. It will bring out the best in your 1.2tl's and you should not settle for less.
    In my case if I was forced to keep just one of the many upgrades I have on my 1.2tl's it would be the dreadnaught hands down.
  • pitdogg2
    pitdogg2 Posts: 24,474
    hauxon wrote: »
    pitdogg2 wrote: »
    just buy it already. This is from our last go around and may not ever be another.

    https://forum.polkaudio.com/discussion/187437/dreadnaught-1000va-complete-package#latest

    ...probably around $700 to my door in Iceland.

    They're the best you can buy period. Special run for us even for common ground amps it makes a HUGE difference. I doubt it will be that expensive to ship. They are shipped from Sri Lanka for us and it doesn't cost near that much.

    just a thought they have been thoroughly reviewed here do a search and tons of info come up you will not buy one better at twice the cost.
  • hauxon
    hauxon Posts: 161
    I should have noted that I already only have one kidney and at the moment the 1000va dreadnought is too expensive for me. It is on the expensive side already and shipping a heavy package to Iceland is expensive plus the 24% VAT.

    So, should I build a cheaper dreadnought (with possibility of later upgrade) or just keep current configuration (bi-amp). Would a cheap version of the AI-1 be worth it?
    SRS 1.2 TL | SDA 2B Studio TL | NAD M51 preamp/dac | DIY SET 300B tube amplifier | Cambridge Audio Azur 851W | Chromecast Audio | RoPieee Roon Raspberry Pi endpoint
  • F1nut
    F1nut Posts: 49,704
    Bridging amps raises the noise floor. You're better off using the amps as you are now.

    FYI, The Dreadnought improves the sound with common ground amps too.
    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

  • DarqueKnight
    DarqueKnight Posts: 6,760
    hauxon wrote: »
    Why didn't Polk suggest these huge AV transformers in the first place if there is a world of difference in sound quality?

    Most manufacturers, of anything, do not volunteer advice on higher performance, higher cost alternatives to products they sell. When specifically asked, Matthew Polk recommended a high quality, high current toroidal transformer in place of the AI-1. A Polk engineer, when I specifically asked about component upgrades to improve performance, recommended replacing the stock electrolytic capacitors and ceramic metallic resistors with higher quality film capacitors and wire wound or metal film resistors, and replacing the polyswitch with a jumper.

    The truth is that it wouldn't look very good from a marketing perspective for a manufacturer to recommend performance upgrades that cost hundreds or thousands of dollars. Furthermore, most people just aren't interested in that level of performance enhancement.
    hauxon wrote: »
    I have a hard time figuring out what specs are important and what impact each has on sound quality. Is bigger automatically better? When do you start overspeccing? Is really more copper the better, one would assume that in many ways that less stuff put in the signal path would be better.

    The overall transformer design and overall performance has to be considered. Ideally you want a low noise 1:1 isolation transformer that is specifically designed for audio applications.

    Bigger is not automatically better.
    hauxon wrote: »
    Are there lesser (cheaper) Avel Lindberg transformers I can use?

    Matthew Polk provided some general specifications for an AI-1 toroidal tranformer and those specs were sent to Avel Lindberg. They only had two products that fit the criteria, the 800 VA and 1000 VA transformers you see discussed in the Dreadnought threads. Other transformer manufacturers I sent the specs to did not respond to my inquiry.
    hauxon wrote: »
    So for a cheap guy, what's the sensible thing to do?
    1. Do nothing - keep the biamp setup
    2. Build a "sensibly" priced AI-1 interface
    3. Sell a kidney to build (or buy) a 1000VA dreadnought

    The best alternative among the three is to do nothing. A cheap AI-1 interface is a path to lower sound quality.

    If you have a local supplier of low noise medical grade isolation transformers, that may be a lower cost option than one of the Avel Lindberg transformers, but it may not perform as well as the A-L units. It will, however, be worlds better than the tinkertoy transformer used in the stock AI-I.

    As for the original AI-I, Matthew Polk admitted that the original units could have issues with poor sound quality due to current saturation. This is something to keep in mind.


    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • F1nut
    F1nut Posts: 49,704
    edited August 2019
    Bad advice such as above is a serious shortcoming of some on audio forums.
    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

  • You two are just never going to agree on anything.
    You need to stop messing up other peoples threads with your **** for tat sniping and just agree to disagree and move on.
  • hauxon
    hauxon Posts: 161
    Well this quest for better sound is what makes us audiophiles. Some will do what they might be needed just to be on the safe side, even if the cost makes no sense. Other are looking for bang for the buck or try to keep things within certain budget.

    So some of the advice given here is simply what people believe is "the best" not what might be most sensible. What is sensible is however dependent on multiple factors. Yesterday I started thinking the Parasound JC5 would be a great match for my 1.2TL's. I however want to keep cost under control so it does not make sense for me at the moment. A $6000 amplifier does all of a sudden make few hundreds in speaker mods sound reasonable.

    K_M has a point. It's easy to get dizzy from all the kind advice and different opinions here on the forum. Opinions are just opinions even though some speak as they tell the "truth" So it is often quite hard to see what's sensible for you because advice is almost always the most expensive option.

    I've decided to put the dreadnought in the freezer for now and finish the crossovers first. Makes most sense to me. Then I might do some more mods or buy a more powerful amp. ..or just go fishing. Whatever makes sense for me to spend $$$ (or Kr Kr Kr ...I'm Icelandic)
    SRS 1.2 TL | SDA 2B Studio TL | NAD M51 preamp/dac | DIY SET 300B tube amplifier | Cambridge Audio Azur 851W | Chromecast Audio | RoPieee Roon Raspberry Pi endpoint
  • K_M
    K_M Posts: 1,627
    hauxon wrote: »
    Well this quest for better sound is what makes us audiophiles. Some will do what they might be needed just to be on the safe side, even if the cost makes no sense. Other are looking for bang for the buck or try to keep things within certain budget.

    So some of the advice given here is simply what people believe is "the best" not what might be most sensible. What is sensible is however dependent on multiple factors. Yesterday I started thinking the Parasound JC5 would be a great match for my 1.2TL's. I however want to keep cost under control so it does not make sense for me at the moment. A $6000 amplifier does all of a sudden make few hundreds in speaker mods sound reasonable.

    K_M has a point. It's easy to get dizzy from all the kind advice and different opinions here on the forum. Opinions are just opinions even though some speak as they tell the "truth" So it is often quite hard to see what's sensible for you because advice is almost always the most expensive option.

    I've decided to put the dreadnought in the freezer for now and finish the crossovers first. Makes most sense to me. Then I might do some more mods or buy a more powerful amp. ..or just go fishing. Whatever makes sense for me to spend $$$ (or Kr Kr Kr ...I'm Icelandic)

    Was trying to help you, since you said financially you were leaning towards cheaper.

    It is easy to spend other people's money for sure!

  • K_M
    K_M Posts: 1,627
    You two are just never going to agree on anything.
    You need to stop messing up other peoples threads with your **** for tat sniping and just agree to disagree and move on.

    I have several know it alls and trouble makers in Ignore, so anything I comment on is to the OP directly.
  • hauxon
    hauxon Posts: 161
    K_M wrote: »

    Was trying to help you, since you said financially you were leaning towards cheaper.

    It is easy to spend other people's money for sure!

    Yes I am. I'm trying to keep things in order. And cheap is of course relative. I'm trying to thread the difficult path of being an audiophile on budget and keeping the marriage intact. :) Since I'm not the prince of Scotland life is a compromise....
    SRS 1.2 TL | SDA 2B Studio TL | NAD M51 preamp/dac | DIY SET 300B tube amplifier | Cambridge Audio Azur 851W | Chromecast Audio | RoPieee Roon Raspberry Pi endpoint
  • verb
    verb Posts: 10,176
    hauxon wrote: »
    K_M wrote: »

    Was trying to help you, since you said financially you were leaning towards cheaper.

    It is easy to spend other people's money for sure!

    Yes I am. I'm trying to keep things in order. And cheap is of course relative. I'm trying to thread the difficult path of being an audiophile on budget and keeping the marriage intact. :) Since I'm not the prince of Scotland life is a compromise....

    Well my friend from Iceland! I can say that this is a journey for sure! Keep an eye out for the dreadnaught, even just the bits and pieces, most likely they will be available! As time goes on, you'll find the deal, or have the parts to build one! :)
    Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
    Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
    Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
    Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
    Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
    Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD.
  • F1nut
    F1nut Posts: 49,704
    You two are just never going to agree on anything.
    You need to stop messing up other peoples threads with your **** for tat sniping and just agree to disagree and move on.

    Don't ever try to tell me what to do.
    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

  • verb
    verb Posts: 10,176
    Hey @hauxon been following your SRS 1.2TL thread too. I recently (less than a year ago) found a minty pair of SRS's that at the time I thought were the endgame for me. Always coveted these flagship speakers.

    But then, as my journey continued, wanted to use monoblocks to power em. Monoblocks require an A1 or Dreadnaught. But to my realization, my early gen SRS's are A1 or Dreadnaught incompatible! Dang!

    So, I learned a lot, have another McIntosh amp in the basement, but my search (I'm patient) for a set of SRS 1.2TL's continues.

    For the record, I don't think I'll be travelling to Iceland if you every decide to sell yours! Wait! Never say never! :)
    Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
    Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
    Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
    Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
    Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
    Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD.
  • F1nut
    F1nut Posts: 49,704
    hauxon wrote: »
    Well this quest for better sound is what makes us audiophiles. Some will do what they might be needed just to be on the safe side, even if the cost makes no sense. Other are looking for bang for the buck or try to keep things within certain budget.

    So some of the advice given here is simply what people believe is "the best" not what might be most sensible. What is sensible is however dependent on multiple factors. Yesterday I started thinking the Parasound JC5 would be a great match for my 1.2TL's. I however want to keep cost under control so it does not make sense for me at the moment. A $6000 amplifier does all of a sudden make few hundreds in speaker mods sound reasonable.

    K_M has a point. It's easy to get dizzy from all the kind advice and different opinions here on the forum. Opinions are just opinions even though some speak as they tell the "truth" So it is often quite hard to see what's sensible for you because advice is almost always the most expensive option.

    I've decided to put the dreadnought in the freezer for now and finish the crossovers first. Makes most sense to me. Then I might do some more mods or buy a more powerful amp. ..or just go fishing. Whatever makes sense for me to spend $$$ (or Kr Kr Kr ...I'm Icelandic)

    There are folks here with extensive knowledge of what works and what doesn't. If you're not sure who they are just ask me.
    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

  • BlueFox
    BlueFox Posts: 15,251
    F1nut wrote: »
    You two are just never going to agree on anything.
    You need to stop messing up other peoples threads with your **** for tat sniping and just agree to disagree and move on.

    Don't ever try to tell me what to do.

    LOL. I thought it was a reasonable suggestion. Not a command. :)
    Lumin X1 file player, Westminster Labs interconnect cable
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  • westmassguy
    westmassguy Posts: 6,850
    hauxon wrote: »

    I've decided to put the dreadnought in the freezer for now and finish the crossovers first. Makes most sense to me. Then I might do some more mods or buy a more powerful amp. ..or just go fishing. Whatever makes sense for me to spend $$$ (or Kr Kr Kr ...I'm Icelandic)

    Sounds like a good plan to me Hrannar.
    Home Theater/2 Channel:
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    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
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  • verb
    verb Posts: 10,176
    hauxon wrote: »

    I've decided to put the dreadnought in the freezer for now and finish the crossovers first. Makes most sense to me. Then I might do some more mods or buy a more powerful amp. ..or just go fishing. Whatever makes sense for me to spend $$$ (or Kr Kr Kr ...I'm Icelandic)

    Sounds like a good plan to me Hrannar.

    Yep. Good plan. But keep being inspired! What a fun journey!
    Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
    Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
    Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
    Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
    Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
    Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD.