Dreadnaught build question
Comments
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I looked around on the A-L web site, and did not confirm that the secondary windings are a different gauge wire from the primary...but I'm sure that's true, too.
The primary and secondary wire gauges sizes are definitely different on the 800V that I bought a few years ago. Just don't recall which was thicker.
SDA SRS 2.3TL's
Silk Audio MS-90-BT integrated tube amp
Yaqin MS-20L integrated tube amp
SDA 2B TL's -
On my 800VA, the blue/gray/violet/brown are thicker than the black/red/orange/yellow. The first set (thicker) says "2 x 115v" on the label. The thinner wires have 2 @ 0 volts and 2 @ 115V.michaeljhsda2 wrote: »The primary and secondary wire gauges sizes are definitely different on the 800V that I bought a few years ago. Just don't recall which was thicker.
Post edited by Viking64 on -
I personally could careless if my 1000V Dreadnought is a true 1:1 ratio per say or not. It works and sounds great, definitely better then the AI-1 Polk made.
I use different length wires since mine sits by one speaker. Using DK's test results I choose to use the shorter wire on the side that tested out to have the minuet lower test result and the longer wire on the side that tested higher.
It's sounds great to me, that's what matters.
Unless someone can come up with a better design this is as good as it gets. Why argue about tech specs when the performance results speak for themselves.
Jealousy possibly... Hard to say. If you don't like it design a better wheel."Make a man a fire and he'll be warm for a day. Light
a man on fire and he'll be warm for the rest of his life." -
On my 800VA, the blue/gray/violet/brown are thicker than the black/red/orange/yellow. The first set (thicker) says "2 x 115v" on the label. The thinner wires have 2 @ 0 volts and 2 @ 115V.michaeljhsda2 wrote: »The primary and secondary wire gauges sizes are definitely different on the 800V that I bought a few years ago. Just don't recall which was thicker.
Looks strangely familiar................Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
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
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
dhsspeakerservice.com/ -
More residual's Dave hehe
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westmassguy wrote: »3. The case I use, which you probably saw in one of the threads, is Cast Aluminum. Aluminum is great for RF shielding. The Copper adds EMI shielding, which is different. The Copper Foil MUST be separated from the Aluminum by etching primer and several top coats of Enamel. Galvanic corrosion will result if you don't.
In what situation does shielding the transformer from stray RF matter? I've got my transformer in a steel case (plenty magnetic). It sits in a cabinet close to the floor while all the other components are about 3 feet up from that. Is it interference from the other components that is the problem or just ambient RF from nearby transmission towers or something like that?
I haven't ever noticed any hum or anything like that. (As an aside, I had a "high-bandwidth" amp once that I could swear would hum differently depending on where it was in the house.) I'm pretty sure I've asked this question before and been told that extra shielding from aluminum is of dubious value, but seems like aluminum is all the rage now.
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It is absolutely not of dubious value.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 -
A guy way smarter than me confirmed the advantages of a shielded enclosure:On3s&Z3r0s wrote: »westmassguy wrote: »3. The case I use, which you probably saw in one of the threads, is Cast Aluminum. Aluminum is great for RF shielding. The Copper adds EMI shielding, which is different. The Copper Foil MUST be separated from the Aluminum by etching primer and several top coats of Enamel. Galvanic corrosion will result if you don't.
In what situation does shielding the transformer from stray RF matter? I've got my transformer in a steel case (plenty magnetic). It sits in a cabinet close to the floor while all the other components are about 3 feet up from that. Is it interference from the other components that is the problem or just ambient RF from nearby transmission towers or something like that?
I haven't ever noticed any hum or anything like that. (As an aside, I had a "high-bandwidth" amp once that I could swear would hum differently depending on where it was in the house.) I'm pretty sure I've asked this question before and been told that extra shielding from aluminum is of dubious value, but seems like aluminum is all the rage now.
http://forum.polkaudio.com/discussion/74472/the-ai-1-dreadnought-project-pt-1/p1
Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
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
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
dhsspeakerservice.com/ -
Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
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
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
dhsspeakerservice.com/ -
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Pugtastic!Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
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
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
dhsspeakerservice.com/ -
Same subject different question. I have a 115/120 VAC Isolation transformer from an old combo veriac/isolation transformer. Would that be OK to use ? Even if it were not an A/L would it make a good experiment ?
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Will it pass 5+ amps without saturating? If so, it's worth a try.
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There are numerous isolation transformers out there, but few are audio grade.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 -
There are numerous isolation transformers out there, but few are audio grade.
Thanks. -
It is absolutely not of dubious value.
<Laughing at self for being a dum bass> My bad for taking the word of the guy I got the case from.westmassguy wrote: »A guy way smarter than me confirmed the advantages of a shielded enclosure:
http://forum.polkaudio.com/discussion/74472/the-ai-1-dreadnought-project-pt-1/p1
Thank you for the link! That thread looks familiar, but I'm sure I glazed over before getting down to the spot with the measurements after the transformer was in the aluminum enclosure. Sounds like whenever I get around to my next batch of 2B upgrades it'll be time to move to the Neutriks since I need a new box anyway. Till then maybe I'll buy some heavy duty aluminum foil and make an AV-1000 sized baked potato.
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Well, got ' er done!
Thank you @DarqueKnight for the science experiment that created the dreadnaught!
Thanks also to @westmassguy, @f1nut and all the other member here who provided invaluable information on building my rediculously Ghetto version. Might be the vodka talking but you guys ROCK!
My case was created out of an old GE aluminum meter box i cut down. I lined the inside with bed liner, then copper tape, wrapped the 800 va transformer with dynomat (probably totally unnecessary), then covered the outside of the box with aluminum tape for that polished look.
This journey was part total PITA/ part fun I'm sure I will be happy with the end results . Now if i can only get my crossovers back from DHS...
Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
You've got nothing to be ashamed of.Thanks also to... ...all the other member here who provided invaluable information on building my rediculously Ghetto version.
JUST WAIT until I finish mine. You guys "ain't seen nothin' yet" in terms of creative re-purposing of goofy old enclosures.
No promises in terms of completion date...it's been two years and counting.
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The transformer was never designed to accept voltage on the secondaries, and then pull current from the primary. We do this, but it's not something the transformer was intended to do. WE use it as a symmetrical device, but that wasn't what it was intended for.
A-L didn't see a problem with using their transformer this way, and the transformers don't seem to mind. My sound stage certainly doesn't mind.
I sent Matthew Polk's toroidal transformer recommendations to three transformer manufacturers. Avel-Lindberg was the only one that responded. They recommended their 800VA Y236906 model. I did extensive listening and measurement tests and found that it performed very well. Another forum member, @RickTfromAZ , found out about the "top secret" 1000VA AV-047548 and mentioned that I might want to have a look. Prior to finding out about the AV-047548, I was considering 1000VA and 1500VA isolation transformers by AnTek, but they were mean to me and would not answer any of my emails. I understand that some manufacturers don't want to deal with you unless you are inquiring about ordering 50,000 or more units.So, yeah, the SDA signal should be louder one direction than the other. DK says it doesn't matter in real life.
I measured a small difference in output level depending on direction. I posted the tables below in a past thread:
Humans typically can hear amplitude differences of 1 dB or more. The amplitude differences I measured were in the range of 0.12 dB to 0.38 dB, which is inaudible for most people. Indeed, such differences are within the range that would be expected between two different channels in an amplifier or two different speakers in a stereo pair.
Does your Dreadnought sound louder in one direction than the other?I say it would be better if it was a true symmetrical transformer.
Better how? What are you basing this on?
What model transformer would you suggest as a higher performance alternative?I looked around on the A-L web site, and did not confirm that the secondary windings are a different gauge wire from the primary...but I'm sure that's true, too.
I have found A-L to be quite responsive to email and phone inquiries. I'm sure they would answer your question.
Proud and loyal citizen of the Digital Domain and Solid State Country! -
With cans on, I used to be able to hear a < .5dB shift, but sitting in a room with all the reflections, you'd never hear any shift at the levels you're talking.
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After 30 years of being around heavy equipment and loud music I'm not sure I'd be able to hear a 5db difference...Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
I started ordering some parts for my Dreadnought build today. I couldn't put it off any longer. I have a question though, what are you guys using to terminate the transformer wires to the back of the speakon connectors inside the enclosure? I've been reading through basically all of the old threads but didn't see it mentioned.
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IIRC
Some use quick connects and some have soldered direct.
Personally I'd be in the gold plated quick connects camp. -
You're twisting two wires together for each connection, fastons are the way to go.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 -
If you add jumpers between the +1 and +2 and the -1 and -2 contacts, you can use a 4-conductor wire for your interconnect cable.
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You're twisting two wires together for each connection, fastons are the way to go.
Which fastons and where is the best place to buy? Do you recommend using the same thing for the wires in the speaker cabinet or solder those since it is just one wire each? -
I use gold plated copper fastons available at AutozonePost edited by RandyCroissant onYamaha RXA1030, Yamaha CD-S2100, Yamaha AS-2200, Bluesound node 2i
Polk SDA2btl highly modded
Polk SDA 1C modded
Polk CS350 LS x2
Kimber 8TC
Sony 55" Bravia
Wish list SVS sub -
I believe this is what I used, but I was ordering other parts at the time so shipping cost was not an issue.
https://parts-express.com/gold-12-awg-1-4-female-disconnect-5-pair--095-810
b]Beach Audio[/b]: Rega RP6 (mods) - AT33PTG/II - Parks Budgie SUT - PSAudio NPC * Eversolo DMP-A6 * Topping D90iii * Joule-Electra LA-100 mkIII * Pass Aleph 30 * MIT S3 * Polk SRS 2.3tl (mods) * PSAudio PPP3
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Town Porch: WiiM Pro Plus * Sunfire Sig II * Canare 4S11 * Magnepan 1.6 * Dectet -
Did you use them for the connection to the neutrik inside the speaker as well? ...also, i was thinking of using canare 4s11 cable for my new interconnect cable since thats what my speaker cables are made from, what gauge should i use for this? I believe i ordered the neutrik connector with the screw down terminal.
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Did you use them for the connection to the neutrik inside the speaker as well? ...also, i was thinking of using canare 4s11 cable for my new interconnect cable since thats what my speaker cables are made from, what gauge should i use for this? I believe i ordered the neutrik connector with the screw down terminal.
Not all the Neutrik's are air tight. If these are on the speaker make sure they are.
Canare 4s11 is only one gauge, so use it. The smaller gauges are 4s6 and 4s8 i believe. Go with the 4s11 and twist 2 of the 4 wires together.
