Another Non-Common Ground Amp Question.
aprazer402
Posts: 3,356
Kind of a two part question. I have an Adcom 5503, it's has not been connected in over two years. I probably should have it checked out first. Question one is strapping the two negative speaker connection posts on the amp with a 10 or 12 gauge quality cable all that is required? Second part would using a AI-1 (I have two AI-1's) and ALSO strapping the negatives be unnecessary? I have a pin/blade cable. Is there any way to test an original Polk AI-1 to confirm if it is working properly (voltmeter maybe) Also years ago there was post by Raife (Darque Knight) reviewing a Polk AI-1and he found that wrapping it in several layers of aluminum foil had a positive effect on the SQ. I think he said the optimum layer of foil was between 6-7 but less than ten? Is this old science by now? I've heard of the Dreadnaught. Thanks.
Best Answers
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The dreadnaught is the way to go these days. I would not strap negatives on the amp, and as far as your AI-1 goes... not much to go wrong there, so you should be alright. Check the center pin for continuity, and you should be good.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2800 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson
How many flies need to be buzzing a dead horse before you guys stop beating it? -
Regardless if the Adcom is common ground or not use the AI-1 as it will improve the sound quality. Strapping is a poor choice and there's no reason to do so since you have the AI-1. Use 10 layers of aluminum foil, no less and no more.
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
Answers
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Thank you.
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I have a Adcom 5503 and it is a common ground amp i swear. i tested it with my voltage meter and will do again if you like. If you have a multimeter it is easy to check.
I have some CRS+ speakers and I will hook it up Tomorrow and check it to be sure it is safe for you to use
and I am going to have Dave (wessmassguy) build me a Dreadnaught as it will improve the sound even if your using a common ground amplifier. 2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge
HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD -
I was always told the Adcom 5503 is a "Non-Common Ground" amplifier that requires strapping the negs. or using an AI-1 or a Dreadnaught with any Pin/Blade SDA's. Please correct me if I'm wrong.
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holy smoke I made a horrible mistake on the Adcom 5503...just check it and it is not common ground, I swore when I check them all for my CRS's I check it too along with my other 3 amps, I could not have metered it and just thought I did...
I Apologize for telling you wrong
2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge
HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD -
Glad we saved your CRS's from any damage, it was a "common" error.
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Yes. It's not the ONLY way, though, IF (big IF) you have SDA speakers that can accept the transformer-coupled SDA interconnect. These are usually (not always) speakers with the pin/blade interconnect cable sockets.aprazer402 wrote: »I have an Adcom 5503...
...is strapping the two negative speaker connection posts on the amp with a 10 or 12 gauge quality cable all that is required?
Yes, it would be unnecessary to strap the negatives when using an AI-1. Given a choice between strapping the negative posts vs. using an original Polk AI-1, I'd test both ways...and likely prefer strapping the negatives especially as the volume went up. The tiny transformer in the original AI-1 won't handle the SDA signal at higher volume. It's just too amperage-limited. By comparison, the 12-gauge wire used to strap the negatives has no such amperage limitation; at least not in terms of audio amplifiers and the SDA signal.aprazer402 wrote: »would using a AI-1 (I have two AI-1's) and ALSO strapping the negatives be unnecessary?
To my knowledge, everyone who has claimed that the transformer-coupled interconnect "sounds better" than the strapped negative posts, has used a HUGE transformer (Dreadnought) rather than the itty-bitty AI-1. (Of course, the transformer-coupled interconnect is NOT AN OPTION for those of us with older SDAs. Only the two newest generations can accept the transformer in the interconnect.)
Ohmmeter. I'm unsure what you could expect for resistance readings; perhaps someone else knows and could post the specs. Wild Guess: If you have continuity through each transformer winding, you're fine. The big Dreadnoughts would measure under one ohm. The little transformer in the original AI-1 would probably have more resistance due to finer wire in the transformer windings.aprazer402 wrote: »Is there any way to test an original Polk AI-1 to confirm if it is working properly (voltmeter maybe) -
To my knowledge, everyone who has claimed that the transformer-coupled interconnect "sounds better" than the strapped negative posts, has used a HUGE transformer (Dreadnought) rather than the itty-bitty AI-1.
This was originally discovered using the AI-1.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
