Can you have two many Adcom Amps voltage drop

polkrt3000p

My setup is a pair of SDA SRS 1.2tls- biamped with two Adcom 555s, Polk RT3000p with Two Mono Block Adcom 565's, 3 centers all Polk CS400s 1 Adcom 2535 Bridged 200watt and 1 Adcom 555, and 1 Adcom 555 running ceiling and small pair of NHT zeros, I have a Sunfire Receiver running a pair of bookshelf NHT.

It works, but I feel that it is not as clear as it could be at higher volumes, the Monster power center shows after all amps running at higher volume it drops from 115 volts to 110 to 108 during harder bass or hits.

I know these are all running on one main outlet or two, but in the same area, guessing they are the same circuit, guessing 15amp. Surprised it never blow a breaker. So I have a total of 7 amps, not including the Sunfire Receiver and, DVD, PS4 etc hooked up. Not sure how to solve this, thought about maybe buying an Adcom 7805-7807 300 watt/ch, or a Sunfire Signature amp. I hate to get rid of the Adcoms as it took me years to get all of them, but reaching a loss of diminishing returns. Thinking it must be the voltage, but not sure.

When I turn off other amps my voltage is back to 115 and the SDA sound better.

My upstairs stereo has a pair of Goldenear One.R running on a Adcom5802, and the Polk 5s and ceiling speakers on a Adcom 555, I feel sounds a lot cleaner. With a Sunfire Preamp.

Just thought I would go to the Polk Forum as you guys are the experts. Would I be better going to 2 Big multichannel amps or maybe 1 big Multichannel amp like an Adcom or Sunfire or better with separates like I have and figure out how to get a seperate outlet. I thought of extension cord but not a fan of running that. I don't want to pay to have one wired from the family room to the garage to get a breaker box. I always thought having separate amps would preform better than multichannel amps but maybe they are just fine some are rating up to 300watts or so. I feel the SDAs need a ton of power to keep them loud and clean. Any comments is appreciated. Thanks.

pitdogg2

The Monster power bar is restricting current. Amps should ALWAYS be plugged into the wall, you need a 20amp circuit or 3 to run that.

polkrt3000p

I could try to hook up the amps directly but I do not have enough outlets. Would a cheap powerstrip work better then the Monster Power 3500. Guessing a cheap power strip is not a good option, but I then would bypass the monster power conditioner.

VR3

Need maybe 4 dedicated circuits with that setup 😁

pitdogg2

polkrt3000p wrote: »

I could try to hook up the amps directly but I do not have enough outlets. Would a cheap powerstrip work better then the Monster Power 3500. Guessing a cheap power strip is not a good option, but I then would bypass the monster power conditioner.

Fire 🔥🔥 could result.
Starving amp of electricity and current is a good way to let the magic smoke out. You probably need to figure out if that receptacle has 14ga or 12ga wire coming to it FIRST.
Report back.

skipshot12

Are you having any voltage dips, at high volume, when the bass hits that cause any lights to dim?

Had that issue with a Phase Linear 400 pushing a pair of Kappa 8’s. Lights would dim every time the bass hit at higher volume listening.

Wonder if a couple of regenerators would help with your setup?

As pit said, I do like the idea of checking on wire gauge.

polkrt3000p

Ok, will have to take a look into that. Also without rewiring the room, would I be better off with one or two multichannel big amps say an Adcoms big 300 per channel like the 7805/7807 or Sunfires 200 or 400 watt multichannel and limit to maybe 2 amps vs 7 separate amps. Not sure if I would gain anything buy moving to a multichannel. Or would another brand with high wattage be an option. Don't want to spend a lot and I would need to sell my Adcoms.

polkrt3000p

I was wondering if having a multichannel would they have the clean sound that I am looking for?

treitz3

Don't get too caught up on wattage, as it's overrated. It is the high current amps you want to look for. A robust power supply is key for achieving high current.

In short, you are currently overtaxing your circuit.

Tom

skipshot12

I’d correct the voltage drop issue first.
Wether that requires splitting circuits, run dedicated line or regeneration.

What size service, in amps, does your home have?
Is your home old or new?
Do you know if you’re the only customer on the transformer feeding your home?

Have to watch dropping voltage on the incoming line as that can put a lot of strain on any compressors in your home.
Anything with high start-up current draw.

If you’re the only customer on that transformer it’s pretty easy to have your power company change the tap and raise your incoming voltage.

You can also put in a low voltage complaint with your power company.
They have RVM’s that will record the voltage coming into the home that checks for any dips, spikes along with any high/low voltage issues in real time.

polkrt3000p

My home is built in 2008, I am the last person on the block, but I do not have the big transformer in my yard, I think a couple houses down. When I turn off all amps except the two Adcom 555s the voltage from the Monster power says 115 volts. But when I turn on the rest of the amps it runs about 110-111 range when turned up to say 3rd volume range. What voltage should I be getting even when pushing the amps. Should I be getting 115-120 or that not possible with the one circuit? I know wattage is not the total answer however, I must say the upstairs stereo I switched out the Adcom 555 with a Adcom 5802. 200 to 300 watt/ch and it did provide clean power at a louder level on the Goldenears. I felt the big SDA SRS would need a ton of power so that is why I tried to biamp it so they are supposed be getting 400 watts/channel. One amp for the highs and one for the lows in stereo mode.

pitdogg2

Ok, will have to take a look into that. Also without rewiring the room, would I be better off with one or two multichannel big amps say an Adcoms big 300 per channel like the 7805/7807 or Sunfires 200 or 400 watt multichannel and limit to maybe 2 amps vs 7 separate amps. Not sure if I would gain anything buy moving to a multichannel. Or would another brand with high wattage be an option. Don't want to spend a lot and I would need to sell my Adcoms.

If you want to run the 1.2tl's then you need a common ground amp or a dreadnought. The big Adcoms I didn't think were common ground. Could they have negative binding posts strapped ? Possibly I do not know.

Watts are not the end all to be all, your amp must also provide high current with those watts. I got a little high current 200 wpc amp that BLEW my Adcom 5802 out of the water, sold the Adcom 5802 very quickly.

polkrt3000p

I am not sure on the 1.2tls as I have been running them for a few years on the Adcom 555s, seem to work. I get it with the watts thing, not always the biggest thing to look at, old day car stereos were plenty of power with like 100-300 watts but now days they start at 800 watts and some are like 2-5k of watts, not sure how that is possible. I have a old school PPI amp back when still made in the US 300watt amp and one sub and they laughed at me saying that won't do nothing, I have to actually turn it down as it is so much bass. So yeah, I gotcha. I am sure there a better amps then Adcom with less watts. I do think it's just a matter of proper current for sure. Just think it would cost a ton just to fix it, unless I can do it myself.

polkrt3000p

Wondering again if I had to go to two amps, would I get the performance on the multichannel amps like a Sunfire or Adcom. Also does anyone know if the Sunfire is better sounding or about the same as the Adcoms? That is if I can't fix the voltage issue with all amps running I would rather keep what I got since they are all working and no extra cost of changing out amps. Or maybe other brands that would be around the same price used could be an option if I can get some money out of mine to pay for the change.

pitdogg2

The Adcom 555's are common ground.

F1nut

the Monster power center shows after all amps running at higher volume it drops from 115 volts to 110 to 108 during harder bass or hits.

That's basically brown out voltage, which means you'd be an idiot to keep doing what you're doing.

Multi-channel amplifiers aren't the answer. 20 amp/10 gauge dedicated lines is.

pitdogg2

You need to figure out the wiring first and foremost before you go forward.
These are a possibility once you get the wiring figured out OR this could just make a bad situation much worse.

https://www.audioadvisor.com/new-pgnpc8-pr?sku=NEW-PGNPC8-PR

invalid

pitdogg2 wrote: »

The Adcom 555's are common ground.

They are, but the OP says he is biamping, now I guess it would work depending on the configuration in use.

motorstereo

Op has gotten some great and spot on advice here. In my case at the beginning of my sda journey some 20 years ago I also started with a pair of 555II's. I found that horizontal bi-amping added nothing but complexity as a single 555 is quite capable of running the big sda's. I also found there are much better amps out there and those adcoms didn't last long here.
My recommendations is sell the adcoms and use the proceeds towards a better amp. As mentioned you're playing with fire running all those amps on a single circuit with a power strip and the real scary part is no speaker protection on those tired old adcoms.
If you're serious about an upgrade stop crying about money and get yourself a quality high current amp and a dedicated line or better yet 2. Until then start pulling plugs on the extra adcoms

polkrt3000p

Thank you guys for your thoughts on this. I think I will unplug some of the amps for now and see what I can do with the situation of power. I didn't realize I put myself in a bad situation, worst case I thought I would blow a breaker, but maybe other things can be damaged or even start a fire. Looking at the main breaker looks to be 12 gauge yellow wire.

polkrt3000p

Also with the post from Motostereo sounds like he biamped with two 555 and didn't notice much difference. Maybe could go back to just one 555 for now. Or I can use one 555 for the RT3000p and use the 565s Monos on the SDAs. I do have the original mono connector made by polk that I use to use for them. That way I could cut down to 4 amps instead of 7. Also people mentioned better amps, what would be something reasonable that would be a nice upgrade.

gp4jesus

You still haven’t posted the (power) circuit’s current rating - 15A? 20A? Also I gather that outlet (thus that system) is on a shared circuit?

Apparently those Adcoms like 115(+?) VAC and you have one or more “heavy hitters*” pulling some juice! Have you considered trying to determine the above* and reconfiguring sans the same*?

I’m w/Jesse on one or more dedicated circuits. Don’t settle for anything less than 20A. Further the Polkie suggestion getting the power company involved may result in the slightly higher line voltage that would make your really “sing😊”

Tony

I wish success in your journey.

skipshot12

Ideally you want to see zero voltage drop all of the time.

The U.S. was originally a 110v system to homes but has evolved to the 120v we all now know.
What we want is for that 120v to stay rock solid but rarely do wee see that in real life as there's cost constraints that need to be considered.

Depending on which utility you are served by their standards require that the voltage provided must meet a percentage min/max.
Most utilities have a 5% tolerance they try to keep within which would mean 6v drop & 6v increase tolerance @ 120v but, that voltage is measured at the service entrance (Meter) and not at an outlet in the home.

If you're dropping to 108v you can see that's an issue needing correction and, it's most likely just an overloaded circuit.

Cheapest solution would be to turn off all other unused amps/systems, not being used, when wanting to crank up the tunes on another system.
Next would be to try and split the load onto different circuits if possible. May require moving components around to make that happen.

Ideal set-up would be to have multiple dedicated circuits fed with 10ga OFCC Cardas Power Wire along with Oyaide 20A R1 Receptacles all coming from an Equitech 20WQ Breaker Panel but we don't all have that kind of scratch in our change drawer.....

polkrt3000p

I appreciate the insight on this, I will look more into what we are getting to the house from the utility company if it is low. I will need to check with a voltage meter to the circuit as well vs on what the Monster is saying, also I will double check the circuit but from what I can see it looks to be only a 15amp. I will need to see if any other outlets are on a different circuit to split it up. That all makes sense to me. I will also look to turn off some amps some to see if I can get the voltage up.

treitz3

To answer your question on which would sound better - The Adcom versus the Sunfire? It has been my experience via listening to many other rigs over the years, that the Sunfire would easily win this battle.

To check what else is on that circuit, take a DVM or, if you don't have one, a lamp with a verified working bulb. Kill the circuit at the panel and check all other outlets in the room and even outside of the room to determine what else resides on that circuit. Note if any lights or other devices are out as well throughout. Typically, you won't have more than 10 outlets on that circuit, but they may reside in different rooms, depending on how the circuit was configured within the walls.

If you have a space heater, small room fridge, portable or window AC unit or something else that draws a significant amount of power on that same circuit, consider moving that device to another circuit.

Under, as well as over voltage can wreak havoc on electrical devices and sometimes severely shorten their lifespan. One other thing to note, I don't know how old your gear is, but old or failing capacitors can also draw excessive current and cause voltage drops. I'm not saying that this is the cause or the case here, but it is a possibility. Especially with so many amps on the same circuit. It could also be the culprit of some of the differences you hear from the rig in question, versus your upstairs rig.

With any circuit, you want to try and keep continuous current at a maximum of 80% capacity or lower.

Tom

polkrt3000p

Good point, easy to check what is all on the circuit. Good to know your honest opinion on the Sunfire vs Adcom amp sound. Maybe I could look into that more. I love the responses on this forum.

audioluvr

I don't have half the electronic crap you do and I'm running 2-20A circuits (different legs on a 240v breaker). You need to upgrade. Also @pitdogg2 said it best. Amps need to be plugged direct into the wall.

Conradicles

Good advice from Tom as well.

nooshinjohn

treitz3 wrote: »

To answer your question on which would sound better - The Adcom versus the Sunfire? It has been my experience via listening to many other rigs over the years, that the Sunfire would easily win this battle.


Tom

Depends on the Sunfire. If it is the 200 watt version, I would say stay with the Adcom. If we are talking about the Sig 400, Sig 600 or the TGA 7400/7401 series, then that is an entirely different amplifier and Adcom would not come close.

treitz3

nooshinjohn wrote: »

Depends on the Sunfire. If it is the 200 watt version, I would say stay with the Adcom. If we are talking about the Sig 400, Sig 600 or the TGA 7400/7401 series, then that is an entirely different amplifier and Adcom would not come close.

polkrt3000p wrote: »

My setup is a pair of SDA SRS 1.2tls- biamped with two Adcom 555s, Polk RT3000p with Two Mono Block Adcom 565's, 3 centers all Polk CS400s 1 Adcom 2535 Bridged 200watt and 1 Adcom 555, and 1 Adcom 555 running ceiling and small pair of NHT zeros, I have a Sunfire Receiver running a pair of bookshelf NHT.

While the receiver might would not power all effectively, Gary (RIP, TNRabbit....we still miss you bro') had a Sunfire at Carverfest that powered "The wall of sound", with a channel to spare. SPL levels were well above concert levels in a large cabin. We did this rig just for fun at the end of the event in cabin 11. Those that were there remember it well, as it was an experience you don't forget.

In that rig were a pair of extermely hard to drive Carver Original Amazings, a pair of decently hard to drive ALSIII's and a pair of easy to drive Platinum's. Lights didn't blink, nor did that amplifier. Since before that and well after, the Sunfire amps always performed and sounded much better than the Adcom's. Not just for SPL, but for sonics, pretty much across the board. Especially in the mids and top end.

So basically, we agree.

Tom

nooshinjohn

As I recall the Rabbit ran a Sunfire Signature 7x425.