What to look for when buying a used amp

[EddieC 17]

I had originally planned on buying a Q2200.1D to power my Ethos. After reading a thread of clamp test numbers and seeing it puts out less that 1.6k after box rise and voltage drop I'm not so sure any more. I've been looking through ads on a local audio FB page and found a SKAR 2500 for less than I'd pay new for the SQ. I know SKAR isn't well liked because of the owner, but I'm not putting money in his pocket. Just looking for the best bang for the buck. Whatever amp I decide on, what should I look for/check? I've always been leery of buying used, but I could stand to save half the cost of a good amp.

Edited October 26, 2014 by EddieC

[Fi 4 life 0]

Ha

[Tirefryr 1,742]

I had originally planned on buying a Q2200.1D to power my Ethos. After reading a thread of clamp test numbers and seeing it puts out less that 1k after box rise and voltage drop I'm not so sure any more. I've been looking through ads on a local audio FB page and found a SKAR 2500 for less than I'd pay new for the SQ. I know SKAR isn't well liked because of the owner, but I'm not putting money in his pocket. Just looking for the best bang for the buck. Whatever amp I decide on, what should I look for/check? I've always been leery of buying used, but I could stand to save half the cost of a good amp.

 

 

If your reasons for not buying the Q are for what you typed, then you've created a standard on which you should judge every purchase from here on out.  Every amp you look at will only compare with that same test.  That will be the only way you will get any objective data, and even then, it's not concrete.

[jcarter1885 995]

Clamp test mean nothing, that amp does what it is supposed to do. If the Soundqubed is flawed then you are saying Digital Designs is flawed as well. Both companies have good track records

[EddieC 17]

I won't share the link (unless asked) as the thread is on another site that will more than likely be ***d. But from all the amps listed there the higher $ amps seem to hold their rated power better. The DD M3B looks like it would be perfect for a reliable continuous output. Am I looking at this the wrong way? The Soundqubed seemed to have the most drop of all, and there are a lot of amps on that list. That is what I'm concerned about. With it being the cheapest, I'm thinking that buying a better amp used would be my best bet. I just want to get a continuous 2200 watts from whatever I get, not this:

AudioQue 2200.1

-1 ohm nominal. Rise to 3.1.

-Drop to 12.7v

-1,582w

[Impious 1,476]

You are not understanding. Clamp test like the one you just quoted are absolutely meaningless. Forget you ever read it, it means literally NOTHING.

[EddieC 17]

You are not understanding. Clamp test like the one you just quoted are absolutely meaningless. Forget you ever read it, it means literally NOTHING.

You're right... I don't understand. This is the first time I've ever ran this much power, and I'm trying to learn as much as possible since I'm doing it all myself. I have to admit that reading that thread concerned me after seeing 1500 watts when I'm looking for 2200. The others didn't have nearly that amount of drop.

I did run across an IA 20.1 (older style) for 350 obo. But that's where I began questioning what do I look for to make sure the amp is in good working condition. Only thing I know to do is have my connections ready to test it when I meet the person. Anything else to visually look for, other than smelling for a burnt smell?

[jcarter1885 995]

You wont get 2200 watts continous no matter what amp you use, no amp is 100% efficient and most power is turned into heat anyway. Buy a reputable amp in the power range you need and your set. Stop over complicating things, no such thing as impedence rise. There is a such thing a impedence curve, the impedence fluctuates.

If an amp is rated at 2200 watts at 14.4 volts then of course you wont see that at 13 or 12 volts, that's why most people get their electrical up to par to minimize voltage drop. Unless you are competing you wont hear a difference between an amp that does 2200 watts, 2500 watts or 3000 watts so its all irrelevant anyways.

Edited October 26, 2014 by jay-cee

[pmureika 31]

I agree 100% ^^^^

[EddieC 17]

You wont get 2200 watts continous no matter what amp you use, no amp is 100% efficient and most power is turned into heat anyway. Buy a reputable amp in the power range you need and your set. Stop over complicating things, no such thing as impedence rise. There is a such thing a impedence curve, the impedence fluctuates.

If an amp is rated at 2200 watts at 14.4 volts then of course you wont see that at 13 or 12 volts, that's why most people get their electrical up to par to minimize voltage drop. Unless you are competing you wont hear a difference between an amp that does 2200 watts, 2500 watts or 3000 watts so its all irrelevant anyways.

With the voltage dropping to 12.75 I'm guessing that they were on stock electrical. I have a constant 14+ with my upgrades with no drop at the battery at all full tilt on around 700 RMS, so I should see more than than they got I would think. So my initial thoughts of a new Q2200.1D may be good after all I guess. Plus I like the idea of buying new just in case there are any issues. Are there any better choices for the $ new?

[jcarter1885 995]

Id rather buy new myself, not saying you can't get some badass equipment and a good deal used. Just my personal preference. Yeah i wouldn't get caught up in the numbers game, just make sure the equipment has a good track record and you're golden.

[EddieC 17]

Id rather buy new myself, not saying you can't get some badass equipment and a good deal used. Just my personal preference. Yeah i wouldn't get caught up in the numbers game, just make sure the equipment has a good track record and you're golden.

Sounds reasonable to me. So do you think the Soundqubed 2200 would be a good amp for the Ethos? They seem to have a good track record with a ton of good reviews, which was why I was considering it first. Plus having that warranty is worth a little extra to me.

[jcarter1885 995]

Id rather buy new myself, not saying you can't get some badass equipment and a good deal used. Just my personal preference. Yeah i wouldn't get caught up in the numbers game, just make sure the equipment has a good track record and you're golden.

Sounds reasonable to me. So do you think the Soundqubed 2200 would be a good amp for the Ethos? They seem to have a good track record with a ton of good reviews, which was why I was considering it first. Plus having that warranty is worth a little extra to me.

I honestly dont know how else to answer your question, its been asnwered plenty of times by now. If the amp meets your budget, power requirements, space requirements, proven company then i dont see why not.

[EddieC 17]

Id rather buy new myself, not saying you can't get some badass equipment and a good deal used. Just my personal preference. Yeah i wouldn't get caught up in the numbers game, just make sure the equipment has a good track record and you're golden.

Sounds reasonable to me. So do you think the Soundqubed 2200 would be a good amp for the Ethos? They seem to have a good track record with a ton of good reviews, which was why I was considering it first. Plus having that warranty is worth a little extra to me.

I honestly dont know how else to answer your question, its been asnwered plenty of times by now. If the amp meets your budget, power requirements, space requirements, proven company then i dont see why not.

You're right. I'm overthinking all this. Sounds like that's the one that fits the best for my situation. Just didn't want to wind up compromising with something if there were better options that could be had by buying used.

[Thumpper 266]

if you are looking to buy used go to E-Bay and hunt down a JBL/Crown BPX-2200.1

it will give you flexibility of getting full power from 4ohm down to 1 ohm and

those things have current servo's with an effective damping factor almost 50 times

higher than the amps you have already discussed...tighter bass

 

it"s what I would buy if I was going used  , those amps are awsome

Edited October 26, 2014 by Thumpper

[Impious 1,476]

those things have current servo's with an effective damping factor almost 50 times

higher than the amps you have already discussed...tighter bass

Damping factor is also effectively meaningless and does not lead to "tighter bass", even if the DF is 50x higher. Once damping factor is "high enough" to not audibly affect the sound, which is true for just about any solid state amp, going any higher doesn't matter...it doesn't sound any betteror "tighter".

[Thumpper 266]

I can tell 20 seconds into a song if the amps have a high effective damping or not

 

I have had pages of discussion about damping factor since the very first car audio forum

when the internet started....not worth arguing about because opinions are like buttholes....we all got one

 all I can say is there is no room in my system for an amp with a low damping factor...I am way

to picky in listening for those micro details hidden in the bass and I like it TIGHT

I always go for the highest damping factor I can afford.. use short wire runs of thick gage pure OFC

 and my systems always sound tighter and more controlled than the systems owned by those who think

DF doesn't matter...first comment I always get is how tight it sounds.......just the way it is I guess....LOL

 

 

anyways..... to the OP

 

seriously....try a BPX 2200.1 if you can find one...you won't regret it

I had four of them along with the big brother A3000gti  and wish I still had them

[EddieC 17]

I can tell 20 seconds into a song if the amps have a high effective damping or not

I have had pages of discussion about damping factor since the very first car audio forum

when the internet started....not worth arguing about because opinions are like buttholes....we all got one

all I can say is there is no room in my system for an amp with a low damping factor...I am way

to picky in listening for those micro details hidden in the bass and I like it TIGHT

I always go for the highest damping factor I can afford.. use short wire runs of thick gage pure OFC

and my systems always sound tighter and more controlled than the systems owned by those who think

DF doesn't matter...first comment I always get is how tight it sounds.......just the way it is I guess....LOL

anyways..... to the OP

seriously....try a BPX 2200.1 if you can find one...you won't regret it

I had four of them along with the big brother A3000gti and wish I still had them

The one thing that stands out on its specs is the 190 max current draw. I have a 220 amp HO alt with Yellow Top under hood and Die Hard Platinum Group 31M in the rear. With the mids and highs amp having a 120 amp rating I have to watch the current draw to ensure I'm not pulling too much. I'll definitely check these out.

[j-roadtatts 1,129]

The amplifiers will not pull max power at all times. Music Is dynamic and so is the current draw. When they draw more than your alt is producing then thats when the battery's fill in as they are your reserve.

As far as DF, once you cross a certain threshold, you will no longer notice the difference.

I personally have been fortunate buying used amps. I collect old school RF amps so have to buy them used. I look for ones that are clean looking and not abused.

The only reason I can think to pick one amp in particular other than the reasons already stated, would be if it has a certain feature or control function you plan on using.

[Impious 1,476]

I can tell 20 seconds into a song if the amps have a high effective damping or not

I have had pages of discussion about damping factor since the very first car audio forum

when the internet started....not worth arguing about because opinions are like buttholes....we all got one

all I can say is there is no room in my system for an amp with a low damping factor...I am way

to picky in listening for those micro details hidden in the bass and I like it TIGHT

I always go for the highest damping factor I can afford.. use short wire runs of thick gage pure OFC

and my systems always sound tighter and more controlled than the systems owned by those who think

DF doesn't matter...first comment I always get is how tight it sounds.......just the way it is I guess....LOL

anyways..... to the OP

seriously....try a BPX 2200.1 if you can find one...you won't regret it

I had four of them along with the big brother A3000gti and wish I still had them

It's not an opinion, it's a fact. The DF of about any modern solid state amp is 1) high enough not to matter and 2) close enough to all the other solid state amps that there will not be an audible difference. Your comment about short speaker cables is equally negligible in terms of audible difference. Cable thickness is likewise a factor where once it is sufficiently thick as to not cause an audible decrease in output (which also means it's sufficiently sized for the current) it's not going to matter. Those few hundredths of a milliohm in resistance are not going to do jack shit to the damping factor when it's connected to a coil with a DCR that trumps all of the resistance throughout the rest of the circuit. Your system may have sounded "tighter", but had absolutely nothing to do with the damping factor, cable thickness or length. You are assigning your results to the wrong variable, plain and simple. Not a matter of opinion here, either. No reason to argue as there is nothing to argue about.

[///M5 2,833]

You're right. I'm overthinking all this.

More like confusing reality. Everything you read that you based this thread on is misinformation and pointless. The ONLY answer is to buy something reputable and don't look back. All "scientific" reasons you are using to make yourself feel better are wrong. Stop reading wherever you are getting that garbage information and think instead about what matters.

[Thumpper 266]

I have read everything there is on damping factor...all the stuff for it and against it

all you have shown me is something I read back in the early 80's

 

no offence but I believe techs from Companies like Crown over your opinion ( not fact )

they revolve their amp design around achieving a high damping factor and their

amps are some of the tightest sounding around..they like other companies that brag

about high damping do it for a reason

 

BTW...I have a real tube amp and no they do not have a high damping....it sounds really

good and smooth but it is no where near as tight as the YBA sitting beside it with a damping of 3000

not even close unless you are completely deaf

[S.DeYoung 968]

Keep drinking the Kool Aid, DF does not matter with amplifiers in the 12V industry. Brad explained it very well

[Impious 1,476]

I have read everything there is on damping factor...all the stuff for it and against it

all you have shown me is something I read back in the early 80's

no offence but I believe techs from Companies like Crown over your opinion ( not fact )

they revolve their amp design around achieving a high damping factor and their

amps are some of the tightest sounding around..they like other companies that brag

about high damping do it for a reason

BTW...I have a real tube amp and no they do not have a high damping....it sounds really

good and smooth but it is no where near as tight as the YBA sitting beside it with a damping of 3000

not even close unless you are completely deaf

Try to keep up with the conversation. I specifically stated solid state amps, a true tube amp (tubes on the outputs) is not a solid state amp. Yes, some tube amps have such a high output impedance that damping factor is audibly affected. Since that's not what we are talking about here, as I mentioned solid state amps and all of the amps discussed here are solid state, your scenario is completely irrelevant.

More on topic, you can very easily calculate the difference in response both in the frequency and time domain and the difference for any two solid state amps is going to be below the audible threshold. It's not a matter of opinion, and it's not "my" opinion. It's a fact of mathematics and physiology. I don't care what engineer told you incorrectly, plenty more engineers along with physics and biology demonstrate otherwise.  Companies brag about damping factor as a matter of marketing, not engineering or performance.  It's a spec that the uninformed will gravitate towards because marketers can make it sound important and "better" when it's not.  Just like other irrelevant paramters that companies promote.  It sounds like you've fallen for that marketing.

I posted a thread years back with writings from 2 highly respected engineers along with another article explaining why damping factor is meaningless. Richard Clark, Stephen Mantz and a paper from audioholics (can't recall the author). 

 

And the effective damping factor of that amp you have isn't anywhere remotely close to 3k.

[EddieC 17]

You're right. I'm overthinking all this.

More like confusing reality. Everything you read that you based this thread on is misinformation and pointless. The ONLY answer is to buy something reputable and don't look back. All "scientific" reasons you are using to make yourself feel better are wrong. Stop reading wherever you are getting that garbage information and think instead about what matters.

I ran across a thread with clamped numbers for several of the amps I was looking at. Seeing the numbers on what I had originally planned on fall short of others, I began thinking maybe I should be looking for a higher priced used amp to get the most power for my money. That's all this was originally about. Everything in this thread has gone over my head and beyond what I expected. I know I've heard people say plenty of times that clamp tests are meaningless, and should not be a concern. But last weekend I went to a local shop to check out some Hertz and Focal speakers for the front and the owner did nothing but rag on Soundqubed. So I was questioning my decision. I've run across some pretty good deals locally on some amps that should be better than the SQ for less $ (IA20.1, etc) and was just wondering what to look for when buying a used amp as I know plenty of people have been burned in the process.