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Questionable Amplifiers

Spkrdctr

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OK guys. I want to try to narrow down the subject of crappy amps sounding different with different speaker wires and/or interconnects. Can everyone please name the amps that do this? I'd like to see a list of these amps that are out in the market place. I "think" that this may fall in the category of BS in todays market, but I'm not sure. If the amp/AVR was made in the last 10 years lets name it. Now, to put it on the list please make sure you personally heard the difference and not heard about it from someone or read about it. Also, when you noticed this phenomenon, how did you conclude it was the amp or was it guess work?

I know I encounter this theory that "some amps" can sound different because they are so poorly made that a different sound is heard using different wires and/or cables.
I would like to get a list of these amps/AVRs so we can steer people away from them when they come on this site looking for help. Thanks guys, I look forward to your posts.
 

JSmith

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guess work
I don't think we should be naming and shaming certain amps based on nothing but subjective impressions and hearsay.

If there is some solid test data or an objective to test various amps, then that's another matter and something that may be of interest. I think you need to be much clearer on the hypothesis here.



JSmith
 
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Spkrdctr

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I don't think we should be naming and shaming certain amps based on nothing but subjective impressions and hearsay.

If there is some solid test data or an objective to test various amps, then that's another matter and something that may be of interest. I think you need to be much clearer on the hypothesis here.



JSmith

That is why I asked how they determined what they heard. Was it just a listen or did they follow up with some type of testing? Was it what they heard from someone else? The issue is at this moment, I don't believe there are any amps built that are reacting to various speaker wire. Well, wire within reason but generally any old 12ga will do. Or, is this a theory passed around the internet and repeated thousands of times with no factual basis for equipment made in the last 10 years. I think it is BS, BUT I don't know and I am willing to hear what others say. To just keep repeating a possibly false theory over and over is not really what helps our audio community.

If someone else can come up with another way of finding out the truth, I'm all ears. But, I'm just tired of reading about this theory in thread after thread and I think it "may" be a falsehood that just keeps on being repeated and does not apply to our modern equipment. I'm open to any ideas on how to proceed.
 

sergeauckland

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That is why I asked how they determined what they heard. Was it just a listen or did they follow up with some type of testing? Was it what they heard from someone else? The issue is at this moment, I don't believe there are any amps built that are reacting to various speaker wire. Well, wire within reason but generally any old 12ga will do. Or, is this a theory passed around the internet and repeated thousands of times with no factual basis for equipment made in the last 10 years. I think it is BS, BUT I don't know and I am willing to hear what others say. To just keep repeating a possibly false theory over and over is not really what helps our audio community.
There are amplifiers that are not unconditionally stable, I could (but won't) name two that immediately come to mind, and if they are used with high capacitance cables, they will become unstable, and likely overheat and destroy themselves. In both cases, the manufacturer sold the 'appropriate' cable to avoid the issue, in one case making the warranty void if their loudspeaker cable is not used.

S.
 
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Spkrdctr

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There are amplifiers that are not unconditionally stable, I could (but won't) name two that immediately come to mind, and if they are used with high capacitance cables, they will become unstable, and likely overheat and destroy themselves. In both cases, the manufacturer sold the 'appropriate' cable to avoid the issue, in one case making the warranty void if their loudspeaker cable is not used.

S.

Well, this site is all about recommendations. If the amps are that bad, why would they remain unnamed? If it was a lousy speaker/DAC or headphones it would be named without hesitation. It seems odd to me that people are afraid to call very poor amps, junk. Why? Why are they getting a special pass? If they are not named they have no reason to make a better product. But that is IMHO.
 

threni

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OK guys. I want to try to narrow down the subject of crappy amps sounding different with different speaker wires and/or interconnects.

If the amp is crappy then the wires won't make any difference and it's crappiness will be evident from the review/measurements. If the amp is good then I don't care how it sounds with crappy wires.

"I know I encounter this theory that "some amps" can sound different because they are so poorly made that a different sound is heard using different wires and/or cables."
"To just keep repeating a possibly false theory over and over is not really what helps our audio community."
"I'm just tired of reading about this theory in thread after thread and I think it "may" be a falsehood that just keeps on being repeated and does not apply to our modern equipment. I'm open to any ideas on how to proceed."

I don't know where you're reading this but I'm going to guess that it's not on this site. Perhaps you should just stop reading it? I must admit that other than being a user of audio products and reading/learning stuff from this site I have no interest in what helps "our audio community". But I'm not really much of a "someone is wrong on the internet!!!" kind of a person. It has to be said that all the nonsense on the internet relating to audio exists despite a lot of clear evidence showing that it is indeed nonsense, and so it's hard to believe a thread consisting of a list of amps which perform badly when connected with crappy wires, according to this or that person, is going to change that.
 

MakeMineVinyl

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An amp by a reputable and well known company is unlikely to be 'crappy'. When considering an amp, looking at who makes it is probably a wise move. ;)
 

SIY

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OK guys. I want to try to narrow down the subject of crappy amps sounding different with different speaker wires and/or interconnects. Can everyone please name the amps that do this? I'd like to see a list of these amps that are out in the market place. I "think" that this may fall in the category of BS in todays market, but I'm not sure. If the amp/AVR was made in the last 10 years lets name it. Now, to put it on the list please make sure you personally heard the difference and not heard about it from someone or read about it. Also, when you noticed this phenomenon, how did you conclude it was the amp or was it guess work?

I know I encounter this theory that "some amps" can sound different because they are so poorly made that a different sound is heard using different wires and/or cables.
I would like to get a list of these amps/AVRs so we can steer people away from them when they come on this site looking for help. Thanks guys, I look forward to your posts.
It's VERY rare in modern amps. I haven't seen it in any of the amps I've worked on in this century.

Back in the day, Naim was notorious for this, but I hear that their contemporary gear is fine. Back about 40 years ago, there was a company called Spectrascan that had very twitchy amps. Ditto SWTP, Rappaport, Quatre.
 

sergeauckland

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An amp by a reputable and well known company is unlikely to be 'crappy'. When considering an amp, looking at who makes it is probably a wise move. ;)
It depends on the meaning of 'crappy'. There are amplifiers from well known manufacturers which measure well and consequently sound fine, but don't have decent short circuit or overload/overtemperature protection, or are only marginally stable. These may be sold with or without warnings about their limitations. They may be sold even with the marketing bollocks that by leaving out protection and output inductor and Zobel network, they sound better. In the respect that I think these are inadequate designs, they could be referred to as 'crappy' , but if used 'carefully', they work OK and therefore aren't 'crappy'.

S
 

anmpr1

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It depends on the meaning of 'crappy'. There are amplifiers from well known manufacturers which measure well and consequently sound fine, but don't have decent short circuit or overload/overtemperature protection, or are only marginally stable. ... I think these are inadequate designs, they could be referred to as 'crappy' , but if used 'carefully', they work OK and therefore aren't 'crappy'.
S
I've gone through a lot of amplifiers, but because I was a hobbyist-enthusiast I never kept anything long term. If I kept an amp six months that was a long time. So I don't have a lot of long term experience with gear.

That said, the only amplifier I owned that repeatedly blew up was from a boutique USA company called Amber. The model Series 70. Went to the factory twice, and the second time it came back I sold it as quickly as I could. Company went out of business shortly thereafter.

I had a Sony ES TAN-77 that was always blowing it's front panel VU lights. But the amp itself worked OK. Sold that one after it came back from warranty repair (to fix the lights) the second time.

I've had gear fried due to lightening, but I don't count that. The only long termer that eventually failed was a Pioneer SA-9500 integrated amp, after about 35 years of use. I was moving, and it was in a closet, so I gave it away to the guy helping me move. I have no idea if he ever got it fixed.

I've had cheap (Dyna, PS Audio) and more expensive (Pioneer Series 20, Counterpoint, Adcom, Yamaha) preamps that developed noisy pots and switches, but that's to be expected.
 

board

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There are amplifiers that are not unconditionally stable, I could (but won't) name two that immediately come to mind, and if they are used with high capacitance cables, they will become unstable, and likely overheat and destroy themselves. In both cases, the manufacturer sold the 'appropriate' cable to avoid the issue, in one case making the warranty void if their loudspeaker cable is not used.

S.
If I prod you a bit would you be willing to say if one of those two was Naim in the past?
I'm using a Naim amp now, and I'm using other speaker cables, and the shop also told me that the thing about only using 3.14 meter long speaker cables, or whatever it was, was a thing of the past. So I won't take offence if you name Naim (pun intended). I'm also considering buying another brand.
 

BostonJack

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There are amplifiers that are not unconditionally stable, I could (but won't) name two that immediately come to mind, and if they are used with high capacitance cables, they will become unstable, and likely overheat and destroy themselves. In both cases, the manufacturer sold the 'appropriate' cable to avoid the issue, in one case making the warranty void if their loudspeaker cable is not used.

S.
I encountered a similar behavior as a (novice) semiconductor test engineer. An analog multiplier (device under test) was directly driving ~3m (<- used meters to make it sound more scientific!) of shielded cable in a piece of ATE gear. Result was oscillation that resulted in unstable precision DC measurements of the part. Solution proposed by fellow engineers was a low offset instrumentation amp on the test board. (too complex). Solution adapted by me was a 100 ohm metal film resistor which had essentially no effect on DC measurements. A valuable lesson in respecting the signal environment.
 
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Spkrdctr

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It appears to me based on the previous posts that this poorly made amp with a wire problem is not applicable anymore. I see it mentioned repeatedly on this site and I didn't want to wade in and say "No, actually there are no amps that are sensitive to copper wires of normal gauge". I normally read it on threads where a new person comes on and says they can hear the difference in xyz exotic speaker wire and cheap 12 gauge wire. Our members than drag out the evidently very old by many decades theory that it could be your amp is so poorly built that you are hearing it. But, all in all, you guys answered my question. Thanks for you posts. A person can learn something hanging around here!
 

anmpr1

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I encountered a similar behavior as a (novice) semiconductor test engineer. An analog multiplier (device under test) was directly driving ~3m (<- used meters to make it sound more scientific!) of shielded cable in a piece of ATE gear. Result was oscillation that resulted in unstable precision DC measurements of the part.

The Quatre DG-250 uses [an] analog multiplier circuit. The typical DG-250 failure seems to be particularly drastic and destructive. Here's the scenario we've been hearing over and over again: the predriver transistor fails and a huge amount of DC, representing a major portion of the rail voltage, appears across the output. Since the amplifier has no protective circuits to sense this type of failure (don't ask us why), the DC passes through the speaker load. The speaker isn't either fused or the fuse doesn't blow fast enough. The speaker goes "arrgh" and that's that. [1977 Audio Critic]

It appears to me based on the previous posts that this poorly made amp with a wire problem is not applicable anymore.

During it's tweako days, Polk Audio sold a cable they called the Cobra. This particular item was deadly to certain amps. Harmless to others. From a FAQ I found while slumming:

Poorly designed vintage SS amplifiers cannot handle the low impedance/inductance/high capacitance of the Cobra cables. They may cause the amplifier feedback loop to go into oscillation. You get a blown fuse if you are lucky. Worse, if you are not.

Typical modern (post 80’s) SS amplifiers: no problems. I have used single run of Cobra cables with my 1989 Accuphase E206, 1997 Linn amplifier, 1984 SAE model A202, 1977 SAE Model 31B, 2017 Yamaha, 2020 Yamaha and other SS integrated and power amplifiers with excellent results with no problems.

Some modern SS amplifiers such as Naim (80-00's), NVA & LFD have low input impedance and/or no protection circuitry in their output stages. DO NOT use Cobras with these amplifiers. Do not use these cables with Vintage Threshold Statis and similar amplifiers.
 

board

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It appears to me based on the previous posts that this poorly made amp with a wire problem is not applicable anymore. I see it mentioned repeatedly on this site and I didn't want to wade in and say "No, actually there are no amps that are sensitive to copper wires of normal gauge". I normally read it on threads where a new person comes on and says they can hear the difference in xyz exotic speaker wire and cheap 12 gauge wire. Our members than drag out the evidently very old by many decades theory that it could be your amp is so poorly built that you are hearing it. But, all in all, you guys answered my question. Thanks for you posts. A person can learn something hanging around here!
I dont exactly consider myself an expert in speaker cables, but from what I understand, cables can actually change the volume level or the frequency response, although I don't think this is very common. As far as I understand most cables don't alter the volume level or the frequency response at all, and the differences in capacitance, inductance and resistance are also usually so small that it's inaudible.
Someone on HydrogenAudio once succesfully ABX'ed speaker cable, and afterwards he did a frequency sweep and saw that one of the cables rolled off the top octave (or then the other boosted it, but it was probably the former).
So, the person who claims to be able to hear a difference with expensive speaker cables might actually hear an audible difference, but most likely it's just placebo, unless his amp really is decades old, as you say.
 

DSJR

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I was going to come out and say Naim, as back in the 80's 'CB stylee' era, they measured rather badly by today's standards, especially at high frequencies and odd order distortion wasn't too good at all. they did have protection of sorts as used with a Quad 63 speaker, the smaller ones would shut down rather than blow up. Driven flat out with a wobbly LP12 vinyl source into 3 ohm Sarah and Isobarik speakers, a 250 would overheat and shut down. TODAY though, the disciples buy the brand-recommended cables the dealers tell them to buy and the smaller models have output inductors on them (Nait 5i certainly) but I can't be sure on the streaming or silly-money top models now.

I know the other brand Serge refers to, but it's a tiny niche brand now.
 
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