The main reason for thru hole parts in low production run products is that it’s easier to assemble by hand. Surface mount is easier for pick-and-place machines to handle. Until recently, getting low-volume pick & place assembly was more expensive than just doing it by hand; now there are several Chinese vendors who will do it at comparable prices (I think it’s a loss-leader for them, and they make it up on the ones that do turn out to become mass-market products). Electrically, there’s nothing inherently superior about either type until you get into microwave frequencies (which is a whole ‘nuther ball game). Also, not all surface mount caps are tiny; some are actually rather large. And you can mix-and-match on any given board: do the surface mount parts first with a pick-and-place machine, run the board thru the reflow oven, and then stuff the board with thru-hole parts and either run it through a wave soldering machine or hand solder it. Btw, it’s actually possible to attach a thru hole part to a sufficiently large surface mount pad on a board; you just have to bend the leads of the part to make contact with the pads, and hold the part in place while soldering it down. This is usually only done when trying to repair a board and you don’t have on-hand or can’t get the proper surface mount part.
@@Shrek_Holmes It’s not impossible, but it does require more equipment and skill. I do hand SMT assembly & rework with a stereo microscope and regular soldering iron for parts that have exposed leads or contact pads, and hot air for those that don’t. What does make repair impossible is if you can’t get the parts, or if they are programmed with code that you can’t get,
The performance depends upon the technologies, materials, construction, material stability tolerances and ratings used. All components have secondary and tertiary characteristics that affect their response to varying signals - For example: capacitors have ESR(resistance) and inductance. Even just wires have inductance, resistance and capacitive coupling.
Yes, and even the leads of TH devices have parasitics that affect the electrical performance. You wouldn't have the internet if the electronics had to overcome them. Also SMT resistors which have external resistive elements that are laser trimmed during manufacture, so they are much more accurate to spec than TH resistors of whatever composition. Even when you order 5% parts, you're getting much tighter tolerances due to the way they're made. You're just not paying for the screening to certify tighter value tolerance. The comparison of a foil cap to a multi-layer ceramic cap is somewhat misleading as the dielectrics are completely different. A more fair comparison would be to compare the SMT MLC to a ceramic disk cap. Which are well known to not sound that great. So for that part of the circuit you are forced to use the TH part.
The one thing I enjoy about through hole components and products that more or less exclusive use said design, is the fact that they're much much much much much much much much much much much much much much easier to repair. For example as a layman or amateur repair tech like myself, if I have a couple capacitors go bad on an amplifier I can go down get a couple replacements and easily desolder the old ones and pop a couple new ones in with nothing more than a basic soldering iron and some solder. With surface mount it can be quite a bit harder and more labor intensive and require more specialized tools.
Surface mount components versus through-hole ones, in my experience of doing DIY electroncs since 1983, it depends on the levels of current flowing through the circuit in question. Through-hole parts sound subjectively better - to my ears - in high current, high power circuits like power amplifiers.
3:30 And thats the crux of the problem: Misunderstanding characteristics of components. This is especially true with things like high-k dielectrics used in MLC (multi-layer ceramic) capacitors can very quite dramatically with both temperature and voltage. See: en.wikipedia.org/wiki/Ceramic_capacitor#Voltage_dependence_of_capacitance In DC blocking applications, this can degrade the low frequency performance and cause distortion. This does not mean that it "sounds worse", but that the designer will have chosen the wrong type of component. For Paul's ultra-posh film capacitors, for DC blocking and coupling of the small driving signals from the tubes those could just as easily be high quality electrolytic capacitors. There would be no measurable or audible difference as the capacitance is not varying with time since the signal is so small compared to the DC its blocking. The only advantage would be long term (like years to decades) stability, but the real elephant in the room there will be the tubes which are horribly non-linear and degrade with total hours of use.
I commend you for taking the time to share the actual scientific explanation to the question, instead of his magic and misleading "does not sound as good" claim. Demystifying audio is a never ending challenge... Would be refreshing sometimes if he just said "I don't know the ACTUAL reason, let me bring in someone who actually does".
X7R and Y5U type multilayer ceramic capacitors change their value quite a lot with variation in applied voltage. If you have an RC low pass filter the capacitor has a varying audio voltage across it to ground. This varying signal voltage causes instantaneous variations in capacitance and this makes for lots of distortion. A coupling capacitor is not the same situation provided it is a large enough in value that the voltage across it doesn't change appreciably during the signal voltage excursions.
Hello. I’m a PCB designer of over 10 years. DIP and SMT packages have their individual advantages. The technology and design of the component will vary by manufacturer. Mainly, DIP packages can be useful in multilayer boards in high speed data situations where you may want to bury the copper signal traces (single or differential pair) between copper ground layers immediately at the exit point of the IC. You can do this with SMT packages, through the use of vias, which can go through all layers of the board, or only some layers (blind/buried) SMT is useful for more obvious reasons, perhaps you only need traces on the same layer as the SMT package, in this case, you do not have extra through-hole pads to worry about. This can be useful when you have many components on the top and bottom layer, in which case you cannot use too many DIP style packages.
Everything between the artist’s vocal chords or fingers, and your ear drums, will impact the quality of the sound reproductions. How a component is attached to the board inside a hifi component is far down on the priority list. Of much greater concern is the room of the recording and the room of the listener, followed by the microphone of the recording and the speaker of the listener, followed by the microphone preamp and the preamp on the listener end, followed by…. It’s a long list to go through before we get to soldering. It’s a fine and interesting question but not one that says much about a listener’s enjoyment of their favorite recording. Sometimes we get too caught up in minute technicalities, thinking those little details hold the key to musical enjoyment. Instead, try finding music you truly enjoy, and the boxes and cables and soldering will just fade away.
Yeah I love it when people talk about audiophile solder. I have absolutely no problem with the fact that people are getting ripped off blind for it. I mean, I should care, and I once did but one can only absorb so much before they just say eff it.
Agree. Too many audiophiles obsess over trivia. Loudspeakers and room acoustics have way more influence on sound quality than any other link in the audio chain.
In my hi-fi chain I tried to get every single device, component or interconnect as good as possible, starting with a turntable and finishing with the loudspeakers. Now I am focused on listening to my favourite music.
The microscopy of the internal components within an op amp is less of a problem to me considering they are within a package that I can desolder without ruining LOL
Great Q&A. Another reason for THT parts is power handling. In your BHK example you are likely dealing with 250V or 600V coupling caps. There is no way to make them smaller and they do not exist in anything but THT. An interesting companion question is does Point to Point sound better than a PCB based topology. Many high end tube amps actually have very simple circuits composed of high quality parts wired the old fashioned way... point to point with wire. There is a school of perfectionists that claim point to point is superior. All done by hand and requires skill in routing, wire twisting and grounding. Likely no PCB in a Decware amp for example.
The "PC boards sound bad" myth comes up often in audio forums. The truth is that even a cheap phenolic base PC board has not appreciable effect at audio frequencies. Now when you get into high speed digital and microwave circuits, there the base board material characteristics do make a difference. All that said, for audio, there are very good PC board layouts and very bad point to point designs. And the reverse is also just as true.
@@andydelle4509 Points well taken. No question that digital and RF circuits excel with well designed multilayer PCB. Tube amps moving bigger currents and very simple circuit do well with point to point (assuming some skill employed).
I have to replace smd parts on a capstan motor board. They are notorious for failing on my 238 Tascam. Would it be better to use THT to replace the smd parts? I'm thinking they might be more resilient in the long run. Thx.
As long as the SMD component is the same type as the THT component, the SMD component will be better due to tighter tolerances. Because SMD components have shorter leads, their stray capacitance and inductance is lower as well. However, some types of components don't exist as a SMD part and are only available as THT component - that's what makes the difference.
The main reason for me to prefer THT components is because I like to be able to service my own gear. With many small SMD components you'd need very expensive soldering equipment, while THT can be serviced using a basic soldering iron.
I'm just glad point to point contact is not a thing at all anymore. Repairing antique radios can be a huge pain and harder than any SMT component because it's such a rats nest.
Point to point is definitely still a thing. High end guitar amps are built with turret boards that make it easier to service, modify, etc. than even if it used through hole boards. These amps are paint by numbers compared to SMD which is more like photorealistic painting lol. But the sound and reliability of these point to point amps means PTP will be around for a while, as these amps could last indefinitely if they are maintained.
If it’s good enough for rockets, it’s good enough for my guitar pedals. However! In power amplifiers and guitar amps I do not accept them to be of any use to me for various practical reasons.
@@laurentzduba1298 I certainly am, but I am not against tubes in my pedals either! Haha there is one overdrive in particular that I love that uses one that Eric Johnson is fond of.
So the PS Audio class AB amplifier with tube input is all Trough Hole so there is your answer. Part 2: Digital is 1s and 0s, it does not matter so much, there is that answer.
OMG! While you are at it, you might as well ask if printed circuit boards are better or worse as compared to point-to-point wiring? Then you can debate whether integrated circuits (ICs) are better or worse than discrete components?
Today I ran into an "MLCC" a multi layer ceramic capacitor. It was about 4mm long, 3mm wide and 3mm high. It was rated (and measured) 12 microfarads at 25 volts.
How does "sound" go through a capacitor? On a more serious note, no pun intended, another major advantage of surface mount is low unwanted inductance due to no lead wire length. And the tight circuit packaging surface mount allows for makes high speed and high frequency designs much easier and cheaper, although this does not matter at audio frequencies.
@@graxjpg Yes, that is quite correct. But my point is that the more "technical audiophiles", meaning those who are more interested in the hardware versus just music lovers, need to study more basic electrical engineering principles. Some of the questions asked in this column are utterly ridiculous.
@@bergennorway A passive speaker crossover is a horrible device - strictly speaking. How can you maintain accurate frequency division with a passive LC filter looking into a 300% impedance variation from the driver. That is what happens in a passive crossover speaker. Now they do work quite well regardless and quite necessary in the bulk of affordable home HiFi systems. But if you really want high end, use active line level crossovers and bi-amp. For me I now use a DSP based crossover. This is a huge advancement in that you can precisely vary the crossover point and slope on a GUI menu. That level of control is not really possible even an analog line level active crossover.
True in low level applications (pre-amp...), not so in high-ish power applications where other characteristics are way more important (stability at high V / I / Temp...). It all depends. But what's true is that it goes way above Paul's head and his limited knowledge in electronics 🤣
I think it was a misnomer that turned into dialect. Language and how weve used it throughout history is fluid, I say it with an L but I see why people say it without.
Well, the worst part might actually be his "does not sound as good" response without any explanation based on actual electronics science. But I bet he just does not know the differences in electrical characteristics between SMT and THT capacitors at different levels of power / voltage / temps... Hopefully his amp designers know better ?
I think THT sound more natural. I repair car amps and listen to all kinds of amps. The newer SMD amps just sound robotic and lifeless to me. Just my opinion.
The main reason for thru hole parts in low production run products is that it’s easier to assemble by hand. Surface mount is easier for pick-and-place machines to handle. Until recently, getting low-volume pick & place assembly was more expensive than just doing it by hand; now there are several Chinese vendors who will do it at comparable prices (I think it’s a loss-leader for them, and they make it up on the ones that do turn out to become mass-market products).
Electrically, there’s nothing inherently superior about either type until you get into microwave frequencies (which is a whole ‘nuther ball game). Also, not all surface mount caps are tiny; some are actually rather large. And you can mix-and-match on any given board: do the surface mount parts first with a pick-and-place machine, run the board thru the reflow oven, and then stuff the board with thru-hole parts and either run it through a wave soldering machine or hand solder it.
Btw, it’s actually possible to attach a thru hole part to a sufficiently large surface mount pad on a board; you just have to bend the leads of the part to make contact with the pads, and hold the part in place while soldering it down. This is usually only done when trying to repair a board and you don’t have on-hand or can’t get the proper surface mount part.
surface mount also makes things impossible to service and really helps the cause of planned obsolescence that electronics makers love
@@Shrek_Holmes It’s not impossible, but it does require more equipment and skill. I do hand SMT assembly & rework with a stereo microscope and regular soldering iron for parts that have exposed leads or contact pads, and hot air for those that don’t.
What does make repair impossible is if you can’t get the parts, or if they are programmed with code that you can’t get,
The performance depends upon the technologies, materials, construction, material stability tolerances and ratings used. All components have secondary and tertiary characteristics that affect their response to varying signals - For example: capacitors have ESR(resistance) and inductance. Even just wires have inductance, resistance and capacitive coupling.
Yes, and even the leads of TH devices have parasitics that affect the electrical performance. You wouldn't have the internet if the electronics had to overcome them. Also SMT resistors which have external resistive elements that are laser trimmed during manufacture, so they are much more accurate to spec than TH resistors of whatever composition. Even when you order 5% parts, you're getting much tighter tolerances due to the way they're made. You're just not paying for the screening to certify tighter value tolerance.
The comparison of a foil cap to a multi-layer ceramic cap is somewhat misleading as the dielectrics are completely different. A more fair comparison would be to compare the SMT MLC to a ceramic disk cap. Which are well known to not sound that great. So for that part of the circuit you are forced to use the TH part.
Valid question, excellent answer(s).
Personally, I prefer through-hole because it's so much easier to repair.
Fantastic question and I was happy to hear the brief yet thorough explanation on the topic. Thanks again Paul.
The one thing I enjoy about through hole components and products that more or less exclusive use said design, is the fact that they're much much much much much much much much much much much much much much easier to repair. For example as a layman or amateur repair tech like myself, if I have a couple capacitors go bad on an amplifier I can go down get a couple replacements and easily desolder the old ones and pop a couple new ones in with nothing more than a basic soldering iron and some solder. With surface mount it can be quite a bit harder and more labor intensive and require more specialized tools.
Surface mount components versus through-hole ones, in my experience of doing DIY electroncs since 1983, it depends on the levels of current flowing through the circuit in question. Through-hole parts sound subjectively better - to my ears - in high current, high power circuits like power amplifiers.
Excellent video. Haven’t missed a video for going on two years, always informative.
3:30 And thats the crux of the problem: Misunderstanding characteristics of components. This is especially true with things like high-k dielectrics used in MLC (multi-layer ceramic) capacitors can very quite dramatically with both temperature and voltage. See: en.wikipedia.org/wiki/Ceramic_capacitor#Voltage_dependence_of_capacitance In DC blocking applications, this can degrade the low frequency performance and cause distortion. This does not mean that it "sounds worse", but that the designer will have chosen the wrong type of component. For Paul's ultra-posh film capacitors, for DC blocking and coupling of the small driving signals from the tubes those could just as easily be high quality electrolytic capacitors. There would be no measurable or audible difference as the capacitance is not varying with time since the signal is so small compared to the DC its blocking. The only advantage would be long term (like years to decades) stability, but the real elephant in the room there will be the tubes which are horribly non-linear and degrade with total hours of use.
I commend you for taking the time to share the actual scientific explanation to the question, instead of his magic and misleading "does not sound as good" claim. Demystifying audio is a never ending challenge... Would be refreshing sometimes if he just said "I don't know the ACTUAL reason, let me bring in someone who actually does".
X7R and Y5U type multilayer ceramic capacitors change their value quite a lot with variation in applied voltage. If you have an RC low pass filter the capacitor has a varying audio voltage across it to ground. This varying signal voltage causes instantaneous variations in capacitance and this makes for lots of distortion. A coupling capacitor is not the same situation provided it is a large enough in value that the voltage across it doesn't change appreciably during the signal voltage excursions.
Hello. I’m a PCB designer of over 10 years. DIP and SMT packages have their individual advantages. The technology and design of the component will vary by manufacturer. Mainly, DIP packages can be useful in multilayer boards in high speed data situations where you may want to bury the copper signal traces (single or differential pair) between copper ground layers immediately at the exit point of the IC. You can do this with SMT packages, through the use of vias, which can go through all layers of the board, or only some layers (blind/buried) SMT is useful for more obvious reasons, perhaps you only need traces on the same layer as the SMT package, in this case, you do not have extra through-hole pads to worry about. This can be useful when you have many components on the top and bottom layer, in which case you cannot use too many DIP style packages.
Everything between the artist’s vocal chords or fingers, and your ear drums, will impact the quality of the sound reproductions. How a component is attached to the board inside a hifi component is far down on the priority list. Of much greater concern is the room of the recording and the room of the listener, followed by the microphone of the recording and the speaker of the listener, followed by the microphone preamp and the preamp on the listener end, followed by…. It’s a long list to go through before we get to soldering. It’s a fine and interesting question but not one that says much about a listener’s enjoyment of their favorite recording. Sometimes we get too caught up in minute technicalities, thinking those little details hold the key to musical enjoyment. Instead, try finding music you truly enjoy, and the boxes and cables and soldering will just fade away.
Yeah I love it when people talk about audiophile solder. I have absolutely no problem with the fact that people are getting ripped off blind for it. I mean, I should care, and I once did but one can only absorb so much before they just say eff it.
Agree. Too many audiophiles obsess over trivia. Loudspeakers and room acoustics have way more influence on sound quality than any other link in the audio chain.
In my hi-fi chain I tried to get every single device, component or interconnect as good as possible, starting with a turntable and finishing with the loudspeakers. Now I am focused on listening to my favourite music.
But much music mastered today goes through even smaller microscopic components inside op-amps.
The microscopy of the internal components within an op amp is less of a problem to me considering they are within a package that I can desolder without ruining LOL
Great Q&A. Another reason for THT parts is power handling. In your BHK example you are likely dealing with 250V or 600V coupling caps. There is no way to make them smaller and they do not exist in anything but THT.
An interesting companion question is does Point to Point sound better than a PCB based topology. Many high end tube amps actually have very simple circuits composed of high quality parts wired the old fashioned way... point to point with wire. There is a school of perfectionists that claim point to point is superior. All done by hand and requires skill in routing, wire twisting and grounding. Likely no PCB in a Decware amp for example.
The "PC boards sound bad" myth comes up often in audio forums. The truth is that even a cheap phenolic base PC board has not appreciable effect at audio frequencies. Now when you get into high speed digital and microwave circuits, there the base board material characteristics do make a difference. All that said, for audio, there are very good PC board layouts and very bad point to point designs. And the reverse is also just as true.
@@andydelle4509 Points well taken. No question that digital and RF circuits excel with well designed multilayer PCB.
Tube amps moving bigger currents and very simple circuit do well with point to point (assuming some skill employed).
1:55 Really the only things SMT parts are "bad for" is our fat, meaty fingers. It is an ever worsening problem.
Thanks Paul l have learned something in today's video. 😁🎧👍
Thanks for the explanation Paul, I was lost when you were reading the question.
Very interesting segment Paul
I have to replace smd parts on a capstan motor board. They are notorious for failing on my 238 Tascam. Would it be better to use THT to replace the smd parts? I'm thinking they might be more resilient in the long run. Thx.
As long as the SMD component is the same type as the THT component, the SMD component will be better due to tighter tolerances.
Because SMD components have shorter leads, their stray capacitance and inductance is lower as well.
However, some types of components don't exist as a SMD part and are only available as THT component - that's what makes the difference.
The main reason for me to prefer THT components is because I like to be able to service my own gear.
With many small SMD components you'd need very expensive soldering equipment, while THT can be serviced using a basic soldering iron.
@@QoraxAudio as soldering technology advances, someday there will be audiophile grade SMD capacitors and resistors LOL
@@graxjpg LOOOL!
That would actually be quite funny and sad at the same time 😅
I'm just glad point to point contact is not a thing at all anymore. Repairing antique radios can be a huge pain and harder than any SMT component because it's such a rats nest.
Point to point is definitely still a thing. High end guitar amps are built with turret boards that make it easier to service, modify, etc. than even if it used through hole boards. These amps are paint by numbers compared to SMD which is more like photorealistic painting lol. But the sound and reliability of these point to point amps means PTP will be around for a while, as these amps could last indefinitely if they are maintained.
@@graxjpg consider me corrected! Thanks for the information!
@@bf0189 haha yes! Point to point will be around at the very least as long as I am making myself little electronic devices haha! Cheers mate
Thank you.
Linn electronics are pretty much smt but I do see loads of through hole caps. I guess you can do hybrid?
Americans don't soldering, they do soddering. Huh?
That’s good to know.
Can't wait to see what AMDs new stacked 3d V-Cache chips are gonna do for electronics world.
cd players, etc were once made with thru hole devices. PERIOD
this is a real question: how do you know a good sound from a bad sound? What sounds are bad? (please answer this with a spectrograph)
If it’s good enough for rockets, it’s good enough for my guitar pedals. However! In power amplifiers and guitar amps I do not accept them to be of any use to me for various practical reasons.
I guess you are too young to remember the days when the Cape Canaveral rocket complex still used 6SN7 tube based telemetry systems, Grant.😁
@@laurentzduba1298 I certainly am, but I am not against tubes in my pedals either! Haha there is one overdrive in particular that I love that uses one that Eric Johnson is fond of.
So the PS Audio class AB amplifier with tube input is all Trough Hole so there is your answer.
Part 2: Digital is 1s and 0s, it does not matter so much, there is that answer.
OMG! While you are at it, you might as well ask if printed circuit boards are better or worse as compared to point-to-point wiring? Then you can debate whether integrated circuits (ICs) are better or worse than discrete components?
And give us the same "does not sound as good" claim without any rational explanation based in electronics science ? Can't wait ! 🤣
Audio grade capacitors are still being through hole parts
Today I ran into an "MLCC" a multi layer ceramic capacitor. It was about 4mm long, 3mm wide and 3mm high. It was rated (and measured) 12 microfarads at 25 volts.
@Douglas Blake It's a capacitor with an extra stamp on it so the buyer can have confidence that they just got F%ED.
@@InsideOfMyOwnMind someday there will be SMD “audiophile grade” caps and resistors.
@Douglas Blake "Military grade electronic components" it's the same thing.
@@graxjpg There are not SMD caps on crossover network board.
Yeah. Thats advanced level ask paul. Still watched it tho.
Nice. Appreciate it 👍
How does "sound" go through a capacitor? On a more serious note, no pun intended, another major advantage of surface mount is low unwanted inductance due to no lead wire length. And the tight circuit packaging surface mount allows for makes high speed and high frequency designs much easier and cheaper, although this does not matter at audio frequencies.
Try changing the capacitors in your crossover, and you will be convinced they have sound!
Well, the electricity within the amp is literally analogous to the sound... so if you affect that AC signal you are literally affecting the sound.
@@graxjpg Yes, that is quite correct. But my point is that the more "technical audiophiles", meaning those who are more interested in the hardware versus just music lovers, need to study more basic electrical engineering principles. Some of the questions asked in this column are utterly ridiculous.
@@bergennorway A passive speaker crossover is a horrible device - strictly speaking. How can you maintain accurate frequency division with a passive LC filter looking into a 300% impedance variation from the driver. That is what happens in a passive crossover speaker. Now they do work quite well regardless and quite necessary in the bulk of affordable home HiFi systems. But if you really want high end, use active line level crossovers and bi-amp. For me I now use a DSP based crossover. This is a huge advancement in that you can precisely vary the crossover point and slope on a GUI menu. That level of control is not really possible even an analog line level active crossover.
@@andydelle4509 I see your point, experiencing music is of course what it’s all about.
I like through hole.
I surface mount to get in the through hole 😉
That cap you say is Expensive, lol ! thats like a 1$ cap, and if you buy hand full's of them its like 0.10$ each... SMD Melf Resistors FTW !
A .01 uF Rel Cap TFT cap retails for $47 to consumers. Even in bulk for a commercial customer it's going to be expensive.
Summary answer: "It Depends."
Talk about Apple Music lossless and special audio grandpa
Send him a question about those things dingus, do you realize he is reading questions he gets sent by people
Only chip amps & class d stuff use SMT as far as I know.
They do but most modern audio equipment do as well.
@@Paulmcgowanpsaudio Do smaller traces (less copper) equate to loss in signal?
Smd sound beter! Because they have low noise…especially thin film resistor, and there are PPS smd caps’
True in low level applications (pre-amp...), not so in high-ish power applications where other characteristics are way more important (stability at high V / I / Temp...). It all depends.
But what's true is that it goes way above Paul's head and his limited knowledge in electronics 🤣
Not wearing jeans, what happened?
I am imagining a house sized amp with a million through hole transistors.
An IC can also be trough hole
Now that would be the ultimate "audiophile system" per his logic. Can't wait to see that ! 🤣
You have a weird way of pronouncing Solder. where is the L ?
I suppose if I were British I might pronounce the "L" but, as an American the "L" is silent.
I think it was a misnomer that turned into dialect. Language and how weve used it throughout history is fluid, I say it with an L but I see why people say it without.
Hahahahaha, oh dear. Yet another audiophool clueless question.
Well, the worst part might actually be his "does not sound as good" response without any explanation based on actual electronics science. But I bet he just does not know the differences in electrical characteristics between SMT and THT capacitors at different levels of power / voltage / temps... Hopefully his amp designers know better ?
I think THT sound more natural. I repair car amps and listen to all kinds of amps. The newer SMD amps just sound robotic and lifeless to me. Just my opinion.