Tube amp for mains only?

[Squishman]

Happy new year! I have Klipsch Forte II's for my mains in my 5.1.2 HT powered by a Yamaha RX-A1060. I have often wanted to hear my Forte II's powered by a tube amp for 2 channel listening (mainly LP's). Or 2.1, actually. But if I found a tube amp and plugged it into the pre-amp outs, would I not be defeating the whole purpose? I mean the AVR would be the weakest link and perhaps it would be an almost indecipherable difference. Comments?

 

[ski2xblack]

So having fairly sensitive speakers has you peering into the rabbit warren of tube gear. That's understandable, but be warned that the whole tube realm is rife with marketing nonsense and enthusiastic adherents who have little clue how any of this all actually works on a reductive level.

Yes, you can get a tube amp and feed it from your AVR's pre-outs.

No, that would not defeat the purpose, if the purpose is to hear what a tube amp driving your speakers sounds like. The proverbial "tube sound" results from tube amplification driving transducers, not from tube buffer stages, whose loads are much easier than a speaker.

Yes, it would likely defeat the purpose if clean, linear response is the goal, but some folks find the audible changes that tube amps produce pleasant.

No, the AVR would not be the weak link in your proposed setup. The tube amp would be the limiting factor.

As far as audible differences, tube gear can span from virtually indistinguishable from ss to highly colored. More specifically, a well engineered, high power pp tube amp would be difficult to pick out by ear, and would necessarily be a complex, very costly affair. Flea watt SET amps, the most rudimentary and simple amps, provide the most colored, tubey sound. SETs are the darlings of many of the old Klipsch farts, fwiw. Despite their simplicity, they too can be very pricey.

 

[Squishman]

Thx ski2Xblack for the detailed and interesting response. Seems like if I got one of the ones around for under a grand, I'd be wasting my dough. Might be worthwhile if I was to find a higher-end unit $2k plus? If that's the case, I'll leave well enough alone. It would still be a blast if I had one for a weekend and plugged my TT into it just for the experiment (no AVR), or shall we say sh--ts and giggles.

 

[PENG]

Happy new year! I have Klipsch Forte II's for my mains in my 5.1.2 HT powered by a Yamaha RX-A1060. I have often wanted to hear my Forte II's powered by a tube amp for 2 channel listening (mainly LP's). Or 2.1, actually. But if I found a tube amp and plugged it into the pre-amp outs, would I not be defeating the whole purpose? I mean the AVR would be the weakest link and perhaps it would be an almost indecipherable difference. Comments?

The AVR (RX-A1060) may not be the weakest link, it depends on the specific tube amp you have in mind. All else being equal, obviously you get a better chance of hearing a difference if you use a tube preamp too, but even just tube power amp could make an audible difference, again it depends on the specific model. Some tube power amps could have low enough distortions for them to be very transparent, like McIntosh's for example, the newer models anyway.

 

[ski2xblack]

Squish, I'm a jaded diy'er, and find pretty much all commercial tube amps a rip-off.

From that perspective, the parts cost alone of a fairly good pp tube amp may push above $1k, plus the time involved actually building the thing, to end up with an amp with little to no qualitative audible differences from conventional amps. For similar outlay and far simpler construction you could get a SOTA hypex based amp with none of the compromises.

I built an amp designed by the Klipsch forum's resident sweep tube guru (Maynard, aka 'tube fanatic') which he aptly named "lil' sweetie". SE, using a 6v6 strapped as a triode. Parts cost was about $300. It does sound sweet, all 2 watts of it.

 

[Squishman]

Squish, I'm a jaded diy'er, and find pretty much all commercial tube amps a rip-off.

From that perspective, the parts cost alone of a fairly good pp tube amp may push above $1k, plus the time involved actually building the thing, to end up with an amp with little to no qualitative audible differences from conventional amps. For similar outlay and far simpler construction you could get a SOTA hypex based amp with none of the compromises.

I build an amp designed by the Klipsch forum's resident sweep tube guru (Maynard, aka 'tube fanatic') which he aptly named "lil' sweetie". SE, using a 6v6 strapped as a triode. Parts cost was about $300. It does sound sweet, all 2 watts of it.

Holy buckets. I am no electronics expert, but I can read directions and solder skillfully. Is this a kit I can buy from you, or have one built for me?

 

[ski2xblack]

Maynard posts schematics of all his stuff on both the Klipsch forum as well as one of the diy sites (I don't recall which one), as well as detailed build threads, and he does sell completed amps on occasion. You should chat him up.

Or were you wondering about hypex amps?

 

[Squishman]

Maynard posts schematics of all his stuff on both the Klipsch forum as well as one of the diy sites (I don't recall which one), as well as detailed build threads, and he does sell completed amps on occasion. You should chat him up.

Or were you wondering about hypex amps?

Sorry, I do not know what hypex means!

 

[mazersteven]

Can this be used?

Monoprice Pure Tube Stereo Amplifier with Bluetooth, Line and Phono Inputs, and Qualcomm aptX Audio - Monoprice.com

The tube amplifier has seen a resurgence in recent years due to the warm, pleasing sound that only a tube amplifier can offer. The Monoprice™ Pure Tube Amplifier utilizes four EL84 tubes for the

www.monoprice.com

 

[Squishman]

Can this be used?

Monoprice Pure Tube Stereo Amplifier with Bluetooth, Line and Phono Inputs, and Qualcomm aptX Audio - Monoprice.com

The tube amplifier has seen a resurgence in recent years due to the warm, pleasing sound that only a tube amplifier can offer. The Monoprice™ Pure Tube Amplifier utilizes four EL84 tubes for the

www.monoprice.com

Oh yeah.... I would need a phono pre-amp! I have a cheap radio shack amp with tt input and tape monitor for outs. But heck.... that would be so lame. I would never do that with even the proposed experiment. ha.

 

[ski2xblack]

Can this be used?

Monoprice Pure Tube Stereo Amplifier with Bluetooth, Line and Phono Inputs, and Qualcomm aptX Audio - Monoprice.com

The tube amplifier has seen a resurgence in recent years due to the warm, pleasing sound that only a tube amplifier can offer. The Monoprice™ Pure Tube Amplifier utilizes four EL84 tubes for the

www.monoprice.com

That's a full integrated amp, not a simple power amp. It's not a hybrid, so there's that (where a tube buffer stage is included, mainly for show, but the output stages are just ss).

Sorry, I do not know what hypex means!

Modern tech, fabulous specs, easy-peasy (relatively speaking) assembly.

Class D and Me Too!... The Hypex Path

@MrBoat beat me to the punch with his exciting IcePower Amp Module thread... https://forums.audioholics.com/forums/threads/class-d-me.118839/ So I pay homage to that, first. :D Also, quick shouts to @PENG and @lovinthehd for helping me out! ;) I just received confirmation from Hypex that my...

forums.audioholics.com

 

[stalag2005]

Noted pure analog (tube) amplifiers is pure sine wave as long as 2 conditions are met.

1. Don't run into clip. This will destroy a speaker
2. Don't run beyond the linear range of the amplifier. Typical is between 20% to 70% of the range. Pushing an amplifier to 100% output leads to condition 1 as well as inducing distortions when in nonlinear output.

Given this, solid state amplifiers are in part subject to the same limitations that tube amps are suspect to as well. But they are less likely to distort, but can enter a solid state clip that will cause the same problems as point 1. Usually solid state amplifiers also have limits and stack the amplification until you get to the final stage. Each step if not perfectly executed can induce distortion. The better amplifiers get around this due to design that works to limit if not eliminate the distortion by feedback loops. Tube amplifiers as well can benefit from a feedback loop but in many cases the tubes themselves act as filters. Quality of the tubes for a tube amplifier are critical for operation. However, tube amps are generally capable of much larger amplifications in a single stage that would not be possible with a solid state amplification typically used. Modern amplification is quite good and works well due the engineering put into it. But it is still advisable irrespective to run an amplifier between 20% and 70% full rating to avoid distortion.

Given the above, and careful shopping for tubes for an old amplifier, one can resurrect the amplifier and get years of good service out of an older device, as long as you keep the unit dusted internally and keep proper airflow for cooling implemented at all times. Some of the old stuff put in use on modern speakers can sound very good. Given this, I have no strong leaning either way, but be careful when shopping, there is a lot of snake oil advertising that honestly does not get you the proper information to buy.

 

[PENG]

Can this be used?

Monoprice Pure Tube Stereo Amplifier with Bluetooth, Line and Phono Inputs, and Qualcomm aptX Audio - Monoprice.com

The tube amplifier has seen a resurgence in recent years due to the warm, pleasing sound that only a tube amplifier can offer. The Monoprice™ Pure Tube Amplifier utilizes four EL84 tubes for the

www.monoprice.com

Thanks for the link, fantastic entertainment for the New year weekend!

"Because of its lossy nature, digital music can often lose some of the depth and warmth that gives it life. Wireless streaming adds an additional layer of digital compression, which can further degrade the audio quality. The addition of tube preamplifier and power amplifier stages adds back some of the warmth and richness, breathing new life into your digital music, while Qualcomm® aptX™ Audio ensures clean and clear Bluetooth® streaming."

Best snake oil available to date, beating the exotic cable varieties??

 

[ski2xblack]

@PENG didn't you build the Amp Camp Amp? An amp whose performance is closer to a single ended 300b triode amp than conventional amps?

Perhaps the OP could benefit from you sharing your own experience exploring esoteric amplification. Presumably you had similar curiosities as squishman at one time.

 

[highfigh]

Holy buckets. I am no electronics expert, but I can read directions and solder skillfully. Is this a kit I can buy from you, or have one built for me?

That's only part of the skill needed to build an amp like this- there's also a need to understand what's happening in it & how to find out if it's operating properly and then, there's the added bonus of knowing that the DC voltage in the amp can kill you if you happen to find yourself between some parts of the tube circuit and the chassis. Some tubes need over 400VDC, where a solid state amplifier often uses 'only' about 100VDC (if that).

I would recommend borrowing one before buying- there's no guarantee that you'll like what you hear and, rather than spend hundreds (or more), it might only cost some time.

 

[highfigh]

Noted pure analog (tube) amplifiers is pure sine wave as long as 2 conditions are met.

1. Don't run into clip. This will destroy a speaker
2. Don't run beyond the linear range of the amplifier. Typical is between 20% to 70% of the range. Pushing an amplifier to 100% output leads to condition 1 as well as inducing distortions when in nonlinear output.

Given this, solid state amplifiers are in part subject to the same limitations that tube amps are suspect to as well. But they are less likely to distort, but can enter a solid state clip that will cause the same problems as point 1. Usually solid state amplifiers also have limits and stack the amplification until you get to the final stage. Each step if not perfectly executed can induce distortion. The better amplifiers get around this due to design that works to limit if not eliminate the distortion by feedback loops. Tube amplifiers as well can benefit from a feedback loop but in many cases the tubes themselves act as filters. Quality of the tubes for a tube amplifier are critical for operation. However, tube amps are generally capable of much larger amplifications in a single stage that would not be possible with a solid state amplification typically used. Modern amplification is quite good and works well due the engineering put into it. But it is still advisable irrespective to run an amplifier between 20% and 70% full rating to avoid distortion.

Clipping from amplifiers, if excessive, will eventually kill tweeters but the effects will depend on the drivers. One reason tweeters die from this is that they have small voice coils and they can't dissipate the heat as easily as a larger driver. Look at guitar amps, as an example of the idea that clipping kills speakers isn't an absolute- they often sound like crap until they distort and the speakers can last for decades, even though they have been fed distorted signal at high power (for them) levels. Whether the amp puts out 6W or 100W, it's clipping but a low powered amp isn't pushing much voltage or current.

 

[highfigh]

Thanks for the link, fantastic entertainment for the New year weekend!

"Because of its lossy nature, digital music can often lose some of the depth and warmth that gives it life. Wireless streaming adds an additional layer of digital compression, which can further degrade the audio quality. The addition of tube preamplifier and power amplifier stages adds back some of the warmth and richness, breathing new life into your digital music, while Qualcomm® aptX™ Audio ensures clean and clear Bluetooth® streaming."

Best snake oil available to date, beating the exotic cable varieties??

I found that my tube amp took the edge off when I would listen to CDs, but this was at the beginning of CD availability and many of them sounded like crap because they blew it at the mastering stage (or did nothing to the CD master, to tailor it to the format). I haven't used that amp in a long time.

 

[fah]

@PENG didn't you build the Amp Camp Amp? An amp whose performance is closer to a single ended 300b triode amp than conventional amps?

Perhaps the OP could benefit from you sharing your own experience exploring esoteric amplification. Presumably you had similar curiosities as squishman at one time.

solid state amplifier that can match 300b?
what amplifier is that?
do you ever listen to it?

 

[steve64]

Sell one of the kids and buy a Mcintosh mc275mkvi! You'll be happy both ways.

 

[MrBoat]

I tried tubes. One was a modernized Dynaco that a friend's dad loaned me. It was very hard to tell if what I was hearing was the amp, or the recording differences. The other thing, it was always hot. The other issue was, me 2nd guessing the status of the tubes if something sounded 'off' to me. As such, I have a start of a collection of used tubes of questionable age/use. I sent the amp back to his dad because I was afraid I would get broken into and robbed of it.

I built the Amp Camp Amp (also built the F5), which is a class A MOSFET amp with what amounts to a pretty crude circuit this day in age. But, it sounds very nice. Better than anything else? No. After 5 minutes, whatever subtle audible differences, cancel out as "I" get broken into the sound. This happens with all my amps. So much so, I have since given up on amp type preference, and opt for cooler and more compact class D amps that I have instead. As long as they have low audible distortion and enough headroom, they all work for my use.