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interesting write up about valve amps


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Very interesting comment about the sound of different valves:

The majority of differences heard are simply gain related, no different than if the volume (level) is changed slightly. Other differences are to do with valve B operating outside of its linear region and the difference heard is excessive 2nd harmonic distortion.

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i have set amps that would change the perception's of some of the opinion proponents but better they continue on their own journey and some of the same mindset followers. i have heard his means of music reproduction and my course is unswayed and true. here ends the reply. insert smilely face.

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i have set amps that would change the perception's of some of the opinion proponents but better they continue on their own journey and some of the same mindset followers. i have heard his means of music reproduction and my course is unswayed and true. here ends the reply. insert smilely face.

 

Which perception are you referring to?

 

The main one in the article is that SET amps act like tone controls. 

 

This can have a wonderfully pleasant effect. Much recorded music sounds much nicer through the shimmery gauze of a classic SET. Especially when combined with the complimentary shimmer of a classic high-efficiency speaker.

 

So the authors of the article aren't questioning the beauty of the music your system produces and which you obviously love.

 

Their point, which I would think is inarguable, is that your beautiful tone control doesn't reproduce (or even attempt to reproduce) the original sound faithfully. Hence it isn't high fidelity. 

 

I like my system to be accurate to a degree, even though I have dipole speakers which add their own enticing signature.

 

You obviously don't.

 

Both are equally valid ways to enjoy music.

Edited by sfdoddsy
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i don't know what SET amplifiers you have been listening to that provide that "shimmery gauze" but it has nothing to do with what i listen too. tone controls are a waste of time and best suited to young spotty boys and elderly cumudegons with leather elbow patchs who think that violin is a tad harsh or the tympany could do with a kick up the backside.

i have always strived for accuracy otherwise my system tells me nothing .

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I'm with Guru/Brian on this one, a really well designed SET amp is off the planet in terms of accuracy and true sound. I did ask a question once on this forum whether valves (given an ideal speaker load) are more accurate than transistors or not in terms of producing a perfect square wave? I think the answer is on the oscilloscope, valves CAN produce an almost perfect square wave, as long as the amplifier s designed with little compromise - end of answer, they are ust as if not more accurate than solid state output devices mosfet or bipolar.

I have owned two of the most accurate and well-implemented amplifying devices I have heard, namely the Supratek Merlot 6C33-CB SET monobloc amplifiers $9K USD and the humble Bakoon SCA-7511 15w/ch solid state amplifier @ $4K, and both are peerless within their topology, and both sounded sublime-ly good imho.

Steve.

Edited by Steve M
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i don't know what SET amplifiers you have been listening to that provide that "shimmery gauze" but it has nothing to do with what i listen too. tone controls are a waste of time and best suited to young spotty boys and elderly cumudegons with leather elbow patchs who think that violin is a tad harsh or the tympany could do with a kick up the backside.

i have always strived for accuracy otherwise my system tells me nothing .

 

A recording may have been EQ'd to death by the time it is distributed.................then there's your room etc.

Tweaking your room via EQ is a very valid thing to do imho.

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  1. Valve amps are high cost, high mass, electroniocally robust, but mechanically fragile.But tubes decay from the day they are 1st turned on.

    Solid-state amps are low cost, low mass, mechanically robust, but electronically fragile.They can stay in spec far far longer than tubes. 

  2. Valve amps naturally tend to maintain constant power into a varying speaker impedance.This is the biggest BS I have ever heard as tube will not double watts with halving impedance.
  3. Solid-state amps can not maintain constant power into a varying speaker impedance.Again the biggest BS I have heard, they do far better job of doubling watts than tubes can.
  4. Shorting the speaker lead has almost no dementral effect on valve amps.That is beacuse they are not direct coupled to the tubes.

    Shorting the speaker lead can easilly destroy some solid-state amps.That is because they are direct coupled to the transistors (best for sound/specs), you could do a MacIntosh and put a transformer on the end then it will be safe to short and sound like a SS Mac (imitation of a tube).

  5. Reactive impedance of cables, speakers and crossovers has minimal effect on valve amps.If they had the HF bandwith of a transistor they would also ring like a bell.

    Reactive impedance of cables, speakers and crossovers can disrupt many solid-state amps.Not if they are desiged right, as many are and considered unconditionally stable even with extended HF

  6. The valve amp output transformer acts as a buffer between amp electronics and the speaker.It also acts like a sponge and without a decent amount feedback around them act very bandwith limited, and damping factor is also limited (not good for bass/specs)  

    Solid-state amp electronics are directly connected to the speaker.The only way to drive a speaker, without caps or transformers in the way. 

  7. Electronic faults within valve amps can not be transfered to the speaker.That's because they are not DC coupled (bad for sound/specs)

    Electronic faults within solid-amps (particularly DC latching) can destroy the speaker.That is because they are dc coupled (good for sound/specs)

 

 

My reply to this write up at the bottom of it..

 

Cheers George

Edited by georgehifi
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I'm with Guru/Brian on this one, a really well designed SET amp is off the planet in terms of accuracy and true sound. I did ask a question once on this forum whether valves (given an ideal speaker load) are more accurate than transistors or not in terms of producing a perfect square wave? I think the answer is on the oscilloscope, valves CAN produce an almost perfect square wave, as long as the amplifier s designed with little compromise - end of answer, they are ust as if not more accurate than solid state output devices mosfet or bipolar.

I have owned two of the most accurate and well-implemented amplifying devices I have heard, namely the Supratek Merlot 6C33-CB SET monobloc amplifiers $9K USD and the humble Bakoon SCA-7511 15w/ch solid state amplifier @ $4K, and both are peerless within their topology, and both sounded sublime-ly good imho.

Steve.

 

Valves, by themselves, are very accurate (low distortion) and have been since the 1930s. Well, triodes are, anyway. Petodes and tetrodes, not so much. In low signal areas, transistors and FETs have had triodes measure since the early 1970s. Prior to that valves were superior. Except for a handful of specialised transistors in the early 1970s (ring emitter devices and some early triple diffused devices from Japan), transistors (BJTs) could not match triodes, though they could easily outperform pentodes and tetrodes. In the late 1970s, we saw the release of some horrible MOSFETs, which took the world by storm, but tarnished the product for a long time. By the late 1990s, we witnessed the release of some utterly superb power transistors, which are marginally more linear than even the best power triodes. Even power MOSFETs have now reached a level where they can come very close to triodes.

 

The big problem with valves has always been the stuff around the valves. Mostly, transformers. Even the very best transfomers shift phase, introduce distortion and increase the cost of the product. Transistor amps do not require transformers, nor coupling capacitors, which is another weakness of most valve amps.

Edited by Zaphod Beeblebrox
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Valve amps are high cost, high mass, electroniocally robust, but mechanically fragile.But tubes decay from the day they are 1st turned on.

Solid-state amps are low cost, low mass, mechanically robust, but electronically fragile.They can stay in spec far far longer than tubes. 

Valve amps naturally tend to maintain constant power into a varying speaker impedance.This is the biggest BS I have ever heard as tube will not double watts with halving impedance.

Not so much, George. Valve amps do TEND to maintain the same power (to a degree), regardless of load impedance. SS amps TEND to maintain the same VOLTAGE output, regardless of load impedance. Hence, SS amps TEND to almost double power output with successive halving of load impedance.

 

Solid-state amps can not maintain constant power into a varying speaker impedance.Again the biggest BS I have heard, they do far better job of doubling watts than tubes can.

They TEND not to supply the same power, regardless of load impedance and nor should they. A *perfect* amplifier is a pure Voltage source. IOW: It will supply the same Voltage output, regardless of load impedance.

 

Shorting the speaker lead has almost no dementral effect on valve amps.That is beacuse they are not direct coupled to the tubes.

The statement is incorrect. Triode amps can be destroyed by short circuits, though destruction may take a lot longer than it does with SS amps.

 

Shorting the speaker lead can easilly destroy some solid-state amps.That is because they are direct coupled to the transistors (best for sound/specs), you could do a MacIntosh and put a transformer on the end then it will be safe to short and sound like a SS Mac (imitation of a tube).

Almost no modern SS amp will be destroyed by a short circuit. Protection systems are well known and almost always employed.

 

Reactive impedance of cables, speakers and crossovers has minimal effect on valve amps.If they had the HF bandwith of a transistor they would also ring like a bell.

It's true that the output transformer and lack of large amounts of global NFB tend to make most valve amps extremely stable. Hence they are preferred by many ESL owners.

 

Reactive impedance of cables, speakers and crossovers can disrupt many solid-state amps.Not if they are desiged right, as many are and considered unconditionally stable even with extended HF

I would be inclined to say that a very small number of SS amps are disrupted by some cables. Naim amps, for instance.

 

The valve amp output transformer acts as a buffer between amp electronics and the speaker.It also acts like a sponge and without a decent amount feedback around them act very bandwith limited, and damping factor is also limited (not good for bass/specs)  

A true statement. The output transformer isolates the output stage from variations and back EMF effects caused by the speaker. Most SS amps use emitter follower configuration, which allows back EMF effects to cause potential problems with output stages. The superior, but more difficult to get right, collector driven loads, acts as an effcient isolation for the output stage and feedback network.

 

Solid-state amp electronics are directly connected to the speaker.The only way to drive a speaker, without caps or transformers in the way. 

 

Electronic faults within valve amps can not be transfered to the speaker.That's because they are not DC coupled (bad for sound/specs)

It's true that the output transformer acts as a protection system for the speakers. However, most SS amps employ a fast acting protection system as well.

 

Electronic faults within solid-amps (particularly DC latching) can destroy the speaker.That is because they are dc coupled (good for sound/specs)

Edited by Zaphod Beeblebrox
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Sorry Zaph, but when someone words it like this, (you read it another way) it looks very much to me like their trying to mislead and say, that tubes can drive and maintain a flatter frequency response (20hz -20khz) into speakers that have varying impedance, which to me is simply BS, many act like fixed tone controls into varying impedances. Well designed solid state does it better and stays flatter in FR.   

 

2: Valve amps naturally tend to maintain constant power into a varying speaker impedance

3: Solid-state amps can not maintain constant power into a varying speaker impedance

 

 

Cheers George

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"Rod Elliott has his own way of describing SET amps.   “I think that SET owners need to have access to serious information that discredits their chosen amp.   I describe the SET amp as an “effects unit†rather than a hi-fi amplifier, since it fails to meet even the most generous definition of hi-fi in all significant respects.   This is a reasonable and accurate description.   Naturally, if people wish to use the “effects unit†that’s entirely up to them, and if they enjoy it, that’s perfectly fine.   What they must *not* do is try to convince me or anyone else that they have a hi-fi setup, because they don’tâ€.
sound.westhost.com / valves "

 

Dumb statement written by low-fi ears.

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By the late 1990s, we witnessed the release of some utterly superb power transistors, which are marginally more linear than even the best power triodes. 

 

Zaph - Can you suggest some part numbers?       Current production ain't important. (Although SITs seem to be rockinghorse poo)

 

(c. late nineties I'd still not found anything with matching linearity _and_ a lower noise floor. Let alone non-signal dependent inter-pin capacitances.  So I'm still stuck somewhere around the point of Mr. Barbour's 1999 IEEE article.  Which is now 15 years ago)

Edited by thoglette
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i have set amps that would change the perception's of some of the opinion proponents but better they continue on their own journey and some of the same mindset followers. i have heard his means of music reproduction and my course is unswayed and true. here ends the reply. insert smilely face.

 

I too have SET amps and love them.  Even when they're not well matched to my speakers (from a load point of view), they still sound very good.  HFs have a delicacy about them and they are very musical.  I haven't used A/B valve amps, so can't really comment on them.  

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Zaph - Can you suggest some part numbers?       Current production ain't important. (Although SITs seem to be rockinghorse poo)

 

(c. late nineties I'd still not found anything with matching linearity _and_ a lower noise floor. Let alone non-signal dependent inter-pin capacitances.  So I'm still stuck somewhere around the point of Mr. Barbour's 1999 IEEE article.  Which is now 15 years ago)

I can't locate any part numbers for old Ring Emitter devices, but the triple diffused devices I am familiar with are part number ED203 and EB203. I may still have a datasheet for the devices somewhere. I'll see what I can find. As for availabilty, I suspect you'll have serious difficulties, as they've been out of production for many years.

Modern devices, OTOH, are MUCH easier to find and VERY, VERY linear. I use these wherever I can:

http://html.alldatasheet.com/html-pdf/30356/TOSHIBA/2SC5200/497/2/2SC5200.html

And:

http://html.alldatasheet.com/html-pdf/30038/TOSHIBA/2SA1943/497/2/2SA1943.html

Check out the linearity (hFE - IC) of these devices. Absolutely astonishing. From 10mA to around 5 Amps. An almost perfect horizontal line.

One word of warning: Watch out for counterfeits! I've never been caught with these devices (though I do source from an acredited Toshiba supplier), but I have been caught by other devices recently.

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  • 2 weeks later...

The article can't change the enjoyment that SET amps bring those that like them. Saying you can't call them HIFi may also be a compliment to some. The biggest insult one Killerdac advocate I know can dish out is that the system sounds like "hifi". I guess no one can have everything. That is to say something that measures with perfect linearity like Hifi gear but sounds as if it does not.

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