SET and pushpull (newbie questions)

[NOSValves]

Mark,

As always reading your explanations is so free flowing and easy for even a laymen to understand. Man would I like to do a Vulcan mind melt with you !! It sure is great your posting again !!

Craig

[rigma]

mdeneen,

Or anyone who would share their opinion on this subject.

If I wanted to spend $1,500 max for a pair of DIY or Kit Mono Blocks to power my Klipschhorns what would you recommend I consider. I listen to Jazz, Blues, Country And classic rock at up to about a 95db level. Currently I have the system Tri-Amped using all Crown amps, With Mac SS AV Preamp and at least for now would like to keep the woofer powered that way, the bass sounds great! I feel the Mid is too bright and harsh. I also have AL's crossover I can use and may want to just Bi-Amp them. I have very good soldering, woodworking and metal working skills but not electronic expertise, although I can read most schematics.

[Colin]

Despite your misgivings, few loudspeakers are capable of pulling the delicacy and details out of flea-powered 2A3 amplifiers like the Welbourne, Wright Sound or Bottlehead Paramours as Klipschs fantastically sensitive corner horns.

[artto]

What model Crown amps are u using & on what drivers?

[rigma]

Crown DC-300A Series II in Mono on woofer, DC-150A Series II in mono on Squawker, DC-75 in mono on tweeter.

[dbflash]

Mark,

Can you please explain "Tube watts are not SS watts".

Is a watt not a watt?

Is a dB not a dB?

Anyone else that wants to explain this please jump in. I would like to put this to bed once and for all.

I know that I am using 3.5W tube amps with my Cornwalls and everyone wants to know where I'm hiding the 1,000W amp.

Thanks,

Danny

[mace]

While I can't add much to this thread... I'd like to thank the guy who posted it since I've been itching to ask the exact same thing... this after being around here for close to 2 years (not 2 weeks). I've picked up some stuff on tubes (obviously) but still don't fully understand the technical differences (or at least can never remember them). With this thread a lot of good info is together instead of scattered about the forum.

So next quesion... where can I get an Eico HF-80?

Mace

[dbflash]

Mark,

Thanks.

That's what I thought.

A watt is a watt.

You also explained what happens to that watt.

Danny

Mace any reason for this? I am using a pair of Wright's with my Cornwalls and just love this combo.

[WMcD]

Whoo boy, this is why I'm not an amp guy.

It seems to me that we're mostly talking about the "final" amplifier in the chain. The one just before the speaker and the "final" amplifier which creates power into the load of the speaker. Most everything in the chain before is operating class A and there is not, here, much discussion of tubes versus discrete s.s., versus op amps. Pause for the land slide, in that area. As Fleetwood Mac says, "I don't wanna know."

Fairly stated, the amplifier can be based on thermionic valves (tubes) or transistors of various constructions (JBT or FET). They all function as "valves" to some extent with their own non linearities. The geometry of the associated circuits make them work with some faithfulness to the input signal.

As I've pointed out before, the amplifer doesn't amplify. It just connects the power supply to the speaker in accord to the input music signal. Of course there is some issue about how the valve may be adversly affected by the load. Getting far afield.

An important issue, for us, is how good is a given amp at the listening level where our Klipsch speakers are operating. That is typically below 10 watts.

In my view, it is missing the point to talk about any valve device (tube or ss), or topology of the circuit (feed back, push pull, etc.). As you might know, the "topology" refers,in an electical engineering sense, to the map of circuit. It generally describes whether there is feedback, feed forward, push pull, biasing, etc.

Rather, the focus should be actual performance at the power level where an amp is operating into our speakers at normal listening levels. Those paramaters are not published. So there is folklore, sometimes accurate, that this or that amp sounds good. However, I believe the good performance can't be accurately predicted by the use of a given device, or a given topology without attention to measured response at the 1 watt level.

I hope, some day to make a measured survey.

Gil (edited once.)

[Super_BQ]

The reason why tube watts seem to be louder than SS watts is due to the nature of the gain device (the valves vs. transistors).

In transistors, the nasty distortion produced is termed 1st order which is most undesirable and highly detectable with the human ear. As mentioned before, the analog waveform is litterally clipped when the transistor is overdriven.

In tubes, the type of distortion produced is mainly odd order harmonic distortion. The characteristic of this type of distortion follows a natural state and is not considered undesirable at levels way beyond what is acceptable with SS distortion. So when a tube is overdriven, the analog waveform is somewhat "squashed" rather than outright clipped. The user can drive the tube into distortion levels without noticing a negative affect on the sound quality. In fact, the user may LIKE this type of "smoothness/roughness?" sound in which they are hearing.

A better analogy would the sound of a guitar tube amp. Where did this electric distortion sound come from on all those guitar rigs? In all mainstream music we hear the distortion sound from the guitars - yet, when we play that song back on our speakers, how come that sound is not perceived as being annoying?

Another important note is speakers DO NOT like clipped distorted signals from the amp. Tweeters can easily be fried without the user noticing any large amount of distortion (what you may perceived as a clean sound may not be in the case for the drivers).

BQ