[Ultralight]

Apologies for a more newbie type question.

Some speakers, such as single full range driver can be spectacular for a particular type of music such as vocal, jazz and small ensembles.  They are less suited for large scale orchestral performances at realistic volumes.

Curious - with SET amp, assuming that power is not an issue/limitation, is there a similar type of limitation as to the type of music they are more suited for?  Or is like any tube amps where they are appropriate for any type of music as long as the speakers are sufficiently efficient.

Again, I realize that for you old timers, this question may be laughably obvious but appreciate your indulgence...

Thanks in advance for any comments.

Thanks!
UL

[2wo]

"Curious - with SET amp, assuming that power is not an issue/limitation, is there a similar type of limitation as to the type of music they are more suited for?  Or is like any tube amps where they are appropriate for any type of music as long as the speakers are sufficiently efficient."

Well if power was not an issue that the answer is no. Most SET amp, with a few notable exceptions run about 8 watts or less. If you have a good set of speakers designed to work well with your amp. you may be good to go. With something like a pair of Klipchhorns and a 3 watt amp you can probably cause brain damage...John     

[Ultralight]

LOL.  Thanks.

Yes, I'll like to avoid that.  The brain damage part...

UL

"Curious - with SET amp, assuming that power is not an issue/limitation, is there a similar type of limitation as to the type of music they are more suited for?  Or is like any tube amps where they are appropriate for any type of music as long as the speakers are sufficiently efficient."

Well if power was not an issue that the answer is no. Most SET amp, with a few notable exceptions run about 8 watts or less. If you have a good set of speakers designed to work well with your amp. you may be good to go. With something like a pair of Klipchhorns and a 3 watt amp you can probably cause brain damage...John     

[JoshK]

I like progressive rock/metal and large scale orchestral and I like SET amps.  It comes down to volume you listen to and how efficient are your speakers.   I don't consider any Full Range speakers to really be that, and usually their efficiency is grossly overstated.

I think large high efficiency horn speakers are really the ticket with SET amp if you want to really hear what they are capable of.  The Klipschorns mentioned above are one such example. 

Speaker matching with SET amps is more critical than with typical SS amps. 

[FullRangeMan]

Imo all kinds al of music run good with a SET, heavy rock is just a electric signal.
If plenty of bass just lower a bit the volume.

[Mags]

Depends on the SET. My 200WPC SETs have no problem driving inefficient Infinity RSIIb speakers to extremely loud volumes, cleanly.

[rockadanny]

   holy crap batman!

[Mags]

A few highlights:

833C output tube, monoblock design
Plate voltage 2.3kV
Plate current 160mA
Two stage, direct-coupled design - no coupling caps
6E5P driver tube
Separate power supplies for driver stage, output stage, and filaments
All supplies LCLC with Schottky rectifiers
Zero negative feedback, global or local
Noise floor at no signal 300uV

Here's a shot underneath:

[FullRangeMan]

Depends on the SET. My 200WPC SETs have no problem driving inefficient Infinity RSIIb speakers to extremely loud volumes, cleanly.

Impressive amp. The 833 have a 100W heating cathode(10VX10A).
Why do you put the 833 closed inside the glass pipe??

[Mags]

Impressive amp. The 833 have a 100W heating cathode(10VX10A).
Why do you put the 833 closed inside the glass pipe??

Safety. The plate voltage is 2.3kV. The outside surface of the 833C reaches several hundred degrees C. The pyrex cylinder helps to keep drunken party guests safe!

Also, the cylinder helps to channel the cooling air around the tube envelope to keep the heat from melting the pin seals. There is a low noise Noctua fan underneath the 833C - it draws warm air from the chassis and circulates it up around the tube, thus cooling the internals of the chassis and the tube at the same time.

If you want to see it without the pyrex cylinder, here's a picture from when I first fired it up on the bench:

[FullRangeMan]

Thanks Bro for the complete explanation.

[JoshK]

Plate voltage 2.3kV
Plate current 160mA    Is no joke! 

Did you stack supplies? 

[Mags]

No. No stacked supplies. Each supply is separate and referenced to ground.

[rockadanny]

Safety. The plate voltage is 2.3kV

Oh man! Take the cover off so can do double duty: audio + bug zapper! 

[JoshK]

No. No stacked supplies. Each supply is separate and referenced to ground.

How stable are the Op.pts?  That is quite the feat btw, mucho respect.  Did you triode strap the 6E5P?  That is quite the driver.

[Mags]

6E5P is triode strapped - great sounding tube! The amp is very stable; once warmed up the bias current is rock steady. I put a meter on the front of the unit just so I could keep an eye on it, and it doesn't move once warmed up.

Filament voltage/current, 6E5P plate voltage, and bias voltages are all regulated, the 833C plate voltage is not regulated. I get around that by regulating the AC going to the amps using a PS Audio P5 (one per amp), so line voltage fluctuations don't impact performance. 

[EdRo]

WOW. That's a great looking chunk of equipment!!! 

[roscoeiii]

With SET amps, you have three factors to consider:

1) Speaker matching due to their low output. As you can see from the examples given above, there are certainly speakers out there of high sensitivity that can be driven to quite loud levels with a SET amp. Klipsch being perhaps the best known. Less efficient speakers are not going to be able to provide dynamics or sufficient bass, and will likely sound poorer in general due to the limited power capabilities of SETs.

2) General considerations related to tube amps. For the most part, the tube magic lies in the midrange. And generally, the choice of a tube amp means sacrificing things in the treble or bass. Both may be a bit rolled off, and in the bass you are likely to have less tight control over a woofer compared to a solid-state amp. This is a tradeoff between tubes and solid state that will depend on listener preferences, and I'd say that very bass heavy music might not be a great match for tubes. That said, as you go into more pricey tube amps, the quality of the construction and parts (Transformers mainly, I believe) will help alleviate these normal limitations of tube amps. And you also read about certain tube amp companies whose bass excels relative to what folks have come to expect from a tube amp (Rogue comes to mind as one of these).

3) Modern vs classic sound. Older tube designs, and older tubes, often have more of a euphonic "tubey" sound, that many folks like. At the expense of some detail, speed and frequency extension. And current designers will also try to replicate this sound that can be referred to as "tube magic". But there are also tube amps with a much more modern sound, with detail and frequency extension approaching what you hear in a solid-state design. You still hear some of the tube magic, but a bit less of it. So less tube coloration of the sound, for better or worse. Depending on taste.

[bonsai]

Nice thread hijacking to show off your amp...  Again..  Nice amp by the way

[Mags]

Nice thread hijacking to show off your amp...  Again..  Nice amp by the way

Just trying to dispel the notion that SETs can only work with efficient speakers. If they can drive the RSIIbs well they can handle most anything!

...maybe a wee bit of showing off, too...sorry.