Tube amp confusion (PLEASE NO FLAME WARS)

[Audio Flynn]

Sorry to bother you guys again but I have a dilemma.

I went to check out the tube amp I was thinking of purchasing today (Shanling stp-80 tube integrated 35 watts ps). I thought it looked and sounded awesome with the Shanling t-80 tube cd player. Sorry I forgot to mention I will be using my Heresy 11's for this 2channel system.

+++++++++++++++++++++++++++++++++++++++++

I would spend less than half the money on a rebuilt Scott integrated that would most likley have a much better phono section than a Shandling.

And better transformers.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5734639185&ssPageName=STRK:MEWA:IT

[mike stehr]

----------------

On 11/28/2004 11:39:10 PM paulparrot wrote:

Delano,

"Here's the thing. A low-watt amp limits you to listening at an unrealistically low volume IF you want to listen to a wide range of recordings without clipping."

*That depends on the size of the room, and if it's a large room, ya sure.....but a smaller room the issue may not that big of a deal.

"Or to just some really crappy female vocalist lounge acts at a natural volume. Some people are not bothered by this clipping, which sounds kind of mushy when it's pushed."

*I'm pretty sure you don't listen to your amps at clipping, why would a low-watt SET user clip the amp that he would use?

If the amps pinching up, turn it down, or look for a higher powered amp.

"What happens, when you're rolling along fine with a recording and there's a big peak, is that the low-watt amp can't handle it, and this peak that you should be hearing--just for an example--maybe 9dB louder than the rest, will be rendered at only 3dB louder, with the other 6dB of what should have been there being smashed flat like you ran the signal through a compressor-limiter."

*If one has a good critically damped PS that can not only maintain constant current, but also keep up with the constant changing current loads, then your point above doesn't really hold water.

If you want all that headroom, then that single-ended stuff ain't gonna do it.

Again,

If the amps pinching up, turn it down, or look for a higher powered amp.

Since you're new to tubes, probably a lot of things are going to sound good to you initially.

*How do you know? What if he just hates the sound of tubes from the start?

"The question to ponder is "Why limit yourself with a low-watt amp?"

Hell, why limit yourself with a tube amp? heh

[edwinr]

The Shanling STP-80 has just been released here in Australia. It looks tempting with it's 35 plus watts per channel. Build quality looks okay, but not outstanding. I haven't heard it with any decent horn speakers so I can't comment on the sound quality.

The Song Audio line level integrated is unfamiliar to me. It obviously has less power, but if matched with a suitably sensitive speaker, and all things being equal, should give you good sound. I prefer to support a local manufacturer rather than one based overseas. What's the build quality like?

The Heresys should be okay with 4 odd watts per channel for lower listening levels and smaller rooms. The La Scala would be a way better choice.

[maxg]

Delano,

Seems simple enough to me. Forget the topology for a moment and consider this:

You heard it.

You loved it.

You reckon you could spend hours listening to it without getting tired.

So the only question is, do you want to spend $2000 to get it?

Minor questions could be:

Are there other options out there? Yes.

Do you really want to spend the next 6 months hunting to find something else that does it for you?

Would it really matter if there was something else that did the same thing for $100 less if it took you 5 months to find it?

Life is too short. Get the amp. Spend the time finding music to play through it. If at some point in the far future you want to play things that this amp wont handle - deal with that then. Right now, from the description of your musical tastes and listening habits - this one fits you like a glove.

[Coytee]

is there any specific benefit to having two mono amps, rather than one 2 channel amp?

What got me thinking this was the two (above referrenced) Mac amps on EBAY, the MC30's. As I looked at them, I just noticed double the tubes, double the power cords, double the maintainence, double the transformers... then imagined them in my system and one side playing louder/softer relative to the other side (something out of balance?)

Ultimately just wondered what the inherent benefits of single amps are, over a 2 channel (if any) Seems to me that a 30 watt 2 channel should do the same damage as two single 30's??

??

[Deang]

You don't have twice as many tubes. The main difference is a dedicated power supply for each channel. Of course, this can be done with one chassis, and be built into dual mono -- there's plenty of those around. As far as the balance issue goes, the same potential problems exist for tube stereo amps as mono amps.

[Coytee]

----------------

On 12/1/2004 9:47:47 AM DeanG wrote:

You don't have twice as many tubes. The main difference is a dedicated power supply for each channel. Of course, this can be done with one chassis, and be built into dual mono -- there's plenty of those around. As far as the balance issue goes, the same potential problems exist for tube stereo amps as mono amps.

----------------

So, is that a different way of saying that it makes "ZERO" difference if one get's a single stereo tube amp, verses two mono's??

I hope that's what you mean

[leok]

The reason two power supplies can be considered preferable is with a single supply, sound from the each channel modulates the supply a little bit (or a lot if the amp is poorly designed) which in turn, modulates the other channel. This crosstalk, or cross modulation adds, in a general sense to "distortion" and can have a substantially negative effect on imaging because of audio "leaking" between the channels. With two mono amps: no leakage at all.

Is it a big deal? Some people notice. Some people don't. Many people, even if they do notice, don't think it's worth the trouble of maintaining 2 amps.

Leo

[Colin]

Paul,

With fantastically sensitive 100dB/w/m big ole horns, things begin to get a little ridiculous compared to the typical solid-state receiver and 85dB/w/m cone loudspeaker set-up. For one thing, the loudspeaker needs only a hundredth of a watt to reproduce a steady tone at conversation levels of 75dB, as measured two (2) meters away. Peaks on CDs are actually only about 12-15 dB above normal levels, requiring only a third of a watt. Therefore, a flea-powered 3-watt tube amplifier will reproduce the musical highs at 90dB with about a third of a watt, while the 25-watt amplifier could produce an ear-splitting 110dB before clipping.

If it wasnt for the low impedances of the woofers, a good low-powered solid-state or tube amplifier is all the power anyone needs with fantastically sensitive big ole horns.

[Parrot]

----------------

On 12/1/2004 10:33:57 AM Colin wrote:

If it wasnt for the low impedances of the woofers, a good low-powered solid-state or tube amplifier is all the power anyone needs with fantastically sensitive big ole horns.

----------------

But, we *do* have those pesky woofers to consider!

The playback of music is a demanding thing, a heckuva lot tougher than computing the theoretical power needs and assuming 100% efficiency in everything, and confirming by measuring some test tone. In the real world, low power doesn't cut it.

If every extra watt cost $1000, it might be important to get by with as few as possible. But since there is no sonic advantage whatsoever to a low-power amp, why restrict yourself to a life of compression.

[maxg]

"But since there is no sonic advantage whatsoever to a low-power amp,"

Tsk tsk tsk. Naughty naughty. Throw in an IMHO around there somewhere and it passes.

And just to be different - i.e. not use SET as an argument:

Avantegard would disagree with you. Their SS amp that they produce specifically for their speakers is rated at 1.5 Watts class A. There is an article on line somewhere where the designer explains exactly why he wanted a low power amp.

AND I CANT FIND THE BLOODY THING - WHY OH WHY DO I NEVER SAVE THESE THINGS IN MY FAVORITES LIST???

If I find it I will post a link. Everyone I know who has heard it has nothing but praise for it. Of course - it does pack some headroom on top of that - to keep you happy no doubt. I think it goes upto something like 35 watts in A/b mode. God only knows how he did that!

[Parrot]

Max,

A bunch of IMHOs clutter things up too much. Any reasonably intelligent person can tell when someone is expressing an opinion and when someone is expressing a fact. The fact is, I've never heard a low-watt amp that can do anything better than a quality higher-powered amp, but a low-watt amp, factually, cannot do a lot of things that a higher-powered one can.

I wouldn't call the amp you mention a 1.5W amp, I'd call it a 35 Watt amp.

[maxg]

Found it:

http://www.6moons.com/audioreviews/avantgarde2/model5.html

I was wrong - it is 0.4 watts class A - or 1.1 into a high ohm load or something.

[Deang]

"I think it goes up to something like 35 watts in A/b mode. God only knows how he did that!"

LOL - simple, you make a 35 wpc amp and call it a 1.5 watt amp.

I'm with Paul on this one all the way.

[leok]

Max,

Thanks for the link. Interesting. This amp is not quite the same as a 20 or 30 Watt ss amp that operates at class-A for the first .5W in that it appears to be optimized for the 0.5W region. It is more like a 20W - 30W tube amp in that regard. I suspect it sounds pretty good. I would like one that does 1W class A into 4 Ohms. I don't have 104dB Avant Gardes, I have 101dB Chorus and RF-7.

Leo

[NOSValves]

----------------

On 12/1/2004 11:05:16 AM maxg wrote:

"But since there is no sonic advantage whatsoever to a low-power amp,"

Tsk tsk tsk. Naughty naughty. Throw in an IMHO around there somewhere and it passes.

And just to be different - i.e. not use SET as an argument:

Avantegard would disagree with you. Their SS amp that they produce specifically for their speakers is rated at 1.5 Watts class A. There is an article on line somewhere where the designer explains exactly why he wanted a low power amp.

AND I CANT FIND THE BLOODY THING - WHY OH WHY DO I NEVER SAVE THESE THINGS IN MY FAVORITES LIST???

If I find it I will post a link. Everyone I know who has heard it has nothing but praise for it. Of course - it does pack some headroom on top of that - to keep you happy no doubt. I think it goes upto something like 35 watts in A/b mode. God only knows how he did that!

----------------

1.5 watts of class A and 35 watts in AB ................ Hate to say it but that is nothing new, special or bragging rights worthy. This is achieved by about every reasonable quality Push Pull tube amp on earth.

Craig

[leok]

Not quite Craig. The amp in question probably has lower output impedance than a tube amp and lower feedback noise than many. It looks like a good combination of the best attributes of ss and tube designs for efficient speakers: Lowest distortion at low powers like tube amps, low overall distortion at higher powers, and low impedance at all powers. I think it would be worth a listen. I'm not totally satisfied with what I get from tube amps, it's just the best I can find, or build. Actually my pwm amp has a bit more punch and more neutral sound. It's just not quite as clean.

Leo

[Hardhead]

First of all, a little self-confidence is in order (no offense).

The only right way to decide this is to DECIDE FOR YOURSELF and don't listen to anyone else. If you listen to others, you'll buy what they like and not what you like. That's like marring a woman because someone else is in love with her. You like the SET, but the concern is whether it is powerful enough. OK, then, go back to both places and audition the amps again, but this time bring the music you listen to, especially full orchestral numbers. Go back as many times as they'll let you, so you can get used to the differences in sound. Don't be shy about turning the volume up, especially on the loud, complex orchestral pieces. Take your speakers, even, or, better yet, borrow the amps and take them home for an audition if you can. Your decision will be easy after that--and it will be the correct one.

[NOSValves]

Leo,

I wasn't trying to say anything negative or positive one way or the other about the amp in question. I was just making it clear the a 1/2 watt of class A and 35 watts of A/B isn't anything special. No big deal one way or the other.

Craig

[leok]

I think it might be a big deal, in the same way pwm amps are. Traditional ss amps had some problems that prevented their promise of clean, low distortion power from being a reality for all but a few designs, if any. The fact that so many people listening to Klipsch speakers use tube amps is clear demonstration that ss has a few problems, especially at low power. If ss designs are developed that address the fundamental ss issues, then there may be real, cheaper, more convenient, alternatives, like pwm, to tube amps with competative sound. I think that is a big deal.

Leo