[dado5]

Now I'm really confused!       

It does make sense to me, those 25 watters of my dads go very very loud... Why wouldn't 8 watts be enough for my small room?   I tried his amps in my setup once and did not go past the 9 "o-clock 

I don't want to ignore your comments, as I've never tried a SET in my setup... and surely you people must no more about it.

25 watts will only give around 4dB more volume than 8.  This is a perceptible but small difference.

If you found 9 o’clock loud with 25 watts, it is very likely 8 would be plenty (9 o’clock on most volume controls is a signal reduction of more than 10 times).  Amplifier sensitivity plays a role here but since it was a 300B circuit and you are looking at SE 300Bs I would say you have no worries.

Push-Pull will give you more power, but again probably not much more actual volume.  Moving to full or partial pentode outputs would up the volume output more noticeably but then you are in a different sonic realm from SETs entirely so you would be defeating the purpose.  If you are looking at 300B, the tube replacement cost of a push pull design is something to think about as well.

[Bob Reynolds]

What I meant was, SET- speaker cable- Subwoofer- speaker cable- speakers...

I really like my speakers, and they are just new ( Went from floorstanders to Bookshelfs)  I bought them thinking the effiency would be enough for a Tube amp....      Would a higher powered (kt88) work better?

Don't worry about giving the wrong advice... Just want to have some opinions from experienced people  

I'm pretty sure that the cabling you indicate will not take the bass load off the SET or the monitors. I see nothing wrong with using an active crossover between the preamp and amp to move the bass load to the sub. If you do that, then just about any flea powered SET will work fine in your smallish room depending on your listening distance.

[duggie]

if you are wanting robust power w/an set amp, try the 6c33c tube.  (not that i think anything is wrong w/push-pull.)  these amps, 45wpc, worked fine on 86db-efficient speakers in a ~16x24 room.  but, i confess they were crossed over at ~80hz to subs.  they alse did well driving ribbons of rm40s,  only from 280hz on up, but still known to be a demanding load.  at $1800/pair brand-spanking-new, i think these amps are hard to beat.


http://www.audiomirror.com/
http://cls.audiogon.com/cgi-bin/cls.pl?ampstube&1167344305

[miklorsmith]

In an outboard XO configuration, you'd take the line-level output to an outboard XO (Behringer?) with one output from the XO to the SET and the other to the sub.  If you set the XO frequency high enough, this could work.  Blending the mains and sub could be an issue, as you may need to go 100 hz or higher with a tiny amp.  Also, it sounded like running line-level wasn't an option.

If you absolutely have to buy something to try this out, find a good deal used or get something with a 30-day return policy.  Beware the unknown brands that seem like a *smokin'* deal.  Even at the *reduced* price, you'd lose your shirt reselling.

[robert1325]

Hi miklorsmith,

Thanks for your sugestion, but I'd rather go for something simple...  right now a 845 tube based SET looks quite interesting ( more than enough power I think)

Or I might go cheap and get a good el34 amp,  probably doesn't have the bass power...    I don't really need that much low-end   as long as it's fast and not flabby.   

[jon_010101]

Thanks for your sugestion, but I'd rather go for something simple...  right now a 845 tube based SET looks quite interesting ( more than enough power I think)

Or I might go cheap and get a good el34 amp,  probably doesn't have the bass power...    I don't really need that much low-end   as long as it's fast and not flabby.   

You know... I don't want to stir things up, but I'd go for a 211 over an 845.  Simply because it is easier to drive, and affordable 211 amps should sound better than affordable 845 amps.  Realistically, it takes a serious tube, like a 300B or a 6L6/EL34/etc. for example, to properly drive a high-power 845 (like in the $$$ Cary 805).  A 211 can be driven by a 5687 / ECC99 / 6SN7 fairly effectively.  Both are huge evil-looking tubes. 

Another thought is something like the parallel-SET KT88 amp from Hyperion.  Looks like a beauty!

Or the nifty SET 6C33C integrated amp from Almarro, the 318A / 318B.  Around $1k used.

[Dmason]

If I were going to try SET amplification on, I would head straight for something like the Sun Audio 2A3 or similar REAL SET, the direct heated tubes, and forget these obscure brands, (not meaning Cary or Almarro,) with mysterious and hidden iron inside, who knows whether the whole thing isnt on a Chinese circuit board type of amp. Forget "SET" done with pentodes, and these big beam tetrodes.... What no one talks about is the fact that those big Russian 6C33C transmitter tubes burn up fast. No one talks much about that. They just put them up on Audiogon. They'll light up your life in more ways than you care to imagine.

 You ~apparently~ want something that will light up the music with pure unadulterated magic. A tube single ended triode amp is only as good as the iron in it, so to do it "right," find a real DHT SET amp with very, VERY good iron. Get off to a flaming start, pardon the pun,  a flamingly enjoyable start that is, because all these other solutions are taking your existing speakers for granted, which are NOT very suitable for an SET amp, and suggesting a 211 amplifier is, I believe, lacking in sensitivity for the poster's reasonable wishes. If I were running with your speakers, I would be looking at a 250 watt solid state amp, not a 3 watt triode amp, regardless of listening levels, or room size. We are talking about Dynaudio drivers, afterall, full stop. They want MORE current, not less, so forget it. So, start your SET quest by looking at more compatible speakers. It will be worth the effort.

The magic of SET, if that is what you are after, is in the simplicity of the circuit. Once you start changing the rules, from single ended to push pull etc,  for what you gain in "PRAT," or "speaker control," you move further and further away from your stated goal, "I want to try SET." Done right, you move to relieve the SET amp of any and all bass duty, and therefore things like damping factors are a moot point entirely, as they should be, in this little realm. With reasonably efficient drivers, -those above 94db, a 3 watt amp shelved >@100Hz can become a monster, with a strong source signal. Both the amplifier and the speaker driver will reward you with SET magic, and emotion, and abundant dynamics, in spades. It does me, daily. ...Otherwise, you will not hear the magic in its correct context. Besides, bass is cheap these days, and available at Costco, if need be, as far as I am concerned, which makes the whole SET thang pretty durn accessible. I hope Gizmo is reading this from ...elsewhere...

[toobluvr]

Thank you,  this makes it a lot easier for me to chose an amp,    Those 845 tube are monsters!

Is SET really that much better than Push-pull triode?    The 845 tube seems a very interesting choice.

I owned these exact amps:

http://www.10audio.com/asl_1006-845dt.htm

I think the reviewer nailed it perfectly, and I concur 100% with his impressions.

Another review:

http://www.avguide.com/products/product-363/

The ASL Cadenza DT is almost 3x the power and reported to be even better.  Since I enjoyed the 1006, if I had the cash and a simpatico speaker, I would give the Cadenza serious consideration....but only at used prices.   

http://www.divertech.com/aslcadenzadt.htm

Plenty of other highly regarded 845 amps out there, including:  Consonance, Cary, Art Audio, DeHavilland, Unison, Audion, Viva, among others.

[duggie]

re: the audio mirror amps, i have had mine for a coupla years, now, & while not in service continuously (i have a few amps), they have been pretty reliable.  they are also made in the usa by a bulgarian emigre.  re: the tubes burning up regularly, well, you could push them & get 60wpc out of my amps, then yes, they would fry quickly.  and, these tubes are cheap, <$15 a pop...

i would also recommend the almarro 318b; i have never heard it, but i own an a205a mkll, w/upgraded caps, & it is fantastic.  i can only imagine an amp by almarro w/the 6c33c tube would also be excellent.

and, if i were wanting a new set amp w/a big tube, china is likely the 1st place i would look.  here's a small sampling:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270056714320


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130047014188


i owned (and sold) an amp like this; its sound quality is excellent at any price, completely amazing at prices like like this particular example:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300049678549


chinese amps are the real deal.

ymmv...

[Dmason]

Actually, those little 6BM8 jobbies are pretty cool. Have you or anyone heard one? I would imagine they all are identical to the Baby Amp, which is supposed to sound VERY sweet, for what it is, and very low s/n ratio.

The Music Angel stuff seems to be pretty well thought of.

I know times are changin' fast with respect to the Chinois offerings, but there are some horror stories. Get Bill Baker to talk to that topic.

[robert1325]

I was actually thinking of going Chinese ,  I got my current solid state amp from www.ornec.com

The yarland amps are suposed to be really good for the price... 

[duggie]

the mengyue mini is an el84 (6bq5) amp, not a 6bm8.  they make this amp w/6aq5 & el34 as well.  the sophia baby is this amp w/the el34. as i said before; i owned the el84 amp - it is an excellent amp at any price, imo, as long as you need only 15wpc.  a bud of mine in upstate ny bought the 10wpc 6aq5 iteration, & he said it's as good as his modded dyna st70, as long as he doesn't over-drive his speakers w/it.  when he 1st got it, he blew up something cuz he thought it was a 6bq5, not a 6aq5 & he swapped out the wrong tubes into it. the tech he took it to for repair said it was as nice sounding as anything he'd seen/heard for $2k.  not sure about that, but it gives you an idea...

yes, you can get burned - w/any gear, not just chinese...

Actually, those little 6BM8 jobbies are pretty cool. Have you or anyone heard one? I would imagine they all are identical to the Baby Amp, which is supposed to sound VERY sweet, for what it is, and very low s/n ratio.

The Music Angel stuff seems to be pretty well thought of.

I know times are changin' fast with respect to the Chinois offerings, but there are some horror stories. Get Bill Baker to talk to that topic.

[duggie]

I was actually thinking of going Chinese ,  I got my current solid state amp from www.ornec.com

The yarland amps are suposed to be really good for the price... 

the yarland/sophia baby/mengyue/aria amps are all the same.  get which ever you find the best deal on...

[Scott F.]

If I were going to try SET amplification on, I would head straight for something like the Sun Audio 2A3 or similar REAL SET, the direct heated tubes, and forget these obscure brands, (not meaning Cary or Almarro,) with mysterious and hidden iron inside, who knows whether the whole thing isnt on a Chinese circuit board type of amp. Forget "SET" done with pentodes, and these big beam tetrodes.... What no one talks about is the fact that those big Russian 6C33C transmitter tubes burn up fast. No one talks much about that. They just put them up on Audiogon. They'll light up your life in more ways than you care to imagine.

 You ~apparently~ want something that will light up the music with pure unadulterated magic. A tube single ended triode amp is only as good as the iron in it, so to do it "right," find a real DHT SET amp with very, VERY good iron. Get off to a flaming start, pardon the pun,  a flamingly enjoyable start that is, because all these other solutions are taking your existing speakers for granted, which are NOT very suitable for an SET amp, and suggesting a 211 amplifier is, I believe, lacking in sensitivity for the poster's reasonable wishes. If I were running with your speakers, I would be looking at a 250 watt solid state amp, not a 3 watt triode amp, regardless of listening levels, or room size. We are talking about Dynaudio drivers, afterall, full stop. They want MORE current, not less, so forget it. So, start your SET quest by looking at more compatible speakers. It will be worth the effort.

The magic of SET, if that is what you are after, is in the simplicity of the circuit. Once you start changing the rules, from single ended to push pull etc,  for what you gain in "PRAT," or "speaker control," you move further and further away from your stated goal, "I want to try SET." Done right, you move to relieve the SET amp of any and all bass duty, and therefore things like damping factors are a moot point entirely, as they should be, in this little realm. With reasonably efficient drivers, -those above 94db, a 3 watt amp shelved >@100Hz can become a monster, with a strong source signal. Both the amplifier and the speaker driver will reward you with SET magic, and emotion, and abundant dynamics, in spades. It does me, daily. ...Otherwise, you will not hear the magic in its correct context. Besides, bass is cheap these days, and available at Costco, if need be, as far as I am concerned, which makes the whole SET thang pretty durn accessible. I hope Gizmo is reading this from ...elsewhere...

Dmason hit the nail on the head. I couldn't have said it better myself

Honest to goodness, don't waste your time or money trying to power Dyns with an SET regardless of wattage. Its akin to trying to drive a Peterbuilt with a Volkswagon engine. The *only* way it might sound OK is if you use something like the ZeroFormer in front of the speakers.

SET's just don't produce enough current to handle the difficult impedance loads that many box speakers present.

[robert1325]

      This is a great thread for me ,  very informative and fun to  read about your opinions concerning SET amps...     I think I understand you about not going for SET with these speakers,   the true potential of SET's will be wasted on them.     

Is this the case with higher powered ( read 20 watts) SETs  to?           Or should I just go for push-pull or stayaway from tubes all together.   ( Just not ready to let go of my current speakers)

[duggie]

    This is a great thread for me ,  very informative and fun to  read about your opinions concerning SET amps...     I think I understand you about not going for SET with these speakers,   the true potential of SET's will be wasted on them.     

Is this the case with higher powered ( read 20 watts) SETs  to?           Or should I just go for push-pull or stayaway from tubes all together.   ( Just not ready to let go of my current speakers)

i *have* to use tube amps.   aa  once i tried 'em, i couldn't go back to s/s.  i honestly don't know if the (relatively) high power set amps - (20-45wpc) would work well w/your speakers.  i suspect in a 10x10 room, they'd be fine.  but i would query the mfr's.  not sure what kinda response you would get from chinese-speaking ebay vendors, but vlad bezelkov of audio mirror is usually good at getting back to you...

[toobluvr]

    This is a great thread for me ,  very informative and fun to  read about your opinions concerning SET amps...     I think I understand you about not going for SET with these speakers,   the true potential of SET's will be wasted on them.     

Is this the case with higher powered ( read 20 watts) SETs  to?           Or should I just go for push-pull or stayaway from tubes all together.   ( Just not ready to let go of my current speakers)

OK class, let's sum up what we have learned today:

(1)  If you want the true magic and potential that SET can offer, ya gotta use the "right" speaker.

(2)  If your current speaker is determined not to be SET simpatico, and you are married to it, then ya gotta look elsewhere for amps.

(3)  If you insist on SET, then you probably need to change your speakers.

 

I'll leave it to those more knowlegable than me to determine if your speaker mates properly with SET.

[Scott F.]

    This is a great thread for me ,  very informative and fun to  read about your opinions concerning SET amps...     I think I understand you about not going for SET with these speakers,   the true potential of SET's will be wasted on them.     

Is this the case with higher powered ( read 20 watts) SETs  to?           Or should I just go for push-pull or stayaway from tubes all together.   ( Just not ready to let go of my current speakers)

If it were my money, I'd go push pull with a bit of negative feedback. That will (nominally) give you a bit more damping factor. The thing I don't think you are understanding is that wattage does not equal current. Your Dyns require lots of current (think solid state) to make sound good. Generally, tube amps don't do current well. One of the very few ways I've found to power difficult speakers is the ZeroFormer. This little gadget will present the amplifier with a stable, benign impedance load which is exactly what a tube amp likes best.

Now, you might get really lucky buying a cheap, no-name amp but I'll bet you a donut in a tittie bar that you'll end up with something that has inferior iron (output transformers) and when mated to your speakers, it sounds like crap (loose, flabby, uncontrolled, vague).

Understand where I'm coming from here. I've lived on the dark side (SET's) for a long time now. I know what it takes to synergize (I hate that word) a system. I also have gone through bad pairings of speakers with push pull amps. I don't want to see you make a mistake because when you hear it done right, we've got our hooks in you forever 

[SET Man]

Hey!

    I see... SET or PP? Don't ask me! I could be a bit biased on this.... see my screen name here?

    It is true that your speaker with Dynaudio drivers are not really made for SET. Well, you might be able to get a way with it if you use the higher wattage SET like 18 to 20... yes this is high for SET world If you are in small room... I think your room fit this....  and don't listen to music loud. But the sound could lack the impact.

   Anyway, we could go on forever on this thread. You will ended up with thousand of answer and opinions here. If you really seriously thinking of getting a SET amp. I think you should do yourself a favor... go out and do you best to find a dealer or... even better find someone with a SET + hi-ef speaker and hear them for yourself!

   This is not for everyone. But... I have to warn you that after hearing the  SET + Hi-ef speaker done right it might change your mind about the speaker you have now

Take care,
Buddy

PS

If you are in or near NYC you are welcome to audition my 18w/ch SET (KR Audio 842VHD tube) with Single Driver 6" Fostex

   

[dado5]

    This is a great thread for me ,  very informative and fun to  read about your opinions concerning SET amps...     I think I understand you about not going for SET with these speakers,   the true potential of SET's will be wasted on them.     

Is this the case with higher powered ( read 20 watts) SETs  to?           Or should I just go for push-pull or stayaway from tubes all together.   ( Just not ready to let go of my current speakers)

Dont' worry about power really.  Your dad's amps tell you this loud and clear.

The issue is that  Dynaudio speakers may be to reactive for SET amps.  Almost always this problem is only audible in the low bass region where the power demand is high. Here the tube may not be able to maintain the require voltage over the changing current demands.  Impedance swings higher up in the frequency spectrum are usually not an issue. 

If this really worries you  (and honestly I would try a SET first to see if this is a real concern for your system) than there are two things you can do to keep the triode vibe alive

-A line level crossover to push the bass frequencies to a sub and keep them out of the SET

-Class A push-pull triodes.  This topology is inherently stable into reactive loads. You have already heard them in your system so this may be the way to go.