High Efficiency / Flea Power

by JediSavant on Tue Nov 01, 2011 6:44 pm

I seem to be developing two parallel streams of listening interest these days. There is the seemingly objective recognition that for the ultimate in rocking dynamics and pace, solid state systems are the way to go, but yet, I'm drawn to the apparent mystique of low-power tube set-ups, and in some cases, solid state as well.

While waiting for a made-to-order 2A3 SET (3.5w pc) to be finished, I went out and picked up a 5w per channel EL84 driven SEP to muck about with, which led to the purchase of some vintage Klipsch T-3000 95db in 8 ohm speakers in order to play it properly.

Small scale jazz and vocal based music are quite interesting through a single-ended set up, and I'm hoping to see what other people's experiences have been like in this particular segment of audio-enthusiasm.

by tlkoo on Tue Nov 01, 2011 9:39 pm

i have 3quarterwatter/750miliwatter & 3500miliwatter driving 93db, we may talk!

by vt4c on Tue Nov 01, 2011 9:58 pm

Dynamics and pace is exactly the what a good high efficiency speaker with the correct power amplifier is all about. Scale of the music reproduction and 'being there' factor are also what high efficiency speaker can do very well.

If you like what you're listening to right now, then, may I suggest that you audition a good proper pair of high efficiency horn-loaded speaker.

by mthoi on Wed Nov 02, 2011 12:17 am

Flea-powered SE and high efficiency speakers are the way to go!

SPL is a function of speaker efficiency and amp-watts. I have heard TLKoo's 750,000 millionthofawatt system and I can attest that it plays just as loud as my 140watt transistor amp driving a Harbeth.

There is something inexplicable and magical about the sound of a vintage tube SE/high efficiency speakers combination. After listening to SE tube amps, I find transistors a bit cold. Must be the 2nd harmonic distortion of tubes - makes the brain hear SE music as "warm and fuzzy".

I spend most of my time listening to a 8Watt 300B driving a 105db/m DIY Altec speakers in the living room. It plays loud and sounds great.

I am now trying to tweek my tube amp/Altec set-up to play Santana. Or at least make it sound like what I remember (vaguely) of Santana "Black Magic Woman" being played in my home town's theater in the late 1960s, before the main feature movie . (I remember they only play Santana music for some reason).

by JediSavant on Wed Nov 02, 2011 12:23 am

Hi tkoo: those are some mighty low wattages... Never heard of anything so diminutive in scale. Dare I ask if they're DIY amps or head-fi amps? what kind of speaker are you using?

Vt4c: I've heard a couple pairs of Avantgarde horns, and i believe in the right room and with the right budget they'd do a sterling job. However, I still require a degree of flexibility (read compromise) as I'm not looking at going full time down the low-watt path. I think those kinds of speakers wouldn't work too well with anything over 20 watts.

The SET valve scenario is intriguing to me simply because of the amount of sonic satisfaction one gets out of seemingly so little! Are the speakers you guys using full range single driver types?

by JediSavant on Wed Nov 02, 2011 12:26 am

mthoi: I think in theaters, they used push pull valve amps running between 12 to 35 watts or so... I've heard some 300b SET systems return pretty punchy sound though... Speaker placement and room treatment seem to contribute, plus efficient cables too...

by mthoi on Wed Nov 02, 2011 12:42 am

JS - I neglected to tell you that I am using a 2A3/845 18Watter for the Santana music. However it is still SE and not PP. Having the extra grunt makes a difference.

I have both full range, 2-way and 3-way high sensitivity speakers set-up with SE tube amps. I like the 3-way best - based on 16" Alnico woofers, large format (3.5" diaphragm) compression drivers with multi-cell horns and super-tweeters with bi-radial horns. Sounds - ? - since I listen to it every day, it sounds the same to me.

by tlkoo on Wed Nov 02, 2011 11:20 am

mthoi wrote:Flea-powered SE and high efficiency speakers are the way to go!

SPL is a function of speaker efficiency and amp-watts. I have heard TLKoo's 750,000 millionthofawatt system and I can attest that it plays just as loud as my 140watt transistor amp driving a Harbeth.

I spend most of my time listening to a 8Watt 300B driving a 105db/m DIY Altec speakers in the living room. It plays loud and sounds great.

you mean the mozzies whispering at your ears?

we'll talk comes our intended playtime!!!

regards

by tlkoo on Wed Nov 02, 2011 11:33 am

JediSavant wrote:Hi tkoo: those are some mighty low wattages... Never heard of anything so diminutive in scale. Dare I ask if they're DIY amps or head-fi amps? what kind of speaker are you using?

"puny" could be appropriate word to describe rather than "mighty" eh! admitedly i wouldn't have built such puny stuff had i been given a choice to start all over again (who will give me a chance again?)

that said, i've tried my very best to squeeze out the stringent tasty juice insofar as musicality calls for!!!

have fun in your quest Razz

by dixchen on Wed Nov 02, 2011 12:05 pm

flea power is not really flea power la...its the first watt that counts..

0.75W into 104db Klipsch Horns or any other more efficient horns can sound really dynamic and ' kick ' and ' slam ' like you cannot believe..with all the beautiful rich 2nd harmonics in single ended mode..

Recently brought over a 1.25W 45 amp to a friends place with the K Horn and it was an Shocked

experience...

by hasnul on Wed Nov 02, 2011 12:41 pm

Single ended so very kuat punya racun Ooo... !! Infact, I'm half way back into the ship !! Got me self a 3 inch Fostex in small bookshelf, now to find a budget triode int amp.

by dixchen on Wed Nov 02, 2011 12:43 pm

Racun sampai ' maut ' Twisted Evil

by JediSavant on Wed Nov 02, 2011 1:15 pm

Dix, your Superflys still with you? They're supposed to be excellent with tubes in particular. I'm also interested in hearing the rest of the Zu range which hopefully should be in KL soon.

by JediSavant on Wed Nov 02, 2011 1:17 pm

Hasnul, you could consider GLOW Audio and Miniwatt. I have the GLOW, which is an EL-84 driven Single Ended Pentode. It's a beast at 5w per channels. Mind sharing the type of bookshelves you have?

by hasnul on Wed Nov 02, 2011 1:48 pm

Hi jedisavant, thanks for the info but I would to aim triode based amps. I'm using small Fostex in bass reflex cab. Sizes about the LS35/a. With front port hole just below the driver. Nothing hi end as these setup is just for fun. Not as my main hifi rig.

by noodle88 on Wed Nov 02, 2011 2:00 pm

dixchen wrote:

Recently brought over a 1.25W 45 amp to a friends place with the K Horn and it was an experience...

Maybe a good 3.5w 2a3 SET amp will push the KHorn to much higher ground.... Very Happy

by JediSavant on Wed Nov 02, 2011 2:24 pm

hasnul, are those speakers still available for sale somewhere as I wouldn't mind checking them out...

by JediSavant on Wed Nov 02, 2011 3:20 pm

And hasnul, the Almarro A205MkII is EL84 also and can be configured to run in pentode or triode mode. It's a damn fine little amp for around 3k...

by dixchen on Wed Nov 02, 2011 4:48 pm

noodle88 wrote:
dixchen wrote:

Recently brought over a 1.25W 45 amp to a friends place with the K Horn and it was an experience...

Maybe a good 3.5w 2a3 SET amp will push the KHorn to much higher ground....

2a3 is definitely more powerful but a 45 is anytime more musical IMHO

just different kind of sound la... Cool

by dixchen on Wed Nov 02, 2011 4:51 pm

JediSavant wrote:Dix, your Superflys still with you? They're supposed to be excellent with tubes in particular. I'm also interested in hearing the rest of the Zu range which hopefully should be in KL soon.

Yup no takers wei...

by JediSavant on Wed Nov 02, 2011 6:06 pm

Can't wait for my 2A3 to be completed...

by Wikin on Wed Nov 02, 2011 9:31 pm

JediSavant wrote:Small scale jazz and vocal based music are quite interesting through a single-ended set up, and I'm hoping to see what other people's experiences have been like in this particular segment of audio-enthusiasm.

Hi JediSavant,

Single ended to me is THE only way for me to see through to the music clearly. Every note, emotion, nuance, touch and feel of the ensemble be it small or large scale pieces are reproduced properly.

I do my single ended amps slightly differently though; made mine to fuse with modern tech stuffs like constant curent source (replace anode resistor which is fuzzy sounding which gives a general bad impression that single ended amps cannot rock), LED bias to replace cathode resistor, kick back diode protection on the output trans etc etc.

cheers

by vt4c on Wed Nov 02, 2011 11:14 pm

JediSavant,

JediSavant wrote:Vt4c: I've heard a couple pairs of Avantgarde horns, and i believe in the right room and with the right budget they'd do a sterling job. However, I still require a degree of flexibility (read compromise) as I'm not looking at going full time down the low-watt path. I think those kinds of speakers wouldn't work too well with anything over 20 watts.

The SET valve scenario is intriguing to me simply because of the amount of sonic satisfaction one gets out of seemingly so little! Are the speakers you guys using full range single driver types?

Well...I support going to the low watt path only when putting the whole signal chain as a complete system; which includes from source to speaker. Among other things, it is important that the power amplifier needs to have the dynamic range or good signal swing and damping factor that is capable of driving the speaker even if it's high efficiency. In other words, interraction between the power amplifier and the speaker are critical. Quite too often, low wattage amp. get its bad name due to this. The understanding of this is important and there is no one size fits all. It this case, low wattage and high efficiency speaker.

I've listened to quite a number of full-range single driver speakers and the best I've heard so far is Feastrex loaded in Hedlund horn....It can play rock music with good fast bass slam. I'm an advocate of high efficiency multi drivers and multi amplifier horn loaded system. Going to a live concert is just within the living room and it rocks!...The snag to this route is a big listening space is needed.

by JediSavant on Wed Nov 02, 2011 11:21 pm

Wow.... I'm dreaming up a quad amp'd 2A3 set up.... Possible??

by 7810sam on Wed Nov 02, 2011 11:24 pm

Me using 8w 300b set driving 102db klipsch cornwall speakers. It give lush mid for cai qin/lily chen numbers and superb bass on Man Yim Hok- poems of chinese drum. Both the speakers and amp are plain simple design, no need expensive cabling.

Yes I also heard one kaki running 2a3 set monoblock(cost arm/legs) with Khorn. Superb.

Next itch will be tube rolling. $$$$$.

by noodle88 on Thu Nov 03, 2011 7:17 am

Yes, 8w for 102db klipsch and 3.5w for 104db kHorn will sound wonderful. But then playing 2a3 amp with sensitivity <94db or < 2w for speaker @ 94db, I have no command. U just can't get the full scale..

Cheers,

by JediSavant on Thu Nov 03, 2011 12:00 pm

Those wonderful looking Klipsch heritage speakers like
Cornwall, Heresy aren't exactly easy to come by in our region these days. If and when the Zu Audio stuff arrives we might see a change in terms of availability of high-eff speakers.

On another tangent, I believe solid state based systems can also benefit from easier to drive loads. Comparing the output from a pair of 90db 2.5 way speakers to the 95db 2 way Klipsch, driven by 35watts of solid state thunder, the 90db speakers were clearer, but much less dynamic.

by tlkoo on Fri Nov 18, 2011 6:41 pm

JediSavant wrote:

While waiting for a made-to-order 2A3 SET (3.5w pc) to be finished, I went out and picked up a 5w per channel EL84 driven SEP to muck about with, which led to the purchase of some vintage Klipsch T-3000 95db in 8 ohm speakers in order to play it properly.

Small scale jazz and vocal based music are quite interesting through a single-ended set up, and I'm hoping to see what other people's experiences have been like in this particular segment of audio-enthusiasm.

your 2a3 set has arrived home? what output transformers deployed?
what el84 sep amplifier was standing in?

is this regarded as small scaled jazz? http://www.diy-audio-guide.com/grp-all-star-big-band.html this was how i caused hoi to claim loudness for me heh heh... in fact signal swing is also crucial to churn out dynamism, not just power amplification!

i have tried sunaudio sv2a3 in my setup, diy 300b set, 60watter t-amp, quad 306 and couple of other el84 sep etc which i may not recall, but still i am keeping the long trusted 750milliwatter and recently have i added an el84 sep

catch up soon to compare notes, hopefully we could!

by JediSavant on Sat Nov 19, 2011 2:02 am

The 2A3 won't be ready for a while yet. Long queue for a hand-made product. It's being made by Don Garber in Brooklyn, New York, and it's called the Fi X integrated amplifier. The transformers are 'Hashimoto' I think or similar, and it's an upgrade apparently from Magnequest which was what Don was building his amplifiers with.

The EL-84 SEP is something called the GLOW Audio Amp One, by a US-based company, but manufactured in China. I'm driving a pair of Klipsch T-3000 95db speakers with it quite satisfactorily and there's even a surprising amount of bass that makes Led Zepelin sound half decent through the amp.

by **WongKN** on Sat Nov 19, 2011 2:38 pm

Jedi, so yr new amp is going to be one of those flea powered but macho priced amps from wat i can c ! Hahaha !

by JediSavant on Sat Nov 19, 2011 3:14 pm

It's quite reasonable for a hand made product. It comes in at around USD1300 before shipping and taxes...

by mthoi on Sat Nov 19, 2011 5:16 pm

JS - Is the Fi-X THE "X" shaped amp? I saw pics of the amp in Sound Practice magazine and it looks great. I think it is a piece of art (without the covers).

At USD 1,300 & Hashimotos OPT, the custom Fi-X is a good deal. The last I checked on ebay, Hashimoto products went up nearly 20%. I was looking at some line transformers to do a DIY a line stage preamp. Must be due to the strengthening Yen. That makes DIY as a hobby more expensive.

I have converted my 45/845 DIY amp to a 2A3/845 amp. It sounds good.

Do consider inviting us over to your place when you have the Fi-X.

by JediSavant on Sat Nov 19, 2011 8:00 pm

mthoi: it is indeed the X-shaped amplifier. It also comes as a 300B upon request. From my last communication with Don, it's around about a 10 month wait for new orders these days.

When I get the amp, it's quite likely that I'll be asking to bring it round to your respective dens to hear it, as I'll have to find and set up a pair of speakers around it!!!

by mthoi on Sat Nov 19, 2011 8:23 pm

JS - looking forward to it seeing this X-factor amp! I have 2 pairs of horn speakers for you to try out. One is 98db/m (Tyler Acoustic) and the other is 105db/m (DIY Altec 828 VOT).

PM me if you want to have a listen to a "work-in-progress" passive biamped system with a pair of monoblocks 300b driving the mid-horns, and a pair of monoblocks 2A3/845 to drive the bass horns.

by JediSavant on Sun Nov 20, 2011 8:02 am

Ahhhh... the poisons are being administered!

Very kind of you sir, and I shall definitely take up your offer!

by tlkoo on Mon Nov 21, 2011 11:03 am

mthoi wrote:JS - looking forward to it seeing this X-factor amp! I have 2 pairs of horn speakers for you to try out. One is 98db/m (Tyler Acoustic) and the other is 105db/m (DIY Altec 828 VOT).

PM me if you want to have a listen to a "work-in-progress" passive biamped system with a pair of monoblocks 300b driving the mid-horns, and a pair of monoblocks 2A3/845 to drive the bass horns.

must jediS bring his new amp to claim entrance? lets try coming long weekend...

forummers be reminded of long weekend eh!!!

by JediSavant on Mon Nov 21, 2011 11:06 am

The new amp has not arrived yet. Can bring the GlowAudio el84 SEP instead...

by dixchen on Mon Nov 21, 2011 11:47 am

JediSavant wrote:The new amp has not arrived yet. Can bring the GlowAudio el84 SEP instead...

Good luck on the extremely long wait Mad

by JediSavant on Mon Nov 21, 2011 12:32 pm

Amazing patience is a virtue of a proper Jedi....

by JediSavant on Thu Dec 08, 2011 10:19 am

Here's a new product by Devore, designed specifically to match with low-power tubes, and it looks a bit like Audio Note speakers if you ask me...
http://www.devorefidelity.com/orangutan.html

by tlkoo on Thu Dec 08, 2011 11:52 am

JediSavant wrote:Here's a new product by Devore, designed specifically to match with low-power tubes, and it looks a bit like Audio Note speakers if you ask me...
[url=http://www.devorefidelity.com/orangutan.html

http://www.devorefidelity.com/orangutan.html[/quote[/url]]

where to find an audition? you're considering?

by JediSavant on Thu Dec 08, 2011 12:02 pm

No one in KL carries it ye as far as I know, but one chap in Adelphi in SGP does, forgotten the name though.

I've heard Devore speakers before and they are quite dynamic and musical. Not the last word in definition, but tonal qualities are excellent.

by tlkoo on Thu Dec 08, 2011 12:05 pm

JediSavant wrote:No one in KL carries it ye as far as I know, but one chap in Adelphi in SGP does, forgotten the name though.

I've heard Devore speakers before and they are quite dynamic and musical. Not the last word in definition, but tonal qualities are excellent.

what about your own high efficiency speakers? you are just waiting for the arrival of your flea-power amplifier?

by JediSavant on Thu Dec 08, 2011 12:35 pm

Mine are old Klipsch T-3000 running around 93db. Thinking about selling them actually. When the amp arrives, I can then start hunting for something more appropriate and fitting!

by mugenfoo on Thu Dec 08, 2011 1:01 pm

It seems that Alan Shaw, owner of Harbeth has recently abandoned the idea that "all amps sound the same (or something like that)", and would prefer than his customers use adequate amplification with his "most natural loudspeakers in the world".

http://www.harbeth.co.uk/usergroup/showthread.php?1449-My-3D-holographic-presentation-from-a-15W-amplifier

From Alan Shaw at the H.U.G.

Alan Shaw wrote:
I don't just dream-up the minimum amplifier requirements for the fun of it. I am aware that if I suggest a minimum amplifier power rating that's too high, those customers with smaller amps may be frightened off Harbeth and select another brand which emphasises higher efficiency. Conversely, I am aware that to produce a reasonable sound pressure level that gives a satisfying quasi-real life experience a certain amount of power is necessary. So the minimum power amp ratings I've listed in the brochure are really minimums bearing in mind that you should interpret the manufacturer's amplifier power outputs with a very large degree of scepticism. Outside the lab, many amps are unlikely to be able to deliver their rated power on music when driving real-world speakers.

What tube fans don't realise (and I've heard SHL5s driven by 300B 7W tubes and sounding good) is that when you connect a 'scope across the 7W amp's output terminals and look at the music waveform, it shows significant clipping. And that clipping may be present for 25%, 50% or even 100% of the time. That shouldn't be a surprise at all: 7W is a minuscule amount of power. So how is it that those users are satisfied with what they hear? Simple - the tube amp (and I stress this, the situation with a transistor amp is totally different) clips is a sonically benign way. In other words, it runs out of power in a way which does not immediately reveal itself to the human ear. It doesn't sound hard or coarse when clipping: it sounds fat and warm. And that's all part of the magic sonic experience of small (tube) amps.

So - rule of thumb: give yourself a fighting chance of high fidelity sound at home: have a sensible amount of amplifier power available at all times.

by mugenfoo on Thu Dec 08, 2011 1:47 pm

JediSavant wrote:Mine are old Klipsch T-3000 running around 93db. Thinking about selling them actually. When the amp arrives, I can then start hunting for something more appropriate and fitting!

BTW, 93dB doesn't really qualify as high efficiency (by SET Amp standards).

There are Horn designs that are efficient to 105+dB, even up to 115dB per watt !
Razz

http://www.enjoythemusic.com/magazine/viewpoint/1099/setamplifiers.htm

SET amplifier 0.5 to 1.9 watts and loudspeaker with 104 to 108dB/W/m
2 to 5watts 100 to 103
SET 6 to 20 watts 96 to 99
20 to 40 watts 92 to 97
45 to 60 watts 90 to 97
65 to 100 watts 89 to 97
< than 100 watts 87 to 94

by JediSavant on Thu Dec 08, 2011 2:11 pm

Most of the SET 3w Club people in the US are comfortably listening to speakers rated between 93-98db but they are mostly crossover-less designs, and some are horn loaded, but mostly full-range single driver with a super tweeter slapped on for fun... Smile

by mugenfoo on Thu Dec 08, 2011 2:39 pm

they must not play very loud then .....

No Metallica or Guns n' Roses for them !
Smile

by mthoi on Thu Dec 08, 2011 2:55 pm

JS - I would join you in the "flea" powered amp-club soon, with my to-be-completed 45 tube amp - at a mighty 1.8W/ch. Unfortunately, it would be part of a tri-amp speakers system, so it may not count.

I still cant get my tube system to play Santana well!

by JediSavant on Thu Dec 08, 2011 4:21 pm

I've heard twin speaker systems driven by single ended 2A3 mono blocks belting out Pink Floyd and Perez Prado percusssion tracks with good gusto! Also full range driver speakers belting out the same using integrated 300bs with good effect. A very full, rounded lush sound that really emphasizes mids. Hard rock isn't the point with these set ups, but much more for music that demands good musicality.