45 tube power SET

[3dzapper]

They say a picture is worth a thousand words , so here is a novel!!

The peak output from this amp into a Khorn with music( it goes up and down from this)What's this about 3/4watt?

The inside of this little EL-84 single end amp.

From the coffee table in fromnt of my listening position(on top of removed Wright Mono 10) 100db!!!!! Yea,there was some distortion.

The open end of the room to open living/dining/kitchen upstairs.

This little amp still sounds good with nice tessitura if not great bass. Some day maybe it will be a project with a beefier power supply. That's probably why it can't reach 1 watt of output.

Rick

Edit: Tony if you are looking at this in the room picture, see where I put the T-350 last night in response to your phasing question. (the light colored, black fronted box up on the front effect HT speaker on top of the Khorn. See the door next to that? My wife says that that is where I/m heading if I don't cool my audio passion.

[sfogg]

Rick,

"I think but don't have the data to proove that amplifier damping is not as much as a factor with a Klipschorn as with a ported speaker. The Khorn driver is in an airtight enclosure and is also loaded from the front end by the slot and horn. "

Damping factor is just another way of talking about output impedance on an amp. A speaker being horn loaded or ported doesn't directly influence the interaction the speaker/amp interaction of an amp with low damping factor (high output impedance).

What really matters is the impedance curve of the speaker. The smoother it is the less of an interaction there will between the amp and speaker. Conversly the more the speakers impedance jumps around by frequency the more it will interact with an amp that has a high output impedance. The interaction literally changes the FR of the amp.

One of the nice things about your ALKs is it presents a smooth impedance to the amp compared to some of the other Klipsch crossovers. That means your K'Horns using the ALKs will interact with an amp less then if you were say using the type AAs.

I know it is an unpopular thing to mention around these parts but this is where some of the difference in sound between SS and tube amps come from. Tube amps typically (but not always) have a higher output impedance then SS amps.

More info:

http://www.transcendentsound.com/amplifier_output_impedance.htm

Shawn

[NOSValves]

Rick,

what is the 1.480 on the meter ??

[Deang]

Volts in AC hopefully. Looks to be about .5 watt at that point.

Rick, a "little" bit of distortion at 100db kind of jives with what I said above: "Dynamic compression is caused by a lack of headroom. A 1.8 watt should sound its best, and not "compress" if not run much beyond .5 watt continuous. I think this might drive a pair of Klipschorns cleanly to peaks a little over 90db at 9 feet away." My point was really one of cleanliness of sound, not total SPL. Also, the meter should probably be off the table and on a tripod -- I'm pretty sure it's picking up reflections from everthing around it.

Adding 15 ohm resistors in parallel to the amp's outputs will smooth the impedance characteristics of the old networks. This is pretty much what Al does by adding the swamping resistor between taps 0 and 5 on the autotransformer.

[3dzapper]

Yes VAC, RMS

This was not for scientific purposes so no tripod.

I have ALK constant impedance type A networks in the Klipschorns expertly fabricated by sfogg.

Rick

[BEC]

Rick,

What Fluke do you have? Mine only does RMS to a few hundred hz. Readings that I get on full spectrum audio are not to be believed. Had to go to a scope to get anything believable.

Bob

[3dzapper]

It's a trusty old 73. Again this is not a scientific study. Just some fun on a Saturday afternoon. My lawn doesn't need to be cut or fertilized (did it Thursday). I've already gone and come back from my archery practice for tomorrow's tournament and gone to the S.A. for some LPs. The wife and mother-in-law are upstairs having a mini quilting bee, the race is over and so there you go!

Rick

[Ho_Leung]

Damping shmamping. .5 to 7 .5 watts ..... what ever. this is way too heady. My speaker are 13 feet across.. I sit 11 feet back. Using a Korneff amp 1.8 watts. The preamp dosn't get past 1 oclock on the dial.. It is very loud!

Set amps don't have allot of bass.

I have recently biamped the Khorns using a Sonic Impact T-amp, and a 500hz harrison Fmod active filter. This is a really nice combo. The bass is glorious, and integrates seamlessly with the whole tonal palet. The T-amp has a gain switch, of which I can only go 75% or there is too much bass.

I have recently purchased Mullard cv181 imput tubes, Premium NOS input tube are worth every overly high priced dollar. I also have a pair of 1944 Slyvania 6sn7w input tubes. Using these Premium NOS input tubes have made a massively huge improvement, a sonic revelation. You can hear the vibration of one instrument, and how it's tone blends with the other instuments creating harmonics and overtones. You can hear the note hang that then decay. Really really low level details. Minute nuances. Shimmering sizzling symbols. I heard a bass wave pulse. A standup bass make a envelope which expanded and balooned and then decayed. Dynamic explosions. Discrete placement. When I play Ornet Coleman and Jack Dejohnette, it all makes sence. You can hear them standing on opposite sides of the stage. And they are blatting nonesence.. Well they are sending out notes and the other one is finishing the note. Bouncing tone off each other. Like tonal pingpong. But now I can see the notes and how they are blending when they get answered on the other side. I hate the term Gob smacked... After about two album sides the system transported to aural wonderland.

I am not sure what the last guy ment about his ASL amps. my Korneff is Astonishingly good.

.5 damping from where I am sitting is way cool.

[mike stehr]

Once again I thank 3D Zapper (Rick) for the wood sidepanels.

[edwinr]

I have a digital sound meter, and when I set it to read music peaks, I can't believe the readings I get. At relatively low average listening levels on well recorded music, the peaks go 5 to 10 db above that average level. And that's assuming my meter is of sufficient quality to record these peaks accurately. Maybe that's why horn speakers have so much 'air' compared to other speakers when listening to music - they don't compress as much. But that's assuming these speakers are run with amplifiers with sufficient ability to drive them.

I'm not talking about absolute loudness. Anything can go loud. I'm referring to the ability of an amplifier to accurately drive the speaker to reproduce the full dynamics of music at whatever average db level the listener is happy with. In relation to SET amplifiers, even these 1.8 watt 'monsters' [], I'm wondering how much influence the output transformers have over the ability of these amplifiers to reproduce music dynamically.

[Daddy Dee]

Once again I thank 3D Zapper (Rick) for the wood sidepanels.

Decent guy, eh?

The thing about SET, IMO, is not that they have enough power to make every taste happy, it's what they do presenting the detail and natural sound of the mids. Diana Krall sounds like she's singing IN THE ROOM.

After listening to SET for a couple of years, with as little as 1.5 wpc, I ended up with Mark III's. What I noticed with 60wpc (supposedly) is that there was something to the bass dynamics that I'd been missing.

However, unlike an apparent significant number of PP fans, I am not in the least perturbed that other people find sET enjoyable.

[tigerwoodKhorns]

I am trying to get teh best of both worlds. I purchased a Yamaha active crossover and will run a QSC 1202 to my woofer, a teac 700 tripath to my tweeter and probably a SET to the midrage.

How does the 300B compare to the 45? (I know it has more power).

Chris

[pauln]

Meter Peaks:

The "peak" setting does NOT show you the instantaneous true peak level, but understates it a lot - the true peak level is about 13dB ABOVE the highest reading (PWK said so). Therefore, when you set the SPL to "Peak" or "Fast" and it gets up to 87db, it's really 100dB.

This is because the peak/fast setting was timed to collect and summate on a period that works best for monitoring the human male voice (from old radio days). The fast peaks in the music won't show on the meter.

So, from now on if you use a SPL meter set on peak to measure the sound level in your room, add 13dB. You should also take this into account when you are doing the math backwards to estimate the watts out of the amp.

Paul

[NOSValves]

Meter Peaks:

The "peak" setting does NOT show you the instantaneous true peak level, but understates it a lot - the true peak level is about 13dB ABOVE the highest reading (PWK said so). Therefore, when you set the SPL to "Peak" or "Fast" and it gets up to 87db, it's really 100dB.

This is because the peak/fast setting was timed to collect and summate on a period that works best for monitoring the human male voice (from old radio days). The fast peaks in the music won't show on the meter.

So, from now on if you use a SPL meter set on peak to measure the sound level in your room, add 13dB. You should also take this into account when you are doing the math backwards to estimate the watts out of the amp.

Paul

One correction how high the actual peak would be above what the meter readings would be very dependant on the the system powering the speakers. It completely possible to have the meter hitting 87dB and the peaks are indeed 87dB.

Craig

[pauln]

Interesting - Please say more about this. Do more powerful amps have greater unregistered peaks? Is this different for tube vs solid state, or other designs?