[Russell Dawkins]

Russell - Funny, I am listening to International Guitar Night II on my M60's as I type.  The tapping on the second cut (Celtic Medley) is spooky...

So you're probably hearing it better than I ever have!

That's the sort of sound I will use to judge the amount of delay to use on the spot mics (to match the arrival time of the sound at the main mic). When the delay is right everything snaps into focus, especially with percussive sounds and also especially with the relative distances and levels in that recording. The main stereo mic (Royer SF-12) was about 10 feet only from the spots and there was about as much contribution from the spots as from the main in the mix, so it was doubly important to get the delay right. In this case it would have been about 10 msec. One regret for me about that disc is not trying to persuade the principals to allow me to include the lengthy (and entertaining) intro to Aerial Discoveries. The player, Clive Carroll, keeps asking for more and more level from the PA guy, while asking the audience (and me, offstage) if it's too loud. When he finally has enough level, the house is singing like an echo chamber and off he goes into the tune. That's when I fade up, but I should have pressed to include the whole thing.

I just finished mixing a recording you would probably like, if you like that one. It was a local young man who plays a phenomenal flamenco guitar. I recorded a concert he did a month ago for his second CD. I did his first 1 1/2 years ago. This time they hired a real Spanish "cantaor" - Antonio de Jerez, based now in Los Angeles, and the energy level stepped up a big notch. The recording is on its way to LA as we speak, to get Antonio's approval for release.
Gareth Owen is his name and he is a bit of a sensation in Jerez, being a blond Welsh/Irish kid and playing so authentically.
http://www.flamencoguitar.ca/

There are sound samples there, but the new one sounds thinner and more authentic and better to all of us, although they were thrilled with the sound of the first one at the time.

I guess that's an embarrassingly long OT diversion - sorry, but I would not start a new thread for this info! 

[lonewolfny42]

Duke...

Which brings up another interesting feature of the Atma-Sphere amps:  They can be run with less than their full complement of output tubes.  I used to do that in the summer in New Orleans.

Duke....how many did you remove ?

[Duke]

I had MA-2s on SoundLabs, twenty tubes per side, and went down to fourteen, simulating MA-1s.  Later with different speakers I experimented with eight per side, simulating M-60s.  I've long since sold my MA-2s, alas.  Here in Idaho on my 16-ohm speakers I've pulled tubes on my S-30 and gone down to three per side (five is normal).

[Wind Chaser]

Duke,

Have you tried the Paul Speltz ZERO impedance autoformers?  I believe he originally designed them with OTL's in mind and has sold many to Atma-Sphere owners.

[OzarkTom]

I have listened to many OTL's for the last 35 years and I never heard a bad one.

[JoshK]

The S-30 has 2 dB of global negative feedback.  The M-60 has 1 dB of global negative feedback.  The MA-1 and MA-2 have zero global negative feedback.  Other OTL amp manufacturers sometimes use higher feedback which results in higher damping factors, making their amps compatible with a wider range of speakers. 

I didn't know that.  I assumed all OTLs had lots of feedback to lower their Zout. 

[wilsynet]

I have a pair of Zu speakers at 12 ohm impedance.  Any benefit to using the Autoformers to double the 12 ohms to 24 ohms?  What would a 24 ohm load do to the S-30 amplifier?

[226bw]

OK, I'm convinced!

Before posting I read a number of glowing reviews of Atma-sphere amps by the audio press, however enthusiastic endorsements from knowledgeable owners are even more meaningful.

Clearly I need to hear these amps.

When I first contacted Duke about purchasing a pair of his speakers, I hoped they would be an exit level speaker - the last speaker I'd purchase. I was hoping the same for amplification but was less optimistic. After reading the rave reviews and comments re Atma-sphere amps, I'm much more confident (at least that is what I'm telling myself and more importantly my wife ).

Thanks!

Cheers,

Chris

[mgalusha]

You won't hear many contradictions to that!  Are the Cyber 845s reliable?

His will be. They used to be my amps and when I received them they worked but one of the PS caps had failed. This was due to a failed bleeder resistor. I rebuild the PS with higher voltage/higher wattage bleeders in addition to replacing all the caps. It's been a very happy camper since then.

Back to the OTL topic now.

[jimdgoulding]

So you're probably hearing it better than I ever have!

That's the sort of sound I will use to judge the amount of delay to use on the spot mics (to match the arrival time of the sound at the main mic). When the delay is right everything snaps into focus, especially with percussive sounds and also especially with the relative distances and levels in that recording. The main stereo mic (Royer SF-12) was about 10 feet only from the spots and there was about as much contribution from the spots as from the main in the mix, so it was doubly important to get the delay right. In this case it would have been about 10 msec. One regret for me about that disc is not trying to persuade the principals to allow me to include the lengthy (and entertaining) intro to Aerial Discoveries. The player, Clive Carroll, keeps asking for more and more level from the PA guy, while asking the audience (and me, offstage) if it's too loud. When he finally has enough level, the house is singing like an echo chamber and off he goes into the tune. That's when I fade up, but I should have pressed to include the whole thing.

I just finished mixing a recording you would probably like, if you like that one. It was a local young man who plays a phenomenal flamenco guitar. I recorded a concert he did a month ago for his second CD. I did his first 1 1/2 years ago. This time they hired a real Spanish "cantaor" - Antonio de Jerez, based now in Los Angeles, and the energy level stepped up a big notch. The recording is on its way to LA as we speak, to get Antonio's approval for release.
Gareth Owen is his name and he is a bit of a sensation in Jerez, being a blond Welsh/Irish kid and playing so authentically.
http://www.flamencoguitar.ca/

There are sound samples there, but the new one sounds thinner and more authentic and better to all of us, although they were thrilled with the sound of the first one at the time.

I guess that's an embarrassingly long OT diversion - sorry, but I would not start a new thread for this info! 

A fan of the art and having listened to the samples, I'm purchasing.  Tho, the samples are of the first one, no?  And I welcome a singer. 

[226bw]

Hi Duke,
Thanks for the reply. I'm afraid you lost me a little on part of the technical explanation (tilting and shelving) but I think I caught the gist of it, to paraphrase:

Your speakers have been design to work with a wide verity of rooms and amplification systems. The speakers are also tunable via user adjustable features to better accommodate variance in acoustic space and amplification. Close?

Cheers,
Chris

PS I'm still hope to make it down your way latter this spring.

[Rocket_Ronny]

Hey Russell:

Were you using the Oktava 012s at the guitar? Did you have them modded? Was it running into a ULN-8? 

Now that's a ribbon sound I like. 


Rocket_Ronny

[Duke]

I have a pair of Zu speakers at 12 ohm impedance.  Any benefit to using the Autoformers to double the 12 ohms to 24 ohms?  What would a 24 ohm load do to the S-30 amplifier?

Estimating here, I'd say that the S-30 is a 35-watt amp into a 12-ohm load and a 45 or 50-watt amp into a 24 ohm load.  That being said, my inclination would be to not purchase an autoformer unless you really think you need the extra power.  Try it without first, and see.  Thirty-something watts into 97 dB (or whatever) is an awful lot.

At RMAF 2007 I showed my 16-ohm, 94-dB ballpark Dream Makers driven by an S-30.  Lynn Olsen, speaker guru dude, played his torture test classical CD at an estimated 110 dB peak at the listening position.  The estimate is arrived at like this:  He sets the level so that he can barely hear the tape hiss, and said that was probably 40 dB.  The CD has 70 dB of dynamic range.  Nothing blew up, and he said mine was the only system he tried that on at the show that didn't compress or distort.  It was very loud.  The numbers favor your Zus over my setup even without the autoformers.

Your speakers have been design to work with a wide verity of rooms and amplification systems. The speakers are also tunable via user adjustable features to better accommodate variance in acoustic space and amplification. Close?

Yup, you got it.  Nice job of translation into English!

One more story I'd like to relate.  I was talking with Ralph the other day and he described an incident from RMAF 2006.  I had a now-discontinued speaker called the Stormbringer showing in a room with his S-30.  Stormbringer was a chunky 93 dB, 8-ohm stand-mount with a 12" woofer, and I think I claimed extension to the mid-30s.  But with the high output impedance of the S-30, the bass extended considerably deeper.  Ralph and a reviewer were together in another room where a megabuck speaker failed to reproduce the 25 Hz note less than a minute into Peter Gabriel's soundtrack from "The Rabbit-Proof Fence".  Ralph invited the reviewer into the room with the Stormbringers and S-30, and that note shook the room.   

There aren't many "free lunches" in audio, but a high output impedance amp on a low-tuned vented box is one of them. 

[Russell Dawkins]

Were you using the Oktava 012s at the guitar? Did you have them modded? Was it running into a ULN-8? 
Now that's a ribbon sound I like. 
Rocket_Ronny

Thanks, Rocket. I'll PM you to keep from derailing the topic.
You, too, Jim and thanks for your comments.
Russell

[Duke]

Hey Russell, ya'll are more than welcome to have that conversation here.  Others might be interested.  I haven't had anything to add, as I've been busy doing other stuff, but don't leave on my account.

Duke

[jtwrace]

At RMAF 2007 I showed my 16-ohm, 94-dB ballpark Dream Makers driven by an S-30.  Lynn Olsen, speaker guru dude, played his torture test classical CD at an estimated 110 dB peak at the listening position. 

That same year I walked in with my CD (can't remember which track I played) but also said I want to play it loud.  You said "have fun".  That moment still sticks in my head as it was insane how loud it would play without any hint of distortion.  I never play music that loud but that speaker just wants it.  It has such a happy factor it's crazy hard to explain unless you hear it for yourself.   

Thanks!
His Royal Highness
Supreme Emperor and Dictator-For-Life
the One, the Only
Duke

(yes, this is what Duke wants to be called)  I've NEVER forgotton!!!!   

[TomS]

Yes, I remember hearing them at RMAF too and was very impressed.  I didn't know much at all about Atma-Sphere at that time but it was an amazing demo.  The Dream Makers were quite appropriately named for sure.

[Russell Dawkins]

Hey Russell:
Were you using the Oktava 012s at the guitar? Did you have them modded? Was it running into a ULN-8? 

Thanks, Duke!
I have already answered Ron and Jim, but for anyone who is interested - yes, the mics on the guitars were (self) modded Oktava 012s with the hypercardioid heads. I don't have and may never get the ULN-8, although if I had the money I would have one already (no-brainer!) and have sold my True Systems 8 channel mic preamp, since the ULN-8's pres are probably better, from what I've seen written. This was recorded into (and mixed in) my Metric Halo MIO 2882+DSP - a stunningly competent box, for those who don't know - the total center of my studio.

As to the sound, Jim, the Gareth Owen samples are from the first CD which we all liked at the time  (Gareth wanted the guitar to sound as big as possible), but this time we opted for a more realistic, less "bottom-y" flamenco guitar sound, and to take some of the body out of the stage thump from the dancer's heals.

Having Ron and Jim's home emails addresses, I sent them a short clip of the new CD in mp3 form.

[Rocket_Ronny]

Hey Duke:

Can you explain a bit more about the difference between the Atma 30 and 60 in terms of sound and the impedance thing.

Thanks.


Rocket_Ronny

[James Romeyn]

That same year I walked in with my CD (can't remember which track I played) but also said I want to play it loud.  You said "have fun".  That moment still sticks in my head as it was insane how loud it would play without any hint of distortion.  I never play music that loud but that speaker just wants it.  It has such a happy factor it's crazy hard to explain unless you hear it for yourself.   

Thanks!
His Royal Highness
Supreme Emperor and Dictator-For-Life
the One, the Only
Duke

(yes, this is what Duke wants to be called)  I've NEVER forgotton!!!!   

Member Bill Berndt is a lucky Jazz Module owner.  Last visit to his place he played an Ozzy Osbourne LP l-o-u-d.  I worked at the Record Plant with 2x JBL 15s and a huge horn lens in each of four corners of a mid-size control room, biamped with a stereo Crown DC300 per corner.  Sly Stone would walk in and just crank up the level as high as it would go without distorting (one of the nicest guys you'll meet...wonder how is ears are).  I'd run from the control room.

Back to Berndt: Source was the custom TT he built with Empire motor/bearing/platter and the rest all new custom (63 lb brute), 200W Jolida Music Envoy monos with transmitter output tube.  The level was beyond discerning the words of someone shouting next to you.  We were about 10-12' away in a moderate sized living room.  It was just a thick, creamy, visceral fog of sound which seemed to move all the exposed hairs on your body.  It was as if the sound became a semi-solid.  No audible distortion whatsoever, like the speakers were yawning and able to do it all day (that was one of the most remarkable items about the experience).  We sat on the sofa looking at each other and back to the system in awe grinning.  I can't say I own any music like that, but would consider buying such after that experience.  It was crystal clean and much fun. 

I looked at the mid-size floorstanders, thinking the output would require something 4ft wide and floor to ceiling.  The mad scientist Dr. Frankenstein aspect to Duke's otherwise normal persona is on record (lucky us).