Long time owner of RS5 based 3T's, but just tried tube amp for the first time

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OmahawkSCM

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My only point here is if you think an extra few watts from the Mini Torri or Rachael are going to provide a good bit more volume, well they don't really.

The Mini Torri and Rachael are fine sounding amps, I could be happy with either one. When you hear all three Back to Back to Back in the same room with the same speakers the differences are more than a bit subtle. The Zen UFO has a bit more Speed, Detail and Transparency which I prefer. The Mini Tori and Rachel are a bit warmer with not quite as much fine detail and I'm sure some will prefer the warmer sound. The Mini Torri is a tube roller and tweakers dream if you are into that.

I honestly don't listen very loudly either. So far, I have had the volume dial under 25% almost all of the time. I think I would be fine with 2 watts. The tori and rachel sound good, but I think since I find the Omegas to be pretty warm already, the Zen might be a better fit.

OmahawkSCM

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Over the last dozen years, I have owned the Omega Super 3i (narrow cabinet), the 3T, and now the Super 7 MK2. 

I found that tubes made the biggest difference with the original Super 3i's.  The Super 3i's play noticeably louder than the 3T's and tubes could also tame some of the honking I would hear on vocals with the 3i's.  The 3T's play smoother than the original Super 3i's, but I thought the 3i's had more energy, whether it was with solid state (Marantz 2240 receiver) or tube (Prima Luna PL 2 integrated) amplification.

The Super 7's MK2 offer the best of both worlds ... play smooth, loud, fast and exciting.  Using a Rega Brio R integrated as I have added a turntable to the mix.

Rich

Thanks for the heads up. I'm looking at the XRS speakers, but don't quite think I want to swing the Alnico XRS. I mean, they are 50% more than the super 7 xrs!

DBC

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Are you referring to the SE84UFO2 that is currently on their website? If so, that would probably be my limit as far as pricing goes. Maybe I can find one used. Thanks for the recommendation.

I will Echo Rob's advice here. My first Decware amp was the SE84C+ which started production in 2008. My second was the SE84CKC also know as the Super Zen which started production in 2013. Current production model is the SE84UFO. If I'm not mistaken all SE84's going back to 2008 can be upgraded to the UFO for about 300 bucks.

All of these amps sound great so if you found a good deal on an earlier SE84C+ I'm sure you would be very happy and save some cash at the same time. You could have the amp upgraded to a UFO later if you wished. I currently own my original SE84C+ (Bone Stock) a SE84CKC (Super Zen) upgraded to UFO. When I play the two Back to Back they both sound Great, but the UFO is clearly the winner.

A lot depends on the Quality of your source and source material. With a low quality source you will hear little difference between the two amps. In my case I don't use a pre-amp, My Oppo BDP-105 is connected directly to the UFO. I have a Decware pre-amp but with the resolution of my UFO / Omega combination the pre-amp warms up the presentation more than I like.

DBC

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For kicks, I tried a recently acquired SE84UFO (this was a 2013 SE84ZS (Select), before being upgraded with the new UFO transformers by Decware a few months ago) with its whopping 2 wpc.  It truly sounded fantastic, and I can see what all the raves and fuss are about, but on my Omega Alnico monitors (in a 20x25+ room), it just isn't enough for me ....  :cry:  I guess I like to play at higher levels, where peaks will come in at 92-95db.  I bet 8wpc would be fine, as is my current 18wpc SET amp.

I will try the UFO on a pair of Omega 3i (RS5s) in a few weeks, and we'll see how it does there. With a smaller room, more efficient and smaller drivers, and a couple of subwoofers, it might be just fine... Otherwise..... bye, bye...

My room is approx 16' x 22', speakers on the short wall, vaulted ceiling, large openings into other areas of the home. Front of speakers are approx 4' off the front wall, placed 9' apart and approx 9' from the listening position. My SAM's are on 10" Isoacoustic stands sitting directly on the floor & tilted up towards the listening position. I find having the Monitors closer to the floor really helps to boost perceived Bass Weight.

My Oppo BDP-105 is connected via interconnects directly to the Decware UFO which is in turn wired directly to the Omega SAM's. Volume level is controlled via a Stepped Attenuator on the Decware UFO. Don't think you can get any more basic than this.



Out of curiosity I spun some Smashing Pumpkin's and Stevie Ray Vaughan while monitoring Sound Level Pressure at the listening position with my Radio Shack analog SLP meter (set to C weighting, slow response). My custom unfinished 15" Low Frequency Open Baffle LOFOB's (pictured) were disconnected during the measurements. I was able to listen at average SLP's of 88 db with peaks to 93 db with no audible distortion from my Decware UFO amp. This is comfortably Loud in my room and the UFO still had some volume left in the tank before audible distortion kicked in.

I should point out that I have a rather lively room (minimal room treatments). I have 3 absorption panels on each side wall at first point of reflections. A bookshelf on the back wall that serves to provide some diffusion but that's about it. If you have a heavily treated room you may get different results.

Canada Rob

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Cool setup DBC.  Tell us more about the LOFOB's and how they're connected.

DBC

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Hi Rob,

Have been posting here as time permits on how I got to tinkering with the LOFOB's:

http://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1454424951

pstrisik

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Hi Rob,

Have been posting here as time permits on how I got to tinkering with the LOFOB's:

http://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1454424951

Very interesting DBC.  Wiring parallel, your sensitivity goes up 3db or so I believe.  That alone would boost gain and dynamics.

It is surprising that running both full range ends up with a smooth response (by ear anyway).  You would think the overlap in FR would create a mid-bass peak.  Given that they are wired together, maybe there is some principle that would explain how the electricity evens out, kinda like water.  But that's wild speculation!

As you may have seen, I've gone the midbass route (http://www.audiocircle.com/index.php?topic=134489.0), more like your original approach with HSU's.  I am using separate amps and the crossover for the SAMs is prior to the amp powering it, so one step better than crossovers between amp and speaker anyway.

..........Peter

DBC

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Quote
pstrisik wrote:

Very interesting DBC.  Wiring parallel, your sensitivity goes up 3db or so I believe.  That alone would boost gain and dynamics.

It is surprising that running both full range ends up with a smooth response (by ear anyway).  You would think the overlap in FR would create a mid-bass peak.  Given that they are wired together, maybe there is some principle that would explain how the electricity evens out, kinda like water.  But that's wild speculation!

As you may have seen, I've gone the midbass route (http://www.audiocircle.com/index.php?topic=134489.0), more like your original approach with HSU's.  I am using separate amps and the crossover for the SAMs is prior to the amp powering it, so one step better than crossovers between amp and speaker anyway.

..........Peter

I've done literally thousands of test tone & frequency sweep measurements over the years. I've found that with adjustments, tweaks, extra gear etc. I've been able to achieve flat in room response. Unfortunately flat in room response does not by itself necessarily translate into an engaging musical experience. I'm sure there are many speakers with multiple drivers that have a much flatter frequency response compared to the Omega SAM's. Common sense would say flatter is better but once you listen to the single driver Omega it's just not the case. Ultimately the human brain decides if it will accept the illusion as a live performance.

When it comes to Low Frequencies (below 500 hz), Humans have honed this sense over thousands of years. Our ability to avoid predators and locate prey for survival depended on a keen ability to use sound for location purposes. Because of this keen sense of hearing our brains can quickly tell the difference between Live Music and something else. The SAM's are often described as having a cohesion (to act as one) in it's presentation. I think it is the cohesion in the presentation that does a better job of selling the illusion to the brain? All frequencies from top to bottom blend together seamlessly.

I think the difficulty with Sub's is that the brain quickly senses a loss of cohesion. The brain in some cases senses a second sound source (crossover set to high) and can sense a difference in volume between Sub and Monitors around the crossover point (Sub volume set to high). Take a typical application where the Sub crossover is set at 80hz. A Bass gutiar can play from 40hz up to over 1,000hz. Sub crossover & volume have to be set just right to maintain a cohesive transition between Sub and Monitors.

On the other hand, with my LOFOB's running Full Range (40 to 3500 hz) they present a cohesive presentation throughout the entire Bass & Mid Bass Region. My SAM's for reasons I don't understand just blend in perfectly. Nor can I explain why there is not a noticeable Mid-Bass peak (no perceived Mid-Bass shout)? I suspect that because the LOFOB's are Di-Pole (firing forward & rearward) That a lot of the acoustic energy is being dispersed more uniformly into the entire listening space. I would have thought this would create a more defuse sound stage but vocals & instruments seem to have noticeably improved focus?

So right now I seem to have more questions than answers but I'm enjoying my music more than ever.


pstrisik

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I've done literally thousands of test tone & frequency sweep measurements over the years. I've found that with adjustments, tweaks, extra gear etc. I've been able to achieve flat in room response. Unfortunately flat in room response does not by itself necessarily translate into an engaging musical experience. I'm sure there are many speakers with multiple drivers that have a much flatter frequency response compared to the Omega SAM's. Common sense would say flatter is better but once you listen to the single driver Omega it's just not the case. Ultimately the human brain decides if it will accept the illusion as a live performance.

I agree.  I had Salk's for a while (SS8's that were more than four times the cost of the Omegas) that were very flat.  I couldn't adapt to them.  It's risky to post something like this.  The last time I did, I was attacked by Salk fans.  One went so far to research my posts on the Salk forum to point out what I've said previously, as if to prove my recent statement wrong.  Jim chimed in and said that some people just don't like a flat frequency response. 

It's interesting as I did a REW sweep with my current setup (I don't depend on this, but I was curious).  Surprisingly flat up to about 11kHz where it rolled off gradually.  When I run test tone files, I find I can't hear anything above that :(.  I don't think it was the flat frequency response that I didn't like.  I suspect it is more the coherence thing. 

Quote
When it comes to Low Frequencies (below 500 hz), Humans have honed this sense over thousands of years. Our ability to avoid predators and locate prey for survival depended on a keen ability to use sound for location purposes. Because of this keen sense of hearing our brains can quickly tell the difference between Live Music and something else. The SAM's are often described as having a cohesion (to act as one) in it's presentation. I think it is the cohesion in the presentation that does a better job of selling the illusion to the brain? All frequencies from top to bottom blend together seamlessly.

Interesting idea.  It makes intuitive sense.  Have you read this in regards to research on the matter or more logic?

Quote
I think the difficulty with Sub's is that the brain quickly senses a loss of cohesion. The brain in some cases senses a second sound source (crossover set to high) and can sense a difference in volume between Sub and Monitors around the crossover point (Sub volume set to high). Take a typical application where the Sub crossover is set at 80hz. A Bass gutiar can play from 40hz up to over 1,000hz. Sub crossover & volume have to be set just right to maintain a cohesive transition between Sub and Monitors.

Again, agree.  I do it by ear.  I play the monitors and mid-woofers only and find the levels that produce the most seamless sound.  My Marchand line level crossover even has a level adjustment for a narrow band at the crossover point in case of peak or null at that frequency, so I can get it sounding very seamless.  With those set, I add the subs and adjust again.  The Rythmik subs have an equalization adjustment for one frequency with adjustment for the width of the band and level up or down, so I can work with the crossover point there also, but haven't felt the need.

Quote
On the other hand, with my LOFOB's running Full Range (40 to 3500 hz) they present a cohesive presentation throughout the entire Bass & Mid Bass Region. My SAM's for reasons I don't understand just blend in perfectly. Nor can I explain why there is not a noticeable Mid-Bass peak (no perceived Mid-Bass shout)? I suspect that because the LOFOB's are Di-Pole (firing forward & rearward) That a lot of the acoustic energy is being dispersed more uniformly into the entire listening space. I would have thought this would create a more defuse sound stage but vocals & instruments seem to have noticeably improved focus?

So right now I seem to have more questions than answers but I'm enjoying my music more than ever.

All the more to keep the magic in the music! 

Louis has said that his 1.5 way design (full range driver plus driver with low pass at 500hz) seem to find a smooth transition, so there must be some principle at work here.

Your approach makes me curious.  But I don't think I'll be making a major change anytime soon.  I could try running both the SAMs and the 8" woofers full range in parallel, but I'll save that for another day!

......Peter


DaveC113

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I've been researching a lot about driver response and perception of speed. I think it comes down to a few of things...

1. The inductance of the woofer motor, too much inductance will roll of the higher frequencies and make them seem to lag behind.

2. The strength of the motor vs the moving mass, I think the best way to look at it is (Bl^2/Re) vs Mms.

3. Driver surface area, the larger the area the better the mechanical impedance match between the driver and the air, similar to a horn's expansion acting as an impedance converter, it takes the output of a small compression driver and allows it to act on a much larger volume/area of air. It's like trying to poke a hankerchief floating in the air vs swatting it with an open hand...  So smaller woofers need more excursion to achieve the same SPL vs a driver with larger surface area, larger driver simply don't need to move nearly as much, which is a big advantage and also allows the larger driver to sound more dynamic and achieve higher SPLs.

Also, the way the woofer is loaded has an influence. Most people think ported cabs sound slower but that's really not the case if the implementation is done well. Ported boxes require FAR less cone excursion vs sealed designs, which is a huge advantage. The downsides are not hard to address with any cheap box design software.

So... I chose a woofer according to those factors and a few others, it's a 15" woofer with very low Le, very high Bl^2/Re, and relatively low Mms. I currently have it crossed over to an RS5 at 400 Hz and the match is seamless.

The lower you go for the xo point the less it all matters. Subs tend to have high Mms, high Le, etc... basically they are all wrong for matching to drivers like Omegas but it still works out at very low frequencies as long as the overall design is competent (NOT a given!).





pstrisik

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The lower you go for the xo point the less it all matters. Subs tend to have high Mms, high Le, etc... basically they are all wrong for matching to drivers like Omegas but it still works out at very low frequencies as long as the overall design is competent (NOT a given!).

Yes, I've found crossing over above 115Hz begins to interfere with that sense of cohesion.  I may be able to go higher with further tweaking of the overall setup, we'll see.

This is with the Omegas (and the low watt SEP tube amp) running with a HPF from the Marchand xover.  So, countering the addition of a crossover, I think there is the benefit of reducing the load on both the amp and monitors.

........Peter

OmahawkSCM

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Well, some additional time with this amp and I think I'm all sold on tubes. Love this amp. This has got me thinking: Since I can still return the current amp and only be out about 20 bucks, should I get a different, nicer amp instead of investing in tube rolling?

I saw a Dennis Had Inspire power amp for sale under 1k. I could buy a schiit SYS to use as a pre for now, and get a better pre later. Any thoughts? Since he doesn't have a website, what is the best way to figure RMS power for this thing?

roscoe65

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Well, some additional time with this amp and I think I'm all sold on tubes. Love this amp. This has got me thinking: Since I can still return the current amp and only be out about 20 bucks, should I get a different, nicer amp instead of investing in tube rolling?

I saw a Dennis Had Inspire power amp for sale under 1k. I could buy a schiit SYS to use as a pre for now, and get a better pre later. Any thoughts? Since he doesn't have a website, what is the best way to figure RMS power for this thing?

The Dennis Had amp will want a preamp to sound its best.  For under $1k, here are some excellent alternatives:

https://www.audiogon.com/listings/tube-eico-hf-81-completely-restored-2016-02-13-integrateds-97207-portland-or

http://www.decware.com/newsite/SE84CKC.html

https://www.audiogon.com/listings/tube-decware-zkit1-se84diy-2016-02-15-amplifiers-88081-chaparral-nm


OmahawkSCM

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The Dennis Had amp will want a preamp to sound its best.  For under $1k, here are some excellent alternatives:

https://www.audiogon.com/listings/tube-eico-hf-81-completely-restored-2016-02-13-integrateds-97207-portland-or

http://www.decware.com/newsite/SE84CKC.html

https://www.audiogon.com/listings/tube-decware-zkit1-se84diy-2016-02-15-amplifiers-88081-chaparral-nm

Will the had amp not work with the SYS? I thought the SYS would be a perfect place holder till I can get a few hundred together for a preamp. I have a HT 7.1 receiver that has pre outs that I could, technically, use in 2 channel mode instead of the SYS. Would that work better instead?

roscoe65

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The Inspire amps do much better with more gain.  I have a Dennis Had KT88 amp and LP27a preamp and the gain from the preamp makes a huge difference.

squirrelman

Well, some additional time with this amp and I think I'm all sold on tubes. Love this amp. This has got me thinking: Since I can still return the current amp and only be out about 20 bucks, should I get a different, nicer amp instead of investing in tube rolling?

I saw a Dennis Had Inspire power amp for sale under 1k. I could buy a schiit SYS to use as a pre for now, and get a better pre later. Any thoughts? Since he doesn't have a website, what is the best way to figure RMS power for this thing?

I had a Schiit Sys that I used as a pre for my KT88 while I was waiting for my LP-27a to be built and it worked and even sounded good, but once I added the LP-27a they both really came alive and sounded great.  I'm actually planning on listing them both soon since I've caught upgradeitis so if you're interested drop me a PM here.

roscoe65

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What are you upgrading to Squirrelman?

squirrelman

What are you upgrading to Squirrelman?

I am going to get a single ended 300B amp, which one I just haven't decided on yet haha.  I have my eye on the Audio Note Kit 1, but am still poking around.  I'm always open to suggestions though!

roscoe65

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IIRC you have a pair of Alnico's.  Rebbi had a pair (now mine) and couldn't get them to work with his Kit 1 to his satisfaction.  I've had a 45 SE amp and currently have a 421a SE amp and a Dennis Had KT88/6L6/6V6.  The Dennis Had amp competes with either of the two and responds well to tube rolling.  The 45 amp (direct coupled) was in a different league and I wish I still had it (late 1990's - CAL Delta/Alpha, Audible Illusions IId, custom 45 SET, custom Cabasse 2-ways, Muse Model 18).

Talk to Peter about his setup - he has been putting a lot into refining his Inspire/Alnico setup.  You may find the Inspire amp will get you further than you think.

dspringham

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Per DBC. . .

"On the other hand, with my LOFOB's running Full Range (40 to 3500 hz) they present a cohesive presentation throughout the entire Bass & Mid Bass Region. My SAM's for reasons I don't understand just blend in perfectly. Nor can I explain why there is not a noticeable Mid-Bass peak (no perceived Mid-Bass shout)? I suspect that because the LOFOB's are Di-Pole (firing forward & rearward) That a lot of the acoustic energy is being dispersed more uniformly into the entire listening space. I would have thought this would create a more defuse sound stage but vocals & instruments seem to have noticeably improved focus?"

Hey, DBC I noticed on a Decware thread that you had shown pics of your LOFOB's in versions utilizing Eminence drivers in both 12" and 15" models. Referencing your comments above, is there any difference in integration with the 15" vs. 12" drivers?

Thanks.