[pstrisik]

Hi all,

I have on order a handmade by Dennis Had 12wpc single ended KT150 based amp.  (Dennis Had is the designer of the Cary tube products.  I have his SLP-05 preamp and absolutely love it.  He also designed the Cary CAD-805 series amps.)

Dennis claims it will power most cone based speakers fine.  I'm skeptical though I will give it a shot.  I have restored AR2ax'.  They are at 87db / 8 ohms.  AR says minimum 20watts - this was stated around 1970.  Great experiment and experience in any case.

So, Omegas may be in my future!    I have no experience with single ended amps or full range drivers, but I like what I am reading.  And looking around at the options, Omegas draw me the most. 

Oh... I'm running a Conrad-Johnson Premier 11A (70wpc p-p amp) between the Cary SLP-05 and the AR2ax'. 

[FireGuy]

Hi all,

I have on order a handmade by Dennis Had 12wpc single ended KT150 based amp.  (Dennis Had is the designer of the Cary tube products.  I have his SLP-05 preamp and absolutely love it.  He also designed the Cary CAD-805 series amps.)

Dennis claims it will power most cone based speakers fine.  I'm skeptical though I will give it a shot.  I have restored AR2ax'.  They are at 87db / 8 ohms.  AR says minimum 20watts - this was stated around 1970.  Great experiment and experience in any case.

So, Omegas may be in my future!    I have no experience with single ended amps or full range drivers, but I like what I am reading.  And looking around at the options, Omegas draw me the most. 


Oh... I'm running a Conrad-Johnson Premier 11A (70wpc p-p amp) between the Cary SLP-05 and the AR2ax'.

I too was quite intrigued by the single-driver design.  In addition to the universal approval of Louis' line up my decision for the Super 5's is for their easy load.  Who can argue at 2 watts to get started.   My other considerations were Ascend Sierra 1, Maggie MMG and Aperion's 5T.  In 3 weeks let the eval begin.

[Louis O]

Hi pstrisik,


Many thanks for your post and kind words. I have seen but not heard the new gear from Dennis Had. It looks great and I'm sure the amps sound great too. Years ago I had an old SLA70 that I liked and had a 300 SEI for a while too.

I hope that single drivers get more popular and looks like more and more low powered amps are coming out.
Now with the RS5's it's a great time to try the 3 series lineup.

Many thanks FireGuy and a good 2 watts is a great way to get started.

Thanks again,
Louis

[pstrisik]

Hi pstrisik,


Many thanks for your post and kind words. I have seen but not heard the new gear from Dennis Had. It looks great and I'm sure the amps sound great too. Years ago I had an old SLA70 that I liked and had a 300 SEI for a while too.

I hope that single drivers get more popular and looks like more and more low powered amps are coming out.
Now with the RS5's it's a great time to try the 3 series lineup.

Many thanks FireGuy and a good 2 watts is a great way to get started.

Thanks again,
Louis

Hi Louis,

Thanks for the welcome!  Dennis finished the amp Thursday and has been listening to it.  It will ship Monday and I should have it by the end of the week.  Then the test with my AR's.  Should I continue towards the full range driver path, I will have lots of questions!

Here's a shot of the finished amp.  Again, single ended, 12wpc, KT150 power tubes (pentode)!

.

[DaveC113]

pstrisik, I have an EL34 SET that needs to be rebuilt at some point.... going from a modded, burnt PCB to ptp wiring since my SET has no driver stage, my preamp has enough gain and can drive the EL34s directly.

I am considering rebuilding the amp with kt150s instead of EL34s, have you heard both by any chance?

[pstrisik]

pstrisik, I have an EL34 SET that needs to be rebuilt at some point.... going from a modded, burnt PCB to ptp wiring since my SET has no driver stage, my preamp has enough gain and can drive the EL34s directly.

I am considering rebuilding the amp with kt150s instead of EL34s, have you heard both by any chance?

No, sorry.  Actually, I haven't heard either... yet!  This will be my first SE amp.  I have a CJ Pr11A that runs 6550 or KT88/KT120.  There is debate about whether the KT150 will be drop in for CJ amps, but CJ hasn't weighed in yet AFAIK.

I'm relying on Dennis Had's advice.  He really likes the KT150 in this design.  This amp has several options for tube combos, including the EL34.  It will output 7wpc with EL34's.  I may try some of the other combos at some point.

These are possible without modifications:

* 5 watts per channel output with 6V6 output tubes and 5Y3 rectifier tube
* 7 watts per channel with 6L6, KT66, 5881 output tubes and 5U4 rectifier tube
* 10 watts output with KT88, EL34, 6550, KT99, KT120, KT150 output tubes with 5U4, 274B rectifier tube
* 12 watts output with KT-88, KT-120 or KT-150 output tubes and 5AR4 rectifier tube

[DaveC113]

Sounds like a nice amp... Other than EL34s I have only tried KT88/6550s in my amp and prefer the EL34s with my Omegas. Currently using the GL KT77s which are really nice.

Let us know how the matchup works out, I'm sure it'll be great!

[pstrisik]

Well, I've been listening and tweaking for a week or two.  I like this amp!  It's not bad with the 87db AR2ax'.  Seems to begin to run out of steam above 85db in an ~23x26 room, listening ~10ft from speakers.  I try to listen at 80db tops, so this isn't bad.  I prefer the 274B rectifier over the 5AR4 even though the latter is 12wpc vs. 10wpc with 274B.  Nicer sound. 

Curiously, I'm ending up running the stock EH tubes in my Cary SLP-05 pre.  Preferring them over some nice Sylvania Chrome Dome NOS tubes that I liked with my C-J amp.

I'm sure I'll try the EL34's at some point as I can just swap them in to take the place of the KT150's.   

Anyway,  I am still interested in the single driver path.  So, recommendations!

I'm partial to monitors and like the size of the Super 6 Monitor.  Thought the Super 5 has better bass response according to the website specs.  Louis, you're raving about the RS5 driver.  Is that what makes the difference, or is there something about the specs that I should consider, eg, Super 6 says down to 55Hz but 45 in room while the Super 5 only says 45.

It seems there is much talk about Alnico based drivers being superior to Ferrite, but the RS5 is the latter and the driver in the Super 6 is the former. 

Bigger drivers on the horizon?  How will these fit in the line up in terms of performance?  Many people here seem to be opting for the smaller drivers.

Just putting some thoughts out there and would appreciate understanding more about your designs.

My room is ~23x26x9 and listening position is ~10ft.  I have a pair of Rythmik FS12 subs.  These are fast as subs go, probably not as fast as your new ones though.

Thank you........  Peter

.

[JLM]

Louis tried for a long time to develop a suitable AlNiCo based small driver, but finally gave up.  AlNiCo has higher flux density and reportedly a warmer sound.

From my readings (and experience beyond his current drivers) the smaller drivers are faster and would integrate better with the proper (fast) subwoofers.  Specifications can't tell the whole story in life.  Common sense says bigger drivers will push more air and provide more feel/substance of the bass.  So with your subs, the RS5 in one of the smaller cabinets would be the direction I'd go.

And frankly whizzer cones confuse me (I've yet to get a good explanation as to what is going on there).  I have 8 inch AlNiCo full range drivers (Fostex F200A, 30 - 20,000 Hz, 8 ohms, 89 dB/w/m, about $425 each) that have no whizzer, which means for better or worse they beam above roughly 4,000 Hz.  I wanted coherence across the entire frequency range, but if doing it again would look into a swam of subs (search Audio Circle, read Floyd E. Toole's 'Sound Reproduction') with the RS5 in one of the smaller cabinets.

Fairly big room, how loud do you listen?  (Like any small extended range driver the RS5 has limited excursion/output, but the subs would help.)

[pstrisik]

Louis tried for a long time to develop a suitable AlNiCo based small driver, but finally gave up.  AlNiCo has higher flux density and reportedly a warmer sound.

From my readings (and experience beyond his current drivers) the smaller drivers are faster and would integrate better with the proper (fast) subwoofers.  Specifications can't tell the whole story in life.  Common sense says bigger drivers will push more air and provide more feel/substance of the bass.  So with your subs, the RS5 in one of the smaller cabinets would be the direction I'd go.

And frankly whizzer cones confuse me (I've yet to get a good explanation as to what is going on there).  I have 8 inch AlNiCo full range drivers (Fostex F200A, 30 - 20,000 Hz, 8 ohms, 89 dB/w/m, about $425 each) that have no whizzer, which means for better or worse they beam above roughly 4,000 Hz.  I wanted coherence across the entire frequency range, but if doing it again would look into a swam of subs (search Audio Circle, read Floyd E. Toole's 'Sound Reproduction') with the RS5 in one of the smaller cabinets.

Fairly big room, how loud do you listen?  (Like any small extended range driver the RS5 has limited excursion/output, but the subs would help.)

I listen at 80db for the most part.  I've found with the new Dennis Had 10 watt single ended amp that I don't need to turn it up quite as much to get the full sound.  I'm hoping that will be even more true with Omegas.  Still, I would like to be able to run comfortably to 90db.  With my current speakers, audible distortion starts at 85db.  Going from 87db sensitivity to 92db+ should do that I think.

Interesting that alnico is really only feasible in larger drivers.  I wonder how much the cone material is affecting the difference between the 6" alnico and the 4.5" RS5?  Or, to put it another way, would the design of the RS5 translate to a 6" driver with alnico motor?

[DaveC113]

There is a 7" version of the RS5 driver, the ferrite motor has no whizzer but the alnico does. A whizzer is a mechanical crossover.... Louis would know a lot more about the pros/cons and design considerations for using a whizzer or not...

[pstrisik]

There is a 7" version of the RS5 driver, the ferrite motor has no whizzer but the alnico does. A whizzer is a mechanical crossover.... Louis would know a lot more about the pros/cons and design considerations for using a whizzer or not...

That's interesting, the first mention of a larger version of the RS5.  I assume it's driver only at this point, ie, no speaker models developed for it (yet?)?

[DaveC113]

It might not be on the website yet, but there was a pic posted of a 7" in an XRS type cabinet so I assume it is orderable.

[Alwayswantmore]

...you may already know this, but every 3db in volume is a doubling of power. So coming from 87 db - and depending on which model Omega you choose - you will likely have the equivalent of 4x or more in perceived power (as an example, 87 to 93db is 2x2 = 4 times.) So a 10 watt amp on your current speakers would sound likes pumping about 40 watts or more in volume on Omega from the same amp. Or in reverse, 10 watts on Omega (assuming 93 db) will be about as loud as 40 watts on the 87db speakers. I hope that makes sense. Kent

[pstrisik]

...you may already know this, but every 3db in volume is a doubling of power. So coming from 87 db - and depending on which model Omega you choose - you will likely have the equivalent of 4x or more in perceived power (as an example, 87 to 93db is 2x2 = 4 times.) So a 10 watt amp on your current speakers would sound likes pumping about 40 watts or more in volume on Omega from the same amp. Or in reverse, 10 watts on Omega (assuming 93 db) will be about as loud as 40 watts on the 87db speakers. I hope that makes sense. Kent

It does make sense, though all relative.  Bottom line is that the Omegas will allow the 10 watt amp to be plenty!

......Peter

[pstrisik]

It might not be on the website yet, but there was a pic posted of a 7" in an XRS type cabinet so I assume it is orderable.

Hopefully Louis will chime in.

By the way, what makes the design XRS?  Is it the baffle width?

[opnly bafld]

http://www.audiocircle.com/index.php?topic=121531.0

[pstrisik]

http://www.audiocircle.com/index.php?topic=121531.0

Thank you!  That seems like the alley to explore subject to more input.  Super 7 Monitors, maybe! 

[pstrisik]

Greetings Omegazoids,

I talked with Louis yesterday.  He was very helpful. 

My biggest decision is Super 7 Monitor vs. XRS.  I like monitors and have good usable stands.  Primarily, it seems the benefit of the XRS is extended bass.  There is also the wider baffle (14") that Louis says increases sound stage and reduces baffle step diffraction.  He makes the monitor with a narrower baffle (10") more for practical reasons - suitability for available stands.  He may be able to make the monitors with the wider baffle, but even if he did, I'm still unsure. 

I'm leaning towards the floor standers as they are still not that tall at 32", only 45lbs vs. 30lbs for the monitors, and have several benefits.  The only benefit of the monitor he identified, other that aesthetic, cost or practical reasons, is the shorter cabinet panels can slightly reduce resonance and increase midrange speed.  Sounds like a very slight difference though.

Regarding drivers...  stock is the 7" ferrite without whizzer.  I can buy the 7" alnico with whizzer as a DIY driver and driver roll!    He says the alnico is warmer and with more texture to the sound, but needs the whizzer to keep higher frequencies.  The ferrite can run without a whizzer as it can provide decent higher frequencies on its own.  I'm a bit sensitive to 3000+ Hz, so it is a difficult choice.  The qualities of the alnico are very attractive.  The whizzer seems like a compromise.  But the ferrite without the whizzer may be less satisfying.  So I may have to go with both and see for my self!   

I'm putting this out there just thinking out loud and am looking for feedback/thoughts to make sure I'm not missing something and to help firm up my decision.

So default order at the moment is:  Super 7 XRS in bubinga with a pair of 7" Alnicos in addition to the stock ferrite drivers.

Thanks!

[Alwayswantmore]

Having obtained two sets of speakers from Louis, my opinion is that he is in the best position to help with a decision like this. Give Louis your priorities and other considerations, then ask him which is best for you based on your criteria. You're not asking him which is a better way to go in generic terms, but rather what would he do if he was in your shoes with your priorities / preferences. Just my 2 cents.

My current speakers are Super 6 Alnico Monitors with Deep Hemp sub. They are a few years old now, and Louis may have some new and improved solution now, but at the time they were the speaker that Louis felt best met my needs. They sound fantastic, so I've never looked back.

K