Driving PLANAR speakers (or large ribbons?) with a Cherry

0 Members and 1 Guest are viewing this topic. Read 3819 times.

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Who's driving Magnepan, Acoustat, or other planar type speakers with Cherry Amplifiers?

Could be electrostatic (Martin Logan, Acoustat, Quad) or electromagnetic (Magnepan, Wisdom, Apogee).

I have a pair of Magnepan 1.7i that sound terrific, and a pair of Apogee Centaurus Slant 6 (pretty old).  Both have low efficiency and like high power amps, but unfortunately, the Apogees can't take being driven very loud without risk of damage.

#Sound #Stereo #MEGAschino #DAC #DACDAC #CherryDACDAC #CherryAmp #CherryMaraschino #CherryMEGA #MaraschinoCherry #SurroundSound #Audio #HomeAudio #Amplifiers #DigitalAmpCo #HighEndAudio #miniCherry #Cherry5ch #cherry5 #5CHerry #4CHerry #3CHerry #2CHerry #HomeTheater #ExtremeAudio
#MartinLogan #Acoustat #Quad #Magnepan #Wisdom #Apogee

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #1 on: 9 Jun 2019, 10:16 pm »
Inspired by this thread because I had MMGs, but the LRS is the same price:
https://www.audiocircle.com/index.php?topic=163203.0

The most recent comment has very good insight about MMG vs LRS:
https://www.audiocircle.com/index.php?topic=163203.msg1746150#msg1746150

This Wisdom vs Magnepan thread is also very interesting, especially if you're not familiar with Wisdom Audio:
https://www.audiocircle.com/index.php?topic=106376.0

I was asked if open baffle speakers are applicable to this, mainly because of the dipole aspect.  Answer is....  I guess so, but it's a bit of a stretch just like a hybrid ribbon and conventional woofer combo....  There are also open baffle speakers with ribbons (Spatial, for one)!  Yes, that counts.

RonN5

Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #2 on: 11 Jun 2019, 03:00 pm »
OK...maybe this isn't exactly the same....but I'm driving the Salk Veracity STs which have the RAAL 70-20X Ribbon that crosses over at about 1.8kz with the 2Cherry amplifier...and the results are spectacular...These two pieces of equipment show off what the other can really do in the production of highly detailed and highly musical sound...I have no doubt that the Cherry Amps mated with Maggies, Eminent Technology LFT-8b and other similar speakers will be equally outstanding!!

AvsFan

  • Full Member
  • Posts: 893
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #3 on: 20 Jun 2019, 07:41 pm »
OK...maybe this isn't exactly the same....but I'm driving the Salk Veracity STs which have the RAAL 70-20X Ribbon that crosses over at about 1.8kz with the 2Cherry amplifier...and the results are spectacular...These two pieces of equipment show off what the other can really do in the production of highly detailed and highly musical sound...I have no doubt that the Cherry Amps mated with Maggies, Eminent Technology LFT-8b and other similar speakers will be equally outstanding!!

I'd love to hear from a Maggie owner who has them paired to the Cherry.

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #4 on: 20 Jun 2019, 07:42 pm »
I'd love to hear from a Maggie owner who has them paired to the Cherry.
I'm one, but biased just a bit  :o

(MMG, Mag 1.7i)

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #5 on: 20 Jun 2019, 07:45 pm »
I'd love to hear from a Maggie owner who has them paired to the Cherry.
LOTS of Cherry customers running Magnepan speakers!!  Not sure how many are on Audio Circle, though.  Maybe post this question on the TRUTH in Audio group (Facebook) for more response:
https://www.facebook.com/groups/TRUTHinAudio/

....Some with 3.7s, and one 20.7 system with Cherry MEGA MONOs (review on the way).

AvsFan

  • Full Member
  • Posts: 893
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #6 on: 20 Jun 2019, 08:01 pm »
I'm one, but biased just a bit  :o

(MMG, Mag 1.7i)

Are you Tom? LOL

AvsFan

  • Full Member
  • Posts: 893
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #7 on: 20 Jun 2019, 08:04 pm »
LOTS of Cherry customers running Magnepan speakers!!  Not sure how many are on Audio Circle, though.  Maybe post this question on the TRUTH in Audio group (Facebook) for more response:
https://www.facebook.com/groups/TRUTHinAudio/

....Some with 3.7s, and one 20.7 system with Cherry MEGA MONOs (review on the way).

I have the new LRS's and was wondering if the normal 48v 125 watt per channel version would be enough to drive them? My SS class A/B NuForce STA-200 at 80 watts per channel is not.

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #8 on: 20 Jun 2019, 08:28 pm »
I have the new LRS's and was wondering if the normal 48v 125 watt per channel version would be enough to drive them? My SS class A/B NuForce STA-200 at 80 watts per channel is not.
We have an email from you....  Hope to reply today.  The Stereo Maraschino (STM) does a GREAT job driving 1.7i speakers, even very loud, so the LRS's would be no problem.

By the way, we have a demo STM in stock.  I'll tell you more in my email reply.  Thanks.

AvsFan

  • Full Member
  • Posts: 893
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #9 on: 20 Jun 2019, 08:36 pm »
We have an email from you....  Hope to reply today.  The Stereo Maraschino (STM) does a GREAT job driving 1.7i speakers, even very loud, so the LRS's would be no problem.

By the way, we have a demo STM in stock.  I'll tell you more in my email reply.  Thanks.

Perfect! Look forward to hearing from you.

mijostyn

  • Jr. Member
  • Posts: 24
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #10 on: 21 Jun 2019, 01:05 pm »
I have Acoustat 2+2s that I modified with adjustable high voltage supplies I designed and Sowter 1/100 transformers. I would love to hear what Mono Mega's would sound like and if the would even drive a load like this which drops to very low impedance at high frequencies. I use class A amps now. I had to add a series resistor to the primaries to keep the amplifiers from overheating. I cross to subwoofers of my own design and construction at 125 Hz using digital bass management.
Another question I have is why do you not have a digital input? Everything in my system passes through a digital processor. My phone amp is converted to 192/24 by a Benchmark ADC. If your amps had a digital input I would not have to convert everything back into analog. Is there a way to add a digital input to your amps?

Mike

rollo

  • Industry Participant
  • Posts: 5440
  • Rollo Audio Consulting -
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #11 on: 21 Jun 2019, 03:34 pm »
  If you are planning on Class "D" or digital no better amp out there for your application IMHO period end of story.


charles

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #12 on: 21 Jun 2019, 05:40 pm »
  If you are planning on Class "D" or digital no better amp out there for your application IMHO period end of story.


charles
Charles,

Thanks very much  :D   Please send me a PM!  Great to hear from you, and hope all is well.

-Tommy O

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #13 on: 21 Jun 2019, 05:50 pm »
I have Acoustat 2+2s that I modified with adjustable high voltage supplies I designed and Sowter 1/100 transformers. I would love to hear what Mono Mega's would sound like and if the would even drive a load like this which drops to very low impedance at high frequencies. I use class A amps now. I had to add a series resistor to the primaries to keep the amplifiers from overheating. I cross to subwoofers of my own design and construction at 125 Hz using digital bass management.
Another question I have is why do you not have a digital input? Everything in my system passes through a digital processor. My phone amp is converted to 192/24 by a Benchmark ADC. If your amps had a digital input I would not have to convert everything back into analog. Is there a way to add a digital input to your amps?

Mike
Mike,

We have considered this.  We have made "direct digital" amps before, but the current lineup of Cherry Amps is analog.  There's digital processing inside, but not A/D conversion in the traditional sense.  It's more a hybrid approach, modulation-wise, so a digital input version would essentially be a DAC DAC driving the amp.  Putting the DAC inside eliminates the interconnects.  There's also the possibility of designing a new "direct digital" amp (digital-only modulation) using what we've learned since our last one, but performance would need to be comparable to our existing amps.  That's no small feat!  This is something I think about almost every day, so you've stirred some new motivation up (:

By the way, we might have a pair of demo MEGA MONOs soon (early July)....  Thanks for your kind post, and have a great weekend.

Best Regards,
Tommy

Freo-1

Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #14 on: 21 Jun 2019, 06:04 pm »
Mike,

We have considered this.  We have made "direct digital" amps before, but the current lineup of Cherry Amps is analog.  There's digital processing inside, but not A/D conversion in the traditional sense.  It's more a hybrid approach, modulation-wise, so a digital input version would essentially be a DAC DAC driving the amp.  Putting the DAC inside eliminates the interconnects.  There's also the possibility of designing a new "direct digital" amp (digital-only modulation) using what we've learned since our last one, but performance would need to be comparable to our existing amps.  That's no small feat!  This is something I think about almost every day, so you've stirred some new motivation up (:

By the way, we might have a pair of demo MEGA MONOs soon (early July)....  Thanks for your kind post, and have a great weekend.

Best Regards,
Tommy


I think you should consider an integrated approach with incorporating the DAC and volume control into the unit.  Given the direction audio is heading, it makes a lot of sense to offer this option.  A much higher quality interface can be achieved by directly connecting the DAC to the amp.


Going forward, I'll only consider solid state options that adhere to this approach. 

I.Greyhound Fan

Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #15 on: 21 Jun 2019, 08:16 pm »
What are the current ratings of your amps?  Just curious as Maggies like high current amps.

mijostyn

  • Jr. Member
  • Posts: 24
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #16 on: 22 Jun 2019, 12:57 pm »
Freo1, My system is a bit different than normal. I use a digital processor that does have a four channel DAC in it and both digital and analog volume controls. All my digital sources are plugged directly into it SPDIF or AES. My phono amp is plugged into a Benchmark ADC which is then plugged into the processor. I can send the signal to an amp either digital or analog. Class D amps by default have to digitize the signal in some way to quantize it. My thinking is why go back into analog only to turn right around and go back into digital when there might be a way to convert one digital signal to another. TACT (RIP) did this with their 2170 amplifiers they were a sort of Class D amp that sampled at 9 meg but in PWM not PCM. Most distortion occurs in the analog realm. Avoiding it is an advantage. Now if you like the Integrated approach Lyngdorf makes a unit with the Processor and amp in the same chassis. The only unit like mine available today that I know of is the Trinnov Amethyst which is still not as versatile as the Tact unit I have although its room correction is more advanced.

Tommy, thanx for such a rapid reply. Please let me know if and when the demo amps become available. I would get them with the 1500 watt transformer and quadruple rail:) Why so much more expensive? The next question is how is your amp sampling. I heard on another chat room that it sampled at 2 meg but what kind of modulation? Why is it superior to other class D amps? Although I plan on switching to SoundLab speakers which are an easier load what are the characteristics of your amp that will allow it to handle a single transformer ESL which is an almost dead short above 10K. I use to own Apogee Divas by the way. They were just too fragile and did not project well in the bass, too short. They did have the best treble only matched by the top Magnepans. Magnepan was thinking about making the 20.7 just under 8 feet tall but decided not too because they figured it would not sell, pity. The idea is to create an infinite line source. The Absolute sound mentions this in their review of the 20.7.

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #17 on: 23 Jun 2019, 11:54 pm »
What are the current ratings of your amps?  Just curious as Maggies like high current amps.
20-50A max, depending on model.  You can calculate max current with power and load resistance (impedance, but we're simplifying to a scalar for purposes of this comment)....

(current is "I", voltage is "V", resistance is "R", power is "P"):
Prms = Vrms^2 / R = Vp^2 / 2*R, and Ip = Vp / R, so....

Ip = Vp / R = sqrt(2) * sqrt(Prms / R) = 0.707 * sqrt(Prms / R)

So, for a Cherry MEGA putting 1000W into 4Ω, Ip = 22.4A

Thus, 50A capability is not really a meaningful limitation into 4Ω!  In fact, it's not even a limitation at 2Ω, which simply requires twice the current (<45A).

I.Greyhound Fan

Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #18 on: 24 Jun 2019, 03:02 am »
20-50A max, depending on model.  You can calculate max current with power and load resistance (impedance, but we're simplifying to a scalar for purposes of this comment)....

(current is "I", voltage is "V", resistance is "R", power is "P"):
Prms = Vrms^2 / R = Vp^2 / 2*R, and Ip = Vp / R, so....

Ip = Vp / R = sqrt(2) * sqrt(Prms / R) = 0.707 * sqrt(Prms / R)

So, for a Cherry MEGA putting 1000W into 4Ω, Ip = 22.4A

Thus, 50A capability is not really a meaningful limitation into 4Ω!  In fact, it's not even a limitation at 2Ω, which simply requires twice the current (<45A).

Thanks, I was just curious.  I think that listing the current of an amp can be helpful when trying to pick an amp with speakers like Magnepans that can sound better with  higher current.  Of course there is more to it than that on many levels.  My Parasound A21 is rated at 60 peak amps, more than my Pass amp I believe but it does not sound nearly as good as the Pass.  Both are listed as 250 wpc at 8 ohms but the Pass is 500 wpc at 4 ohms and the A21 400 at 8 ohms.    The A21 otherwise has better specs than the Pass but the Pass is more dynamic, punchier, has more depth, plays louder and is clearer but also has better tone with a larger sound stage and better transparency.

AmpDesigner333

  • Industry Participant
  • Posts: 2973
  • Detailed AND Musical
    • Digital Amplifier Company
Re: Driving PLANAR speakers (or large ribbons?) with a Cherry
« Reply #19 on: 24 Jun 2019, 03:14 am »
Thanks, I was just curious.  I think that listing the current of an amp can be helpful when trying to pick an amp with speakers like Magnepans that can sound better with  higher current.  Of course there is more to it than that on many levels.  My Parasound A21 is rated at 60 peak amps, more than my Pass amp I believe but it does not sound nearly as good as the Pass.  Both are listed as 250 wpc at 8 ohms but the Pass is 500 wpc at 4 ohms and the A21 400 at 8 ohms.
Actually, it is a good rule of thumb, and that counts extra for Mags!  You make another good point about sound quality.