AudioCircle
Audio/Video Gear and Systems => Owner's Circles => Digital Amplifier Company Owners => Topic started by: AvsFan on 9 Aug 2019, 03:51 pm
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So I have had the Stereo Maraschino for over a month now and am highly impressed! What a superb amp. I have the 48v version right now and have it paired up with some super efficient and easy to drive ZU Audio Omen Dirty Weekends. The combo is amazing. I did try it with my new Magnepan LRS’s but wasn’t quite enough juice. And as I understand the STM in 48v form puts out 125 watts per channel into 4ohms. I have always heard Maggie’s are demanding and now I am experiencing that for myself. So I am upping the power supply to 60v. Which the specs on that is 400 watts per channel at 4ohms. Which if that isn’t enough to easily drive the Maggie’s, I simply give up. Lol :D :D
My question though is, can someone explain to me how the amp can go from 125 watts to nearly 4 times that at 400 watts? And that increased power to the STM, are there any concerns of it putting too much of a load on that amp? Especially driving power and current hungry Maggie’s?
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So I have had the Stereo Maraschino for over a month now and am highly impressed! What a superb amp. I have the 48v version right now and have it paired up with some super efficient and easy to drive ZU Audio Omen Dirty Weekends. The combo is amazing. I did try it with my new Magnepan LRS’s but wasn’t quite enough juice. And as I understand the STM in 48v form puts out 125 watts per channel into 4ohms. I have always heard Maggie’s are demanding and now I am experiencing that for myself. So I am upping the power supply to 60v. Which the specs on that is 400 watts per channel at 4ohms. Which if that isn’t enough to easily drive the Maggie’s, I simply give up. Lol :D :D
My question though is, can someone explain to me how the amp can go from 125 watts to nearly 4 times that at 400 watts? And that increased power to the STM, are there any concerns of it putting too much of a load on that amp? Especially driving power and current hungry Maggie’s?
No problems here driving Magnepan 1.7i with the 60V STM!
Regarding power output, Pout = Vout^2/R, so you'd expect 4 times the power from TWICE the voltage, not 1.25 times the voltage! Well, the limitation at 48V of the STM is from the power supply itself, which can output about 260W peak. That drives BOTH channels plus the other circuitry in the amp. Desktop and In-Line Maraschinos have individual power supplies for each channel, so they can output about 250W into 4Ω per channel. Our 60V 1kW power supply can output enough power to drive BOTH channels to 400W into 4Ω in the case of the Stereo Maraschino (STM).
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Here's the LRS's impedance curve. More like 3Ω nominal than 4Ω!
(https://www.audiocircle.com/image.php?id=207366)
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Here's the LRS's impedance curve. More like 3Ω nominal than 4Ω!
(https://www.audiocircle.com/image.php?id=207366)
Heavy load to drive for a lot of amplifiers. Explains why i went through 4 amps. I am adamant about buying serious power, current and an amp with balls for anyone considering the LRS.
All 4 amps I used sounded good, with each upgrade they sounded better, but you''re really not going to hear the full potential of the LRS's until you get them proper amplification.
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Hey Tommy,
Am I going to be okay with 48v DTM mono blocks into Maggie .7?
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Hey Tommy,
Am I going to be okay with 48v DTM mono blocks into Maggie .7?
Yes because they have independent power supplies for each channel. You can calculate the maximum volume with the output power and efficiency....
I think in feet. For the sake of easy calculation, I'll make the assumption that 3 feet is close enough to 1m. However, 1m is actually 3.28 feet.
Mag .7 efficiency is rated at 86dB 2.83V/1m. 2.83V is used since 2.83V (RMS) into 8Ω is 1W. Power is not used for sensitivity ratings because response is based on a fixed voltage, not a fixed power. If power was fixed, the voltage used for testing would need to be varied over frequency based on the change in impedance -- that gets unnecessarily messy, so the standard is voltage. Anyway, we need to know the impedance to calculate how much power 2.83V requires. In this case, it's 2W because the .7's impedance is 4Ω NOMINAL. I suspect it's closer to 3Ω. It takes more power to drive 3Ω than 4Ω. 1.33 times the power (!), actually, but we can adjust for the difference later.
Normal listening is more like 2m away, so you lose 6dB from dispersion. However, 2 speakers (stereo) gives you 3 more dB. So, we start with 6 feet from 2 speakers at 2W (each) for a net loss of 3dB for 83dB.
That will be important in just a bit....
Now, we double the power iteratively until we get close to the amplifier power, adding 3dB each time (not exactly, but very close)....
4W for +3dB
8W for +6dB
16W for +9dB
32W for +12dB
64W for +15dB
128W for +18dB
256W for +21dB
512W for +24dB
1024W for +27dB
Since the 48V STM outputs roughly 120Wpc up to 8Ω (due to the power supply's limits, so even into 2Ω, it's still 120Wpc max), and that's close enough to 128W, we get +18dB for a total of 101dB SPL. Please note that's MAX!
Since the 48V DTM outputs roughly 240Wpc into 4 Ω, and that's close enough to 256W, we get +21dB for a total of 104dB SPL.
In both cases, the power supply output power limits the SPL in more than one way. Since the load with LRS or .7 Mags is likely closer to 3Ω, using a 60V power supply enables the DTM or STM to output more power into 3Ω than 4Ω, so.... With the STM, the power supply drives two channels, so I recommend the 60V power supply for an STM driving Mags. Since DTMs are monoblocks, that issue goes away....
60V DTMs output >530W into 3Ω. That adds more than 3dB for >107dB SPL MAX in this case.
Here's a handy calculator for SPL:
https://myhometheater.homestead.com/splcalculator.html
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Thanks. I won’t concern myself with upgrading the power supplies for now.
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Now that’s what I call an explanation! I’m curious to hear your thoughts on the .7’s with that DAC amp you have.
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Well I can tell you one thing for sure, Tommy’s DAC is very, very special :thumb: :thumb:
This DAC has given me a whole new appreciation for the amps. :thumb: :thumb:
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Well I can tell you one thing for sure, Tommy’s DAC is very, very special :thumb: :thumb:
This DAC has given me a whole new appreciation for the amps. :thumb: :thumb:
Okay, are you talking about his amps or DACs? Lol. But both are VERY special! Sometimes in this audio game, even after you do a ton of research, you still end up with gear that’s not anything special. I mean most gear out there is pretty good. At least companies on these forums and so on but not all of it is revolutionary. Tommy’s gear is special! I got lucky in putting my faith in him and his products. I know in the past, I have gotten excited about new gear, but eventually it wears off and when I really listen, it’s nothing spectacular. But it’s been about a year now with DAC gear, and it impresses me every time I turn on the music. Special indeed.
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I’ve had the amps for 3 years and I’m not the least bit interested in any other amp or amps out there. The Maraschino’s are truly end game amplifiers.
I held off on the DAC for a long time because it only has one input. But now that I have it, I am completely astonished by how good it is. It has given me a whole new appreciation for the amps. Like the Maraschino’s the DAC DAC is truly an end game DAC.
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Thank you for the compliments, guys! I'm honored (:
The Cherry DPA will be a like a DAC with added features/processing.
In fact, the balanced DAC portion of the circuitry is nearly identical to the DAC DAC 2 HS (slightly higher output swing). There is also a separate single ended output (stereo) with selectable functionality. Can't disclose the details just yet, but soon. There are multiple sources: COAX1, COAX2, Optical, and Analog.
Adding a Cherry USB package (includes UHF/BNC SPDIF Cable, and Gold Plated USB Cable) will be optional, at a discount. This is only needed for systems using a PC to drive the DPA. The Cherry USB has the same footprint, so it's stackable with the Cherry DPA.
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The Cherry DPA will be a like a DAC with added features/processing.
In fact, the balanced DAC portion of the circuitry is nearly identical to the DAC DAC 2 HS (slightly higher output swing). There is also a separate single ended output (stereo) with selectable functionality. Can't disclose the details just yet, but soon. There are multiple sources: COAX1, COAX2, Optical, and Analog.
Well this certainly sounds interesting. 8)
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I’ve had the amps for 3 years and I’m not the least bit interested in any other amp or amps out there. The Maraschino’s are truly end game amplifiers.
I held off on the DAC for a long time because it only has one input. But now that I have it, I am completely astonished by how good it is. It has given me a whole new appreciation for the amps. Like the Maraschino’s the DAC DAC is truly an end game DAC.
I am in COMPLETE agreement! The Golden Cherry Monoblocks are the end of the road for me. I know a lot of us, like Arnie climbing up the water tower in Endora, say "This is the last time." But this is truly the last time for an end game amp for me. The only way I will get rid of these, is if they just stop working, but I'll send them back to Tommy to be fixed. I seriously doubt I have to worry about that though.
Now with that said, I do need two more amps for other systems. I am positive that I will go with a 3-CHerry for my theater system.
Which DAC DAC do you have?
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I’ve had the amps for 3 years and I’m not the least bit interested in any other amp or amps out there. The Maraschino’s are truly end game amplifiers.
I held off on the DAC for a long time because it only has one input. But now that I have it, I am completely astonished by how good it is. It has given me a whole new appreciation for the amps. Like the Maraschino’s the DAC DAC is truly an end game DAC.
So by your banner sig, avatar, whatever you want to call it, you are using Spatials with the DAC Amp?
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Which DAC DAC do you have?
The 1 HS. I bought it off a doctor who said it kicked the shit out of far more expensive very highly regarded DAC by PS Audio. The only reason he sold the 1 HS is because he upgraded the the 2 HSV.
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So by your banner sig, avatar, whatever you want to call it, you are using Spatials with the DAC Amp?
Spatial isn’t merely a brand, but an idea. And yes, I’ve been using Spatial speakers for the last 3 years now.
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The 1 HS. I bought it off a doctor who said it kicked the shit out of far more expensive very highly regarded DAC by PS Audio. The only reason he sold the 1 HS is because he upgraded the the 2 HSV.
Yeah, the 1HS is ridiculous. I miss it so much! I had it myself. Upgrading to the 2HS. I shouldn't have read that review on the 2! Damn internet! :D
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Spatial isn’t merely a brand, but an idea. And yes, I’ve been using Spatial speakers for the last 3 years now.
I met him a couple of years back at RMAF and saw him again this past year. Cool dude. Came real close to pulling the trigger on Spatials a few times, especially when I was looking into the LRS's, but it ultimately came down to the bargain basement price on the LRS's.