@Buckeye Amps i ordered a purify amp several weeks ago. Are you sticking with estimated shipping dates? Or are you holding off on shipments until you figure out the cause of the distortion?
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Buckeye 3 Channel Purifi Amp Review
- Thread starter amirm
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Sticking with estimated ship dates unless the customer requests holding off
Great. Thank you. Very excited to receive this amp.
squared80
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Any updates on finding the issue?
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Waiting on delivery of a few components to check a couple more variables.
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Update:
We have measured a good amount of variables and scenarios. All of the preliminary data we have points to the distortion rise NOT stemming from our input buffer board.
But I am not declaring this as fact. We are sending off a few different test setups to a secondary party for them to measure and make sure they are seeing what we see, to rule out our test bench as a contributing variable.
Again, not at all saying "this is not our fault" and washing our hands of it. The opposite. We are leaving no stone unturned but as you can see it is taking some time.
We have measured a good amount of variables and scenarios. All of the preliminary data we have points to the distortion rise NOT stemming from our input buffer board.
But I am not declaring this as fact. We are sending off a few different test setups to a secondary party for them to measure and make sure they are seeing what we see, to rule out our test bench as a contributing variable.
Again, not at all saying "this is not our fault" and washing our hands of it. The opposite. We are leaving no stone unturned but as you can see it is taking some time.
squared80
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Appreciate the update.
Would it make sense to have Amir test another one? Maybe the first one had something defective.
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(Don't take this as me sounding harsh or dismissive)
Amir should definitely not be used as a test bench in terms of a possible problem. Since we were able to replicate the distortion on our end/test bench setup, it would not be beneficial to either Amir or myself to send anything to him until it is ready.
Ah, I didn’t realize that you replicated the distortion. Makes sense.
OldFart
New Member
Change of subject but related to review.
Question for those who know more than me. I have a Adcom rated at 200 watts (8 ohms) per channel RMS amp driving my old 4 ohm MK 100Bs.
The spec on the Buckeye amp states 225 watts per channel at 8 ohms, but the review states 156 watts at 8 ohms.
Would I be loosing power and/or dynamic range replacing my old Adcom 555II amp with the Buckeye Purifi 1ET400A 2 channel amp?
I don't understand the power rating compared to the review. Thank you in advance....
Question for those who know more than me. I have a Adcom rated at 200 watts (8 ohms) per channel RMS amp driving my old 4 ohm MK 100Bs.
The spec on the Buckeye amp states 225 watts per channel at 8 ohms, but the review states 156 watts at 8 ohms.
Would I be loosing power and/or dynamic range replacing my old Adcom 555II amp with the Buckeye Purifi 1ET400A 2 channel amp?
I don't understand the power rating compared to the review. Thank you in advance....
charlielaub
Senior Member
There is some interpretation to the power ratings and how to define "max power". Typically this is when the distortion level at some high power level increases to some predefined level such as 1 percent. 1 percent is the same as -40dB. When you look at the distortion measurement from the review below (continued):
... you can see that -40dB is reached for a power level of about 200 W. The distortion starts to climb at the lower power level of 156W but there the distortion level is only circa -87dB or 0.005%. Some amplifers NEVER reach that for any power level, and I have wondered why this is assigned the "max power" level by Amir in other reviews as well.
There is an old GFA-555 II review with good measurements you can compare to here:
There is a lot of good info contained therein. A plot of distortion vs power shows that the distortion level of the Adcom stays pretty low and constant at about 0.0005% at below 1W to about 0.0015% above 1W until turning up at 100W. This was when "new", and this is getting long in the tooth at this point and some component aging has likely occurred. Your amp may be performing much worse than this but you wouldn't know unless there was a major failure somewhere. The ear is just not all that sensitive to distortion.
What the Adcom amplifier (if it is actually performing up to original specs, likely not due to age and some PS cap degradation) offers is some headroom above the max power spec, for brief transients and with elevated distortion. The review lists that a power level of 265W was obtained with 0.68% THD (still not at 1 percent!).
IMHO overall the Buckeye amp's performance will be superior in terms of distortion at pretty much any power level up to about 100W, is brand new, running at spec (minus the current bug that is being worked out), and has a lower noise floor. The GFA-555 II is a very well regarded amp, but at this time you would be getting better performance out of the new Buckeye amp. I do not think you will miss the last 50 Watts or so, that is only 1dB or so difference at 200W and unless you are listening so that your ears bleed you will never reach these power levels except on transients.
It's possible to get the Adcom completely overhauled, with PS caps checked and lots of other components replaced and updated. This is another option you might consider. It's a very good amp when working well and up to spec.
The other option that I have to bring up, and one that might make a much bigger difference overall, is to upgrade those M&K speakers. I auditioned them IIRC in the late 1990s against a pair of Snell K-IIs that I owned and I was shocked how much worse the M&Ks sounded at the time. If you want to upgrade your "sound" you might start there and not with the amplifier. Lots of good commercial speakers under $2k these days. Just my unsolicited 2 cents. Take it or leave it.
... you can see that -40dB is reached for a power level of about 200 W. The distortion starts to climb at the lower power level of 156W but there the distortion level is only circa -87dB or 0.005%. Some amplifers NEVER reach that for any power level, and I have wondered why this is assigned the "max power" level by Amir in other reviews as well.
There is an old GFA-555 II review with good measurements you can compare to here:
There is a lot of good info contained therein. A plot of distortion vs power shows that the distortion level of the Adcom stays pretty low and constant at about 0.0005% at below 1W to about 0.0015% above 1W until turning up at 100W. This was when "new", and this is getting long in the tooth at this point and some component aging has likely occurred. Your amp may be performing much worse than this but you wouldn't know unless there was a major failure somewhere. The ear is just not all that sensitive to distortion.
What the Adcom amplifier (if it is actually performing up to original specs, likely not due to age and some PS cap degradation) offers is some headroom above the max power spec, for brief transients and with elevated distortion. The review lists that a power level of 265W was obtained with 0.68% THD (still not at 1 percent!).
IMHO overall the Buckeye amp's performance will be superior in terms of distortion at pretty much any power level up to about 100W, is brand new, running at spec (minus the current bug that is being worked out), and has a lower noise floor. The GFA-555 II is a very well regarded amp, but at this time you would be getting better performance out of the new Buckeye amp. I do not think you will miss the last 50 Watts or so, that is only 1dB or so difference at 200W and unless you are listening so that your ears bleed you will never reach these power levels except on transients.
It's possible to get the Adcom completely overhauled, with PS caps checked and lots of other components replaced and updated. This is another option you might consider. It's a very good amp when working well and up to spec.
The other option that I have to bring up, and one that might make a much bigger difference overall, is to upgrade those M&K speakers. I auditioned them IIRC in the late 1990s against a pair of Snell K-IIs that I owned and I was shocked how much worse the M&Ks sounded at the time. If you want to upgrade your "sound" you might start there and not with the amplifier. Lots of good commercial speakers under $2k these days. Just my unsolicited 2 cents. Take it or leave it.
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Klipshaholic
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Been reading a lot about the purifi amps and have always had my eye on the buckeye 3 channel amp. I currently have a monster power mpa 3250 amp and has been great sounding. Been looking to get a smaller footprint amp. Would I regret going to purifi from a class a/b that has more power?
Only you can determine if you would regret it.
I wouldnt and am glad (for many reasons) i did it.
Klipshaholic
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What kind of amp did you have before? And what changes made you not regret it? I had crown xls 2502 before so I like the efficiency but they were noisy.
I don't wish to be rude, but if you're going to change the subject start a new thread.
OldFart
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"Thread softly..."
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Looking forward to to the 2.0 version!
Too bad the boxes are not better. My amps sit in the open so esthetics are also important to us!
HarmonicTHD
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@Buckeye Amps
Is it correct to assume you replicated Amir’s initial measurements so the increase in SINAD at higher power is not related to this?
Post in thread 'Hypex NCx500 Class D Amplifier Review'
https://audiosciencereview.com/foru...0-class-d-amplifier-review.41007/post-1451614
Thanks in advance for clarifying.
Is it correct to assume you replicated Amir’s initial measurements so the increase in SINAD at higher power is not related to this?
Post in thread 'Hypex NCx500 Class D Amplifier Review'
https://audiosciencereview.com/foru...0-class-d-amplifier-review.41007/post-1451614
Thanks in advance for clarifying.
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