Buckeye Amps: Purifi 1ET6525SA (the successor to the 1ET400A)

[Stereoed]

From the results of my testing, it can be seen that when 1ET400A is turned on, there is sometimes a popping sound in the high-frequency part, which is very low and not always present. 1ET7040A also has it, but the impact sound is changed to the low-frequency part. 1ET6525 and 1ET9040 have not found any popping sound at the moment, but for these two models, if they are turned on at a high input signal volume, they may not start and will repeatedly flash twice before starting. At this time, there will be a popping sound and they will work normally again.
All models are DC coupled. If there is DC input into the amplifier in the front stage, even if it is very small, it will repeatedly start, and there will be a loud popping sound at this time.
If there is a popping sound every time the power is turned on or off, it may be because your soft start settings are not done properly.

Thanks for this great post.
Regards, Edi

 

[TunaBug]

Dylan (or anybody actually), which size spade lugs will fit the binding posts on my new 2ch 1ET6525SA amp from you? I'm trying to choose between the 6.3mm, 7mm, and 9.2mm from Blue Jeans Cable.

 

[TunaBug]

Yes! My "squelching" amps have both been Adcoms too: a GFA-535 and then a GFA-5400. I sold them both a couple of years ago, but they were rock-solid dependable for many years. The lack of built-in speaker protection, though... never was an issue for me fortunately, but still, I probably wouldn't buy such an amp again at this stage in my life when the passive speakers I'd use with such an amp would be a good deal more expensive than what I could afford when I was younger.

Still, I have a soft spot for those old Adcoms.

I have a GFA-555 that has been unused in the attic for 10 years that I need to part with (first amp I ever purchased, kinda sentimental). Power on/off pops were a non issue for me: within a couple of months the contacts of the power switch welded themselves closed, I assume from large inrush current. The dealer replaced the power switch, and a couple of months later it welded itself closed again. I accepted as normal that it would be permanently On. So normally no pops.

But on the rare occasion I had to unplug it, or the power went out, there were pops.

 

[tmtomh]

I have a GFA-555 that has been unused in the attic for 10 years that I need to part with (first amp I ever purchased, kinda sentimental). Power on/off pops were a non issue for me: within a couple of months the contacts of the power switch welded themselves closed, I assume from large inrush current. The dealer replaced the power switch, and a couple of months later it welded itself closed again. I accepted as normal that it would be permanently On. So normally no pops.

But on the rare occasion I had to unplug it, or the power went out, there pops.

Yes, those power switches were something!

 

[Mort]

When is this recommended over the NCx500?

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[Hapo]

Yes, those power switches were something!

...I use a rebuilt ABE-515 power conditioner to turn my Adcom GFA 5500 on and off...I never touch the power switch...have not had to rebuild the GFA 5500...

...I will likely be looking at one of these buckeye amps to replace it someday...

 

[Rit]

When is this recommended over the NCx500?

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I gravitated toward the Purifi module based on reviews and comments on this forum, can’t speak about the ncx500. I am completely satisfied.

 

[BassThatHertz]

Is 1 Hypex SMPS1200A400 enough to drive 3 1ET6525SAs to full power? I'm considering buying the 3-channel Buckeye which uses 1 of that power supply.

My FL and FR speakers are the Dynaudio Emit 50 towers (4 ohms)
My centre speaker is a Monolith by Monoprice THX-365C (4 ohms)

The amp would be fed by the pre-outs of a Denon AVR-X3600H.

 

[Rit]

Is 1 Hypex SMPS1200A400 enough to drive 3 1ET6525SAs to full power? I'm considering buying the 3-channel Buckeye which uses 1 of that power supply.

My FL and FR speakers are the Dynaudio Emit 50 towers (4 ohms)
My centre speaker is a Monolith by Monoprice THX-365C (4 ohms)

The amp would be fed by the pre-outs of a Denon AVR-X3600H.

I would call Dylan at Buckeye directly.

 

[Buckeye Amps]

Is 1 Hypex SMPS1200A400 enough to drive 3 1ET6525SAs to full power? I'm considering buying the 3-channel Buckeye which uses 1 of that power supply.

My FL and FR speakers are the Dynaudio Emit 50 towers (4 ohms)
My centre speaker is a Monolith by Monoprice THX-365C (4 ohms)

The amp would be fed by the pre-outs of a Denon AVR-X3600H.

Not for all 3ch into the 2ohm rating. The SMPS1200 has a peak rating of 1350w so if you were to drive all three channels into max power for a 2ohm load you'd be losing about 50-75w per channel. For a 4ohm load into all three channels simultaneously at full power it would be close but there would still be some power loss per channel.

But luckily, consumer content (even at reference levels) does not tax an amp like benchtop testing does so there will be no issues.

 

[BassThatHertz]

Not for all 3ch into the 2ohm rating. The SMPS1200 has a peak rating of 1350w so if you were to drive all three channels into max power for a 2ohm load you'd be losing about 50-75w per channel. For a 4ohm load into all three channels simultaneously at full power it would be close but there would still be some power loss per channel.

But luckily, consumer content (even at reference levels) does not tax an amp like benchtop testing does so there will be no issues.

Thanks. Would it be okay to put my centre speaker on top of the 3ch amp?

Edit: Just realised that's where the vent holes are so it's probably not something I should do.