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

Stereoed said:
Dylan. It was an oversight. I was editing from my translation program. Sorry. But I think that's the end of it for me with Purifi and Hypex. I consider them to be faulty designs. Probably not because it can't be done, but because it would be too costly to solve the problem properly. And that would make these products too expensive. Or why doesn't Yamaha have this problem?
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Funny, but my Bryston amp (NOT a Class D) has a start-up pop. And the amp was overhauled a couple years ago by Bryston and it did not change that minor issue.
 
thegeton said:
I'm the original owner of an Adcom GFA-555 that has done a bit of both all of its life, almost 39 years. Still works like a champ.
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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. :)
 
BlackTalon said:
Funny, but my Bryston amp (NOT a Class D) has a start-up pop. And the amp was overhauled a couple years ago by Bryston and it did not change that minor issue.
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Thanks. But what's so funny about that? I don't understand.
 
tmtomh said:
I get that different modules, designs, units, and so on have different levels of turn-on and/or turn-off sounds. But unless it's fairly loud, I have trouble understanding how it could be considered a design fault. I've had A/B amps that made popping sounds turning on, or that made a sort of low-level "squelching" sound when turning off (I assume from capacitor discharge and no power-off mute). I was never concerned about it - that's just the way some designs are, yes?
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It's pretty loud. I never claimed it was a quiet power-on noise.
 
RickS said:
The Yamaha is an integrated amplifier and likely the inputs are not dc-coupled. Power amplifiers tend to be dc-coupled. Have you measured for dc in your system? DC offset can make the problem worse. Some of the older Hypex MP series had some uglier power up behavior, but they have improved.

I have a Purifi EVAL1 connected to SPK4 speakers (with expensive Mundorf AMT). It is powers via an Alexa-controlled power strip and get a slight click at power up. If your problem is DC, not likely to damage a passive speaker in any case. If you cannot measure for DC, do you have a preamp?
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Hi Rick, thanks for the helpful answer.
Unfortunately, I can't measure the DC current. I'd have to buy a voltmeter and read up on how to measure it.
Yes. I also think the Yamaha isn't DC-coupled. However, the Class D monoblocks are current models. It's a Hypex Nilai. I connected the power amplifiers directly to the Eversolo A8 via XLR. I thought the Eversolo A8 was also a preamplifier. Unfortunately, I don't have a separate preamplifier at the moment. What Class D power amplifiers would you recommend? And would a Topping DX9 be suitable as a preamplifier?

Thanks in advance.
 
Stereoed said:
Hi Dylan,
You wrote that your monoblocks with the Purifi 6525 module have a soft start and soft shutdown.
Is this a special feature of Buckeye Amps? Or is it built into the Purifi module?
I have the problem that my Hypex Nilai monoblocks make noise when turning on and off. It bothers me, and that's how I came across your post here in the forum. The Nilai monoblocks are connected to the Eversolo A8 via XLR and trigger. I've already asked Hypex itself, and they blame it on the Eversolo A8. In the meantime, however, I've found out that this problem is known with the Hypex Nilai, Hypex NCX500, and Purifi 7040. Now I'm thinking about buying the Purifi 6525, and of course I want to rule out the possibility that these Purifi 6525 modules also have this problem.

Thanks in advance
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My experience has been that most power on/off pops are caused by upstream equipment, not amplifiers. I use a power sequencer (Furman PS-8R) to solve that problem. When it gets the "on" trigger from the preamp it waits a few seconds before powering on the amplifier. That gives the preamp and any other upstream equipment time to settle down before the amp comes on. On "power off" it reverses the sequence. The Furman is a little pricey, but there are other cheaper sequencers out there.
 
Stereoed said:
Hi Rick, thanks for the helpful answer.
Unfortunately, I can't measure the DC current. I'd have to buy a voltmeter and read up on how to measure it.
Yes. I also think the Yamaha isn't DC-coupled. However, the Class D monoblocks are current models. It's a Hypex Nilai. I connected the power amplifiers directly to the Eversolo A8 via XLR. I thought the Eversolo A8 was also a preamplifier. Unfortunately, I don't have a separate preamplifier at the moment. What Class D power amplifiers would you recommend? And would a Topping DX9 be suitable as a preamplifier?

Thanks in advance.
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What happens without the trigger cable? Realize is not convenient but may yield some clues as to how to remediate. Turn Eversolo on first and then the amp.

When turning off, start with the amp. Which speakers are you using?
 
RickS said:
What happens without the trigger cable? Realize is not convenient but may yield some clues as to how to remediate. Turn Eversolo on first and then the amp.

When turning off, start with the amp. Which speakers are you using?
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Hello, the problem persists even without the trigger cable. If I start the power amplifiers after the Eversolo has booted up, the noise is quieter. If I turn the power amplifiers off first, the noise is also quieter, but not gone. How can a separate preamplifier change this? Would the Topping DX9 be a solution? My speakers are Triangle Quator.
 
Stereoed said:
Hello, the problem persists even without the trigger cable. If I start the power amplifiers after the Eversolo has booted up, the noise is quieter. If I turn the power amplifiers off first, the noise is also quieter, but not gone. How can a separate preamplifier change this? Would the Topping DX9 be a solution? My speakers are Triangle Quator.
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As mentioned, is a common problem with separates. A preamp can act as a buffer (notably if not dc-coupled). Since you do not have one, it matters less...

I asked about the speakers mainly as have had heard some differences. Not sure whether is because of tweeter type or sensitivity or something else. If the manual power up improves the situation to a large extent, then a power sequencing power strip is a good investment.
 
RickS said:
As mentioned, is a common problem with separates. A preamp can act as a buffer (notably if not dc-coupled). Since you do not have one, it matters less...

I asked about the speakers mainly as have had heard some differences. Not sure whether is because of tweeter type or sensitivity or something else. If the manual power up improves the situation to a large extent, then a power sequencing power strip is a good investment.
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Ah. Thanks. Can you name a power sequencing power strip?
 
Stereoed said:
Ah. Thanks. Can you name a power sequencing power strip?
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Furman was mentioned but I do not have any to suggest. Notably, 240 Vac ones. Perhaps one of our European members can recommend.
 
RickS said:
Furman was mentioned but I do not have any to suggest. Notably, 240 Vac. Perhaps one of our European members can recommend.
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Thank you Rick. Greetings from Germany
Edi
 
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Buckeye Amps said:
I can only give the evidence I have based on testing and customer feedback. From those sources of data, there are a majority of users who report no sounds/pops during startup or shutdown.

Regarding speaker sensitivity, that would make sense but my JBL speakers were 101dB and had no pop sound at all.
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No pop in my system.
 
Stereoed said:
Hi Rick, thanks for the helpful answer.
Unfortunately, I can't measure the DC current. I'd have to buy a voltmeter and read up on how to measure it.
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Buying a DMM is the best thing you can do, even if you didn't have a problem as this one.
A cheap one (not dirt cheap though) could become handy in numerous situations.

By measuring the outputs of A8 (or any DAC/pre/etc) you could narrow or eliminate them as the cause.
I would also measure amplifier's output for DC right at the speaker terminals if I were you.
 
Stereoed said:
That's fine. I think I try the 6525.
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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.
 
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