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Buckeye Amps: Purifi Mono, 2ch, and 3ch Official Thread

Buckeye Amps

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Purifi 1ET400A specs:
- 450w @ 2ohm (per channel, peak)
- 425w @ 4ohm (per channel, peak)
- 225w @ 8ohm (per channel, peak)

Purifi 1ET7040SA v2 specs:
- 950w @ 2ohm (per channel, peak)
- 500w @ 4ohm (per channel, peak)
- 250w @ 8ohm (per channel, peak)

Custom Input Buffer Board w/:
- Neutrik XLR connectors
- OPA1612 Input Stage
- TI TPS7A49/30 Voltage Regulators
- Clipping Indication (via Front Power LED)
- Error Indication (via Front Power LED)
- Muted Soft-start/shutdown (minimizes speaker “pop” when turning on and off)
- Low, Med, High Gain settings
- Auto On/Off (along with Always On and 12v options)

Gain settings:
4ohm - 25.5dB/2.17Vrms (High), 20.5dB/3.89Vrms (Medium), 15.5dB/6.93Vrms (Low)
8ohm - 25.5dB/2.24Vrms (High), 20.5dB/4.02Vrms (Medium), 15.5dB/7.16Vrms (Low)

1ET7040SA Mono Amplifier v2 (Full Power Output):
(1) Purifi 1ET7040SA
(1) Micro Audio SMPS1k-PFCR2
Neutrik XLR inputs
Standard 5-way Binding Post outputs
10"x13"x3.5" Aluminum case

1ET400A Mono Amplifier:
(1) Purifi 1ET400A
(1) Hypex SMPS1200A400
Neutrik XLR inputs
Standard 5-way Binding Post outputs
10"x13"x3.5" Aluminum case

1ET400A 2ch Amplifier:
(2) Purifi 1ET400A modules
(1) Hypex SMPS1200A400
Neutrik XLR inputs
Standard 5-way Binding Post outputs
10"x12"x3.5" Aluminum case

1ET400A 3ch Amplifier:
(3) Purifi 1ET400A modules
(1) Hypex SMPS1200A400
Neutrik XLR inputs
Standard 5-way Binding Post outputs
12"x12"x3.5" Aluminum case

*Rackmount case upgrade available for $150

*Free US Shipping
*International shipping available

Email directly ([email protected]) for buying or if you have any questions at all

Visit our website for up to date specs, pricing, and pictures:
Buckeye Amps Official Site
 
Last edited:
OP
Buckeye Amps

Buckeye Amps

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So, the current approach is either going to be using the stock Purifi EVAL1 setup with an SMPS1200A400 OR using the Neurochrome Input Buffer

As of right now, using this thread to gather interest and whether the EVAL1 board is perfectly suited or if the Neurochrome is the better way to go.
Remember, my builds are meant to get the sound as "uncolored" as possible, so I would not be using any type of custom or aftermarket OP Amps.
 

beren777

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I'd be interested in seeing a x3 L/C/R build with the modules oriented vertically on heat sink trays, or the traditional horizontal orientation if vertical would be too tall. They could probably all share one SMPS1200A400 with a three-way splitter and still be fine for most purposes.

Would the Neurochrome do anything better than the EVAL1 or EVAL2 buffers?
 
OP
Buckeye Amps

Buckeye Amps

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I'd be interested in seeing a x3 L/C/R build with the modules oriented vertically on heat sink trays, or the traditional horizontal orientation if vertical would be too tall. They could probably all share one SMPS1200A400 with a three-way splitter and still be fine for most purposes.

Would the Neurochrome do anything better than the EVAL1 or EVAL2 buffers?
Depending on what people are willing to pay, this could be an option.
 

Doodski

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I think I am going to go the Neurochrome route. It seems straightforward and well regarded.
The Eval 1 PCB has all those connectors mounted on it and that can be a bad thing because the solder joints and copper traces break off the PCB when flexed. Not saying they will all fail although there is a reason better amps have separate connectors mounted on the chassis.
 

amper42

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The Purifi Eigentakt Stereo amp with OPA1612 differential input buffer has been measured and it's the standard that I really like. Has Amir measured the Purifi with the Neurochrome Input Buffer? If so, what's the link? Thank you!
 
OP
Buckeye Amps

Buckeye Amps

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The Purifi Eigentakt Stereo amp with OPA1612 differential input buffer has been measured and it's the standard that I really like. Has Amir measured the Purifi with the Neurochrome Input Buffer? If so, what's the link? Thank you!
I couldn't find a review. Maybe I'll be the first for Amir to review with the Neurochrome? ;)
 

thegeton

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I also like the possibility of an OPA1612 differential input buffer as well.
 

Madjalapeno

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Depending on what people are willing to pay, this could be an option.

When I have the design done I'll send you my CAD ;)

index.php
 

amper42

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I'm looking for Stereo Purifi amps. No need for heat sinks. The Purifi design runs amazingly cool. My P452 never gets warm in it's aluminum case. The NC502MP generates quite a bit more heat so I can see the value heat sinks might add there with long hours of use. But if Buckeye is trying to keep cost down on the Purifi build - heat sinks will increase prices and may not make much of a difference with a stereo Purifi design.
 
OP
Buckeye Amps

Buckeye Amps

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A fellow member reached out to me just now on designing a custom input buffer board using the OPA1612. Will keep everyone updated.
 

goryu

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I would be interested in a stereo amp with xlr's, speakons, and the Purifi buffer. As good as the neurochrome is, I doubt it has any audible benefits over the Purifi buffer.
 
OP
Buckeye Amps

Buckeye Amps

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I would be interested in a stereo amp with xlr's, speakons, and the Purifi buffer. As good as the neurochrome is, I doubt it has any audible benefits over the Purifi buffer.
Depending on pricing, I actually might not use the EVAL1 Purifi buffer. I am looking into an alternative board built around the OPA1612 and possibly having auto sense on/off technology
 
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