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

[amper42]

I can do proper trigger control as well, have a toggle switch for always on, trigger, or auto sense

That's what I like about Buckeye Amps. Dylan's not just building what he thinks he can sell but also an amp he wants to use personally.

 

[Matias]

I only suggest to keep in mind that the more powerful Purifi module is just about to be released when designing the chassis you could have it work for both options (1 PS + 2 standard modules or 1 PS + 1 high power module).

 

[bo_knows]

I would be interested in a Purifi amp that has RCA inputs as well and it can be fully driven by 2V coming from Denon Receiver. I believe Apollon has such a design.

 

[amper42]

I would be interested in a Purifi amp that has RCA inputs as well and it can be fully driven by 2V coming from Denon Receiver. I believe Apollon has such a design.

With a 26.5dB gain the Purifi amp works fine with the Denon 4700 using the Monolith XLR to RCA cables. Audyssey increases the levels +2 dB to match the internal AVR amps. Adding RCA plugs to the Purifi build adds cost for everyone while most will use it with XLR DAC's and Pre-amps. There are many different brands of XLR to RCA cables available that work for this purpose. The key will be having a 26dB gain stage on the Purifi if you plan to use it with the Denon 3700/4700/6700.

Amazon.com: 3 Foot - RCA to XLR (Male) Cable Pair - Canare L-4E6S Star-Quad Audio Interconnect Cable & Neutrik-Rean NYS RCA & Neutrik Male XLR Gold Plugs - Custom Made by WORLDS BEST CABLES : Musical Instruments

Amazon.com: 3 Foot - RCA to XLR (Male) Cable Pair - Canare L-4E6S Star-Quad Audio Interconnect Cable & Neutrik-Rean NYS RCA & Neutrik Male XLR Gold Plugs - Custom Made by WORLDS BEST CABLES : Musical Instruments

www.amazon.com

Monoprice 6ft Premier Series XLR Male to RCA Male Cable, 16AWG (Gold Plated) - Monoprice.com

An XLR to RCA cable converts a balanced audio signal into an unbalanced signal. This is good for sending audio signals from an XLR source to an RCA input, or vice versa. Regardless of direction, the r

www.monoprice.com

 

[Keened]

With a 26.5dB gain the Purifi amp works fine with the Denon 4700 using the Monolith XLR to RCA cables. Audyssey increases the levels +2 dB to match the internal AVR amps. Adding RCA plugs to the Purifi build adds cost for everyone while most will use it with XLR DAC's and Pre-amps. There are many different brands of XLR to RCA cables available that work for this purpose. The key will be having a 26dB gain stage on the Purifi if you plan to use it with the Denon 3700/4700/6700.

Amazon.com: 3 Foot - RCA to XLR (Male) Cable Pair - Canare L-4E6S Star-Quad Audio Interconnect Cable & Neutrik-Rean NYS RCA & Neutrik Male XLR Gold Plugs - Custom Made by WORLDS BEST CABLES : Musical Instruments

Amazon.com: 3 Foot - RCA to XLR (Male) Cable Pair - Canare L-4E6S Star-Quad Audio Interconnect Cable & Neutrik-Rean NYS RCA & Neutrik Male XLR Gold Plugs - Custom Made by WORLDS BEST CABLES : Musical Instruments

www.amazon.com

Monoprice 6ft Premier Series XLR Male to RCA Male Cable, 16AWG (Gold Plated) - Monoprice.com

An XLR to RCA cable converts a balanced audio signal into an unbalanced signal. This is good for sending audio signals from an XLR source to an RCA input, or vice versa. Regardless of direction, the r

www.monoprice.com

I'd rather have multiple gain options built right in then have to open it up and use jumpers. Especially since a lot of AVRs use ~1v outs. Also XLR -> RCA isn't always done in a standardized way, I'd rather have RCA in and keep things to a known simple standard. The Neurochrome board can take SE in and send balanced out safely.

Essentially, I'd like to see the Apollon general design without the extra overhead of Op-Amps by default (although a space add on them on afterwards would be prudent).

Vertical design is also nice, but it should be packed tighter together otherwise what's the point?

Also in the DIY thread they were discussing a new Hypex SMPS that will have all three channels the same instead of having to reverse one of the channels for 3 channel output and on the DIYAudio forums they were suggesting that the new powersupply would also have some other benefit with 'pumping' or something like that. So maybe wait for those.

 

[amper42]

I'm looking for great prices on a quality Purifi stereo amp design with XLR inputs that beats VTV prices and build quality. If you guys start asking for RCA inputs, overload LEDs, front on/off switch, multiple gain switching, the ability to switch out buffer modules, heat sinks and other stuff that are not required for a great sounding amp then the Buckeye build will be closer to a $1700 design like Boxem or March Audio.

 

[Hcg76]

I’d be interested in a 4 channel Purifi amp.

 

[617]

A collab with TC would be cool and would be my choice.

 

[Buckeye Amps]

It may detract some buyers, but the design I am going for is XLR in only. A properly wired RCA to XLR cable will still always be all that is needed for those with RCA.

There will be adjustable gain.

The goal is affordable yet excellent performing product.

 

[Dundas]

I can do proper trigger control as well, have a toggle switch for always on, trigger, or auto sense

I know you can but when you start talking about custom buffers I wonder what the effect will be on the price. Would this still be a Neurochrome buffer?
As the wish list grows so does the price. Clipping indicators, power regulators, soft start, dual selectable balanced/unbalanced inputs, externally adjustable gain. Where to stop?

 

[Buckeye Amps]

I know you can but when you start talking about custom buffers I wonder what the effect will be on the price. Would this still be a Neurochrome buffer?
As the wish list grows so does the price. Clipping indicators, power regulators, soft start, dual selectable balanced/unbalanced inputs, externally adjustable gain. Where to stop?

At the moment I am pricing a custom input buffer that has the following:
- OPA1612
- Similar voltage regulator(s) as the EVAL1 board
- Hypex SMPS1200A400 input
- PCB mounted Neutrik XLR connectors (with screws to secure the connectors to the back chassis for extra durability)
- Speaker binding posts (not PCB mounted)
- Slide switch for Auto Sensing, Always On, 12V Trigger in (12v trigger PCB mounted)
- Slide switch for Low, Medium, High gain

Depending on cost, I may eliminate a feature or two. Waiting for the quote.

The input board would be for 2ch and then a similar board for 3ch.

 

[Dundas]

It may detract some buyers, but the design I am going for is XLR in only. A properly wired RCA to XLR cable will still always be all that is needed for those with RCA.

There will be adjustable gain.

The goal is affordable yet excellent performing product.

As I'm sure you know Neutrik make an RCA jack that would be a low/no cost directs swap for the XLR that could take advantage of the single ended capabilities of the Neurochrome buffer. While I personnaly use XLR not everyone wants or needs it.

 

[Buckeye Amps]

While I initially mentioned Neurochrome, at this time I am pursuing my own custom board. If that doesn't work out due to price, then I will revert back to the Neurochrome OR go with the EVAL1 for simple 2 channel.

 

[Dundas]

At the moment I am pricing a custom input buffer that has the following:
- OPA1612
- Similar voltage regulator(s) as the EVAL1 board
- Hypex SMPS1200A400 input
- PCB mounted Neutrik XLR connectors (with screws to secure the connectors to the back chassis for extra durability)
- Speaker binding posts (not PCB mounted)
- Slide switch for Auto Sensing, Always On, 12V Trigger in (12v trigger PCB mounted)
- Slide switch for Low, Medium, High gain

Depending on cost, I may eliminate a feature or two. Waiting for the quote.

The input board would be for 2ch and then a similar board for 3ch.

Wow, hard to keep up!
So Neurochrome out 3 channel in?

 

[Deleted member 23424]

The custom board I am exploring would have Auto Sensing On/Off

This already exists on the @boXem | audio Purifi. It's a brilliant function.

 

[Buckeye Amps]

Wow, hard to keep up!
So Neurochrome out 3 channel in?

2 and 3 channel options.

 

[Matias]

The input board would be for 2ch and then a similar board for 3ch.

Why not mono input boards and you can scale them for 1 to N channels in the future?

 

[Buckeye Amps]

Why not mono input boards and you can scale them for 1 to N channels in the future?

That is factoring into the price. Though for right now I would only be targeting two and three channels. If once I roll everything out there is interest from people who REALLY want to use Purifi modules for surround and Atmos speakers...

 

[jtwrace]

I think you must produce MCH amps too.

 

[AudioJester]

The problem with custom boards is many of them dont measure well. However, gives other features like adjustable gain or bypass etc.