DIY Purifi Amp builds

[mocenigo]

Maybe a chance for you as a DIY supplier. Why not to design an input buffer with gain = 1 and high input impedance, based on JFET/CMOS input opamp like OPA2156?

OPA2156 data sheet, product information and support | TI.com

TI’s OPA2156 is a Low noise (3-nV/√Hz @10kHz), high speed (25-MHz, 40-V/µs), CMOS precision RRIO dual op amp. Find parameters, ordering and quality information

www.ti.com

Tom already has one. It is a composite one and it can be configured to have unity gain.

 

[restorer-john]

Received a replacement sample from Soundimports and it works fine. Nice customer service! Appreciated!
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Can you post a 1kHz loopback of the measurement system without the Purifi (same 10V range). How much of the harmonic structure is due to the ESS A/D-D/A system itself Pavel?

So we've got 60uV of A-WTD noise in addition to the measurement system (~2.0uV). Is the software you are using, performing "noise in the presence of signal test" or a typical S/N test? (short the inputs, measure the output noise, reference it to the power level you are using). Does the noise floor of the Purifi change through its power band?

Why 22W? Why not 1W, 5W or full power?

 

[Iwf]

Sorry for butting in. Does anyone have a diagram showing how to use a SMPS600n400 with the mono eval kit. I’ve a Nord based 2 channel amp, but thought I’d have a go at a mono for my centre speaker. The mono eval kit arrived last week and I’ve. SMPs left over from an old hypex build.

Thanks in advance

 

[coreyriggle]

Are there kits or enclosures available to build a 4+ channel with the EVAL2 Mono 1ET400A evaluation kit. Basically I want a 4+ mono amplifier in a single chassis. Similar to what apollon is doing. https://apollonaudio.com/apollon-audio-premium-amplifiers/
I'd love to DIY it. Cheers.

 

[Rick Sykora]

Are there kits or enclosures available to build a 4+ channel with the EVAL2 Mono 1ET400A evaluation kit. Basically I want a 4+ mono amplifier in a single chassis. Similar to what apollon is doing. https://apollonaudio.com/apollon-audio-premium-amplifiers/
I'd love to DIY it. Cheers.

Welcome to ASR!

There are plenty of cases and suppliers depending on how much you want to spend and whether you are willing to do metalwork. Unless you can get OEM pricing on the Purifi modules AND power supplies, it will be hard to compete with those that do. Even if you need to double up on complete 2 or 3 channels amps, it will still be a challenge for DIY to be cost effective. Ofc this depends on what kind of case you want and whether you can customize it for your project.

As BIY (Build It Yourself) goes (no metalwork), here is a simple example.

A 2-channel Ghent case can be had for around $240 shipped, and it has all the wiring and connectors. An Purifi EVAL-1 board is about $750 shipped. So, before power supply, you are at $990. A Buckeye 2-channel Purifi amp goes for $1125. So, this leaves you with $135 to find a decent power supply. It is close, but likely you will need to spend more. Btw, the Buckeye amp gives you auto-on/off, trigger input and multiple gain settings that you did not get with the DIY effort.

Hope this helps but can get more specific once you divulge your budget and willingness to metalwork.

 

[ryanosaur]

Are there kits or enclosures available to build a 4+ channel with the EVAL2 Mono 1ET400A evaluation kit. Basically I want a 4+ mono amplifier in a single chassis. Similar to what apollon is doing. https://apollonaudio.com/apollon-audio-premium-amplifiers/
I'd love to DIY it. Cheers.

I did a BIY with Hypex NC400s and Ghent Chassis... Was it worth it? yes. Was it a complete PITA? Oh helz yes it was.

While I enjoyed the process and have two Ghent chassis contains 5 mono block channels, I would most likely just buy from Buckeye next time I add some Amps to the party.