Review and Measurements of Purifi 1ET400A Amplifier

[JimB]

I have ordered some as well. I have tried engaging Ghent a couple times about these over the past few months, including sending mechanical details. Hopefully, we will see some good case options, soon.

 

[Massimo]

No, but Purifi has a cable set that costs very little and it is only a matter of plugging into the right holes, I believe they explain how.

The cable set is shown on the Purifi online shop. They are only terminated with connectors on the Purifi side. You need to work out the power supply side and terminate with connectors to suit your power supply. Purifi does not provide any instructions for cable terminations on Hypex power supply. But it’s easy enough to work out.

 

[JimB]

The cable set is shown on the Purifi online shop. They are only terminated with connectors on the Purifi side. You need to work out the power supply side and terminate with connectors to suit your power supply. Purifi does not provide any instructions for cable terminations on Hypex power supply. But it’s easy enough to work out.

Referral to those details, perhaps on another site, so others don't have to work it out individually, each time, or (heaven forbid) get it wrong?

 

[Sir Sanders Zingmore]

Slightly modified VAF i93 MK2 Signatures. Probably unknown outside of Australia. Forgive my poor photos but my room is so dark and has a lot of acoustic curtain (theatre black) so it’s very hard to get decent photos in there. View attachment 42358

VAF make some very nice speakers indeed.
From memory Philip Vafiadis worked with John Dunlavy (who may be better known to non-Aussies).
My memory is poor though so I hope I’m not just making this up

 

[Zoomer]

I have tried engaging Ghent a couple times about these over the past few months, including sending mechanical details. Hopefully, we will see some good case options, soon.

So he responded positively and is working on it? That would be great.

 

[Dion_Sinewave]

VAF make some very nice speakers indeed.
From memory Philip Vafiadis worked with John Dunlavy (who may be better known to non-Aussies).
My memory is poor though so I hope I’m not just making this up

That’s correct as far as I am aware. and I absolutely love my VAFs. I auditioned dozens of speakers before I chose my i93s

 

[JimB]

So he responded positively and is working on it? That would be great.

He has not responded about this. He might need to hear from more people with intent to buy. Then again, he might be ready to offer them.

 

[Zoomer]

Yep, I reached out myself last week to express interest, but no reaction so far. Busy drilling the holes in the right places I hope

 

[JimB]

Referral to those details, perhaps on another site, so others don't have to work it out individually, each time, or (heaven forbid) get it wrong?

A place to start on ASR:
https://www.audiosciencereview.com/forum/index.php?threads/diy-purifi-amp-builds.10478/#post-289105

 

[Julf]

Exactly, I didn't want to sell that nice looking amplifier, the result is much better than NC250MP based original was.

Better in what way?

 

[bill poster]

Wd op amp rolling be a worthwhile option on these purify modules? Thinking Burson V6 classics

 

[g29]

Wd op amp rolling be a worthwhile option on these purify modules? Thinking Burson V6 classics

You might find this review helpful.

OP Amp Review

 

[Julf]

Wd op amp rolling be a worthwhile option?

No.

 

[LondonLad]

Hello all, I'm new to the DIY amp/speaker world, would like to try out building some of these kits, I am not an electrical engineer but I have soldered on a PCB. I'm just trying out new things whilst in retirement and thought maybe I'd give Purifi a go. I'm learning as quickly as I can, so if my questions annoy the more seasoned of you, well, what can I say, try to keep in mind that you were once where I am knowledge-wise. One nube question that I have is how does the 1et400a board "know" what impedance my speakers are (they are manufacture-rated at 6 ohms, 3 ohms minimum, and are 86dB sensitive)? Second question, how does the board "know" what voltage it's being supplied (230 vs 120)? Or is this independent of the Purifi board and related only to the power supply board? Third, if I buy the Eval-1 kit from Purifi and pair that with a Hypex SMPS1200A400 2x64 VDC 1200 watt switch mode power supply, making sure all connections are correct, that's all I need to do to try out the Purifi "sound" (outside of installing everything in a box), yes? (If so, it almost seems radically too simple for an uninitiated person like me.) Forth, do I need to take into consideration the particular output specs of a preamp (or if no preamp a DAC) in order to fully test (sonically) this kit?

 

[Julf]

One nube question that I have is how does the 1et400a board "know" what impedance my speakers are

It doesn't, but it doesn't care either. As long as it is above the specified minimum, the amp is OK with it.

how does the board "know" what voltage it's being supplied (230 vs 120)? Or is this independent of the Purifi board and related only to the power supply board?

Purely an issue for the power supply, and at least the hypex SMPSs are autoswitching.

Third, if I buy the Eval-1 kit from Purifi and pair that with a Hypex SMPS1200A400 2x64 VDC 1200 watt switch mode power supply, making sure all connections are correct, that's all I need to do to try out the Purifi "sound" (outside of installing everything in a box), yes? (If so, it almost seems radically too simple for an uninitiated person like me.)

You might need a cable kit.

Forth, do I need to take into consideration the particular output specs of a preamp (or if no preamp a DAC) in order to fully test (sonically) this kit?

Not really. The output voltage of the preamp is likely to be close enough to what the purifi amp expects.[/quote][/quote]

 

[LondonLad]

Ok, Julf, fantastic. Many thanks.

Follow up, given the relatively lower sensitivity of the speakers I'm using, is there a sonic (or otherwise) advantage to using two (2) 1ET400As instead of the single EVAL1 board?

 

[Julf]

Follow up, given the relatively lower sensitivity of the speakers I'm using, is there a sonic (or otherwise) advantage to using two (2) 1ET400As instead of the single EVAL1 board?

Remember that the difference is only 3 dB - I would definitely start with a single one.

 

[mk1classic]

Ok, Julf, fantastic. Many thanks.

Follow up, given the relatively lower sensitivity of the speakers I'm using, is there a sonic (or otherwise) advantage to using two (2) 1ET400As instead of the single EVAL1 board?

The EVAL1 board is a stereo board. Bridging of 1ET400A is not recommended, at the moment, due to the feedback circuit according to Purifi.
I know developers are looking at bridging the two 1ET400A modules, but not sure about the outcome.

 

[LondonLad]

Ok, Julf and mk1classic, good to know. Many thanks again. Cheers.

P.S. Once I get this kit assembled and hooked up, is it unhelpful bad form to post my subjective sonic observations vis-a-vis the tube amplification I currently run?

 

[Julf]

Ok, Julf and mk1classic, good to know. Many thanks again. Cheers.

Cheers - and good luck!

P.S. Once I get this kit assembled and hooked up, is it unhelpful bad form to post my subjective sonic observations vis-a-vis the tube amplification I currently run?

Only if you assume / imply they have some more general validity.