Hypex DIY Preamplifier Kit Review

[Hapo]

Hmm, hopefully this will not trigger the analog-preamp purists again regarding digital volume control.

...everyone keeps telling me to use a SMSL DO 100 for preeeamp...!!!...

...didna they see this thread...!?!...it not even the only one...!!!...

Topping E70 randomly went to MAX volume..

Not sure what happened but all the sudden the E70 went from -30db or so to 0db. Basically blew out my ears for a few seconds and it was stuck on 0db, I couldn't even lower it. Tried spinning the volume control on the E70 for a few seconds, it was locked at 0db. Afraid to put my windows volume...

www.audiosciencereview.com

 

[DanielT]

This should be done by Hypex. How much it would cost and how technically difficult it is, those who are more familiar with the economy and technology can find out:
Basic functionality with pre amp X number of inputs and Y outputs. In addition to that, you should be able to choose to add different functions (plus number of inputs and outputs) with SIMPLICITY. Whatever they may be. Just pay a little more to get access to…The main pre amp card is the same. You only select add on functions.

Edit:
Yes, I know physically adding more outputs and inputs with various contacts may not be the easiest, but this is just a thought. Maybe something that would be viable, sellable?

 

[sarumbear]

Hmm, hopefully this will not trigger the analog-preamp purists again regarding digital volume control.

It is an analogue signal path. Only the control is digital.

 

[Hapo]

 

[DS23MAN]

There are insert connectors that can well be used for filters to form a crossover and another connector for something called Fusion.

View attachment 276653

This pre amp will also suitable as a head unit for the Fusion plate amps, had something to do with the preconception of this nice little piece of gear. This idea was mine (Fusion). Those insert connectors are for the EQ board.

 

[BR52]

How is it done please give me idea of the signal chain. @sarumbear

 

[sarumbear]

This pre amp will also suitable as a head unit for the Fusion plate amps, had something to do with the preconception of this nice little piece of gear. This idea was mine (Fusion). Those insert connectors are for the EQ board.

In other words we are reading a review of an incomplete unit.

 

[PeteL]

When you say "Digital volume control", I assumed digitally controlled but analog? Or the actual inputs are digitized?

 

[FrankW]

Must be missing something but why does one need multiple analog balanced ins? The expansion slot will seemingly add another analog (unbalanced) and maybe multiple digital ins.
That would cover it for all my sources, but I guess not others that have multiple XLR out sources?

 

[sarumbear]

How is it done please give me idea of the signal chain.

Here is an example of a digitally controlled analogue volume control IC.

MAS6116 – Stereo Digital Volume Control IC | Micro Analog Systems

www.mas-oy.com

 

[amirm]

When you say "Digital volume control", I assumed digitally controlled but analog? Or the actual inputs are digitized?

Nothing is digitized.

 

[sarumbear]

When you say "Digital volume control", I assumed digitally controlled but analog? Or the actual inputs are digitized?

There is no digitisation of signal on this device.

 

[BR52]

Nothing is digitized.

Ok thanks

 

[sarumbear]

Must be missing something but why does one need multiple analog balanced ins? The expansion slot will seemingly add another analog (unbalanced) and maybe multiple digital ins.
That would cover it for all my sources, but I guess not others that have multiple XLR out sources?

A DAC and a disc player?

 

[JDS]

This is a review and detailed measurements of the Hypex DIY balanced Preamplifier and headphone amplifier Kit. It was sent by the company and kindly assembled by @Rick Sykora. It costs € 1.225,00 excl. VAT (US $1,331).
View attachment 276518

I very much like the larger form factor here and especially the very large graphical display. Alas, as you see, very small fonts are used to show the input and volume level. On power up you see a massive logo of the company and I expected to see that here. Good news is that the display and operation is quite responsive. A remote control is provided in addition to rich set of capabilities as far as renaming inputs, setting gain, balance, etc. Back panel configuration seemed puzzling to me:
View attachment 276519
I had to read the manual to confirm that there are two XLR outputs but only one input! Seems backward to me. What is the use for dual set of XLR outputs? In my system I have two XLR sources so this rules it out for my own configuration. There is RCA to balanced configuration although some would want to see RCA output as well.

The right blank cover is interesting as the company talks about DAC, phono stage, streamer and even some kind of EQ capability to go there!

Digital volume control is provided and reassuring set of relays click when changing inputs.

Let's see how it measures.

DIY ClassD Preamplifier Measurements
I started with XLR in/out and adjusted the volume to get unity gain:
View attachment 276520

This is most excellent with vanishingly low distortion at -140 dB! Some noise pulls SINAD down to still a transparent value of 119 dB. Switching to RCA input with 2 volts in, costs you a few dBs but still transparent:
View attachment 276521

Noise performance is excellent:
View attachment 276522

Frequency response is very extended and ruler flat in audible band:
View attachment 276523

Crosstalk is near state of the art:
View attachment 276524

IMD graph shows slightly higher noise than best there is but still excellent:
View attachment 276525

Similarly to what we see as far as distortion relative to frequency:
View attachment 276526

And level:
View attachment 276527

Hypex DIY Preamplifier Headphone Measurements
Let's start with our unity gain dashboard measurements:
View attachment 276528

This is excellent performance and good attempt at getting into the room with best of the best:
View attachment 276529

SNR is not as good as it could be because there is no low/negative gain mode to reduce noise:
View attachment 276530

This only impacts very sensitive IEMs though:
View attachment 276531

Other the aforementioned slight noise penalty, the level of output with 300 ohm load is very good:
View attachment 276532
I like to see minimum of 100 milliwatts which we have. Then again, for desktop products, we are used to 300+ milliwatts.

I was surprised to see a less competitive showing with 32 ohm load:
View attachment 276533

We are current limited as we see better in this graph:
View attachment 276534

I expected to see a "checklist" headphone amp but this performance is a lot better especially if you use high impedance headphones.

Hypex DIY Preamplifier Listening Tests
I drove the unit using RME ADI-2 Pro balanced output and listening using Sennheiser HD650. The experience was superb with excellent detail and dynamics. There was plenty of volume, capable of getting good bass out of this headphone. As measurements predict, switching to my everyday Dan Clark Stealth headphone resulted in static and distortion at anything but very mild volume level. Really not useful with this power hungry headphone.

Conclusions
We are used to seeing power amplifiers from Hypex. It is nice to see them get into preamplifiers by producing a unit with exceptionally low distortion and quite competitive noise performance. I like the large form factor and display but wish the company revises the firmware to show larger text for input and volume level. Having two balanced output at the expensive of another balanced input doesn't make sense to me but maybe one of you will enlighten me.

I expected the headphone amp to be as we say in the industry, "phoned in," but it actually turned in very good performance for high impedance headphones. It should also be OK with lower impedance headphones as long as they are sensitive.

I am happy to put the Hypex DIY Preamplifier and Headphone Amp Kit on my recommended list. Look forward to new option cards for it!

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As always, questions, comments, recommendations, etc. are welcome.

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In the 1950s, my parent's built a (mono) Dynakit amplifier and preamplifier. I don't know the original prices, but the price of this preamp translates to around $120 in 1957 dollars. I'm guessing that's what the Dynakits cost back then. In the 1980s I built a Hafler amp kit. It cost about $1000 in 2022 dollars. So the cost of this unit may seem high, but only because of the embarrassment of riches in high-performance, low-cost alternatives today.

The part that surprised me -- a DIY preamp that does not require a soldering iron.

 

[sarumbear]

The part that surprised me -- a DIY preamp that does not require a soldering iron.

Blame the shipping costs from the East.

 

[DS23MAN]

In other words we are reading a review of an incomplete unit.

No, this the basic unit as a analog pre amp with MOLA MOLA specs and internals.

 

[HarmonicTHD]

Wouldn't connecting a DAC directly to a power amp risk frying your speakers if there's a bug in the DAC firmware that randomly resets/ changes its output volume? See horror story linked below.
Not trying to save this particular product, just asking as a newbie.

Topping D70S fried my speakers...

I don't know why but today when I switched on the Topping D70S the volume was at -0db. Of course, i never set the volume so high, and usually the dac reminds the volume of the previous time, but not today. Result: the amplifier fried the tweeter of one loudspeaker. I don't know what the Topping...

audiosciencereview.com

I have connected DACs to poweramps for 10 plus years into expensive speakers. Never had a problem.

In this particular case of the Topping. Either don’t buy the model, stay clear of the brand, switch on the DAC first or if you really must add a passive attenuator in between for a fraction of the cost.

 

[sarumbear]

No, this the basic unit as an analog pre amp with MOLA MOLA specs and internals.

Where do you see the range that you say it’s the basic configuration?

 

[DS23MAN]

Where do you see the range that you say it’s the basic configuration?

Do you want me to dig up my early drawings of this pre amp?