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First One - mosFET amplifier module

hi
zman01, yes the comparaison is with the that1200 module when using the hypex, and then yes I can say that the 2 smps did bring something more in the separation and details... from a crosstalk standpoint I dont understand why, maybe this is the fact that you remove one device in the signal path...
This would require complete ABA test with a bit of a test equipement to make swaping easier so please do not take the comment as pure science but after this test, if I add to choose between one big spmp or two "smaller" for a comparable budget (or even less with the Sale), I d go with 2 :)

LC, thanks for asking, I m in the process of building my ultimate biamp with 4 modules and a pair of hypex, so the volume is one part of it and I come to the conclusion that I have to reshuffle the PCB... but the topic is still very valid and count on me to share as soon as I feel confortable. By the way, what do you think about the possibility to put a -6/-12/-18db attenuation with 2 relays and 2 resistor just in // of the 4x2200 resistor ?? as it is CFA this should be ok ? I like this idea which would bring better snr than upfront attenuation. And with such attenuation in the amp, then a digital volume control in a DAC might be very acceptable...

That said, I ve made some deep simulation in the past days to find the best way to combine 2 FO on a single hypex and also to find a smart solution for bridging 2 modules which I m gona implement on my quad-FO in order to compare bi-amping and bridging ... and I ll keep you posted on that.
 
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Preparing First One 1.2 for audition

It is going to be pwoered by SMPS 600/1200W from Crescent

Hopefully would be able to hear it by next week :)

Very thrilled to hear it playing

Btw LC, any news on First one L?


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Sent from my ONE A2003 using Tapatalk
 
Preparing First One 1.2 for audition

It is going to be pwoered by SMPS 600/1200W from Crescent

Hopefully would be able to hear it by next week :)

Very thrilled to hear it playing

Btw LC, any news on First one L?

I have several of those SMPS at home, including some Hypex and I still have to update my old thread about SMPS and FirstOne amplifier started a year or two ago (maybe more). But after listening several hours of both, I can confirm at least to my ears, that the Crescent is on par with the Hypex and seem to have a better drive once the output caps are replaced with same low ESR type but higher capacity. Definitely worth buying in my book. I'm talking about the latest 600W model. I will most likely sell the Hypex in the near future or assign them to another project.

Do
 
Here's mine, now working

Hi !

I finally found time to finish installing my 1.4M modules in my (not so) old chassis (Hifi 2000 2U 400mm, previously used with LM3886 modules).
Dual mono PSU, with 2 300VA 2x24V transfos.

Sound wise : huge improvement in the low medium and bass range.
40°C on the radiators.

The case is still open, and a couple of pictures .........

Very thankful for these excellent modules - and their very reasonable price.

J-M
 

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I have several of those SMPS at home, including some Hypex and I still have to update my old thread about SMPS and FirstOne amplifier started a year or two ago (maybe more). But after listening several hours of both, I can confirm at least to my ears, that the Crescent is on par with the Hypex and seem to have a better drive once the output caps are replaced with same low ESR type but higher capacity. Definitely worth buying in my book. I'm talking about the latest 600W model. I will most likely sell the Hypex in the near future or assign them to another project.

Do

That's interresting, I read your previous comparo and indeed it would be nice to have it updated with the Cresnet, especialy given the high Hypex prices.

It would be also interresting to find out if changing the Cresnet caps is still worth doing once the additional caps are installed with the 1.4M modules.

Or, if not, if Cresnet plans a dedicated version for LC :)

Are the Cresnets as safe and as easy to install than the Hypex? Or are there trade offs or mods required?

Thanks again for your feedback!

Claude
 
Hi Everyone,
in the past days I had the chance to test my dual FO 1.4M with 2 smps from audiopower.it version DPS-400/S1 and I thought I could share some info and picture.
I knew this supply from a previous project 2 years ago, and till then they have revised this smps with a new transformer and the overall power is said to be supporting 600watt and more than 600ma continuous current (bias) wihout any overload problem.
I wanted to keep the overall temperature of the amp below 50°C and then I have chosen a 2x52V version, which is 10V less than hypex, so the overall dissipation (without signal) is 29watt per heatsink instead of 35watts, reducing the heatsink temperature of about 3 degrees.

The result is amazing good soundwise. with the 2 smps, obviously the result is better than with 1 big hypex!. I can hear more séparation across the 2 speakers. for the bass, it is a mater of volume listening.

the SMPS is quite compact (105x105) and can be fixed on a standard 2U 300x80 heatsink, with the FO.

the only drawback I see is that the supply do not have the posibility to directly connect a DC current protection (as sold by LC) as its standby mode is not "latched" so if your concerned by DC protection you have to add a traditional relay based protection.

here we are with another alternative to make compact dual mono system, for example using the "mini dissipante" case.
An externally hosted image should be here but it was not working when we last tested it.

Very good price for audiopower.it SMPS! It would be interesting to hear a direct comparison with Hypex and especially to see it under the scope...
 
That's interresting, I read your previous comparo and indeed it would be nice to have it updated with the Cresnet, especialy given the high Hypex prices.

It would be also interresting to find out if changing the Cresnet caps is still worth doing once the additional caps are installed with the 1.4M modules.

Or, if not, if Cresnet plans a dedicated version for LC :)

Are the Cresnets as safe and as easy to install than the Hypex? Or are there trade offs or mods required?

Thanks again for your feedback!

Claude

The SMPS-600 is safe 100%, And its very easy to mount.

There is no dedicated version at all. I only update / upgrade as per users request.

Dominic used expensive capacitors for his SMPS units.

The SMPS uses highest quality parts, being sold at low price to make it available for everyone.

Thanks
 
I will have to update it but not now. I'm finishing up a pair of Troels Gravesen ATS-4, also an amplifier for a friend and I really have to finalize my FO v1.4 which was previously working with the AudioPower SMPS (This was my v1.2 & v1.3 setup last year). Had to remove them since once the cover was closed, the SMPS would go into overheat protection and shutdown. I have since bought some other SMPS as stated in other post.

I'm not letting you down LC, just need to find more time!

Do
 
Crestnet's SMPS are very interesting.
Remember that instead of swapping caps you can also add capacitance for improved performance, as LC did. I use Thermistors in series with the primaries just in case...

I used the SMPS800RE from connex for another project (500W amp) and added 12mF without troubles.
This is the best connex has produced so far, IMHO.

Cheers,
M.
 
Hi !

I finally found time to finish installing my 1.4M modules in my (not so) old chassis (Hifi 2000 2U 400mm, previously used with LM3886 modules).
Dual mono PSU, with 2 300VA 2x24V transfos.

Sound wise : huge improvement in the low medium and bass range.
40°C on the radiators.

The case is still open, and a couple of pictures .........

Very thankful for these excellent modules - and their very reasonable price.

J-M

Hi JM,
good to see another FO 'in the box' !
on your pictures, it seems you use a spealer protection which is on a single board in the midle of the case, right ?
correct me if I m wrong but I think this board is connected on both GND of each side ... therefor removing the main benfit of dual supply which is to separates ground till the original RCA socket say in the DAC...
doing so reduce damping, signal/noise, create some hum (even if you dont hear it it will modulate the signal and create IMD) and finally impact cross talk.

I recomend 2 separated speaker protection, in order to avoid the internal gnd connection.
cheers / enjoy the FO sound !
 
Preparing First One 1.2 for audition

It is going to be pwoered by SMPS 600/1200W from Crescent

Hopefully would be able to hear it by next week :)

Very thrilled to hear it playing

Btw LC, any news on First one L?
Hi Aradan

Thanks for posting, couldn't find time to gratitude you on the build before. Great to see FO v1.2 still around occupying some new chassies, playing music. :up:
Regarding FO L, just holding the boards, looking great, their trip continues on Monday going into modules production. :)