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USSA-5 PCB GB

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M

meanie

Member
Joined 2018
tomtest said:
Hi Meanie,

I have had a quick look at Digikey, they have both in stock. Hope that helps.

By the way have you made a comparison between the SLB power supply and another maybe the one from Project16 / Prasi?
I have get my SLB PCB yesterday.;)

Kind regards
André
Click to expand...


Thanks Tomtest, I will start collecting the necessary parts soon.

I have bench tested a few power supply with my F6, M2X and Ussa5 modules while they are not properly housed into a chassis yet. All 3 amps have humming from the CRC, CRCRC and SLB, it was later that i found out that those hums came from ground looping issues. For M2X, the autotrafo has to be shield magnetically from the main Transformer.

Regarding the hissing noise from the tweeter, the first time i used the SLB, they are almost gone, i can only hear faint 50Hz signatures due to the hums from ground loop.

After i resolved the grounding issues, both hums and hiss are gone! The amp sounds a lot cleaner and sweeter in the high, eerily quiet in between music.
I m surprised that my F6(pretty lay back sounding) is almost comparable to M2X musically. Some may not agree to this...
And because it is so quiet, it's time for me to explore high efficiency speakers.

This is a new discovery to me, now i believed in capacitor multiplier power supply for ClassA constant current load.

I got 2 more sets of USSA5 pcbs coming soon, i will build each with a CRC, and CRCRC, then i can have a better comparison, to be fair.
 
hallcon83

hallcon83

Member
Joined 2008
Hi Fab , Thank you for checking the sound quality issue of going to a low bias into class A -------- Yes if necessary the 10 watts is possible . . . . just hoping for a little smaller carbon foot print if it could be worked out, a need to keep a long time wife happy - I may have after all these years have finally grown wiser, "happy wife happy life" - as it turns out may actually to be a real "thing" - :)
 
Vunce

Vunce

Member
Joined 2014
Paid Member
tomtest said:
By the way have you made a comparison between the SLB power supply and another maybe the one from Project16 / Prasi?
I have get my SLB PCB yesterday.;)
Click to expand...


Hi Tomtest,

While I haven’t compared the SLB against a conventional CRC using the USSA5, I have with a couple other Class A amps.
Alpha20 with DIYA store universal psu
Alpha BB monoblock with Project16/Prasi psu
MoFo with SMPS
The Alpha’s had a slight bit of hum I couldn’t get rid of. Not enough to be obnoxious but when I got close to the speaker the hum was audible. The MoFo was always quiet.
Swapping to the SLB made a big improvement, the Alpha’s were now dead silent at idle. (Less than 1mV ripple) As far as sound quality improvement that’s a harder item to quantify, I did feel there was improvement, but was it because of no background noise or the influence of the ideal rectifier vs. bridge rectifier
Anyway, I never gave a thought to power the USSA5 with a conventional bridge rectifier/CRC psu, SLB all the way!!
 
fab

fab

Member
Joined 2004
fabaudio.online
Paid Member
arthur said:
Fab, you have good memories
I just gathered 4 pairs of driver Mosfets and 8 pairs of the output Mosfets .
As the latest 5.1 can use Darlington transistors to drive the output Mosfets, I will try assembly them in the Christmas Holiday.
Then I will compare the sound quality with my newly bought Firstwatt Sit-3
Click to expand...
Arthur, well I remember the names that I put in the customs papers for shipment...
You want to build 2 x USSA5 amps during that time, that would be impressive :p
Sit-3 is a 4000$ USD amp so that would be quite a challenge for the USSA...:rolleyes: ensure you have a good PSU and many hours of break-in....
There is a review here where the SIT-3 is compared against others PASS amps such the J2 and the F7.

First Watt SIT-3 Amplifier Review | Part-Time Audiophile

Fab
 
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H

Harry3

Member
Joined 2005
Off topic comment

I don't think price has anything to do with it.
The architecture and the implementation is the most important aspect.

The guys here are using the latest and "best" components and power supplies that they can get their hands on.
Sure there are custom made stuff that manufacturers use but a good DIY can use alternatives or different methods to get great results.

I listened to a $45,000 valve amp and the owner admitted it was crap compared to a DIY amp that another friend had brought with him.....
 
A

AnthonyA

Member
Joined 2017
Harry3 said:
I don't think price has anything to do with it.
The architecture and the implementation is the most important aspect.

The guys here are using the latest and "best" components and power supplies that they can get their hands on.
Sure there are custom made stuff that manufacturers use but a good DIY can use alternatives or different methods to get great results.

I listened to a $45,000 valve amp and the owner admitted it was crap compared to a DIY amp that another friend had brought with him.....
Click to expand...
Yes.. Agree to proper implementation.. And correct topology.

Have to be patient.. Keen ears..


Example... Clc crc slb whatever.... All could work... Provided its properly implented each with own merit.. I used crc natural bloom with a little peaking on top. Capacitance multiplier, just clean. Better staging No noise.. But no bloom... Each have their unique way to overcome.. And not all expensive equipments are quiet.. Think about it.

Also handmade same brand and series..tube stuff Diff sound.. Some good some bad. Diy just need some luck and patience..
 
A

AnthonyA

Member
Joined 2017
fab said:
Arthur, well I remember the names that I put in the customs papers for shipment...
You want to build 2 x USSA5 amps during that time, that would be impressive :p
Sit-3 is a 4000$ USD amp so that would be quite a challenge for the USSA...:rolleyes: ensure you have a good PSU and many hours of break-in....
There is a review here where the SIT-3 is compared against others PASS amps such the J2 and the F7.

First Watt SIT-3 Amplifier Review | Part-Time Audiophile

Fab
Click to expand...

As papa Nelson always say
What speaker do you have.
What source and accessories do you have..
Under the right conditions.. All can be magical.

There is many diy sit here. And I say it's all about implementation and accompanying equipment.. The way I think... It's better to have every part is average good and well matched . Rather than one part bad one part excellent... Say we got best ampli. But lousy speaker lousy dac.. Scared of electricity bills.. Think about that also.. Furthermore... We can simply get a good tube preamp 2nd hand schitt Freya? There we get a balanced triode ..it might be cheaper to buy a set of good cable. Reliably good equipment.. Happy camper.
 
hallcon83

hallcon83

Member
Joined 2008
Hi Fab, I grew up in Washington state near the Canadian border - I actually Like the cold - :D . I sometimes wonder how I got here - life can be strange. I miss the temperatures dropping at night - it can be 100 in the day and 98 at night - a few years back we went almost 3 months with every day over 100 degrees - LOL
My wife is actually pretty easy going about my audio hobby, not every woman lets her partner/husband have horn speakers in the living room! - she's just become more concerned over the years about the environment -- so I make the effort to make her happy when I can too :) .
 
T

tomtest

Member
Joined 2018
Hi meanie and Vunce,

Thanks a lot for your feedback and impressions.
I will appreciate to hear your findings when you compare the different PSUs sound wise to each other.
I will hurry myself to build my own SLB PSU so I could share my findings too.
Still thinking about to split my USSA-5 into two mono blocks. If the PSU needs to much space than the decision is made.


Fab, thank you for all the ideas and support! I still have one set of PCBs which I wanted to use for a USSA-3, but if you need another person to try out your new ideas I could use it for this. Let me know if I could help.

Good luck with all the buildings and enjoy the results (as me).

Greetings
André
 
fab

fab

Member
Joined 2004
fabaudio.online
Paid Member
Hi Tomtest
You could probably test the USSA5B version if you do not mind to invert the collector-emitter pins of the output transistors....
I am also close to be able to listen to it so you can wait if you prefer... thanks for your offer.:)

If you send me again your email address I could send you the new manual (v 5 and 5.1) for your review if you have the time.
Fab
 
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fab

fab

Member
Joined 2004
fabaudio.online
Paid Member
Group buy status

Group buy status:
Fab - 4 pcs
Vunce - 2 pcs- USA :8$ or 15$ , PAID
Meanie -4 pcs- Singapore: 11$, paid
Brianco -2 pcs- UK: 11$ PAID
Boba1000 -2 pcs- USA: 8$ or 15$ (tracking)
FAA -2 pcs - USA: need postal code
Coolnose - 2 pcs- France: 11$, paid
Funke and Speedy - 4 pcs- Germany: 11$, paid
Gary s - 2 pcs- Australia: 12$
Potstip - 2 pcs- Turkey: 12$
mbrennwa - 2 pcs- - Switzerland: 11$, paid
Bfpca - 2 pcs - Canada : paid
Speedy - 2 pcs - Germany: 11$
Praudio - 2pcs - Canada : paid
Randytsuch - 2 pcs - USA: 8$ or 15$ (with tracking)
Arthur - 2pcs - Hong Kong :
Hallcon83 - 2 pcs - USA Texas:

Total pcbs: 40/40

Reserve list:
Myl - 2 pcs - Hong Kong -


Add 1$ for packing
Add 16$ for each pcb pair
Add 2$ for PayPal fee but only if gift not selected for reason

All in CAD $

Fab
 
Last edited:
fab

fab

Member
Joined 2004
fabaudio.online
Paid Member
Group buy status

Group buy status:
Fab - 4 pcs
Vunce - 2 pcs- USA :8$ or 15$ , PAID
Meanie -4 pcs- Singapore: 11$, paid
Brianco -2 pcs- UK: 11$ PAID
Boba1000 -2 pcs- USA: 8$ or 15$ (tracking)
FAA -2 pcs - USA: need postal code
Coolnose - 2 pcs- France: 11$, paid
Funke and Speedy - 4 pcs- Germany: 11$, paid
Gary s - 2 pcs- Australia: 12$, paid
Potstip - 2 pcs- Turkey: 12$
mbrennwa - 2 pcs- - Switzerland: 11$, paid
Bfpca - 2 pcs - Canada : paid
Speedy - 2 pcs - Germany: 11$
Praudio - 2pcs - Canada : paid
Randytsuch - 2 pcs - USA: 8$ or 15$ (with tracking)
Arthur - 2pcs - Hong Kong :
Hallcon83 - 2 pcs - USA Texas:

Total pcbs: 40/40

Reserve list:
Myl - 2 pcs - Hong Kong -


Add 1$ for packing
Add 16$ for each pcb pair
Add 2$ for PayPal fee but only if gift not selected for reason

All in CAD $

Fab
 
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