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ggetzoff
Messages : 7
Date d'inscription : 17/11/2017

USSA 5 build and questions

le Ven 17 Nov 2017 - 23:44
Thanks to Fab and Alex I have a beautiful design and pretty boards: 


1. How many BC550C, 560Cs should I order to get Hfe <30%, <50% per manual?

2. Project16, do you still have PSU boards? I have very large PSU boards for Pass amps, too large for this build.

Looking forward to building this amplifier. Going to do mine in a 3U chassis. Already ordered the laterals from the UK and matched 2013/313s. Those were the unobtanium parts!!!!!!

Again, thank you Fab!!!!

Cheers,

Greg
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Fab
Messages : 1223
Date d'inscription : 29/03/2013
Age : 97
Localisation : Voie Lactée

Re: USSA 5 build and questions

le Sam 30 Déc 2017 - 22:56
Hi Greg
Happy holidays !
Any update on your build?

-----------------------
Quel est ton niveau d'avancement?

Fab
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ggetzoff
Messages : 7
Date d'inscription : 17/11/2017

Re: USSA 5 build and questions

le Dim 3 Juin 2018 - 16:14
Then slowly, with many containers of bananas consumed .....






Then matching of input BJTs ....






Ready to test the front-end: I did not follow Fab's amazing manual instructions and built both boards at the same time .....




Then Testing .....




The Profusion Fets are still available in a few matched sets. I bought the FETs from this thread:


http://www.diyaudio.com/forums/vendor-s-bazaar/291486-selling-zhou-fang-remaining-stocks-including-rare-toshiba-transistors-26.html 






Then one channel finished:






Now the PSU boards. Thankfully, Project16 via Prasi (diyaudio name) provided beautiful boards: 


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ggetzoff
Messages : 7
Date d'inscription : 17/11/2017

Re: USSA 5 build and questions

le Dim 3 Juin 2018 - 16:24
PSU boards populated, soft start added, CL-60's added for ground loop breaking on each side: 

Soft start module: http://sjostromaudio.net/shop/mains-circuits/13-sst01-softstart-for-toroidal-transformers.html



Then burning each channel in and bias after 45 minutes. Then amplifier was biased again with lid on after some 1 hour of "baking in the oven" in my wimpy 3U chassis:



However, first I needed to calculate output Mosfet VGS.....both Fab (after a case of bananas sent and Project16 verified my numbers)


Then board 2: 



Then.....break-in and some listening!!!!





And finally done!!!!
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ggetzoff
Messages : 7
Date d'inscription : 17/11/2017

Re: USSA 5 build and questions

le Dim 3 Juin 2018 - 17:37
The amplifier now has some 50 hours of burn-in. Therefore I can now do the review:


Speaker used: Martin-Login Montis electrostatic loudspeaker with powered woofer
Pre-amp: DCB1 hot-rod (high-current, shunt-regulated buffer) with DACT 21 style shunt attenuator (I am now listening with just my attenuator)
DAC: Eastern Electric Mini-Max Supreme 12AU7 buffered ES9018
interconnects: pure-silver in PTFE insulator
Source: Tidal music accomplished via Roonlabs from a dedicated Windows 10 server.
Amplifiers compared: VHEX+ and Aleph J (both built by me)


I didn't really know what to expect with this amplifier. I had never owned a Class-A amplifier of this power rating. With my incredibly sensitive loudspeaker I knew that it would be enough power, but would it be different from others amps I've heard, such as the Aleph J that I built? 


So, I started off with Adele 25, Hello






Adele's vocals on this album are stunning and breathtaking, my  jaw dropped with the clarity that the USSA-5 was revealing. You have to understand that my loudspeaker, with ~500 sq. in. of radiating area reveals everything in both the recording and the equipment: nothing can hide from this speaker, nothing. Now back to the vocals. 
What I hear from this amplifier in this recording is each track of the stiched together by recording engineer Ariel Rechtshaid. I've heard this type of clarity before in an amplifier, but I've never heard warmth and the focus like this. A transcendent experience.


Hearing that focus is incredibly rare from a piece of audio equipment. What the USSA-5 does is peel back the the layers (banana peel if you so choose) and allows the recording to be heard. Another way to describe this amplifiers sound would be that of headphones: the presentation is tightly focused right at the listener. Not to say that the presentation is too forward or too narrow. It is not. What it is brilliance in engineering. 


The reality is, that although this is a simple amplifier in name and parts count, it is not in its design. Each iteration of the USSA-5 has built upon and benefited from the experiences of each iteration. When it comes to engineering anything, IMHO, circuit design is number one, followed by active devices, then distantly by passive. So, you can buy all the boutique audio parts you want, but they will not help a poor design. For that reason, I built the USSA-5 with those parts specified in the BOM, with the exception of C2 (Sonic Cap Gen I).


Back to listening. Fab was a little concerned that the LF of his amplifier design would not come through my powered woofer the Montis. I can tell you that it does. Let's take another recording:






This album was originally  supposed to be written by Johan Johansson (sadly, he has passed away), however, creative differences led to a change. Hanz Zimmer and Benjamin Wallfisch provide us with a descending sonic roller-coaster, dropping us from an apex into a sledgehammer of low frequency and power. The Montis excited and resonated my slab home (5,000 sq. ft.) to its core. Oh yes, the USSA-5 does LF! But, this isn't one-note bass. This is articulate mastery of low frequency the likes I've never heard out of my system. This is a PHD of low frequency: tone and emotion are vivid and illuminated. That's what this amp does: it simply illuminates the recording. Wire with gain.  


The album finishes with the sweet and supple vocals of Lauren Daigle in Almost Human. In this track, Lauren gives us enormous vocal range: softly, then soaring to Alto with tremendous control. The USSA-5 separates her vocals, allowing them to crescendo in the room while still maintaining spectacular separation and timber of accompaniments. 


Then I-shifted to Some Great Jazz Reviews another from German: Klaus Doldinger's Best:


Can't say enough about this guys work. Track one: Blues for George. The USSA-5 allows us to crawl into and take a respite from the world inside of Klaus' saxophone. Piano accompaniments notwithstanding. The USSA-5 foams with clarity, and openness with this album. Touch and emotion abound. You are transported to another time and place, floating in the ether of audio bliss. Oh yeah, this is really a good amplifier. 


Compared to my other amplifiers what can I say? The VHEX+ is a class A/B design, with much more power. This amplifier is revealing but nowhere near what the USSA-5 provides. It can drive my panels very well with no strain. But it misses on emotion. The Aleph J is closer in its design and intent: a voltage source, class-a amp by the brilliant Nelson Pass. Nevertheless, it simply cannot compete with Fab's design. At this point it is an older design, better by his newer ideas. 


I have never heard any of the other First Watt designs, therefore, I cannot comment on how they compare to the USSA-5. 


A little bit about myself. I work at a very short work week, and while at work, I am constantly working at home. I spend a lot of time listening to music. I can afford any amplifier product. But, I have never heard an amp that sounds this good. Yes, there are commercial products that may be good, but you will pay dearly for them. I've been building loudspeakers for 30 years and have started building my own electronics about 10 years ago. I'm not good at it, but i'm learning. I don't buy "snake oil" products: I build everything myself. Sometimes I buy things because it is just frankly easier to do so when a commercial product is better design then I can find out there. Enough about myself. 


In closing, the USSA-5 is brilliant engineering: it is a triumph of both emotion and truth. 


Isn't that what we are looking for in life?


Cheers,


Greg
ClaudeG
Messages : 21
Date d'inscription : 22/06/2016
Age : 47
Localisation : Paris

Re: USSA 5 build and questions

le Lun 4 Juin 2018 - 7:47
Très beau reportage photo et un CR d'écoute très détaillé - merci beaucoup de ce partage!

C'est encourageant, voie tentant, les réalisations de Fred commence à faire du bruit, enfin plutôt beaucoup de musique!

Je te souhaite une excellente écoute et beaucoup de plaisir

Claude
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Project16
Messages : 737
Date d'inscription : 03/10/2015
Localisation : Cognac (France)
http://project16.altervista.org/

Re: USSA 5 build and questions

le Lun 4 Juin 2018 - 10:57
Congratulations, so here again congratulations Greg for this beautiful layout of your very own realization and then this return on your musical plays are really fun.
I think it's really a nice thank you to Fab who shared this design that leaves nothing to chance and that really deserves to be recognized by many.


---


Bravo, alors là encore bravo Greg pour cette belle mise en page de ta réalisation très propre et puis ce retour sur tes écoutes musicales font vraiment plaisir.
Je trouve que c'est vraiment un beau remerciement à Fab qui a partagé ce design qui ne laisse rien au hazard et qui mérite vraiment d'être reconnu par beaucoup.


Wink
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pinnocchio
Messages : 2505
Date d'inscription : 25/03/2013
Localisation : Montreal

Re: USSA 5 build and questions

le Lun 4 Juin 2018 - 11:01
Salut ggetzoff,
Superbe réalisation!! Je suis très content que tu aimes cet ampli. Je suis entièrement en accord avec ce que tu dis de cet ampli, c'est d'ailleurs pour moi aussi mon ampli préféré.


Hi ggetzoff,
Superb build! I'm so thrilled you like the amplifier. I'm also entirely in agreement with you about what you say about the amp, it is also my favorite amplifier!


Gros merci à Fab pour ce merveilleux cadeau qu'il nous a fait!

Do
pjr3s
Messages : 179
Date d'inscription : 24/06/2013

Re: USSA 5 build and questions

le Lun 4 Juin 2018 - 18:47
Hello Greg,
thanks for great report....two questions !  what solder are you using for this project and where are you located ?

Quel soudure tu utilise et tu demeure où ?

Pierre
pjr3s
Messages : 179
Date d'inscription : 24/06/2013

Re: USSA 5 build and questions

le Lun 4 Juin 2018 - 18:53
Greg,
by the way is it possible to get pics of your hot-rod DCB1  .

des photos de ton DCB1 serait apprécier .
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Fab
Messages : 1223
Date d'inscription : 29/03/2013
Age : 97
Localisation : Voie Lactée

Re: USSA 5 build and questions

le Lun 4 Juin 2018 - 22:57
Greg
Great build and Excellent detailed review of your USSA-5 amplifier! Thank you for sharing. Feedback like yours is music to me and it justifies the amount of work I put in this sharing.Very Happy
About yourself I also remember that you mentioned to me you've played a music instrument for several years too so you know it's sonority....
Happy listening cowboy of the south west of the United States (from your diyaudio forum profile)!

--------
Greg
Tres bonne construction et Excellente revue  détaillée de votre amplificateur USSA-5! Merci pour le partage. Un feedback comme le tien est de la musique pour moi et ça justifie la quantité de travail que j'ai mis dans ce partage.
À propos de toi Je me souviens aussi que tu m'as dit que tu avais joué d'un instrument de musique pendant plusieurs années donc tu connais bien sa sonorité   ...
Bonne écoute cow-boy du sud-ouest des États-Unis (à partir de ton profil de forum diyaudio)!

Fab
nounouchet
Messages : 204
Date d'inscription : 03/03/2015
Localisation : Lyon - France

Re: USSA 5 build and questions

le Mar 5 Juin 2018 - 17:13
Bonjour ggetzoff,


Très belle construction pour un ampli qui le mérite amplement !
Et merci pour le CR.
Finalement il y a assez peu de USSA de construit et cela est vraiment dommage car Fab nous fait profiter d'amplis extraordinaires.


Nounouchet
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Fab
Messages : 1223
Date d'inscription : 29/03/2013
Age : 97
Localisation : Voie Lactée

Re: USSA 5 build and questions

le Mer 6 Juin 2018 - 15:32
nounouchet a écrit:.... 
Finalement il y a assez peu de USSA de construit et cela est vraiment dommage car Fab nous fait profiter d'amplis extraordinaires.


Nounouchet
Cela veut dire que je ne suis pas un bon promoteur .... ni les 
contructeurs des amplis USSA... Wink

En fait, à part quelques exceptions après plusieurs années, il n'y a pas vraiment beaucoup 
de construction d'un même projet Diy en général... beaucoup de vente de pcb mais peu 
de construction.
Fab
lamouette
Messages : 131
Date d'inscription : 27/06/2015
Localisation : France

Re: USSA 5 build and questions

le Mer 6 Juin 2018 - 15:42
On peut dire que c'est dommage, mais ça nous fait aussi plus de transistors rares pour nous Laughing . Malheureusement il n'y en n'a pas assez pour faire beaucoup d'amplis  , il faudrait trouver des substituts et ça n'a pas l'air facile. Je commence bientot le n°3 , ça ne sera pas une paire de PCB  pour finir dans un placard. Wink
nounouchet
Messages : 204
Date d'inscription : 03/03/2015
Localisation : Lyon - France

Re: USSA 5 build and questions

le Mer 6 Juin 2018 - 17:48
Fab a écrit:En fait, à part quelques exceptions après plusieurs années, il n'y a pas vraiment beaucoup 
de construction d'un même projet Diy en général... beaucoup de vente de pcb mais peu 
de construction.
Alors c'est peut-etre une opportunité pour moi de trouver une paire de pcb USSA-5  Smile
Je veux faire un autre USSA-3.
J'ai déjà approvisionné les composants critiques.

Je lance donc un appel aux possesseurs de pcb qui finalement ne les utiliseront pas.

Merci
Nounouchet
zman01
Messages : 15
Date d'inscription : 22/09/2017

Re: USSA 5 build and questions

le Mar 12 Juin 2018 - 11:05
Salut ggetzoff, 

Félicitations pour la finition de votre construction. Merci de partager les photos de construction, très beau travail. Merci également de partager vos impressions à l'écoute, apprécié lire votre avis. Apprécier la musique!


---------------------------------------------------------------------------------------------------------------------------------------------------

Hi ggetzoff,

Congratulations on finishing your build.  Thanks for sharing the build pics, very nice work. Also thanks for sharing your listening impressions, enjoyed reading your review. Enjoy the music!
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pinnocchio
Messages : 2505
Date d'inscription : 25/03/2013
Localisation : Montreal

Re: USSA 5 build and questions

le Mar 12 Juin 2018 - 11:17
Salut Nounouchet,

J'ai peut-être une paire de PCB de dispo. Je vais vérifier et te revenir avec une réponse.

A+
Do
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ggetzoff
Messages : 7
Date d'inscription : 17/11/2017

Re: USSA 5 build and questions

le Mar 12 Juin 2018 - 21:30
pjr3s a écrit: Greg,
by the way is it possible to get pics of your hot-rod DCB1.

pictures of your DCB1 would appreciate.

Yes, I will post some pics of it when I get home. However, it is going out of service as I am building a BA-3 front-end as a preamp for the USSA-5.


Cheers,


Greg
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