Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

USSA-5 Build with Review
USSA-5 Build with Review
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 12th June 2018, 04:21 AM   #1
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
Default USSA-5 Build with Review

USSA-5 build and review:

Amplifier Design/layout: Fab (The Great and Powerful Ape)

Amplifer PCB Layout: Alex

PSU Design/Layout: Project16

PSU PCB Production: Prasi


I couldn't stop thinking about this amplifier. The obsession began with a few fleeting traces of it's existence. The few members that have actually completed it were mostly silenced by its greatness. When I had enquired about it, people simply said "Oh, the USSA-5? It's the best amp I've ever heard."

I had to build it. But, the great mind that designed the amp wasn't going to just give me the boards. I offered to build a children's wing at his nearest hospital in his name. He said no. I said I would make huge donations to wildlife preserves around the world. He still said no. He was like talking to Willy Wonka and I was Charlie Bucket. I needed a golden ticket....

In the end, what worked was honesty and a promise to do two things: to build the amplifier and write a review.

So, here it is.
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA
  Reply With Quote
Old 12th June 2018, 04:22 AM   #2
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
Saved
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA
  Reply With Quote
Old 12th June 2018, 04:22 AM   #3
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
saved
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA
  Reply With Quote
Old 12th June 2018, 04:56 AM   #4
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
The schematic:

image_zpsf6undgwq.png

The boards:

11171712.jpg

Populating:

pic8.jpg

Matching the CCS fets:

pic6.jpg
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA
  Reply With Quote
Old 12th June 2018, 05:01 AM   #5
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
Ready to set the front end CCS:

pic5.jpg

Setting:

pic9.jpg

The unobtanium 2sk313/2013s and the mythical profusion laterals installed:

pic14.jpg

PSU boards thanks to Project16 and Prasi, softstart boards by Sjostrom audio:

pic17.jpg

pic13.jpg
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA

Last edited by ggetzoff; 12th June 2018 at 05:12 AM. Reason: content
  Reply With Quote
Old 12th June 2018, 05:03 AM   #6
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
Initial Biasing:

pic12.jpg

Then I buttoned it up and let it bake for awhile:

chassis rear.jpg

pic16.jpg

Then rebiased...to 65 mv.
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA
  Reply With Quote
Old 12th June 2018, 05:07 AM   #7
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
The last thing prior to listening and bias was to determine the output Mosfet VGS for each board.....both Fab (after a case of bananas sent and Project16 verified my numbers:

From Fab's amazing manual:

thumbnail (3).jpg

thumbnail (2).jpg


Now the part you've been waiting for....
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA

Last edited by ggetzoff; 12th June 2018 at 05:16 AM. Reason: content
  Reply With Quote
Old 12th June 2018, 05:16 AM   #8
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
USSA-5 Build with Review
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_-_25_(Official_Album_Cover).png


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:

220px-Blade_Runner_soundtrack_album.jpg


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:

51E-y8GGxOL._SY450_.jpg

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?


Is it the best amp I've ever heard? Emphatically, yes it is.

Cheers,


Greg
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA

Last edited by ggetzoff; 12th June 2018 at 05:19 AM. Reason: content
  Reply With Quote
Old 12th June 2018, 06:29 AM   #9
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
USSA-5 Build with Review
Greg,

Thanks for sharing the build pics and review. Congratulations on a successful build of this well reputed amplifier. I have started to collect the parts required to build a USSA 5, and now looks like I should speed up!
  Reply With Quote
Old 12th June 2018, 07:25 AM   #10
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
USSA-5 Build with Review
Thanks for sharing you awesome looking build. Nice work! Also, thanks for detailed listening impressions. Both Zman and myself have been collecting the parts for the USSA5, and it's a small ransom in parts cost when one goes with the specified parts in the BOM, so I am glad it worked out. You may be the first on DIYA outside of Canada that has built and posted on this foru.
Congratulations, and happy listening!
Cheers,
X

__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote

Reply


USSA-5 Build with ReviewHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Odd Watt Audio Alpha Build and initial review cgnman59 Tubes / Valves 6 26th April 2017 04:12 AM
SMPS vs LINEAR PS: Let's build up a serious technical review-list Centvrion Power Supplies 18 7th March 2011 05:09 AM
Honest opinion (peer review) about this 4Way before I build it Yoshy Multi-Way 54 16th December 2010 07:37 AM


New To Site? Need Help?

All times are GMT. The time now is 12:07 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki