Alpha Nirvana 39w 8ohm Class A Amp

Very superb work there, Wirewiggler! You got the full SLB and SFP treatment in a separate chassis going on. That allows you to change amps later if you want. What are you using for power supply interconnect to the amp module?
 

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Those were amp plugs in that picture and I could not get them to work with the 16 gauge silicone wire. I would have used the powercon ones you recommended but they were only available in 3 prong and I wanted 4 to include tying the chassis grounds to each other. I ended using a Uxcel 25A aviation plug from Amazon. I have been avoiding the 107 degree days hiding out in my place in the mountains. Will leave the wife here tomorrow and go home and move these into the living room and when she gets home beg for forgiveness. The plan moving forward is to build my power supplies into separate chassis, I am almost ready to place order with Sami for a pair of his SMPS and cap boards . Will place cap boards in amp chassis with sissysitR3 crossing fingers will not have start issues.

Bill
 
Alpha Nirvana first impressions

Ok left the wife at the other house and came home and had some fun. I know I may have pissed some neighbors off, but I live in a 55 and over community maybe I got lucky and no one heard anything. First of all I had to ditch the Martin Logan’s I new the Alpha would not like the load, no love loss on my part when we moved in the new house I let my wife choose the speaker and she chose them go figure. I moved back to my North creek Borealis D28 and figured I should give a hour listen to the old amp to make a fair comparison. Also I needed to measure the room acoustics and load a Dirac Live filter into the mini dsp DDRC-24 for this house. I will have to create a new filter for the Alpa but this worked fine for first impressions.
To summarize Hugh and X got everything pretty right on this iteration ( I am glad I waited). Acoustic instruments I was able to judge the aggressiveness of the pluck and hear the full decay of the note. You could hear the full harmonics of the piano notes without any harshness a lot of people are unaware how difficult it is to reproduce piano notes until you see how much cpu power it takes to synthesize it. Electric guitar you are able to distinguish effects and echo used. Saxophones were romantic, and percussion was fast Congo’s felt next to you in the room. Soundstage was large but never overwhelming, and was solid and did not drift. I suspect this is why it was resolving such detail. Complex music passages never lost detail or sounded congested. I am fortunate to have all my music on Roon and was able to listen to about 30 tracks I was pretty familiar with then just put it on random play for another 3-4 hrs. Evan at lower volume settings the soundstage still remained consistent and older songs I have grown tired sounded interesting again and some stuff I didn’t like I actually enjoyed. The only weakness I encountered was male vocals it was having a little difficulty resolving Sugar Ray Rayford voice however that was early on and about an hour later it seemed to do well with Lyle Lovett I will revisit this again. From their I let it play for about 10 hrs so I would imagine most components have made their largest change in formations and will just be subtle differences moving forward. Sorry to drag it out but their it is.
Bill
 
Great AN Review!

Thank you Bill!

You have done our AN proud..... the idea was always to push the electronics to the background so you could really hear the music.
The only issue for Class A is the heat, and where you live the climate is pretty hot in summer!

From the other side of the planet I thank you for building the Alpha Nirvana. There is another guy here in Melbourne with an active system with AN using the SB Acoustic open baffle Satoriis - a very expensive, minimalist system - and it sounds absolutely spectacular.

Ciao,

Hugh
 
Hugh,
I would like to discuss Andy’s system with him sometime, I will read up on it first. I would like to build something similar. I am going to drop by Wisdom Audio in Carson City some time to Liston to their Sage L75 they are line source speaker with 4 - 6” woofers with 2 -24” planer magnetic drivers. George Short who was the designer of my Northcreek D28 Borealis speakers works there now. I want to audition them but I will dammed if I am willing to pony up $18,000 for a pair.

Bill
 
I agree Bill, $18k is a LOT of money and speakers don't deserve that sort of commitment........

Andy has the moniker AndyR here. You will find quite a bit of comment from him, and a review of his system recently at #1598 on this very thread.

Thank you for building the Alpha Nirvana. X and I love it when people build our circuits.

Hugh
 
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Hugh,
I would like to discuss Andy’s system with him sometime, I will read up on it first. I would like to build something similar. I am going to drop by Wisdom Audio in Carson City some time to Liston to their Sage L75 they are line source speaker with 4 - 6” woofers with 2 -24” planer magnetic drivers. George Short who was the designer of my Northcreek D28 Borealis speakers works there now. I want to audition them but I will dammed if I am willing to pony up $18,000 for a pair.

I have built a lot of speakers and have heard a lot of speakers, but these remain the main speakers in my listening room/lab for nearly 6 years now. That's a long time.

Bill

Are you interested in a DIY speaker that I can gurantee you, sounds superb? About $600 to $750 in parts and materials (depending on choice XO caps and wood finsih) if you make the TL cabinets yourself. I have heard a lot of speakers and these are up there with the top 3 I have heard.

The TL is the one that will beat most $12k to $15k speakers in sound quality with superb imaging, naturalness, deep bass, smooth midrange, and timing accuracy (being 1st order transient perfect XO).

10F/8424 & RS225-8 FAST / WAW Ref Monitor

Plans:
826339d1584679921-10f-8424-rs225-8-fast-waw-ref-monitor-rs225-tl-0-75inply-v2-jpg


XO:
656203d1515700364-10f-8424-rs225-8-fast-ref-monitor-xrk971-10f-rs225-fast-schematic-jpg


A modern implementation by Moutik:
956993d1622710562-10f-8424-rs225-8-fast-waw-ref-monitor-20210601_151535-jpg
 
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......To summarize Hugh and X got everything pretty right on this iteration ( I am glad I waited). Acoustic instruments I was able to judge the aggressiveness of the pluck and hear the full decay of the note. You could hear the full harmonics of the piano notes without any harshness a lot of people are unaware how difficult it is to reproduce piano notes until you see how much cpu power it takes to synthesize it. Electric guitar you are able to distinguish effects and echo used. Saxophones were romantic, and percussion was fast Congo’s felt next to you in the room. Soundstage was large but never overwhelming, and was solid and did not drift. I suspect this is why it was resolving such detail. Complex music passages never lost detail or sounded congested. I am fortunate to have all my music on Roon and was able to listen to about 30 tracks I was pretty familiar with then just put it on random play for another 3-4 hrs. Evan at lower volume settings the soundstage still remained consistent and older songs I have grown tired sounded interesting again and some stuff I didn’t like I actually enjoyed. The only weakness I encountered was male vocals it was having a little difficulty resolving Sugar Ray Rayford voice however that was early on and about an hour later it seemed to do well with Lyle Lovett I will revisit this again. From their I let it play for about 10 hrs so I would imagine most components have made their largest change in formations and will just be subtle differences moving forward. Sorry to drag it out but their it is.
Bill

Hi Bill,
Congratulations on your sweet pair of Alpha Nirvana monoblocks!! You did a great job neatly fitting everything required for forced cooling in a small sized chassis. The dual SLB psu unit rocks, Well done 😉

Enjoy your setup!!

:cheers:
 
Dual PS, one traffo

“The dual SLB psu unit rocks”

I’m as attracted to dual mono as the next seeker of the best. But I’ve generally avoided it, more than anything … because of the added bulk of two transformers, usually requiring if not two chassis, one that’s bigger or tighter

It’s great to hear how good fans are now allowing class A amplifiers to be built without being so large. I’ve got a 40 wpc Pass A 40. in a blue case … it was nicknamed the blue monster

Vunce you just just triggered a thought bubble. esp by reading it among you guys responsible for the very sweet innovation of modularising amplifiers with amplifier daughterboards.

Would this be kinda a PS implementation of the Pareto rule. 80 or 90(??) % of the benefit for ~ 60(?) % of the weight and size - not full proper dual mono. Use a single larger transformer, but after that separate regulation.

Preferably on the SLB
 
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Here is a shot in my system. I tried the water slide decals printed on laser printer not real happy, I am just going to have to break down and do screen printing. X the fast system interest me wish I were closer to audition. Funny thing on my first listen the male vocals were off a hair but came pretty well after a little burn in time , the rest of the resolution was not lost by the amp but by my Dac. I played my new HiBy R6 and it was resolving vocal details much better. Wow I posted this picture 4 times 3 times it was upside down this one on its side I give up.
 

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Hi Wirewiggler,
Here is the trick I use with photos taken on your phone. Take a screenshot of your photo (this shrinks the pixels down to a reasonable size). Use the crop and rotate tool to rotate the image properly right side up. Save it. Now post the image from your phone. It will be correct and properly scaled and sized circa 1200 pixels wide.

You can use a label maker to print the temp and clip light labels. Neat feature to have temp. Maybe have it tied to auto shutdown if exceeded?

If you are ever in DC area, let me know and you can come by for a listen.
 
Well, I’ve finally solved a problem which had been bugging me for a number of weeks! 🙂 Yay!

I had always been getting a slight hash noise from the mid/bass drivers on both channels - and had thought it must be that the interconnects which go into the amps must be passing too close to the amps' power cords. So I experimented with shielded power cords - and this cured the problem in one channel ... but not the other! 🙁

The noise was not loud (you couldn't hear it from the listening position) but it bugged me.

Anyway, this arvo I swapped the amps around - and afterwards ... I found the hash was coming out of the right channel (not the left)! So it was intrinsic to the amp - nothing to do with interconnects!

Now, the way I laid out these amps was - so as to have the shortest possible input & output wire lengths:
• the amp PCBs are located at the back of the case
• and their SLB PCBs are located at the front
• with the power transformers mounted vertically in the front corners.

So, the mains power going to the power traffos runs up the centre line of the case, from the power switch on the back panel. And either side of the centre line are the SLB PCBs, mounted vertically.

The pair of off-board power transistors in each SLB are mounted on a heatsink attached to each side of the case. So there are 2 sets of 3 wires going from each SLB to the transistor pair.

I saw that the front-to-back mains wires were closer to these 3-wire sets on one side of the ‘noisy’ amp ... than the other. And the side where the mains wires were closer ... was the side driving the mid/bass drivers (where the hash noise was coming from)!

So I moved the 3-wire sets on this side, slightly away from the central mains wires ... and the hash noise went away! Yay! Perfect silence out of each channel, now. 🙂

Hugh,
I would like to discuss Andy’s system with him sometime, I will read up on it first. I would like to build something similar. I am going to drop by Wisdom Audio in Carson City some time to Liston to their Sage L75 they are line source speaker with 4 - 6” woofers with 2 -24” planer magnetic drivers. George Short who was the designer of my Northcreek D28 Borealis speakers works there now. I want to audition them but I will dammed if I am willing to pony up $18,000 for a pair.

Bill

PM me, any time, Bill. 🙂

Andy
 
Thanks Andy,
I have a few projects before I look into speakers. Just switched from my Martin Logan’s ( for sale) back to my North Creeks and like new speakers for a while. These amps are resolving such details I am finding faults in my front ends. I purchased a set of Yarra boards half heartily but I think I will place it on the list of projects, might as well keep everything dual mono.

Bill