Dreaming of a DIY 8W Class A amp designed by Nelson Pass?

Looks like an interesting project, Erik!   First order of business after you complete it, linear power supply:

https://www.ebay.com/itm/150VA-DC24V-5A-Low-Noise-LPS-HI-END-Linear-Power-Supply-for-Audio-PSU/11299...

Have fun with it!

First order of business after you complete it, linear power supply:

I knew someone else would immediately comment on the supply so I left it out of my description. :-)

Well if the Mean Well SMPS is good enough for Nelson Pass, then perhaps it’s good enough for us 🧐

I think it was meant to bring the cost of the kit down to enable more people to experiment with the First Watt type circuit.  The power supply in an amp is a significant part of the cost and increases the size of the chassis.  In fact, I think the power supply is at least 50% of how good an amp really is.

@grannyring that is true, but we all know what an over designed power supply can do for the sq of an amp ( any product, actually ). @erik_squires , as an individual who has not found Pass to be your cup of tea, I believe this ACA kit will change your mind, at least understand, what Nelson is all about. I say go for it. I am also, apologizing to you, for my recent negativity I have shown you. Your threads are always interesting, and the " meter " one, is hilarious. Always, Enjoy ! MrD.

@erik_squires , as an individual who has not found Pass to be your cup of tea, I believe this ACA kit will change your mind

<< sigh >> I can't tell you guys how sad I am that I actually don't have the time and energy to try this kit.

I built a pair of the current 2.0 version for a bedroom system, substituting Audio Note electrolytic and ClarityCap film coupling caps, Welwyn resistors, and silver wiring throughout.  It's an easy build and a sweet-sounding and resolving amp.  Apart from its power limitation, it acquits itself honorably relative to the XA-160.8 monoblocks in my main system.

I built a stock stereo unit, (except for the wiring) from the very first pre-order batch.  What a fun build and this thing really sounds GREAT...within it's power limitations.

I tried quite a few different speakers with it and you do indeed need to match carefully, but WOW, the ACA is pretty killer with the right speakers.

HIGHLY recommended for the fun of building it and a +1 for the sound!

@erik_squires time should not be an issue, as you can build it at your own pace. But energy.....yes, I understand that very well. At 65, my soldering skills ( eyesight, steady hands, and patience ), are not what they once were. Very different than applying Dynamat around horns and equipment chassis’s, as I still often do, for myself, and clients. I do agree with the above posters, as it is worthwhile to do, " if you can ".....

@erik_squires time should not be an issue, as you can build it at your own pace.

Really can't have one more project taking up another piece of furniture for six months! :)

No, this is one more project I simply can't start. :)

@erik_squires then why start this thread ?

the time you spend on threads, you could build an amp,  then report back...

@erik_squires It takes around 8 hrs. to build two of ’em-- not much of an investment of time. BTW, for me an illuminated magnifier is essential for proper soldering.

Can an inexperienced solderer build one ?

I have to say, they do have a point, Eric.
Bob

OH, also, have I mentioned to you guys about the six monoblock amps I have in the apartment gathering dust, in addition to the stereo amp I'm listening to right now?

I was just making a joke on the SMPS. I would build a LPS for this amp also plus use upgraded caps, resistors and wiring as @dgarretson has done. What a gift to DIYers from Mr. Pass. 

@erik_squires then why start this thread ?

There’s a reason I didn’t respond to your apology, and here it is.

I won’t be policed by you or anyone else. I started this thread because it looked fun and I like sharing fun projects. I especially like to encourage people to DIY things so more Audiophiles will have first hand knowledge.

I can’t believe I have to explain that. Nor do I need to justify to anyone that I have my hands full with non-electron bearing projects, but I still really really like this project kit idea. I can do both. I can want stuff I can't have right now.

Excellent kit!

I have been using one ACA (stereo) with a pair of custom designed wide band speakers with wonderful success.  I’m thinking of building a dual mono pair for another system.

I have been using the supplied Mean Well power supply, but have some interest in a linear design.  As mentioned above, if it’s good enough for Mr. Pass, it’s good for me, so I’m thrilled with the sound.

What speakers are you using with the ACA?  I’ve been listening to a lot of high efficiency/sensitivity speakers and would love to get your recommendations.

@erik_squires , I do not need a response to my apology, but, you create more threads than anyone else here on the "Gon, which is " time ". I mentioned before to you, when do you take time to listen to music ? I " take " at least an hour a day. Enjoy ! MrD.

@jl35 Nelson conceived this as an entry-level kit.. The associated blog reveals that most problems result from bad solder joints. Most problems are remediated by re-flowing the joints. I suggest that you use a magnifier lamp or loupe and solder each joint on both sides of the PCB. The kit has a low parts count and good videos for guidance..

@mrdecibel


How I spend my time each day, whether or not I'm listening to music right now is zero of your business. Z-E-R-O.

I suggest if you'd like to see audiogon go another way you contribute your own worthwhile threads.

@erik_squires .....I will no longer give my time to you, or your threads....As I do not feel most of them are " worthwhile ", and you are, well, you can guess what I am thinking...............Happy ? Enjoy ! MrD.

@auxinput I’ve had good results with the Chinese Zerozone LPS in other applications. It’s a modest gambit to order two and compare to the Meanwell SMPS. I’ll make that comparison and report back.

Nice kit I built the bigger 25 watt class A - F6 you can mods them before you build I put dual dual piltron transformers or a bigger single, 
you can put Vishay naked resistors, in any area 1/2 watt or less which adds 
nice resolution use only 1% resistors ,and Top Belleson regulators , Neotech -0 Crystal copper Teflon wire , for sure buy a Furutech Copper IEC input ,
night and day better sounding then cheap stock tinned input 
and use the New top synergistic  Research Orange fuse
use good caps , brand name poly coupling caps , and electro Lytics 
Swiss Elna, Nichicon gold  power caps. That’s if you want to squeeze the most fidelity out of it . Max it out while you are building it t may cost a few  hundred more but you will thank yourself later !!

Teradak also makes some nice once’s with RCore trannys. Look on eBay! 

@audioman58 

Wow....that’s a heavyweight mod!

There are some mods recommended for the ACA on DIYaudio that I’ve considered.  It’s nice to know there are some DIY people on here.

@dgarretson - the link to those 24V linear power supplies are just on the border of current requirements (5A).  If you want a power supply with more current, you could look at one of these and ask them if they can make a 24V version.  It would probably come out to be 24V at 7.5A of current.

https://www.ebay.com/itm/New-TeraDak-DC-12V-15A-linear-power-supply/323443214646?hash=item4b4eb7c936

https://www.ebay.com/itm/High-Power-300VA-DC12V-15A-Ultra-low-noise-linear-power-supply-HIF-LPS-L14-62/123782483364?hash=item1cd202cda4:g:kf4AAOSwX09cm51~

The Hi Power (Zerozone) power supply is a lot more expensive, but it looks like it uses Nichicon FG caps inside.  The Teradak probably uses Panasonic hi temp (105 degree).

@mrdecibel exactly. @erik_squires why do you start this thread? Need attention? Your approach is not appropiate. 

when Erik first joined this site , he was real big on pushing the diy speaker build and putting pillows between the speakers . it also seemed that he always had an answer for everything.   
after a while I thought maybe it’s just me as I was growing tired of him and his threads as it seemed he was just trying to stir the pot on here......but with the recent pass labs amp thread and now this one, he obviously has nothing better to do.  
have seen it many times where a member will wear out his welcome here and threads will get ignored and that member will eventually go away......

Erik,

Your magnanimous gesture of encouragement has not gone unnoticed by we audio serfs.

Perhaps you need to understand that you share the same spot in the audio food chain as everyone else on this site.

 two things one I've already own a pass lab amp and the second one is 8 watts you would be severely limited to the speakers that you can hook up to it sorry to be such a drag

@dutchydog  It develops around 16wpc when wired as a bridged or balanced monoblock.

I'm in agreement, for someone that has not built electronic equipment before (myself included), the Kit looks like a lot of fun.
I tend to get confused when people with experience begin talking about upgrades that will increase the level of the builds. I'm in favor of the upgrades but my inexperience makes the upgrades look confusing because I no longer have the step by step directions to follow with the exact parts I need.

@lak

Ignore the upgrade discussions then. Make your build, and then see if you feel like tweaking. For instance, the question of the power supply is something you can experiment later. Is the switched mode supply really worse than linear?


Well, in a year you can build a linear power supply and find out. The neat thing about kits like this is that they are yours. Not just you brought them home from the store, but you put it all together and you can take it apart and change things around.


Nothing on earth gives you this level of first hand experience, far better than merely reading.

The power supplies are external and easily swapped. However if you want to try alternative resistors, caps, and internal wire, de-soldering the original pieces from the PCB is a PITA. Consider researching substitutes for the initial build. The schematics identify the necessary values. I used Welwyn RC55Y resistors in the 1/4W positions(excellent at @$2), an Audio Note Kaisei electrolytic in the large coupling cap position(in parallel with the largest film cap that would fit across the top of the Kaisei), a 4.7uf ClarityCap film cap in place of the small electrolytic at input of signal path, and Panasonic FM or FC electrolytics in the power filtering positions. The point-to-point wiring can be whatever you like.
No, I have not heard the amp equipped with stock piece parts.
These mods add a few hundred bucks to the build.
BTW, these amps have relatively low gain. A preamp with gain may be appropriate when matched with less sensitive speakers.

this is the first discussion i see from erik without negativity. 
give him a break guys maybe he is tired of arguing.
ide love to buy a used assembled kit .in the world of guitar amps there are good examples of kits by mojotone that you can buy assembled already .i only want to worry about swapping tubes not soldering i'm spoiled and couldn't be bothered it's easy to screw up if you are not experienced in such things and professionals will do a better job. 

I've also heard great reports on the Elekit tube integrated amp kits. 

this is the first discussion i see from erik without negativity.

I’m sorry, I think you’ve missed a lot of my threads which were pro something, which then the trolls jumped into.


Please don’t blame me for threads the trolls have had to ruin.

Even in this thread, I say "Hey, I saw a cool kit" and some one had to come in and throw shade. I won’t be responsible for the trolls in the peanut gallery who have to find something wrong with it. Trolls are going to troll, but please don’t blame me for their acts.

I’m sorry, I think you’ve missed a lot of my threads which were pro something, which then the trolls jumped into.


Please don’t blame me for threads the trolls have had to ruin.

Even in this thread, I say "Hey, I saw a cool kit" and some one had to come in and throw shade. I won’t be responsible for the trolls in the peanut gallery who have to find something wrong with it. Trolls are going to troll, but please don’t blame me for their acts.

You bring this on yourself.....and maybe one day you will realize this.

You bring this on yourself.....and maybe one day you will realize this.

Feel free to start another thread where you enumerate the causes, and leave this thread alone.

erik_squires"Feel free to start another thread where you enumerate the causes, and leave this thread alone."

Just so everyone who doesn't understand this group perhaps newcomers can understand you do not need Erik's permission to start a thread or to post in this one he is not one of the moderators or representatives, spokesmen, or managers of Audiogon I have confirmed this directly. 

leave this thread alone.

and who are you to tell me what to do ?

amazing how many keyboard warriors there are out there.

and who are you to tell me what to do ?

Of course, do as you will. Sit here and troll all day long, and be seen for that.

he is not one of the moderators or representatives, spokesmen, or managers of Audiogon I have confirmed this directly.

That’s’ literally the most ridiculous thing I’ve ever read on here.

I’ve never claimed otherwise. I do claim to know how adults of good character behave, and am pointing the way.

Those who act like petulant children will be seen as such.

The floor is yours to show yourselves to be either.

Ah, how I used to enjoy Audiogon, having been a member since 2001. Things used to be shared in a nice, positive manner, threads had meaning and life was merry. Though I usually avoid Audiogon's Forum as it tends to be more negative than positive at times, I have been intrigued by the postings of Mr. Squires. He does state that he has posted positive threads. Frankly, with approximately 289 postings / threads by Mr. Squires I have not the time to read them, as I have not the time, even though I am retired. In Audiogon, the "High End Community", I would think that the enjoyment of music would be the thing that takes up most of our (collectively speaking) time. It seems that the equipment and even some "sniping"  is becoming the center of many postings. As my father once said, (and this is a quote) " Verbosity wastes a portion of the reader’s or listener’s life.”  So, with all these postings, replies, "trolling", more postings, I have a difficult time taking the member who started the original post somewhat seriously. 289 postings is a lot. I have no qualms with people seeking help, or an occasional comment about something they have experienced, but to talk about building something, then have several good people responding only to then say it is a project that he has not the time for, well, then there is that wasting of the reader's time and perhaps even good will. I believe wiser people than me have addressed the virtues of speaking less than more as it does tend to lend credibility to the party who speaks only when making a point or addressing an issue now and then. I for one, am going to avoid this forum and look to the one on US Audio Mart. Things seem to a tad more calm there and less "emotional".
And it appears to me after reading some of Mr. Squire's postings that he has no love for anything Nelson Pass related so while reading the whole posting I was waiting for the bomb to drop in the attempt to destroy a piece of Pass equipment. Odd...

I built an F4 from diyaudio and it changed my life.  Just finished the DIY version of the SIT3 and it is beautiful.  I've got two monoblocks that each have an F4 and SIT3 in them... roughly $6400 worth of amplifiers that I built for $2000, and the process teaches you about how electronics work.  Now I can troubleshoot and fix my own equipment. 

Thanks Nelson, it's amazing that you allow people to do this with your intellectual property.

I enjoy most of Erik’s threads, which often raise unusual topics that break the tedium of too many repetitive threads. It’s irrelevant whether the OP decides to build the kit. A good thread is like a large inflated ball that we used to see bouncing across the crowd top at outdoor rock concerts. No one worried about the motivation that put it there. If it comes to you just hit it and keep rolling.

BTW, there are better forums for DIY than Audiogon, and more than a little bias against DIY found here. But members with an interest usually find a way to contribute something worthwhile in that niche.

BTW, there are better forums for DIY than Audiogon,

True, but since DIYers invented HIFI I think it is healthy to do a little cross-pollenating. The more hands on audiophiles, the more helpful, friendly and useful the community becomes, whether or not they agree with me.

and more than a little bias against DIY found here.

Sadly also true, but if things get too electrifying, those posters usually find better forums. The lack of pictures in a post is actually something that keeps DIY stuff out of here too.

reading some of Mr. Squire’s postings that he has no love for anything Nelson Pass related so while reading the whole posting I was waiting for the bomb to drop in the attempt to destroy a piece of Pass equipment. Odd...

I am not tribal. Nelson Pass is an undeniable, enviable technical and professional success. As has been pointed out by others, he’s been a huge contributor to the DIY community for which he deserves nothing but praise.

I also have opinions about gear I like and gear I don’t like to listen to. That doesn’t make gear I don’t like bad gear, or Pass a bad person. I just may not like the sonic outcome.

You learn nothing however if you only ask people who agree with you what they like. By asking those who disagree with you to be specific in their experience and path you may learn something.

Above all, nothing makes me happier than learning about audiophiles who have found their final set of gear, regardless of whether I happen to be a fan boy of the brand.


Best,

Erik

mrdecibel
@erik_squires then why start this thread ?

As usual, this thread "had" an ulterior motive behind it, and the OP as usual has egg all over his face again, as those here are getting used to what he plays at.

Cheers George