Catching up on 15 years of PASSt projects...which amp to build first!

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Hi folks,

Pull up a chair and favorite beverage...this is a long winded post. :)

As I sit here in the campsite, in the middle of the woods with my son building Lego on the blanket, truck parked just right so I can get 1 bar on the cel phone wifi to my laptop, and I sitting next to him, reading through a complete ream of paper printouts I made, of all PASS amp projects from A75 thru Burning #3, about 20 variations on a theme, I am slowly starting to get my brain back in designer/builder/modifier mode and want to build some more amps. The last one I built from scratch was the A40, in the early 90's. Lost interest in hifi for a while and switched to ham radio, then continued to tinker with modifying audio only, but no scratch building. I have designs on cleaning out one room in the shop, about 300 sq', to make my new electronics lab, with 3 work benches, assembly and test stations etc. I will finally be able to setup my scopes, distortion analyzers and such in a manner in which I can use them properly, not propped up on the floor in my 100 sq' office in the house. I have about 20, 2 cu' boxes of parts, R's, C's xstrs etc that I collected over the years and want to get all those organized on shelves and all in one area. Wow! Will that ever be nice. Wood heat in the shop and all cozy warm for winter building...ahh I can hardly wait.

Anyway, I digress. What I would like to build is a really nice clean sounding amp, which can drive the various speakers I have collected over the years, and maybe even build 2 or 3 different amps. :) I have a few tube preamps, Dyanco PAS 3 and IV, a nice Chinese modern tube phono/line stage, Music Reference RM-5, Opera Audio Consonance.....mmmmm a certain lack of solid state equipment....perhaps another project to contemplate as well. :D And of course, a PASS design. I really enjoy reading Nelson's articles and appreciate his point of view, and thoughts on new designs.

The speakers I have collected are as follows, and each have different drive requirements.

Yamaha NS-1000's 2 pairs
B&W 802
Audio Techniques Big Red studio monitors (Altec 604E)
PSB Stratus Minis
ProAc Tablette III
Mission 717
Linn Nexus
EPI 100
Dynaco A-25
Accustat 2+2 (which won't fit in the current house)
Mirage OM-9

And probably a few others which I can't recall at this time, but as you can see, most are sort of mid efficiency 87-90 dBWm with the exception of the Altec 604E's.

So, after reading all the past 15 years worth of articles and designs, I am left wondering.....which amp would best suit my needs? My brain is spinning trying to digest all that has transpired in 15 years. My listening room is 15X35' sort of combo living-dining with the TV nestled in between the speakers and I don't listen at "live" levels (for the most part) and mainly Jazz, 60's-80's rock/pop and some classical to keep my ears tuned and everything in perspective. I am leaning towards the F5 or F5 turbo, but also like the Aleph J and Burning 3. I have loads of torroids with dual 20-30VAC 5-8A windings in the correct size, 300W plus and some others with different windings, big caps and such are all stock here. Even have some big axx heat sinks waiting to be used. The Zen series of amps are interesting as well...with all 9 variations but not sure if that is where I am heading.

So, all of you wise guys, (I mean with much more wisdom than I) and having built many of these yourselves...which amp should I start with? I will probably end up building a few. :confused: I guess also the question should be asked, are the latest designs superior to the older Zen like designs, i.e. have the designs and details therein progressed to where I should only be looking at the newest versions of each iteration, such as F5 over the F1, Aleph J or Burning 3 over the 1 etc. Also, the Aleph X looks mighty cool too, holy cow, where to start.

I look forward to hearing from you....and when I get home...I still have the Threshold Stasis 2 to rebuild. Yikes!

Cheers

Paul
 
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maybe even build 2 or 3 different amps. :)

Paul

This is exactly what you should do...

Build a push pull amp like the F5, then a single ended one such as the Aleph J and see what you think. Boards are available (or will be soon) in the store. I have a BA-1 (well, monoblocks) that I continue to be very pleased with myself. But anyhow, build all this stuff and have fun, take some pictures and share 'em with us.
 
PS upgrade on the already-built A40...

Well, it's pretty up to date. As I built it in the 90's, I used some of the more modern output devices, can't remember, and used WIMA MKP10 caps, made my own boards so I could use the fancy caps and R's and pretty much built it top notch to start with. Double torroids in the PS, basically dual mono with only the power cord being common. It was before digital imagery so I will have to take a few pics and post them here. I actually built 2 and were running them bridged and feeding them balanced with my Classe DR-6, and were driving my Accustat 2+2's. Pretty nice sounding system with lot's of praise from local audio guys.

That was then, now have smaller house and one less wife and one beautiful son. Getting back into the hobby as time permits.

Cheers

Paul
 
Okay,

So I have reread all 2 lbs of paper and thought about your recommendations....and it looks like the F5 and the Aleph J to start with. I coincidentally just rx'd and email stating that DIY now has cct brds available for the F5 so I checked them out...and they are for V2 not V3 like I wanted to build...rats! :rolleyes: Has anyone done artwork/Gerbers for V3? I will search when I get home. I see the Aleph J brds are available which is great! I haven't found an actual A J builders thread, or even an article from NP specifically for the Aleph J, however I am sure it is out there but I just haven't spent enough time looking. Still out camping.

Now, for semi's, I have lot's of 2SJ175, 2SK240, 2SJ75, 2SK389 and 2SJ109 from previous projects, but no 2SJ74 or 2SK170's. Darn! Anyone have some extras you want to sell or know of sources? I also have some power MOSFETs from previous projects but again, will have to find them in all the boxes of stuff when I get home.

Cheers for now and THANKS all!

Paul
 
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And to add a non related, human interest note...here is where my son and I are camped right now...ahhhh fun fun fun

And now back to the BBQ chicken, refreshments and tonight...Smores!

Cheers

Paul
 

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