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DIY Pass Labs First Watt F5 amp impressions

I recently acquired a well- built DIY First Watt F5 amp for the cost of the parts, which is the understanding among those that build the designs that Nelson Pass has made available to the DIY folks.  I have been using a McCormack DNA .05 Deluxe amp and a Don Sachs 6NS7 tube amp to drive my Spatial Audio M4S Turbo S Hologram open-baffle speakers, which are ~94 db efficient.  I have raved about the McCormack amp on this forum, but swapping the F5 for the McCormack amp has been a  sheer revelation.  I have had dozens of tube and class A/B amps my system over the past 4 decades, as well as a couple of very good class D amps recently, but the tonal accuracy and 3-D representation of music with this F5 is simply stunning.  It is offers a glimpse into the inner details of the music.  I do not have the superlatives to describe the musical enjoyment of the addition  this amp provides to my system.  I am put off the heat his amp generates -- similar to that with a tube amp with a quad of KT88's, but it is a fair bargain for the most ruthlessly revealing sound reproduction I have ever heard in my system.  My regret is that I waited so long to have a Nelson Pass-designed amp in my system.  If your speakers are quite efficient, there are several variants in the First Watt line of amps that might be a great match for your system.  Mark at Reno Audio is the guy to help you sort out the best amp for your needs.
Cheers, Mark
whitestix
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gdhal
1,641 posts
 
@kdude66 and @whitestix 

Thank you. Your response does clearly answer my inquiry. And in fact, after checking some more, I failed to take note of https://www.passdiy.com/ which further explains DIY.
timlub
2,041 posts
 
I'm wondering if anyone has Tried the High Output version of the F5.... The F5 Turbo.  It outputs more power,  or maybe the F6, wondering how they would compare.
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skiroe
131 posts
 
Mark,  You've got me itching to fire up  the xa30.5  here tomorrow.  Maybe the cool mornings  here the last 4 days or so  in Oaktown will accommodate me. .  Its like my Pass amp just sits there draped in the t-shirt dust cover and patiently awaits -- thinking hmm.   he's got those Emotiva monos on a lot lately-- he must be just be so distracted or preoccupied with something.     lol.   
cisgo
30 posts
 
I agree Mark at Reno HiFi is pleasure to deal with. I have a J2 powering a pair of M3 Turbo S Spatials (just sent in for Triode upgrade). Very happy with the results and looking forward to the 16ohm version. 
whitestix OP
721 posts
 
Update:  I earlier stated that the F5 runs as hot as a tube amp with four KT88 tubes.  That assertion is clearly wrong.  While the F5 runs much warmer than class A/B amps I have had, it generates nowhere near the heat generated by a robust tube amp.  My HK Citation II toasted the self above that in which it resided, but with the F5, the upper shelf is unaffected.  In conclusion, the F5 runs much warmer than a class D or class A/B, but far cooler than a tube amp.  Whitestix
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