Messed up my chassis cuts -- need advice about layout

[Paul Joppa]

Here is the thread that Derek refers to a few posts up:

https://www.audioasylum.com/forums/set/messages/8/85736.html

I highly recommend the comments by Ralph (Ralph Karsten - Atma-Sphere founder) just below my post in that thread. He expands on the subject. (Derek, I think you reversed my remarks on distortion ... but your description of what you hear is consistent with my understanding of the effects.)

[Deke609]

Oops. Yes, I did mess that up. Apologies. I was going by memory. So it's dynamics versus clarity.  I hear a soundstage/depth versus clarity relationship. I will edit my post.

cheers and thanks, Derek

[Deke609]

@ Lee - assuming your question about fitting two Lundahls under one cover wasn't in jest (i.e., poking some good natured fun at the huge size of the covers on my rebuild), you might also consider using a hammond enclosure upside down. The painted ones look pretty good, and if you go with bare metal, you could get them powder-coated or otherwise finished to taste.  AND -- I think this would be truly helpful -- the screw holes intended for the cover that you'd instead use to affix the box to the chassis are built into the side edges instead of jutting out, which means more usable space under the cover. 

But if just meant in jest: then, Hah!, yes, everything about the amp is oversized. It is a true beast befitting its name.  It weighs a ton. I'd guess easily 60+ lbs. And it sits at the top of my rack - so I need to lift it above my head to put it into place. That's another reason I don;t want to tweak it anymore -- too much physical effort!  Which reminds me of a project that I really will turn to next: a new heavy duty audio rack. While going through my shed looking for some materials for some roof squirrel-proofing, I discovered a huge Ikea butcher block countertop -- real butcher block, not the laminated stuff Ikea sells now.  Sweet! I thought I had gotten rid of it b/c it had developed a slight bow lengthwise.  Good enough for audio rack shelves -- if the bow is noticeable I'll say it's Japanese cupped bench style.   

cheers, Derek

[Thermioniclife]

Hey Derek i was not in jest. I am awaiting a pair of LL1663's for a upcoming build. I have a Hammond 1590v diecast enclosure in black that i know will fit these under one inverted enclosure. I built an amp and separate power supply 20 or more years ago see pic.
the only thing i do not like about the Hammond is the fact that the sides have a draft angle (taper) which is necessary in die casting.
It is just a pet peeve not a deal breaker. I took a look at your link and some others and sadly the sizes that will work are far to large.
The 1590 is very compact so i will stick to that. Thanks for the reply. Stay tuned for this build which will pair with my Fi-Play III.
Lee

[Thermioniclife]

Derek by the way, Do you or anyone else for that matter have a pair of worn out but still functioning 2a3's that i could use for experimentation for a reasonable(cheap) price?
Thanks

[Deke609]

You're building an X?!  Whatever it is, I'm looking forward to the build thread.

I've got two pairs of spare Sovtek 2A3's but I'm keeping for my own tests (aka accidents).  No other 2A3s.  But I'm sure someone else must. 

cheers, Derek

[Thermioniclife]

That's a good guess Derek very good indeed, but sorry, you may be on the right track though. Stay tuned. I did in fact use the word "experimentation" for the more accurate term "Accident" or the plural there of. Thanks.

[Deke609]

Looping back to PJ's and Ralph Karsten's points about the relationship between distortion and perceived "dynamics" (punch, loudness, slam, etc.) As I interpret him, Karsten suggests that the ear/brain uses the presence of higher order harmonic distortion as an indication of loudness. So, for example, 1 kKz tone played at 90dB will sound softer than the same 90 dB 1Khz with a tiny amount of added 2nd harmonic distortion (2KHz). In the presence of the 2kHz distortion, the brain will produce the experience of a loudness that isn't really there: if measured, the two tones would have equal loudness.

Karsten also points out that distortion is proportional to power output as a percentage of max power.  I take it from this that, other things being equal,  a 2W-max 45 amp putting out 1.5W will have more distortion than than a 8W-max 300B amp putting out the same 1.5W.  AND that the 45 amp may sound "louder" doing so. Further, Karsten points out that transients produce peaks of distortion. So I think it follows that the same transient on the two amps may be perceived as much louder (punchier, having more slam) on the 45 amp.  My pick of 45 and 300B amps isn't random. I have a bunch of past posts where I note that my SII-45 was my loudest amp - louder than my SII-2A3 and my Kaiju 300B. And in terms of "punch" it beat out the 2A3 (but not the Kaiju).  This always baffled me. Perhaps I now have an explanation.

All that said, I'm not convinced that distortion, and in particular 2nd harmonic distortion, is bad.  Ultimately, I don't really care what the amp and speaker/headphone is putting into my ears -- all I care about is how the ear/brain converts it to perception/experience.  If distortion gets me to "that sounds great", I'm all for it. it's a question of the striking the right balance for my particular ear/brain interface. 

cheers, Derek