DIY progress report

Coulomb said:
Ahh, but I did say my argument is regarding True RMS, not instantaneous current at extremly short intervals. I would argue that can a speaker really react that fast in any significant way? I am not a speaker expert so I can only speculate.

I guess we can look at this multiple ways...
As mrfeedback pointed out, an amplifier's RMS rating can be considered true and accurate as long as the amp can achieve that rating cleanly given an unlimited supply current. Now, one can argue that an amp (theoretically 100% efficient) capable of >1380W RMS (80% of a 15A circuit) should not be supplied with a 15A plug. Plugging such an amp into a 15A circuit means that you will achieve well over 1725W when playing music, but playing a sine wave at these levels would eventually trip the breaker, and would violate, to some degree, the electrical code since the circuit is running at >80% capacity.

I also do not want to be guilty of thread piracy, but as we were poking Mr Pass with a stick, like children would poke a bear to see if he really is asleep, about a monster amp I felt it was on topic.

I also apologize for this diversion... I just found it rather amusing to contemplate the power bottleneck for an enormous amp. :scratch2:

:xmastree: :santa2:
 
balanced line stage and... SOZ

uvodee said:
I have NEVER done any electronic project in my life, meaning i have never drawn on a pcb etc etc...
i did finish the balanced line stage and found it quite relaxing! Jean-Pierre


Now I am laughing all the time when i look at the amps at Best Buy. I JUST FINISHED THE SOZ!!!!!!! without any pre-knowledge except for the websites of passdiy and other related sites I managed to finish the pre- and main amp. hummmm!!! I do not care if any or all of you guys are laughing with me or not.
And for those who are still reading.... for now i just connected a cd player (pioneer) and i used old Epicure speakers! they are very 'sensitive' so sensitive that i always had to block the output of my nakamichi to 5 watts in order to touch the volume knob!
Yes i have nakamichi material and now my wife does not understand how it is that my scrap boxes(that's what she calls my projects) sound better than the 1000 dollars of shelf material! It is unbelievable, I could swear I can hear Callas breath while singing Tosca on a recording of 1953, something i never heard before! And during the violin concerto from Beethoven with Mr. Perlmann you can hear his fingers sliding over the wood stock ; this is out of this world!

Jean-Pierre
(proud, happy and bragging all day long!)
 
The one and only
Joined 2001
Paid Member
Sorry about the delay. I have been very occupied with launching the Rushmore and the XA160 and revising the XA200, and I'm just starting to see the light at the end of the tunnel.

Also it will amuse you to know that I function as the head bookeeper at PL, and it's tax time....

In any case, I am preparing an interim quickie of Zen variations that didn't make the cut as full projects, but which will be of some interest. Also, as soon as I write the text, Wayne's remote volume control will be published.
 
Stefan reads my mind and beats me to it!

Nelson Pass said:
....In any case, I am preparing an interim quickie of Zen variations that didn't make the cut as full projects, but which will be of some interest. Also, as soon as I write the text, Wayne's remote volume control will be published.

We're looking forward to all of that, and the active crossover :nod: . Thanks a million! Get your bean counting done. I hope it looks good!
 
Nelson Pass said:
Sorry about the delay. I have been very occupied with launching the Rushmore and the XA160 and revising the XA200, and I'm just starting to see the light at the end of the tunnel.

Also it will amuse you to know that I function as the head bookeeper at PL, and it's tax time....

In any case, I am preparing an interim quickie of Zen variations that didn't make the cut as full projects, but which will be of some interest. Also, as soon as I write the text, Wayne's remote volume control will be published.

Wow it is a busy time! I can't wait for the articles.

BTW: Have you given thought to an XA16? :) Maybe an XA8? I might (maybe) be able to afford one of those off the shelf.

(Possibly could lift it out of the trunk after bringing it home, too! *heh*)

eL
 
Pass DIY Apprentice
Joined 2001
Paid Member
Any chance Wayne's volume control has configurable impedance? I was just thinking how great it would be to a have a seperate bal/unabal passive control unit so my BOSOZ, XBOSOZ, and other preamp projects could be built as simple black boxes. I'd never have to build all that volume and selection stuff again!

Thanks

Mike

The usual suspects 20K, 10K bal - 5K, 10K, 20K, 50K, 100K unbal

Dumb question: What's the output impedance of a passive preamp? The same as the input?
 
Impedance issues...

Actually that would be the maximum impedance,

You are absolutly rigth...sorry i think that was clear....
at the mid point

Its only at the mid point when the pot is drived by a 0 impedance source...

It will be a lower value at other points.

Of corse at 0 volume it will be o or near 0 output impedance...and at maximal volume it will be near the driving impedance...

Regards