Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

nakamichi pa7 mrk2
nakamichi pa7 mrk2
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 12th December 2017, 07:44 PM   #1
jamie123 is offline jamie123  United Kingdom
diyAudio Member
 
jamie123's Avatar
 
Join Date: Feb 2017
Location: brighton. uk
Default nakamichi pa7 mrk2

ive been thinking of buying a pa-7 amp for a while now and up pops a mark2 European model.
reading up about it on the web and i found this and i quote,

" They were supposed to just license his STASIS technology, which combines the benefits of Class A amplification without the drawbacks (runs stupid hot = very low reliability) into a hybrid Class A/Class AB power amplifier with optical bias. Well, they didn’t just license STASIS. Rather, the first generation of the PA-7 is a direct copy of the equivalent Threshold amp. A lawsuit ensues, then Nakamichi releases the PA-7II with an altered design providing 25 more WPC (watts per channel) and a higher price tag. But everyone knew then and knows now that the original PA-7 was, “the one to get”.

is this true? is the first model better? or would a threshold s 200 be better for driving yamaha ns1000's speakers?

  Reply With Quote
Old 12th December 2017, 07:58 PM   #2
adason is offline adason  United States
diyAudio Member
 
adason's Avatar
 
Join Date: Nov 2004
Location: Maryland
I would not know, but where is diy?
  Reply With Quote
Old 12th December 2017, 08:38 PM   #3
jamie123 is offline jamie123  United Kingdom
diyAudio Member
 
jamie123's Avatar
 
Join Date: Feb 2017
Location: brighton. uk
thanks for that very informative post!
  Reply With Quote
Old 14th December 2017, 06:33 PM   #4
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
nakamichi pa7 mrk2
Quote:
Originally Posted by jamie123 View Post
" They were supposed to just license his STASIS technology, which combines the benefits of Class A amplification without the drawbacks (runs stupid hot = very low reliability) into a hybrid Class A/Class AB power amplifier with optical bias. Well, they didn’t just license STASIS. Rather, the first generation of the PA-7 is a direct copy of the equivalent Threshold amp. A lawsuit ensues, then Nakamichi releases the PA-7II with an altered design providing 25 more WPC (watts per channel) and a higher price tag. But everyone knew then and knows now that the original PA-7 was, “the one to get”.
This story is speculation that doesn't match the facts.
  Reply With Quote
Old 15th December 2017, 12:27 PM   #5
jamie123 is offline jamie123  United Kingdom
diyAudio Member
 
jamie123's Avatar
 
Join Date: Feb 2017
Location: brighton. uk
cheers for clearing that up.the internet is full of stories,in this instance its great to hear from the horses mouth so to speak.
  Reply With Quote
Old 16th December 2017, 01:55 AM   #6
electrafixion71 is offline electrafixion71  Canada
diyAudio Member
 
electrafixion71's Avatar
 
Join Date: Aug 2007
Location: The Independent Republic of Alberta
nakamichi pa7 mrk2
If you read through some of the other threads on this site about Nakamichi's Stasis amps you find more about history of how they came to be, as well as questions and answers that dispel some of the urban myths that surround that part of history.

One of the interesting things noted by others is that Nakamichi actually used the wrong capacitor in the feedback circuit on the original PA-7 (they transposed voltage and capacitance), compromising its function. Nakamichi made a number of changes on the MK2 (improved layout, parts changes, power supply bypass caps on the amp boards, better internal wiring), and also rectified the feedback capacitor error. Given these facts, it's hard to believe the MKI is "the one to own", but I've never heard them side by side.

Last edited by electrafixion71; 16th December 2017 at 01:59 AM.
  Reply With Quote
Old 16th December 2017, 09:19 AM   #7
nicoch58 is offline nicoch58  Europe
diyAudio Member
 
Join Date: Oct 2004
stasis dont have fb ,I'm wrong ?
  Reply With Quote
Old 16th December 2017, 02:02 PM   #8
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
nakamichi pa7 mrk2
wrong

__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 26th December 2017, 07:05 PM   #9
kalinga is offline kalinga  Sri Lanka
diyAudio Member
 
Join Date: Aug 2008
electrafixion71 is right, MK2 is the fixeruper or the bug fix version of the mk1, there has been many post here talking about how to make the mk1 better, aka mk2, go for the mk2; an owner here of both mk1 and mk2, both to me sound the same. but keep in mind, your buying 30+ year old electronics and capacitors needs changing. including the BIG PSU one that cost $100 or so each, there are 4.

but its worth every penny, also you need a full recap with calibrations, service manual is out there with little bit of googling.
  Reply With Quote
Old 26th December 2017, 07:36 PM   #10
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
nakamichi pa7 mrk2
I do not recall bug fixes for the first version. I do recall Nakamichi's lead
designer modifying the circuit, specifically by decoupling the front end supply.

This probably gave some improvement at audio frequencies and power levels
but did result in issues at high frequency clipping.

Fortunately, this was not a normal operating condition, but the recovery
was a rail-to-rail spike.

I informed the head of Nakamichi USA of this, but we were not communicating
well, and I did not hear back about it.
  Reply With Quote

Reply


nakamichi pa7 mrk2Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
nakamichi-500 or 550? jkojic Analogue Source 5 26th December 2017 10:39 PM
Nakamichi CA-5-E back Pass Labs 4 27th March 2017 05:42 PM
What instead Nakamichi? frobek Car Audio 1 12th February 2013 12:47 PM
Nakamichi OMS-5 gaborbela Digital Source 122 25th August 2012 10:11 PM
Nakamichi OMS-5 Help Ed A Digital Source 4 28th February 2011 03:56 PM


New To Site? Need Help?

All times are GMT. The time now is 06:38 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki