Tapeheads Tape, Audio and Music Forums
Universal Capstan Motor

Go Back   Tapeheads Tape, Audio and Music Forums > Service, Restorations, Helpful How-Tos, Parts and Manuals, Ads and More! > Pacific's Restorations

Pacific's Restorations You can see all of Pacific's vintage gear restorations here.

Donate to Tapeheads!
Reply
 
Thread Tools Display Modes
  #1  
Old 06-02-2012, 09:31 AM
Pacific Stereo's Avatar
Pacific Stereo Pacific Stereo is offline
Sendust for brains
 
Join Date: Feb 2010
Location: Somewhere in paradise!
Posts: 11,586
Pioneer Spec-2 in the lab...

Well, I've been having fun with a Spec-2 rebuild. This thing came in blowing the 12A mains fuse, and initially I thought the worst. I expected to find shorted (and very expensive) output devices. But it turned out to be a stupid shorted pipsqueak 1A diode in the power supply (!) taking the fuse out. When I got it, it looked like this (sorry, my camera didn't focus quite correctly and I didn't know it until later):



Dirty, ugly, cooked. It received a total rebuild on both amp boards, power supply overhaul, power meter driver board overhaul, disassembly and repair of all four large relays, new bias relays (this is an adventure, as originals are NLA and there are no modern equivalents with the same pinouts), Wifa film input caps, new pots, replacement Unobtanium 2SA798 dual transistors and of course, alignment. The current-limiting adjustment is quite fun. Basically you drive the amp into clipping at 4-ohms, and then set two adjustments. The amp heats up quicker than your electric stove when doing this, and you have to make this adjustment FAST. Here's what it looks like now:



See the little red Wifas below? They take the place of some crappy-sounding tantalums.



This thing had a really beat-up top cover. I've come up with a method to perfectly duplicate the original factory splatter effect, so I flipped the top cover upside down and performed the magic. Perfect!



And of course, there are the obligatory Pacific glamor shots:







This thing makes big, big power into 8 and 4-ohm loads. Sonics-wise, it's a bit lacking in the upper octave, but the flip side is that you could use this as an arc-welder when you're not listening to music, so not a bad compromise!

All photos copyright 2012 Pacific Stereo. All rights reserved, no use without prior authorization from me. If I see these photos in an eBay auction, it will be taken down faster than you can say VERO!
__________________
pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #2  
Old 06-02-2012, 09:40 AM
Old Busted Hotness's Avatar
Old Busted Hotness Old Busted Hotness is offline
Am I doing this right?
 
Join Date: Aug 2011
Location: Cleveland, OH
Posts: 2,233
That's a beauty!
__________________
Open-Reel: Pioneer RT-1020L, RT-701, TASCAM 34 Cassette: Yamaha KX-630, Denon DR-330

All she knew about music was that it came out of funny looking machines, and you didn't want to marry the people who made it.
  #3  
Old 06-03-2012, 09:44 AM
Elite-ist's Avatar
Elite-ist Elite-ist is online now
Serious Tapehead
 
Join Date: Feb 2009
Location: Squamish, B.C. Canada
Posts: 9,647
Very nice PS! A Pioneer Spec 2 or Spec 4 amplifier is high on my list to add to my current system. I always wanted to have a fully racked Spec series of components.

Nando.
  #4  
Old 06-03-2012, 01:21 PM
Nakdoc's Avatar
Nakdoc Nakdoc is offline
Highly Biased
 
Join Date: Nov 2008
Location: Nashville, TN
Posts: 6,395
Were the bias relays the Hitachi reed relays? I have stashed a few of these. That would not be fun to sub.
  #5  
Old 06-03-2012, 03:13 PM
Parnelly's Avatar
Parnelly Parnelly is offline
Serious Tapehead
 
Join Date: Dec 2011
Posts: 2,814
Any of the spec gear is really nice. What kinda power is that thing pushing? 200 a side?
__________________
Everybody Says I Want, Things That Ive Already Got.
  #6  
Old 06-03-2012, 03:15 PM
Pacific Stereo's Avatar
Pacific Stereo Pacific Stereo is offline
Sendust for brains
 
Join Date: Feb 2010
Location: Somewhere in paradise!
Posts: 11,586
Quote:
Originally Posted by Nakdoc View Post
Were the bias relays the Hitachi reed relays? I have stashed a few of these. That would not be fun to sub.
Yes, those are the SPST Hitachi relays (or Hitachi-style, anyway). Yep, they are a pain to sub, as there is nothing that will just drop right in.
__________________
pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #7  
Old 06-03-2012, 03:16 PM
Pacific Stereo's Avatar
Pacific Stereo Pacific Stereo is offline
Sendust for brains
 
Join Date: Feb 2010
Location: Somewhere in paradise!
Posts: 11,586
Quote:
Originally Posted by Parnelly View Post
Any of the spec gear is really nice. What kinda power is that thing pushing? 200 a side?
250 a side at 8 ohms.
__________________
pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #8  
Old 06-03-2012, 03:22 PM
Parnelly's Avatar
Parnelly Parnelly is offline
Serious Tapehead
 
Join Date: Dec 2011
Posts: 2,814
Quote:
Originally Posted by Pacific Stereo View Post
250 a side at 8 ohms.
Is it different at 4ohm?
__________________
Everybody Says I Want, Things That Ive Already Got.
  #9  
Old 06-03-2012, 08:36 PM
Pacific Stereo's Avatar
Pacific Stereo Pacific Stereo is offline
Sendust for brains
 
Join Date: Feb 2010
Location: Somewhere in paradise!
Posts: 11,586
Yes, it is. But I don't know what it is. I don't typically do power measurements at 4-ohms, and I did not do it this time, either.
__________________
pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #10  
Old 06-04-2012, 03:53 AM
Parnelly's Avatar
Parnelly Parnelly is offline
Serious Tapehead
 
Join Date: Dec 2011
Posts: 2,814
Quote:
Originally Posted by Pacific Stereo View Post
Yes, it is. But I don't know what it is. I don't typically do power measurements at 4-ohms, and I did not do it this time, either.
Is that simply because 4ohm is not common in household setups? Or is there another reason?
__________________
Everybody Says I Want, Things That Ive Already Got.
  #11  
Old 06-04-2012, 08:19 AM
Pacific Stereo's Avatar
Pacific Stereo Pacific Stereo is offline
Sendust for brains
 
Join Date: Feb 2010
Location: Somewhere in paradise!
Posts: 11,586
It's because testing at 4-ohms is just tempting fate. I don't like stressing 35 year old products to their absolute limits unless there is a good reason to do so.
__________________
pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
Reply


Would you like to see your company or site here?  CONTACT US
For more Tapeheads affiliates and links, see the Links and Resources page.


Thread Tools
Display Modes

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
Pioneer Spec 1 jazzyguy Receivers, Amps, and Preamps - Solid-State 13 09-14-2013 03:51 PM
Pioneer Spec Systems oldaudioscho Complete Systems 4 05-01-2013 07:18 PM
Pioneer SPEC 2 vs. SPEC 4 Socal Sam Receivers, Amps, and Preamps - Solid-State 6 11-13-2008 06:08 PM


All times are GMT -7. The time now is 10:28 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2016, Tapeheads.Net. All rights reserved, no use of any element incorporated into this site without express written permission.