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August 24, 2019, 07:30:02 AM

Author Topic: Legacy Repair Gallery/Blog  (Read 2531 times)

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Offline Gregory Peyton

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Re: Legacy Repair Gallery/Blog
« Reply #15 on: December 26, 2018, 09:54:56 AM »
 Now that I have had a chance to photo, and disassemble the unit, here is what you are looking at. Basically a Quickie and PJCCS that need attention. I must add that the 3 position Glassware A3 volume control is a stepped attenuator arrangement for 1) master volume (center dial), 2) left and right separate volume (flanking dials). This isn't the issue..... Believe it or not, I am unable to get the PJCCS working when wired to the Q. The Q works on it's own. Each time I make one of these simple kits, this same thing happens when the PJCCS is wired in, i.e. no signal at output. I realize that this is something that I am getting wrong, but I have simply lost patience.
« Last Edit: December 26, 2018, 10:00:59 AM by 4krow »
Greg Peyton
 System makeup: Decware "Rachael" integrated amp.;Rega Apollo 'R'; Emotiva ERC3 CDP; Decware ZOB speakers W/FRX2 drivers; Audio Nirvana subs w/Velodyne SMS-1;  Blue Heaven Nordost cables, Pangea/PS Audio power cables, BPT power conditioner

Online Paul Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #16 on: December 26, 2018, 11:11:01 AM »
That's probably a little beyond my skill set. 
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

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Re: Legacy Repair Gallery/Blog
« Reply #17 on: March 21, 2019, 12:31:59 PM »
I took this pair of old Paramours in for repair recently.  One of them somehow developed a short between B+ and the chassis through debris in the 9 pin socket.
Paul "PB" Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #18 on: March 21, 2019, 12:34:20 PM »
Since I had the amps in hand, I talked the owner into letting me install the Iron Upgrade package that we offer for older SEX amps.  It fit, but just barely!  I had to trim off some of the mounting tab on each output transformer so it would clear the wood base.
Paul "PB" Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #19 on: April 03, 2019, 01:37:43 PM »
This project I am building up for my own personal uses.  Way back 20+ years ago, I won a set of 300B-glow amps on eBay back when eBay was pretty new.  I was working at a hifi shop at the time and had them shipped there, and I got to audition the amps against power amps that (at the time) were $25,000+.  Needless to say I don't work at a hifi shop anymore! Anyway, this pair of really old and crusty original "SEX" amps showed up on the local Craigslist for a fair price.  They really have very little left from the original SEX monoblocks, except maybe two of the octal sockets.  The presence of the PGP-8.1 and TFA-204 made it obvious that I should rewind the clock and make some new B-glow amps.  Stay tuned for more photos!
Paul "PB" Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #20 on: April 24, 2019, 11:38:18 AM »
Much, much earlier this year, I sent out a pair of repair boxes for some "Paramours".  When I eventually received them, they were more like cap coupled Paraglows with lots of Magnequest transformers and fancy parts inside.  Ultimately some flaky hardware was to blame for the issues the amps were having, but I managed to talk the owner into letting me convert these old amps into a fresh stereo amp.
Paul "PB" Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #21 on: April 24, 2019, 11:42:08 AM »
Here's the completed amplifier.  I recycled a significant number of components from the original build, but combined it all into a three sided aluminum enclosure with alder side rails.  To spice things up visually, there's a pair of 100mA ammeters that display the operating current for each 2A3. 
Paul "PB" Birkeland

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Offline borism

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Re: Legacy Repair Gallery/Blog
« Reply #22 on: April 24, 2019, 03:38:45 PM »
Looks beautiful! How does it sound?
Boris

Online Paul Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #23 on: April 24, 2019, 03:53:15 PM »
Looks beautiful! How does it sound?
Excellent, the TFA-2004 is a very solid performer and a big step up from the Speco matching transformer provided with the old Paramour.
Paul "PB" Birkeland

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Offline sl-15

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Re: Legacy Repair Gallery/Blog
« Reply #24 on: April 24, 2019, 04:43:52 PM »
Wow that is a very impressive conversion and a neat looking amplifier. Great workmanship!
stefan hampel
ortofon sl-15 with step-up, modded technics sl-1200mkII, seduction c4s, eros phono, extended foreplayIII, pioneer spec4/mc225, sonus faber electa

Online Deke609

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Re: Legacy Repair Gallery/Blog
« Reply #25 on: April 25, 2019, 03:24:09 AM »
Ditto. Looks great. I like what you did with the metal chassis and front and backplates. I may poach that for a re-build I have in mind using copper plate (I don't think my existing 30 gauge will stand up to the test of time)

Those output transformers are HUGE.  Why so big?
Derek
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Roon Intel NUC ->  Yggdrasil DAC -> BeePre (w/ BeeQuiet and EML 300B)  -> Stereomour IIs (2A3 [EML 2A3 Mesh] and 45 Conversion [EML 45B] - both fully upgraded)  -> Audeze LCD4

Online Paul Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #26 on: April 25, 2019, 06:09:18 AM »
Those output transformers are HUGE.  Why so big?
They look bigger in the photos than they are in person.   A transformer stacked with all nickel laminations will also need to be a bit bigger than its grain oriented steel counterpart.
« Last Edit: June 19, 2019, 10:37:42 AM by Paul Birkeland »
Paul "PB" Birkeland

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Online Paul Birkeland

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Re: Legacy Repair Gallery/Blog
« Reply #27 on: June 19, 2019, 10:42:03 AM »
I finally got some spare time to work on those Craigslist amps that I bought.  PJ was kind enough to scan and send me his B-glow manual, and he also provided some information on DC heating a 300B from the PGP8.1.  The chassis plates of these amps are powder coated with green vein powder, the sides are 1/4" cherry over plywood since you don't see the edges, and I used a couple of motor run caps in the power supply.  A little extra B+ is dropped by using a different power supply choke, and bias is monitored with a meter so it can be more precisely adjusted.  A scrap preamp prototype from Doc B's basement provided the old school C4S boards that I thought would be fun to use in this recreation.

If you have a crusty old pair of B-glows sitting around, I am certainly available to freshen them up!
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Karl5150

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Re: Legacy Repair Gallery/Blog
« Reply #28 on: June 20, 2019, 03:00:41 AM »
Beautiful.
I like how each restoration is unique: They all require similar components to function, but the final results are certainly not "cookie cutter". Objets d'art, capable of stimulating multiple senses.
Karl
Analog: Planar3>Eros>Stereomour II>Tekton OB4.5 & DIY "S8" subs
Digital: CD5004>Quickie>Seductor>FH3
Office: Schiit Modi Uber 2/Sirius Tuner>SEX 2.1.1>µFonken/FF85WK