Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Topic started by: Paul Birkeland on November 13, 2018, 07:28:51 AM

Title: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on November 13, 2018, 07:28:51 AM
We still offer repair services on anything we have ever sold! 
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on November 13, 2018, 07:31:23 AM
This was a pair of Paraglows I received for repair that got the special treatment by the shipping company.  The most sensible course of action turned out to be having new top plates cut out of thicker material in a physically larger size.  These were powder coated in textured black powder and the extra space allowed me to spread out the build components a little bit. 

All capacitors and most of the resistors were replaced during the rebuild.  I will do my best to maintain an inventory of these new chassis plates as undoubtedly there are other Paraglows out there that have suffered a bit while traveling. 
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on November 13, 2018, 07:44:05 AM
Since this project is technically built from Paramount parts, I suppose it belongs here. 

I was approached and asked if it would be possible to build a parallel feed 2A3 monoblock where the output transformer could be changed out easily.  This morphed into monoblocks with polypropylene power supply/cathode bypass caps, then naturally shunt regulated 2A3 amps.  Leftover Paramount parts were used, and the TFA-2004JR transformers can be unplugged and unscrewed from the top side of the chassis (with the amp off of course) to facilitate iron rolling. 

The chassis height was increased to accommodate some enormous Clarity Cap  parallel feed capacitors, and they were even given their own wood stretchers to attach to!
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on November 13, 2018, 09:16:13 AM
This is one of a pair of Paramour I amplifiers that came to me with blown Hammond power transformers.  Although our replacement PT-2 power transformer is no longer in production, our PT-10 power transformer has the perfect high voltage winding and a low voltage winding that is happy heating a 2A3 provided a DC supply is used.  Along with new power transformers, I replaced all the power supply capacitors. 
Title: Re: Legacy Repair Gallery/Blog
Post by: Karl5150 on November 14, 2018, 03:49:10 AM
Having only been onboard since the introduction of the Reduction, I really like seeing the photos of older BH products.
Karl
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on December 22, 2018, 07:37:31 AM
I took this pair of Paraglows in for repair/rebuild recently.  I like seeing our older amps in this condition, as it means the owner has been using them nearly daily for the better part of 20 years.  This pair had tons of bulging capacitors and cooked resistors, so a complete rebuild was in order.
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on December 22, 2018, 07:40:17 AM
Here they are all redone with everything spread out. 
Title: Re: Legacy Repair Gallery/Blog
Post by: 2wo on December 22, 2018, 02:38:48 PM
Wow, nice work...John
Title: Re: Legacy Repair Gallery/Blog
Post by: tsingle999 on December 22, 2018, 05:27:34 PM
It is fun to see your wok Paul! Some great rebuilds! I am familiar with your rebuilds as you have done a couple for me! The SR2A3's are amazing!!! Thanks
Title: Re: Legacy Repair Gallery/Blog
Post by: JamieMcC on December 22, 2018, 10:06:46 PM
What a difference nice work  :)
Title: Re: Legacy Repair Gallery/Blog
Post by: Raymond P. on December 23, 2018, 05:54:21 AM
Enjoy seeing the befores and afters.
Title: Re: Legacy Repair Gallery/Blog
Post by: Bonzo on December 23, 2018, 07:06:50 AM
Enjoy seeing the befores and afters.

Me too! It's one of the most interesting thread of the forum, so full of ideas...
Please, keep on posting Paul!
Title: Re: Legacy Repair Gallery/Blog
Post by: 4krow on December 25, 2018, 11:01:01 AM
 Paul,

   I have a small project that will likely not be completed soon enough, so I am asking you assistance. It is a basic Quickie kit, a PJCCS, and a FIX all combined within one chassis. I have gotten as far as making the Q work, yet, the PJCCS needs your help, as well as the Fix in the final product. Here is a shot in case you are interested.
 My attention has been side lined for a SS amp project, so this needs attention in the meantime.
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on December 25, 2018, 05:21:21 PM
I often find that one of the tougher things to do is to work on partially completed custom pieces.  How much space is there inside your preamp?
Title: Re: Legacy Repair Gallery/Blog
Post by: 4krow on December 25, 2018, 05:48:05 PM
Paul,

 I completely agree. Let me get some photos together for you. What helps is that the chassis can be disassembled to the point where it is pretty accessible. The Fix portion is a bit tight being in there though, so it might end up unused.

  Greg
Title: Re: Legacy Repair Gallery/Blog
Post by: 4krow 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.
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland on December 26, 2018, 11:11:01 AM
That's probably a little beyond my skill set. 
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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.
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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.
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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!
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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.
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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. 
Title: Re: Legacy Repair Gallery/Blog
Post by: borism on April 24, 2019, 03:38:45 PM
Looks beautiful! How does it sound?
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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.
Title: Re: Legacy Repair Gallery/Blog
Post by: sl-15 on April 24, 2019, 04:43:52 PM
Wow that is a very impressive conversion and a neat looking amplifier. Great workmanship!
Title: Re: Legacy Repair Gallery/Blog
Post by: Deke609 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?
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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.
Title: Re: Legacy Repair Gallery/Blog
Post by: Paul Birkeland 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!
Title: Re: Legacy Repair Gallery/Blog
Post by: Karl5150 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.