Ok, pics coming soon...   
      
   First step was to take voltage measurements off the bias and HV+ rails.    
   Here's what I got on my S-5000.  By the way, there are two variants of the   
   S-5000 that I will discuss later, basically the older, longer version and the   
   newer, shorter version.  The    
   one I am working on here is one of the shorter types.   
      
   After the 20uf cap coming off the rectifier, there is a 33 ohm 7w resistor   
   connecting to the next cap section, 40uf@500v.  According to documentation,   
   this point should measure 415v (plate) but I often find that it reads higher.    
   This particular amp is    
   currently measuring 438v on the plates!  This is why you really have to have a   
   7189 here, or at least a beefy 6BQ5 that is known to handle high plate   
   voltages.  I've seen lesser Sovteks arc over in these amps before.   
      
   So, according to my Sams photofact, the correct voltages going down the HV+   
   rail are as follows on the left, and this amp is as follows on the right:   
      
   Photofact             This S-5000   
      
   C1/A - 420v             442v    
   C1/B - 415v             438v   
   C1/C - 350v             365v   
   C2/A - 275v             285v   
   C2/B - 225v             204v   
      
   So right off the bat something looks amiss - All these voltages are a bit   
   higher than listed, but that is ok.  What is odd is that they're all higher   
   except for one, which is quite a bit lower.  That second section of C2 should   
   be higher than 225v, since    
   everything else is higher than listed.  Instead, it's 21 volts lower than   
   listed.  I suspect this points to either that dropping resistor or that cap   
   section being leaky.  Either that, or current draw after that dropping   
   resistor is higher than it's    
   supposed to be for some reason.  We'll have to get to the bottom of that.   
      
   Now on to the bias supply.  It's interesting to note that the bias supply also   
   supplies DC filament current to the two phono preamp tubes, which makes it   
   even more interesting that I've never gotten a US made 12AX7 to sound good in   
   those positions,    
   getting hum regardless.  I suppose it means that it was more induced hum from   
   the surroundings than from the filaments as I had stated earlier, or perhaps   
   there was something amiss in the amp in which I tried it.  I will have to   
   re-visit that whole thing    
   once this is finished.   
      
   There are no real test points listed in the bias supply other than the final   
   ouptut voltage, which is supposed to be -20v.  This amp is currently putting   
   out -21.8, which is probably right on target considering the plate voltage is   
   running a tad high -    
   the extra bias voltage is welcome.  In fact, I'd like to see it a little   
   higher, and once the selenium rectifier is swapped out for silicon diodes,   
   I'll expect to see closer to -23v.  A real indication of the health of this   
   circuit will be the DC    
   voltages at the phono tubes, since these actually have some current draw to   
   them   
      
   Sam's Photofact         This S-5000   
      
   C3/A - Unlisted        -29.3v   
   C3/B - 24v             22.74v   
   C3/C - -20v            -21.8v   
   V1 Fil - 24v           22.74    
   V2 Fil - 12v           11.06   
      
      
   So the bias supply looks good, but the DC voltages to the phono preamp section   
   looks a tad soft.  Who knows, filament starving can have nice effects, but   
   It'll be interesting to see what happens when the selenium rectifier and those   
   electrolytics are    
   replaced.  I always see the bias voltage increase, so the filament should as   
   well.  This SAM's photofact has the polarity of the bias cap backwards, FYI.    
   I will post it all soon when I figure out where to put all the uploads for   
   this project.   
      
      
   It should be noted that this amp currently works and sounds fantastic.  No   
   signs of hum, very clean sound, no issues at all except the power transformer   
   gets a little bit hotter than I think it should be.  Thermal gun measurements   
   have gotten close to    
   136F.  My experience tells me that the second rev. of the S-5000, which this   
   one is, tend to run a little hotter due to smaller iron.  However, I still   
   feel this one is a bit hotter than it should be after two hours of running and   
   I think a power supply    
   rebuild might lower that figure by 10 degrees.  Still, for a bone-stock amp   
   built in 1959, this thing is nothing short of amazing.   
      
   More to come soon!   
      
      
   -forkinthesocket   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)