Now To See If It Works

faskenite

New member
Just completed, resistance checks passed.  Getting my rubber soled shoes on and sticking my left hand in my pocket for the voltage checks!
 

Attachments

  • Stereomour II No. 1.JPG
    Stereomour II No. 1.JPG
    675.2 KB · Views: 121
  • Stereomour II No. 2.JPG
    Stereomour II No. 2.JPG
    1.7 MB · Views: 79
Passed the voltage checks, up and running.  My manufacturer bias has to be taken into account, but in these early days I am very impressed.  Previous main amps have been by Manley and Wavelength, but this thing is something different.  I confess that I substituted quite a few parts, but I am sure that what matters most is the fundamental design.  And this is the quietest tube amp I have ever had in the system!  Initial impressions are that detail and flow are entirely different from what I have experienced previously.  But I think the main point has to be that this thing sounds great.
 
Thanks for the interest!  For a long time I have wanted to try a 2A3 SET amp in my system.  I have previously had a 300B stereo amp and 300B monblocks (2 per side, switchable from single ended to push pull).  I have been in this hobby (Hi-Fi, not DIY) for a long time and wanted to put together something I thought might be extra nice.  So my changes do not reflect any degree of seasoned electronic wisdom, but rather the choices of a fairly hapless hi-fi enthusiast picking things he thought might be nice, or at least fun, after doing some research.
On the top I used Mullard 12AT7’s that I have had but have not used for a long time.  Years ago they were used in a full function preamp.  They are exceptionally quiet and sound good.
I kept the stock Sovtek 2A3’s, although my past experience with Sovteks has not been great. ( To say nothing of those Russian ‘Gold Lion’ 300Bs, although I may have just had a bad batch - I replaced them with Emission Labs, which are great.)
This was my second DIY project, after building the Quickie last winter.  While building said Q I screwed up some RCA soldering and in trying to undo my error pretty well munched one of the stock RCA’s.  This time I decided to use something I thought could be more robust (and silver!) so I got some Audio Note RCA’s. 
I have always liked the Cardas binding posts on my 300B SET so I got some rhodium (silver!) ones for this project.
On the Quickie I used an Audio Note volume control which I like, so I used one of those here too.  The balance and selector controls are stock.
Down below I went a little cap crazy.  Jupiter HT’s for the 3.3 caps and V-Caps for the 1.0 uF’s. 
For reasons that probably defy rational analysis I used Duelund and Neotech solid core copper hook up wire. I used the stock green wire from the power transformer.
When wiring the RCA inputs the supplied Cat-5 wire pretty much got the best of me.  So for two of the three inputs I used twisted pairs of the Duelund and Neotech.  In the result those inputs are very quiet, and I think they have a fuller and richer sound than the Cat-5 input.  But I have not spent a lot of time on the comparison.
I don’t think I have forgotten anything.  This amp sounds great.  Quietest I have ever had in my system (music is almost 100 per cent vinyl, currently with Lowther Medallions, so if there is noise you’ll get it - they are supported by an REL sub).  I am eyeing Emission Labs mesh 2A3’s but with no urgency whatsoever. I am enjoying this amp too much as is.
I’ll post a pick of the innards later, can’t do it from this iPad.
 
Back
Top