UpGrades!!!

[Alonzo]

I couldn't leave well enough alone.  Burned some "sick time" from work to do some upgrades.  Amp sounds great but I couldn't resist tinkering.  Took out some bypass caps, replaced BH-5 Ni outputs with EXO-145 NI Litz.  This will play until Supremes are delivered, then will upgrade my Obligatto output caps.
Here are some pics; the upgrade parts, a before pic and a comparison of the output sizes.  I'll post a final after changing outputs and trying some bypass caps and silver wire.
So far it sounds great, streaming Pandora via Sonos now, dead quiet and seems.  As soon as I finish adding some bypass caps in the Seduction, I'll give Miles Davis- Porgy and Bess a spin to see how it sounds with more sensitive gear.
Does anyone know how long it takes to "season" output iron? I'm a firm believer that the sound changes as the system ages and components work together for awhile.

 

[Doc B]

I don't have an exact length of time, but it sees to me the bulk of the breakin happens in the first 20 hours or so regardless of the core material with the biggest changes happening in the first hour or two. I think there is a slow and subtle continuation of the process after that, and it's probably more or less complete after 100 hours or so. Determination of this breakin time frame can be hampered by magnetization of the core by a turn on thump. Nickel is of course more sensitive to this than M4/M6. It usually seems to take about 20 minutes of music play to demag after a good startup jolt. So maybe hold your judgment of how far along the iron is until it's had a chance to settle down with some music each time you try it out.

 

[Alonzo]

I know what you mean by the immediate de-mag and settling.  On Grainger's advice (or a blatant copy, I don't remember which) I added a shorting switch to the outputs and turn them on for a couple or 20 minutes before switching in the outputs.  Everything seems cleaner after a half hour of playing or so.
I was just hoping for some magical "umami" flavor that these will achieve since they are the last iron this amp will see and cost more than all the other components combined.

 

[mcandmar]

Good god those obligatos are huge.  Excuse the dumb question, but which amp is it under all those caps?

 

[Alonzo]

45 parafeed, started out as a JE Lab 45/2A3 SE but morphed as the stereomour came out and I got a stereomour top plate, now I would say it's more single chassis Paramour II setup for 45's...mucho mucho goodness. 

 

[aragorn723]

Good god those obligatos are huge.  Excuse the dumb question, but which amp is it under all those caps?

630V DC, nuff said  8)

 

[jrebman]

Hey Alonzo,

I was just looking at my stereomour top plate on one side of my bench and the exo-145s on the other side (figuratively, of course) and I had to wonder if thosetransformers would fit the stereomour chassis as it is -- well, bingo!, perfect fit and plenty of room inside. So now if there will be no issues with adding a 5k opt to the stereomour with 45s, that's what I'm going to do. my guess is that there will be no problem, maybe just a small adjustment in the cathode resistor and maybe the power supply resistor. I had planned on using this amp in our quasi home theater setup, but have decided to go with the SS ACA amps or s.e.x., and the stereomour in my main system.  This is going to simplify things a whole lot, at least to begin with.

Nice going and let us know how those opts sound with some break in.

-- Jim

 

[Matts]

Looks sweet! I put some new xfmrs on my old Pararmours not too long ago- MQ 5K Ni/M4hyperpinstripe PF Robin Hoods, and they sounded great from the start (how could they not?), but I noticed slight improvements almost every week for awhile.  I sort of quit listening to them critically, but all of a sudden, one night several weeks later, they grabbed me and sounded totally different, with much increased detail & smoothness. That was probably after about 60 hours on them.  I don't know if the breakin is real or psychological, but it sure sounds real. That's what matters...  Good luck with yours- they should sound great.

 

[Paul Joppa]

It's real. At least that's my conclusion. I've done breaking with and without listening during the process, and confirmed that my hearing does not change, I hear good sound on the pre-broken-in part and no change as it ages, and I hear bad sound, transitioning erratically to good sound during the breakin. Often I hear the sound actually getting worse over the first few hours before it gets better.

 

[Alonzo]

Well these get a couple hours work every night, there hasn't been a bad period yet, but I'm still under 30 hours run time.  The amp sounds great, I can't imagine it getting better but I do expect the break-in to improve the sound.  I've got 4.7uF Supremes ready to replace the 10uF Obligatto golds but they are wrapped up with a "Do Not Open Till May" note.  I figure to add them in and replace the grid chokes with High Nickel versions for the next change.

 

[Grainger49]

I wonder if break in for a transformer is akin to annealing? 

When I worked for Alcoa one of my buddies at work was the man who patented the annealing process used for can stock.  We talked a lot about the process and grain structures.

 

[Matts]

I've heard it frequently with caps, too, the same pattern as Paul describes- different phases of decent, bad &  worse.  I didn't hear any real "bad" with these new xfmr's, because they were a big change from the original "upgrades" that were sold many years ago.  But when they did finish their breakin, I was able to hear so much more detail, especially in orchestral music.  I let mine warm up 20-30 mins before playing music, and usually left them on for about 3-4 hrs a session.  Not sure how long it took overall, because I quit paying attention, but a couple months.