jhoak Posted June 24, 2011 Share Posted June 24, 2011 Lookee what I builded today... [] I had lined up someone to build it for me since a previous experience with one of these amps had me seriously doubting my ability build one successfully. On the same day that Mr. Latino shipped it my builder decided to go to South Carolina and work on his vacation home for a month or so. CRUD!!! Pretty much everyone who has built one of these has advised that it be done over several days. That really was my intent but I just couldn't seem to find a "stopping place" today. I started at 05:30 this morning and at 15:30 this afternoon I did the initial startup. It came up perfectly. No hums, buzzes, sparks, flashes, or smoke. I was able to dial in the bias within seconds. In other words a VERY successful build. Much... no MOST of the credit goes to Mr. Latino and his excellent build instructions. At the moment the tube compliment is a set of 3 JAN Philips 12AT7s, a quad of Ruby Tubes KT88s and a JJ GZ34 rectifier. I have a set of NOS Mullard CV4024s that I'll put in once I'm happy that it's "stable". I also have a Weber Copper Cap SS rectifier on the way to me. Right this minute it's belting out a little Mark Knopfler in triode mode. Let's just say it has my newly minted Cornscalas singing. [] Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted June 24, 2011 Share Posted June 24, 2011 Looks great! How does it sound? Let's see a picture under the hood. Quote Link to comment Share on other sites More sharing options...
jhoak Posted June 24, 2011 Author Share Posted June 24, 2011 It's sounding pretty good to me. The best part is I know it'll only get better. I'll swap in the NOS Mullards in a few days once I'm convinced that it's not going to go "thermonuclear" on me. After that comes 100 to 200 hours of break-in. It'll be close to a month before it's truly completely settled in. It'll be a bit before I take it back out to get an "under the hood" shot. Be prepared to be completely underwhelmed though. I'm not as "fastidious" as most. By no means ugly but certainly not what one would call pretty. Quote Link to comment Share on other sites More sharing options...
Boxx Posted June 24, 2011 Share Posted June 24, 2011 Really a nice setup... I'll be anxious to hear a report after the break in period... Quote Link to comment Share on other sites More sharing options...
jhoak Posted June 24, 2011 Author Share Posted June 24, 2011 Thanks. And more changes coming. On Monday I'll be receiving a McIntosh C32 preamp that I'm hoping (1) arrives in one piece & (2) will be come the centerpiece of my "last" 2-channel system. If my hopes are realized I should be pretty close to done. Yea... I know... Famous last words. I have been systematically selling off much of my collection. In particular the secondary and tertiary systems. It's kind of dumb for a single guy living in a small house to have 4 unique stereo systems. Especially when the house is wired such that every room (OK... Not the bathrooms... at least not yet) can have sound drom the main system. Quote Link to comment Share on other sites More sharing options...
Bob Latino Posted June 24, 2011 Share Posted June 24, 2011 Hi Jeff, Nice work ... If you follow the assembly instructions the amp should come up with no issues as your amp did. You are correct in that it will take 100 to 200 hours of play time for the amp to completely break in. Once broken in, the amp will smooth out and have a more liquid sound. I have heard this effect many times on a number of new amps that I have personally built. I am not exactly sure what happens during this break in period but it is probably something on the "molecular level". Some doubters have said to me that this break in factor is just your ears getting used to the sound of the new piece of audio gear. Personally, I don't agree with them. Maybe one day someone with the proper test gear can find out exactly what happens? Maybe do a before and after electron microscope photos of the inside of a capacitor or resistor? I had someone mention to me that he thought that the "slew rate" (voltage change per microsecond) of the amp gets faster as the parts break in? (voltage changes can occur in a shorter time period) I honestly don't know why amps smooth out after 100 to 200 hours - but my ears tell me that they do ... Bob Latino Quote Link to comment Share on other sites More sharing options...
MechMan Posted June 24, 2011 Share Posted June 24, 2011 Very nice work J. I've always wanted to hear one. Good on ya for knocking it off in one day. Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted June 24, 2011 Share Posted June 24, 2011 Jeff, I'm sure that Bob gave you extra instructions related to installing the Russian PIO caps! (you know I've never said anything before!) I love my VTA-120, now that it's problem has been finally resolved (thanks Bob!). Enjoy yours. I also have a NOSValves VRD ST-45 that I also love. I also want to try a McIntosh MC-2102. (and perhaps a pair of Bob Latino's new M-125 Monoblocks). Quote Link to comment Share on other sites More sharing options...
jhoak Posted June 24, 2011 Author Share Posted June 24, 2011 Thank you!!! I really did NOT intend to "knock it out" in one day but a whole pot of coffee at 05:00 and a few cans of Mountain Dew during the couse of the day tends to keep one "driven". It's actually sounding much better than I expected or anticipated right out of the box. I'm rather surprised. I will say that the one thing that it "enlightened" me to was just how good my old Onkyo/Integra M506RS sounded. The VTA-120 is better driving the Cornscalas than the Onkyo but not by as much as I would have thought. I guess that's a testimony to just how good those old "Oinker" amplifiers really are. After the public beating that I took over the last time I took a soldering iron to a VTA-120 I was VERY reluctant to venture in to that world again. On the other hand I have purchased a proper soldering station and a magnifier visor since then. I now can apply enough heat to a solder joint AND see it clearly enough to do a decent inspection. Bob, I do have a couple of very small problems that I'm trying to work through. Not really "problems" per se but just things that doesn't work the way I think they should. If I can't figure them out on my own I'll drop you an email. I would however like your opinion on the "low gain" version of the VTA board versus the standard version. I have a hunch that moving away from the CV4024s costs more sound wise than going to "low gain" board gives back. Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted June 24, 2011 Share Posted June 24, 2011 PS: Mark Knopfler is so good! Quote Link to comment Share on other sites More sharing options...
jhoak Posted June 24, 2011 Author Share Posted June 24, 2011 PS: Mark Knopfler is so good! YEP!!! But we've moved on... Currently playing is some old Fleetwood Mac and on deck is some very nice Supertramp on vinyl no less. Looks like I'm not going to get a whole lot accomplished for the next couple of days. [] Oh well... Quote Link to comment Share on other sites More sharing options...
mustang guy Posted June 24, 2011 Share Posted June 24, 2011 Sexy amp! Quote Link to comment Share on other sites More sharing options...
Dennie Posted June 24, 2011 Share Posted June 24, 2011 Congratulations Man, you did a great Job. That looks great and I bet it sounds great also! Nice Work! Dennie Quote Link to comment Share on other sites More sharing options...
Boxx Posted June 24, 2011 Share Posted June 24, 2011 Hey Jeff... You can't beat this support group.... lol.... Quote Link to comment Share on other sites More sharing options...
Dennie Posted June 24, 2011 Share Posted June 24, 2011 Hey Jeff... You can't beat this support group.... lol.... Support Group? Don't you mean "Addiction Counselors" ! Dennie Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted June 25, 2011 Share Posted June 25, 2011 Hi Jeff, Nice work ... If you follow the assembly instructions the amp should come up with no issues as your amp did. You are correct in that it will take 100 to 200 hours of play time for the amp to completely break in. Once broken in, the amp will smooth out and have a more liquid sound. I have heard this effect many times on a number of new amps that I have personally built. I am not exactly sure what happens during this break in period but it is probably something on the "molecular level". Some doubters have said to me that this break in factor is just your ears getting used to the sound of the new piece of audio gear. Personally, I don't agree with them. Maybe one day someone with the proper test gear can find out exactly what happens? Maybe do a before and after electron microscope photos of the inside of a capacitor or resistor? I had someone mention to me that he thought that the "slew rate" (voltage change per microsecond) of the amp gets faster as the parts break in? (voltage changes can occur in a shorter time period) I honestly don't know why amps smooth out after 100 to 200 hours - but my ears tell me that they do ... Bob Latino I'm not sure why either, but I've been through enough amp rebuilds to have heard that phenomena too. There is a coherency, liqidity, and "continuousness" to the presentation after the break-in. I refrain from doing any tube rolling until that process is done, as it keeps the circuit unchanged - and therefore takes guesswork out of asking "is this troubleshooting issue because I rolled the tube - or a build/parts issue?" Even the best builders can have a part defect or connection issue on rare occasion, and my way of verifying the build is to refrain from tube rolling until the amp is well broken in. The "sonic colors" of those rolls will be more evident/beneficial on a fully broken in amp as well. Quote Link to comment Share on other sites More sharing options...
jhoak Posted June 25, 2011 Author Share Posted June 25, 2011 A couple more pictures from the project. I prepped the work area Friday evening. The table top under the cardboard is black granite. I didn't think that the granite would be especially good for the transformers nor would the transformers be kind to the granite. When I unboxed it I laid it all out in a fairly orderly fashion. This is in my dining room. As I did the work I only carried the parts I needed for that step to the kitchen. I knew I was done when the table contained no more baggies. Yes I am single... Why do you ask? [] Quote Link to comment Share on other sites More sharing options...
fini Posted June 25, 2011 Share Posted June 25, 2011 Jeff, that looks like SO much fun! 10 hours?? That's awesome! Quote Link to comment Share on other sites More sharing options...
Guest davidness Posted June 25, 2011 Share Posted June 25, 2011 Jeff, In the end, how useful was having the magna-glases? Do you wear corrective lenses? Quote Link to comment Share on other sites More sharing options...
jhoak Posted June 25, 2011 Author Share Posted June 25, 2011 In the end, how useful was having the magna-glases? Do you wear corrective lenses? I wear glasses to read but they're not real strong. +1.5 I think. I'd have to check to confirm that. The magnifier was quite helpful. It is a 3X and 6X. I used it to inspect solder joints on the VTA board. [] It wasn't much help on the main chasis though. I have to hold things pretty close when using the visor. Hoisting all of that iron to look at a just finished joint was out of the question. Quote Link to comment Share on other sites More sharing options...
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