[NeilR]

Quote:

Originally Posted by n_maher I didn't say I was done building them , just done messing with those infernal PCBs! NO MORE GROUP BUYS . Truth be told I'm pretty much done building as well. I really just have to get mine started (like it'll ever be done, pfff) and that's it.

Yea yea yea... I've heard this before. I'll believe it a year from now when you haven't built anything for a year.

Take a week or two off; you'll be back building your brains out and running 5 simultaneous group buys and revving that board. It's in your blood and it's highly addictive.

eh eh eh...

 

[n_maher]

Quote:

Originally Posted by NeilR Yea yea yea... I've heard this before. I'll believe it a year from now when you haven't built anything for a year.

Clarification, I'm nearly done building Milletts

. The rest of the project list is way long at this point so talk to me in a year and see if I've got half of that stuff done! PINTs, phonostages, tube-amps, oh my!

 

[NeilR]

Quote:

Originally Posted by n_maher Clarification, I'm nearly done building Milletts . The rest of the project list is way long at this point so talk to me in a year and see if I've got half of that stuff done! PINTs, phonostages, tube-amps, oh my!

Ok. We'll let you take a Millet break. You earned it.

 

[dsavitsk]

Quote:

Originally Posted by NeilR I think the problem is the resistance chosen for your formula. In the thread I linked, I indicated that my trim pot was set at about 1K (12AU6A). My notes indicate precisely 1.17K. Changing your formula to 1K and 75uF, the corner frequency is slightly above 2HZ, which was the goal in that discussion.

Very interesting. I am surprised these amps are not clipping a lot -- or maybe they are

Anyway, with this amp, a 2Hz 3dB point is probably unnecessary. Halving the cap will still only put you at 4Hz which I would think is fine. Heck, you can just leave the cap out too. It will increase distortion a little and lower the gain, but it might not sound too bad.

 

[NeilR]

Quote:

Originally Posted by dsavitsk Very interesting. I am surprised these amps are not clipping a lot -- or maybe they are Anyway, with this amp, a 2Hz 3dB point is probably unnecessary. Halving the cap will still only put you at 4Hz which I would think is fine. Heck, you can just leave the cap out too. It will increase distortion a little and lower the gain, but it might not sound too bad.

Just remember that the point of this is to create the ultimate maxed out uber amp. We don't want it to sound "not too bad", we want it to sound like $120 worth of Black Gates

 

[dsavitsk]

Quote:

Originally Posted by NeilR Just remember that the point of this is to create the ultimate maxed out uber amp. We don't want it to sound "not too bad", we want it to sound like $120 worth of Black Gates

Ah, right, which, if it were me would mean $120 worth of output iron and some better sounding tubes

Anyway, by not too bad I really just meant that it might be a little different, and not necessarilly worse. Which does less damage in the signal path, a resistor and thus some feedback or a cap?

 

[NeilR]

Quote:

Originally Posted by dsavitsk Ah, right, which, if it were me would mean $120 worth of output iron and some better sounding tubes Anyway, by not too bad I really just meant that it might be a little different, and not necessarilly worse. Which does less damage in the signal path, a resistor and thus some feedback or a cap?

That is something I plan to try when I build my "Minimalist Millet". I'm very curious what, if any, benefit we get from the cap, especially since the gain is a bit high to begin with, at least with the 12AU6A's.

 

[peterpan188]

Wow, I missed quite a lot of discussion here. Thank you, davistsk, for all you input for the technical part of cap selection rather than insanity of what I have been doing.

So, for C2, eventually it is better to just stick with a 100uF, instead of anything much higher (my BG NX 680uF), because of phase distortion and harmonics?

Just to clarify, its not $120 bucks worth of Blackgate, it included the resistors

. You guys making me sound like I am out of my mind.

Nate, DON'T QUIT yet, no need for minimalist MH, let all dive in for the uber-MH

Peter

 

[dsavitsk]

Quote:

Originally Posted by peterpan188 So, for C2, eventually it is better to just stick with a 100uF, instead of anything much higher (my BG NX 680uF), because of phase distortion and harmonics?

Too high won't cause phase distortion, too low will. But, too high won't help anything. It is just throwing away money. Caps in tube circuits are not like caps in solid state circuits. In a solid state amp, you can tune the sound to an extent by adding or removing caps from the rails. In tube amps, this doesn't really work. Moreover, the cathode bypass cap is really just a short circuit for the AC music signal. So, 100uF is a decent choice. As noted, you can go lower, but 100uF is probably a good choice.

 

[n_maher]

Just some motivation for you Peter, I finished up this little project last night. It's not quite an "uber-Millett" but is definitely up-spec. All Elna and Wima caps, DB's, TREAD power supply, etc, in a very compact package. Again, regrettably, it is not mine but another built entirely (minus the case) from spare parts that I already had on hand and sold for the cost of those parts.



Just one more project to get off the bench so I can start my Millett (man, that song is getting old

).

 

[MASantos]

Quote:

Originally Posted by n_maher ...so I can start my Millett...

"Nathan Maher's Millett Hibrid. The legend of a cursed DIYer!"

 

[NeilR]

Quote:

Originally Posted by dsavitsk Caps in tube circuits are not like caps in solid state circuits. In a solid state amp, you can tune the sound to an extent by adding or removing caps from the rails. In tube amps, this doesn't really work.

Can you expand on this?

 

[peterpan188]

Quote:

Originally Posted by MASantos "Nathan Maher's Millett Hibrid. The legend of a cursed DIYer!"

LOLZ, Nate should put that in his sig.

 

[peterpan188]

Getting myself into confusions again. Quality-wise, which one is better? BG std, Cerafine or Nichicon Muze? If I am going to use a 100uF for C2, I would want to keep the cap on top of the board, just for the neatness. I looked up for 100uF, BG N is too big for the space, Muze 25V fits fine for $.40 and Cerafine 16V is for $.95.

The real thing that troubles me is that Handmade has minimum order of $12.50, all those Muze costs less than a dollar each, and I really don't have much else to order from there. Same goes to Welborne, but there is no minimum order but shipping counts in.

Thinking about the case desgin, I should name the amp as "THE ALL BLACK UBER MILLETT HYBRID", going with the fact that all the electrolyic caps are in black, and may be put a bright white LED under the tubes with clear top plate, sounds like its gonna look quite appealing to me.

Regard,
Peter

 

[dsavitsk]

It depends a little on what best is to you. Blackgate Std are very good caps. They are clear and crisp, but maybe just a tad thin on the bass -- what sonme like to call neutral. Cerafines are sort of Std lite in that they have a similar sound signature, but are not quite as good. Welborne says he thinks they are 98% as good, and I think he is probably about right.

On the other hand, BG N series, K series, and FK will be a bit warmer and fuller. Nichicon Muse ES series are very warm and bass heavy -- euphonic, but not as detailed. I am actually a big fan of the ES's, but you have to be careful as they are easy to over do. Muse KZ are less warm, still bass heavy, more detailed than ES (though less than BG) and to my ear can sound a little hard on the top.

How any of these will influence the particular amp is hard to know, and i think any of them are fine. I used BG Std's in one Millett and it sounds slightly better to me that the one I used Muse KZ's and cerafines in.

So, I'd pick caps from one vendor for the whole project and you should do fine. All elna, or all Muse or all BG will be fine in any case.