MAX OUT STEPS+MH, Questions
Jun 8, 2006 at 5:03 PM Post #76 of 89
dsavitsk,

Thanks.... I was curious why you suggest that power caps make more of a difference in solid state amps than tube amps (technical reason?).

Edit: or maybe I am confused over quantity vs quality....

Regards,
Neil


Quote:

Originally Posted by 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.


 
Jun 8, 2006 at 5:03 PM Post #77 of 89
Quote:

Originally Posted by NeilR
Can you expand on this?


I am assuming you have experienced adding more caps to a CMoy or something and increasing the bass. As I understand it, this is really a function of solid state amps generally using low voltage and high current and tubes using high voltage a low current. With solid state, the caps need to provide instant current that cannot simply be drawn from a vreg or something like it because there is not a big enough store, and because the output impedence of such devices is too high. With a tube circuit, the caps are not about current storage, but instead are to provide filtering for turning AC to DC and keeping ripple out. Obviously there is more to it that this and note that in the Millett, since it is a hybrid, the buffers do need that instantaneous supply.
 
Jun 8, 2006 at 5:41 PM Post #78 of 89
Thanks, dsavitsk. Good explanation. As you say, the Millet is in some never-never world in between.

I use high impedance phones so the difference in cap values is not as obvious to me as it would be with, say, Grado users. A 300R load is not exactly brutal
biggrin.gif
 
Jun 9, 2006 at 2:33 AM Post #80 of 89
Peter,

If you use the 470uF NX BG's, think about the height- 36mm. If you are using a 2" tall case, your board will have to be very close to the bottom, which means your tubes won't stick out as much as you might like. If you use a board mounted RK27 you may want that centered vertically. You have to put all that together to figure out what parts will fit and how you use them. You may even want to attach "risers" (stiff solid core wire) to the tube socket pins to elevate the tubes a bit.

For C2, I think the only 100uF BG NX that fits is the 6.3V, which is why I went down that road. I'm not getting into the Ford/Chevy debate over the best caps
very_evil_smiley.gif


Neil

Quote:

Originally Posted by 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


 
Jun 9, 2006 at 3:54 AM Post #81 of 89
Great! Here we go another ALL BLACK MH.

Neil thanks for the advise. See this is where the problem comes in, where the case has to be considered into the the component selection. There's a better choice right here, BG NX 680uF, which is D16xH24. For C2, I found a BG Std 220uF, which is 16V, D10xH20.

Do you need a help in the BOM? I think I have a pretty comprehesive one right here by me, listing most of the caps options for each position of MH.

Peter
 
Jun 9, 2006 at 4:05 AM Post #82 of 89
Hi Peter,

Thanks. I think I have my BOM more or less finalized and I think it is identical to yours as far as the electrolytics go- there aren't really many viable options. If you care to PM it to me, I'd like to compare notes.

I bought a diyfidelity stepped attenuator kit, which I think I will try to use. Until that arrives, I won't even know if that monster will fit in a 2" Hammond. This thing won't get built next week
biggrin.gif


Oh yea, don't forget the $200/pair Rhodium plated RCA jacks with matching $200/pair matching Rhodium plated plugs.

Regards,
Neil
 
Jun 9, 2006 at 4:21 AM Post #83 of 89
Quote:

Originally Posted by NeilR
Oh yea, don't forget the $200/pair Rhodium plated RCA jacks with matching $200/pair matching Rhodium plated plugs.

Regards,
Neil


Oh my, you're crazy. Any preference on tubes?
 
Jun 9, 2006 at 4:43 AM Post #84 of 89
Quote:

Originally Posted by mb3k
Oh my, you're crazy. Any preference on tubes?


Oh yea, only those Black Plate 12EA6A's that go for $275/pr on Ebay will do
very_evil_smiley.gif


Just kidding... about the jacks and plugs too. The nice thing about the Millett is that it's really hard to spend more than $10 a pair for tubes. I haven't settled on a favorite tube yet- I have several pairs of all 3 types and I swap them around for variety.
 
Jun 9, 2006 at 5:09 AM Post #85 of 89
Neil, I attached the BOM with this post, anything bolded are the parts that I will order for now. Please let me know your comment.

You found a $200 pair of 12AE6A? Why didn't you let me know earlier? YOU RUINED MY DAY.
k1000smile.gif
evil_smiley.gif
very_evil_smiley.gif


Just kidding, I am still looking for the tubess, everywhere I sent them a email about asking for matched pairs and with brand names on, they never really replied.

No too fancy RCA jacks right here, just a pairs of Cardas GRFA.

Peter
 
Jun 9, 2006 at 5:14 AM Post #86 of 89
Quote:

Originally Posted by NeilR
Peter,
If you use the 470uF NX BG's, think about the height- 36mm. If you are using a 2" tall case, your board will have to be very close to the bottom, which means your tubes won't stick out as much as you might like. If you use a board mounted RK27 you may want that centered vertically. You have to put all that together to figure out what parts will fit and how you use them. You may even want to attach "risers" (stiff solid core wire) to the tube socket pins to elevate the tubes a bit.


Looking at partsConnexion,
Quote:

BLKGATE-60209 N 470 6.3v 13 x 24
BLKGATE-60210 NX 470 6.3v 13 x 24
BLKGATE-60095 N 470 16v 16 x 24
BLKGATE-60090 NX 680 35v 16 x 24


Where did you get your dimensions from?

Peter
 
Jun 9, 2006 at 12:44 PM Post #87 of 89
Quote:

Originally Posted by NeilR
I bought a diyfidelity stepped attenuator kit, which I think I will try to use. Until that arrives, I won't even know if that monster will fit in a 2" Hammond. This thing won't get built next week
biggrin.gif



It'll be close Neil, but I've got a spare SA at home that I can check with tonight, when I start soldering on MY MILLETT!!!

And Peter, I think if you're going to the insane expense of BG's, Rikens and so on it would make sense to look at case options other than the bone stock standard Hammond.

nate
 
Jun 9, 2006 at 7:40 PM Post #88 of 89
Nate, I was thinking about a good Par-Metal case, but I never ordered from them before. How's their quality? How long is their turnaround time?

Any case, I need to order some standoff and screws from MC, glad that Par-metal and Hammond both uses 6-32.

Peter
 
Jul 8, 2006 at 10:41 PM Post #89 of 89
After much work, the combo is done today and tested to be working. The final configuration is the following:

STEPS:
Pretty much followed the part list from Tangent, but changed the regulator to a LM338T, and tranfo is a 70052.

Milllett:
All elecrolytic for power are Muse KZ 220uF, C2 is BG Std 220uF and C7 is BG NX 680uF. I added the bypass caps for power as Wima MKP10. Still have listen more closely for whether to add the signal bypass caps, I got both MKP10 and Pany ECQ-P on hands.

For the first impression, using a pair HD497 and a pair of E4C, it gave me quite a surprise. The high is a lot smoother than the other MH I built. Bass has a little more impact, depending on the tube used. Vocal POPS out form the background, the exact sound I like. If this is not for my friend's birthday, I probably would just take it for myself, definitely worth the extra money.

Pictures of build will come soon, and now it's time to think about casing.

Regard,
Peter
 
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