[BoilermakerFan]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif The regular MAX board is still the preferred choice for a MOSFET-MAX.

Thanks Tom. I was concerned about the extra heat since I'll be running about 3 times the bias current.

 

[amphead]

Still enjoying my Millett Max thoroughly, when I get the time. Sounds like you will be building another one soon BMF. The Mojo thread makes the front page again!

 

[tomb]

Quote:

Originally Posted by amphead /img/forum/go_quote.gif Still enjoying my Millett Max thoroughly, when I get the time. Sounds like you will be building another one soon BMF. The Mojo thread makes the front page again!

Yes, thanks - and a V1.2 PCB is in the works.

 

[BoilermakerFan]

Quote:

Originally Posted by amphead /img/forum/go_quote.gif Still enjoying my Millett Max thoroughly, when I get the time. Sounds like you will be building another one soon BMF. The Mojo thread makes the front page again!

I have two BJT units in the works and a MOSFET-MAX, but the MOSFET is going to hold out for the V1.2 board.

Just went and visited my favorite local body shop for an estimate on my car (wife induced damage) and he said he can paint the yellow zinc plated NABU chassis with no problems. So when the car goes in, there might be a couple of chassis in the trunk too.

 

[slowpogo]

I have a question about the Muse ES caps. On the Max Boutique page (and many places in this thread), it is said that they have amazing deep bass slam. But it is also said on that page that they can "approach Black Gates for detail and neutrality."

I would think those statements are somewhat mutually exclusive. Deep bass with good slam, I would say the caps are bass-heavy, not neutral. What am I missing?

 

[BoilermakerFan]

Quote:

Originally Posted by slowpogo /img/forum/go_quote.gif I have a question about the Muse ES caps. On the Max Boutique page (and many places in this thread), it is said that they have amazing deep bass slam. But it is also said on that page that they can "approach Black Gates for detail and neutrality." I would think those statements are somewhat mutually exclusive. Deep bass with good slam, I would say the caps are bass-heavy, not neutral. What am I missing?

I don't think it is mutually exclusive. The Muse ES caps have the ability to provide tremendous bass slam when paired with certain tubes, BJT DB buffers and the VitQ bypass caps. When the same caps are used with the 2238/968 pairs and FK6 tubes, then you 'll see a little less bass slam, but the reward is the detail and neutrality approaching the BG NXs. Once I get my two BJT boards populated, one will have Muse ES caps, the other will have Silmic IIs. The third board was designated to be a MOSFET build, but I'm waiting for the V1.2 board for it. It will be built with Cerafine caps. All three builds will use the VitQ .18s for by-pass duty.

I'll be able to swap 11 pairs of BJTs in and out and I have 3 MOSFET pairs in addition to the 11 BJTs for MOSFET-MAX so I will be able to closely audition many cap/DB combos. Unfortunately, I didn't think to double up a few of the more popular combos so I could do side-by-side, real-time swaps. I will be able to swap between the two BJT amps in real-time using the same source and same headphones and when I find a combo I really like, I'll swap the DBs to the other board and listen again. Eventually I'll boil down my favorite combo for the two BJT boards and I'll order duplicates if it ends up being one single DB set, but I doubt that will happen since tubes will also play a factor, so I suspect I'll have a favorite tube/Db combo for the Muse caps that is different than the Cerafines or Silmic IIs. Oh, I forgot, I have the Muse KZs and another cap combo too, so I may use the KZs instead of the Silmics since the Silmics are supposed to be so close to the Cerafines.

 

[tomb]

BMF is correct for the most part. However, the context of saying that is relative to the bypass film cap. The ES's have tremendous bass slam - no doubt. However, they are also a very transparent cap - more so than BG's, for instance (MHO). So, there is potential for a great system if paired with an optimum film cap. When paired with Wima's or even more so - the Russian K42's - bass slam is tremendous. However, VitQ's bring out enormous detail. At the same time, VitQ's cut the bass response to a certain degree.

So, it's the combination of caps that I was commenting on. With many bypass caps, the ES's live up to their reputation of bass slam. With VitQ's, IMHO, the detail is such that they compete well with Black Gates. This is because while the combo still lacks a small amount of detail compared to the BG's, the greater transparency gives them an added edge.

Anyway, none of this is contradictory - it's just that the combinations yield sometime unique results.

 

[slowpogo]

I decided to measure the voltage across CA7 when my Max is turned on. It starts low and slowly climbs to 23.4v, stays there several seconds and then falls down to the 13.5v bias level. I did this a few times and it was the same on both caps.

So if I wanted I could try some 25v caps in CA7 (like the Muse KZ), and unless the amp malfunctions they will be fine, correct?

And if the amp does malfunction what is the worst that can happen? They will see 27v and wear out very quickly, or worse than that? There doesn't seem to be much risk, esp. with the Muses being not expensive at all.

 

[cetoole]

Honestly, you could probably get away with it just fine, and I have done the same measurements. Neither Tom or I will suggest doing so though (think I am safe putting these words in that particular horse's mouth).

 

[slowpogo]

Well, based on that idea I threw the 1000uf Black Gates I used to have in CA2 into CA7. I currently have some BG FK series in CA2. (I have been experiencing some kind of cap-rolling mania lately -- seriously, sometimes I question whether DIY is healthy for me!)

Sounds great! Basically like the 680uf Black Gates, but the bass is a little deeper, which you would expect with the lower corner frequency. I also have always had doubled-up Vitamin Qs bypassing CA7 (0.44uf) so that probably helps with the extra capacitance.

So there's an idea for y'all...it will never be officially endorsed, but go ahead and get 4 of the 1000uf 25v Black Gate NX caps for CA2 and CA7. It will be just as good as "can't miss build #1" but with deeper, liquid bass.

 

[slowpogo]

Well, based on that idea I threw the 1000uf Black Gates I used to have in CA2 into CA7. I currently have some BG FK series in CA2. (I have been experiencing some kind of cap-rolling mania lately -- seriously, sometimes I question whether DIY is healthy for me!)

Sounds great! Basically like the 680uf Black Gates, but the bass is a little deeper, which you would expect with the lower corner frequency. I also have always had doubled-up Vitamin Qs bypassing CA7 (0.44uf) so that probably helps with the extra capacitance.

So there's an idea for y'all...it will never be officially endorsed, but go ahead and get 4 of the 1000uf 25v Black Gate NX caps for CA2 and CA7. It will be just as good as "can't miss build #1" but with deeper, liquid bass.

 

[cetoole]

Quote:

Originally Posted by slowpogo /img/forum/go_quote.gif Well, based on that idea I threw the 1000uf Black Gates I used to have in CA2 into CA7. I currently have some BG FK series in CA2. (I have been experiencing some kind of cap-rolling mania lately -- seriously, sometimes I question whether DIY is healthy for me!) Sounds great! Basically like the 680uf Black Gates, but the bass is a little deeper, which you would expect with the lower corner frequency. I also have always had doubled-up Vitamin Qs bypassing CA7 (0.44uf) so that probably helps with the extra capacitance. So there's an idea for y'all...it will never be officially endorsed, but go ahead and get 4 of the 1000uf 25v Black Gate NX caps for CA2 and CA7. It will be just as good as "can't miss build #1" but with deeper, liquid bass.

Glad it worked out for you. The only real concern is possibly in an error state, and then long term longevity. BTW, you know there is a 1500uf 16v BG NX which is the same size as the ones you are using, and would be suitable for cathode bypass.

 

[slowpogo]

Quote:

Originally Posted by cetoole /img/forum/go_quote.gif Glad it worked out for you. The only real concern is possibly in an error state, and then long term longevity. BTW, you know there is a 1500uf 16v BG NX which is the same size as the ones you are using, and would be suitable for cathode bypass.

I think the cap you speak of is actually 10v - still usable? And I'm guessing the main benefit there would be more bass?

I'll probably stick with the FK's there...plenty of bass as it is, and the FK has a more direct, airy sound that acts as good "preparation" for the more rich NX at the output. Using NX for both, I found the sound to be very dynamic and detailed but lacking impact and bite. Percussion sounded a bit too polite for example.

 

[cetoole]

Eh, yeah, you are right, it is 10v. Still usable though, it would have to be a really weird problem to get anywhere near that voltage on the cathode.

 

[soloz2]

for those using a Max to drive k701's what bias have you set the diamond buffers to?

I've got a Can't miss #1 with GE style side ring 12AE6 tubes that will be primarily used with k701's, but I don't have any k701's on hand to tweak the amp. I would imagine higher bias would probably be better, but around 85-90mV seems to sound pretty good with my Senns.