[tomb]

Quote:

Originally Posted by fault151 /img/forum/go_quote.gif Yeh thats what i thought/hoping! I haven't taken it apart yet to have a look, bts getting late here. I just wondered where would be the best places to look. I guess is should try headphone jack and rca's first?

Both the headphone jack and the pot are board mounted in a standard-build MAX. I'm pretty sure yours was that way. That means the L and R wires from the RCA jacks are switched in the input terminal block.

It's trivial - a small screwdriver to loosen the outer two screws on the terminal block and swap the wires. I have some sort of mental block and get them switched on a regular basis.

I sort of gave up trying to keep them straight on mine.

 

[chilly]

Hey everyone,

I had finished my Max about a month and a half ago, it was my second DIY electronics project. The soha was my first. ok so I got bit by the bug... damn you all...

I'd post pic's but it looks like all the black maxes out there.

I (well actually my wife did) ordered another Max kit from Jeff at Glass Jar (thanks Jeff). But I am going to jazz it up a bit this time. My first max was with the Nichicon Muse ES's and VitQ's from Beezar ( thanks Tom). I'm very happy with the sound, but I feel maybe just maybe I can squeak out even better performance...

Since I have no clue about electronic circuitry... I'm going on what is written in these forums and well all of you, who I value so much.


SO I think I'm going to do the boutique build #1 using Black Gates, and VitQ's as well, leaving C9 blank.


CA7 - black gate
CA2 - black gate
CA8 - VitQ .22uf or the .18uf if those would be better
CA9 - blank

I also have the transitors 2344 and 1011, but am wondering if the 3422 and 1359 is a better match for me as I do like good strong but accurate bass.

I have already purchased a pair of WBT next gen sockets, and will soon be purchasing a neutrik locking plug, and Wire from Navships.

My questions are:

Are the VitQ's the best for the job in CA8 or is there a better film cap? ( like cardas, or mundorf, or angela )

could I use VitQ's for CA3 and CA6 instead of the wima's? would it improve the sound?

I'm making a custom case for this amp as well, I will be air wiring the Pot, and the headphone jack, and I will also be air wiring the tubes to fully poke them out of the case. Does anyone see any problem with airwiring the tubes? it will only be like 3 inches at the most.

My case will be wood will that be a problem? only the top plate and the rear will be metal, probably stainless steel.

I will probably be using 12ae6a's as I think they have the tightest bass, I love the 12fm6's but the bass can get a little mushy to me, but oh, the midrange is heavenly.


If anyone has any ideas for making this an even better amp, please let me know, I can't say this is a money no object amp, cause its not but I would be willing to spend a little more. Please keep in mind that I use IEM's UE-5c's to be exact. Yes I know IEM's may not be the best for a tube amp.... but the current Max I have is virtually silent with the exception of an occasional cell phone interference buzz. I do have a 10ohm resistor at RB14.

Ok enough rambling,

cheers

 

[Beefy]

Quote:

Originally Posted by chilly /img/forum/go_quote.gif Are the VitQ's the best for the job in CA8 or is there a better film cap? ( like cardas, or mundorf, or angela ) could I use VitQ's for CA3 and CA6 instead of the wima's? would it improve the sound?

I read about 100 forum pages about the MHM last night, before placing my orders. Hopefully, this is an accurate summary.......

Vitamin Q 0.22µF at CA8 is about as good as you can get. Anything better is simply too large to fit on the PCB. Everywhere else, Wima is the best choice. Even CA9 should be a Wima - unless you have BG NX, in which case you leave it out, as you correctly intend to do.

Quote:

Does anyone see any problem with airwiring the tubes? it will only be like 3 inches at the most.

I really don't think that will be a good idea. Not any specific info, just a very big hunch.

Quote:

If anyone has any ideas for making this an even better amp, please let me know, I can't say this is a money no object amp, cause its not but I would be willing to spend a little more.

You might want to use larger caps than Jeff provides at CA4 and CA5. By default Jeff supplies 470µF Muze KZ, which are nice caps but tomb thinks they are simply too small. I'm swapping mine to 1000µF Panasonic FM or Nichicon UPW. You can go up to 1800µF if you really want to.... perhaps I'm a bit naive, but I don't see how 7200µF of capacitance could POSSIBLY be required there - my M^3 has nowhere near that, and is almost capable of driving speakers.

I can't help you out with transistor selections, because I didn't really research that. Only other major suggestions is perhaps a stepped attenuator instead of the volume pot? Its a very popular upgrade in many DIY amps.

Hope this helps!

 

[amphead]

Congrats Migroo! Another Max Lives!

So many ways to box it up, but the Hammond enclosure works very well.

 

[tomb]

0.18uf, 100V 96P-series ("THE" Vitamin Q) VitQ's are also up.

 

[tomb]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif You might want to use larger caps than Jeff provides at CA4 and CA5. By default Jeff supplies 470µF Muze KZ, which are nice caps but tomb thinks they are simply too small. I'm swapping mine to 1000µF Panasonic FM or Nichicon UPW. You can go up to 1800µF if you really want to.... perhaps I'm a bit naive, but I don't see how 7200µF of capacitance could POSSIBLY be required there - my M^3 has nowhere near that, and is almost capable of driving speakers.

Hmm ... I thought Jeff had started putting bigger caps in there. FYI, the M3 uses a capacitance multiplier in the circuit so that the effective on-board capacitance is over 10,000uf. That's why AMB has a lot of warnings about don't dare increase the size and number of the capacitors.

That said, I think 1000uf is a happy medium. If you go on and use the same 50V caps that are in the PS, that sends the number to 8, and it's a small matter to order two more to get the per-10 price break.

I use 1800uf in mine, but the bigger you go, the bigger the voltage spike your headphones see at turn off.

Quote:

I can't help you out with transistor selections, because I didn't really research that. Only other major suggestions is perhaps a stepped attenuator instead of the volume pot? Its a very popular upgrade in many DIY amps. Hope this helps!

Steinchen's transistor reviews for his revMH Millett DB's are still the standard reference. I basically describe them the same way on beezar with a bit of embellishment.

 

[Beefy]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif 0.18uf, 100V 96P-series ("THE" Vitamin Q) VitQ's are also up.

Ah crap, I bought the 0.22µF just 3 hours ago, to go with Muse ES. And now you have these better ones, at just $1 more for the pair?

Is it possible to swap them, even after my order has been confirmed? Last communication I got was that the order was 'Processing'.......

[EDIT] Emailing you directly.....

 

[Beefy]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif FYI, the M3 uses a capacitance multiplier in the circuit so that the effective on-board capacitance is over 10,000uf. That's why AMB has a lot of warnings about don't dare increase the size and number of the capacitors.

I thought it was because of inrush current causing a temporary short circuit in the S11 PSU. Might have to research capacitance multipliers.....

Quote:

I thought Jeff had started putting bigger caps in there

Jeff's email says "I have switched out some of the 470uF already to 1000uF Panasonic FM caps". That's fairly ambiguous as to whether they come with it by default. Perhaps best to check as I did

 

[tomb]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif I thought it was because of inrush current causing a temporary short circuit in the S11 PSU. Might have to research capacitance multipliers.....

Well, yeah - but something causes that current inrush.

Remember also that 4000uf of the onboard capacitance in the MAX is the Power Supply. The M3 doesn't even count that.

 

[Beefy]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Remember also that 4000uf of the onboard capacitance in the MAX is the Power Supply. The M3 doesn't even count that.

Sorry to keep dragging this off-topic, but I'm still learning

I was thinking that post-voltage-regulator C7 on the M^3 board (3000µF max) is analogous to CA4/5 on the MHM (4000-7200µF).

And that pre-voltage-regulator C5 on the S11 board (3000µF) is analogous to CR1 on the MHM (4000µF).

 

[tomb]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif Sorry to keep dragging this off-topic, but I'm still learning I was thinking that post-voltage-regulator C7 on the M^3 board (3000µF max) is analogous to CA4/5 on the MHM (4000-7200µF). And that pre-voltage-regulator C5 on the S11 board (3000µF) is analogous to CR1 on the MHM (4000µF).

Yes, but the 10,000uf effective capacitance on the M3 board should only be compared to the MAX's CA4L/R and CA5L/R caps, in order to do apples to apples. If you compare by also including the MAX's PS caps, then you have to add the M3's 10,000uf plus whatever is in the S11 or STEPS, meaning you're comparing about 14,000uf for the M3 to that supposedly over-loaded 7200uf on the MAX.

1800uf caps on the MAX doesn't seem like that much put in that context.

 

[Beefy]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Yes, but the 10,000uf effective capacitance on the M3 board.....

That's fine, I'll have to learn about how this effective capacitance trickery actually works!

Oh, and I tried responding to your PM you re: the Vit Q's, but you've exceeded your quota. Sent an email to tomb AT beezer.com instead.......

 

[tomb]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif That's fine, I'll have to learn about how this effective capacitance trickery actually works! Oh, and I tried responding to your PM you re: the Vit Q's, but you've exceeded your quota. Sent an email to tomb AT beezer.com instead.......

Yep - I cleaned it up, but it was too late.

 

[Beefy]

Ok, I think I've now got the skinny on capacitance multipliers.....

The big 3000µF capacitance at C7 on the M^3 supplies power to the MOSFETs. This appears to have no capacitance multiplication.

But the M^3 does use a capacitance multiplier on the 100µF capacitors at C5 (or is it technically C4?). This cap provides a source of clean power to the OPAMPs, effectively filtering away any ripple introduced by the MOSFETs.

This is all very interesting.... so many different ways to skin a cat

 

[fault151]

Cheers for alll your replys guys. It's definitely not the headphones the wrong way. checked them + my other two amps i tried them work fine. I guess it must be the rca's.

I'll take them apart tonight and swap them over. Hope it works!

I'll update you all.

Cheers.

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Both the headphone jack and the pot are board mounted in a standard-build MAX. I'm pretty sure yours was that way. That means the L and R wires from the RCA jacks are switched in the input terminal block. It's trivial - a small screwdriver to loosen the outer two screws on the terminal block and swap the wires. I have some sort of mental block and get them switched on a regular basis. I sort of gave up trying to keep them straight on mine.