[TheEKey]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif First of all, thanks for all the photos. It will make trouble-shooting this a lot easier! The first thing I noticed is that perhaps you're wiring up the 3.5mm jack wrong in the first place. If I'm not mistaken, the longest lug coming off of the 3.5mm jack is Ground. You have the blue wire connected to that. Yet, you're connecting the blue wire to the Left channel (OL). Things can get mixed up quickly like this - it may even be that you have the inputs crossed, too

Thank you, TomB. I mismatched the L/R/G for sure. Now it's fixed. Enjoying it for couple hours~!
Start to feel the itch to play around with the output caps. Need some vitamin and volka...

BTW, any DIYer's ever tried to build a switch for different output caps for MHM? Do you think it's worth bothering or just better stay single-minded?

TheEKey

 

[tomb]

Quote:

Originally Posted by TheEKey /img/forum/go_quote.gif Thank you, TomB. I mismatched the L/R/G for sure. Now it's fixed. Enjoying it for couple hours~! Start to feel the itch to play around with the output caps. Need some vitamin and volka... BTW, any DIYer's ever tried to build a switch for different output caps for MHM? Do you think it's worth bothering or just better stay single-minded? TheEKey

Glad to hear you got it working!

As far as a switch for the output caps, I'm not sure that would be a good idea. Even if it were just switching the bypass caps, the momentary charges and discharges might bleed through the switch with arcing. This could expose your headphones to transient spikes or worse. I've just not seen it done, maybe for the same reason that most don't socket capacitors, either.

I've switched the output resistors before and that works well if you want to try to that - switching between 10 ohms and 100 ohms, jumpers and 47 ohms, or something like that. This can easily be accomplished with a DPDT switch.

If you're really interested in the best output cap, IMHO you won't find anything better than a 196- or 96-series VitaminQ at the prices we have. Beyond that, you're talking $tens of dollars to get noticeable improvements with Mundorfs and the like, IMHO. We did a lot of experimentation early on with the MAX regarding the output caps.

 

[TheEKey]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Glad to hear you got it working! As far as a switch for the output caps, I'm not sure that would be a good idea. Even if it were just switching the bypass caps, the momentary charges and discharges might bleed through the switch with arcing. This could expose your headphones to transient spikes or worse. I've just not seen it done, ....

Yea. Feels awesome to get rid of some sticky bugs. Especially this one was particularly easy to do.

I'm done with the output resistors during the building and settled with jump.

For the output caps, I really think the default Muse ES provides too much bass. Looking for more muscial and vocal caps. I should try the VitaminQ.

TheEKey

 

[tomb]

Quote:

Originally Posted by TheEKey /img/forum/go_quote.gif Yea. Feels awesome to get rid of some sticky bugs. Especially this one was particularly easy to do. I'm done with the output resistors during the building and settled with jump. For the output caps, I really think the default Muse ES provides too much bass. Looking for more muscial and vocal caps. I should try the VitaminQ. TheEKey

Well, remember that the MAX's sound is a combination of many factors. It's true that the ES's provide a lot of bass, but they are very transparent as well. Much of that bass can come from the tubes - especially 12AE6's, although it still depends on the particular pair of tubes. I don't know what you have in there (I'll have to look at your pics again), but you may find the high end changes a lot with 12FM6's or 12FK6's.

The VitQ's will also definitely make a difference. It's been stated many times, but I think the combination of ES's bypassed by VitQ's comes very close to the detail of Black Gates.

 

[BoilermakerFan]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Well, remember that the MAX's sound is a combination of many factors. It's true that the ES's provide a lot of bass, but they are very transparent as well. Much of that bass can come from the tubes - especially 12AE6's, although it still depends on the particular pair of tubes. I don't know what you have in there (I'll have to look at your pics again), but you may find the high end changes a lot with 12FM6's or 12FK6's. The VitQ's will also definitely make a difference. It's been stated many times, but I think the combination of ES's bypassed by VitQ's comes very close to the detail of Black Gates.

And let's not forget the subtle or not-so-subtle differences the DBs make too.

TheEKey, I think I would roll a few different tube sets in and out with the ESs bypassed with VitQs. Then decide if you still think there is too much bass even with 12FK6 tubes. I don't recall seeing which DBs you're using, but you might try a different set of DBs too before rolling Cerafine, Muse KZ, or Silmic II caps into your MHM. I have a buddy who really likes forward, bright highs and less bass. He loves SR-325i over the RS-1s and also loves his Markl modded Denon D2000s. His tastes are different than mine, but I'd build his MHM with 12FK6 tubes, KZ caps and VitQ bypass caps. I forget the recommended DB combo right now, but it leans to the high with a more clinical sound...

 

[TheEKey]

Quote:

The VitQ's will also definitely make a difference. It's been stated many times, but I think the combination of ES's bypassed by VitQ's comes very close to the detail of Black Gates. __________________ TomB

Quote:

Originally Posted by BoilermakerFan /img/forum/go_quote.gif And let's not forget the subtle or not-so-subtle differences the DBs make too.

Currently I use 12FM6. Is this considered heavy bass? Will it contribute the most of the responses.

I would definitely like to try out more tubes.

First of all, I'll try out as many as combinations shown in the Max Boutique. Hope that I will hit the right one.

For DB, I think I will leave it to the next MHM ( I'm amazed that Bantam DAC is included in the MHM 1.2 board)

Cheer~!

TheEKey

 

[tomb]

Quote:

Originally Posted by TheEKey /img/forum/go_quote.gif Currently I use 12FM6. Is this considered heavy bass? Will it contribute the most of the responses. I would definitely like to try out more tubes. First of all, I'll try out as many as combinations shown in the Max Boutique. Hope that I will hit the right one. For DB, I think I will leave it to the next MHM ( I'm amazed that Bantam DAC is included in the MHM 1.2 board) Cheer~! TheEKey

No, 12FM6's are not bass-heavy. I'd suggest those VitQ's as the first thing you try, then.

 

[Dan55]

Quote:

Originally Posted by cetoole /img/forum/go_quote.gif OK, I have a guess, and it isnt good, but here goes: when you had DR1D in backwards, that effectively shorted the wallwart's output, and probably blew an internal protection fuse, which means that wallwart is now basically toast. Let us do some measurements though, and if you can, please dig up another source of AC voltage you can use to make sure your meter is working properly. Basically, I would like you to unplug the wallwart from the Max, and try and measure the AC voltage on the output with no load, then do the same with another AC wallwart which is known good.

I finally picked up a new AC wallwart, and the Max is working beautifully (I think). Thanks for all the help!

 

[cetoole]

Quote:

Originally Posted by Dan55 /img/forum/go_quote.gif I finally picked up a new AC wallwart, and the Max is working beautifully (I think). Thanks for all the help!

Awesome! Great to have some closure on that, and glad that Another Max Lives!

 

[amphead]

Another Max Lives! All is right with the world again.

 

[rbx]

First of all let me thank you for this thread, which inspired me to buy the Millett Hybrid Maxed kit from glass jar audio and following to build this great amp about 6 months ago (first DIY amp build

):

Unfortunately since some time the left channel started to hiss and then slightly hum/crack from time to time (ca. 10-20 sec.) I changed the cd-player with another one in order to eliminate the fault in cd-player - the problem persisted. Eventually the slight hiss/hum/crack was there even when I turn off the cd-player - slight hiss/hum/crack in the left channel from time to time. Setup is standard - 27V supply voltage, 13,5V tube voltage, 110mV on the output stage. 220V to 110V adapter before the power supply.

I'll be grateful if you could help me to determine the source of the problem, in case you know/have had similar problems. Please keep in mind my somehow limited electric circuit schematics understanding skills

.

 

[BoilermakerFan]

Quote:

Originally Posted by rbx /img/forum/go_quote.gif First of all let me thank you for this thread, which inspired me to buy the Millett Hybrid Maxed kit from glass jar audio and following to build this great amp about 6 months ago (first DIY amp build ): Unfortunately since some time the left channel started to hiss and then slightly hum/crack from time to time (ca. 10-20 sec.) I changed the cd-player with another one in order to eliminate the fault in cd-player - the problem persisted. Eventually the slight hiss/hum/crack was there even when I turn off the cd-player - slight hiss/hum/crack in the left channel from time to time. Setup is standard - 27V supply voltage, 13,5V tube voltage, 110mV on the output stage. 220V to 110V adapter before the power supply. I'll be grateful if you could help me to determine the source of the problem, in case you know/have had similar problems. Please keep in mind my somehow limited electric circuit schematics understanding skills .

Did you swap the tubes left and right to eliminate the possibility of a failing tube? If you swap and the problem follows the tube to the right channel, then you just need a new tube.

 

[rbx]

@BoilermakerFan: Thank you for the suggestion, just tried it, but the hum stays on the left side, alas it is not the tube. The noise resembles something like a AM tuner noise between the stations, and its level is independent from the volume level.

 

[tomb]

Quote:

Originally Posted by rbx /img/forum/go_quote.gif @BoilermakerFan: Thank you for the suggestion, just tried it, but the hum stays on the left side, alas it is not the tube. The noise resembles something like a AM tuner noise between the stations, and its level is independent from the volume level.

It could be a loose input wire connection. I had a recent scare on mine and checked everything, only to discover that the stupid little 3.5mm jack on my BantamDAC was starting its expected routine of losing continuity. Rotate the plug about an 1/8th turn - everything's OK. Rotate it back, and huge hum and noise on the left channel. -Sigh- I'm going to learn not to use those things one day.

Check your terminal block wiring and make certain that the lead in wires haven't worked loose, oxidized, or been crushed into nothingness (my particular problem from repeatedly tightening the terminal block screws).

 

[rbx]

@tomb: Thank you for the advice. At the first glance the terminal connections seem fine, and the hum appears as well without any interconnects put in. I'll nevertheless check them thoroughly again and resolder the RCA jacks and ground to be sure for a cold joint.