[Beftus]

Quote:

Hi,
 
I've got two small questions about the build of my MSSH!
 
First, ArtemF told it was possible to differenciate the pins of th power jack using a multimeter to solder the wires in the right way, how can I do that?
I also wonder how to put the tube sockets. I'm not using the PCB, and I bought a Hammond Case, but I don't know how to put it in the case, so that it won't move, I tried to find some pics of builds, but I couldn't find any help, could someone give me a solution?
 
Thanks!
 
Antoine

 

Take your DMM, set it to measure conductivity or resistance. Touch the center pin with one probe then the probe contact pins of the power jack. When your DMM beeps (conductivity) or reads zero ohms (resistance) then you've found the corresponding contact pin. The center pin is positive, the sleeve is negative.
 
What kind of sockets did you buy? Sockets come in two flavours: PCB mount and chassis mount. You need chassis mount sockets since you don't use a PCB. Chassis mount sockets usually have solder eyelets.

 

[hellomoto]

Hi!
 
First, thank you for your reply!
 
I realized that I had PCB Mount, problem resolved, thanks!
 
Antoine

 

[wiisus]

So, I have mine all setup and it sounds pretty good!  I have to go through and rewire it with some better wire soon (waiting for solder to come), and some kind of better grounding.  Whateves.  But, one of my tubes is a good deal brighter than my other one.  But there isn't any channel imbalance or anything.  They are different brands, though, could that be the reason?  I've rechecked my wiring multiple times and it looks correct.

thanks

 

[c12mech]

I had that same issue with the tubes not being the same brightness.  I swapped them from side to side.  One tube is just a little brighter than the other no matter where it is.  It's just the tube itself.  On my amp there is about a half volt difference between sides and I thought that was the reason but I guess not. 

 

[jamesbobo007]

I kind of lost track of things here. Was there ever any solution to the DAC issues ? and was it ever determined if it was just the Alien DAC or all DAC's ?
 
c12mech and wiisus, what tubes did you build with? Adding tube led's might be a nice solution.

 

[Juaquin]

No true solution, but you can build your own power supply since it's thought to be caused by the Cisco PSU. Advice is to leave the DAC connected to the amp at all times to prevent a charge from building up and zapping the DAC when you plug it into the amp. That's been working perfectly with my GrubDAC and SSMH for months now, but it's not a guarantee. The issue was supposed to be confined to the Alien/Bantam but there have been a couple reports of it frying the Gamma1/2 over on the AMB forums. Since the issue is believed to be due to the Cisco supply, has anyone who's built their own supply been able to verify that their amp does not fry an Alien/Bantam?

 

[Beftus]

 
Grid stopper question.
I have a built the 12AU7 version that I like very much. It suffered from some noise when I touched the (grounded pot) volume knob and also when I touched my iPod. Did some reading on grid stoppers and installed R14 and R15, both 1K, right before pin 2. No more noise. Good!
 
I just found this way back in this thread:
 
 
Quote:

Originally Posted by nikongod /img/forum/go_quote.gif
 
5&6 are the grids (inputs) of the tube
Attach a smallish resistor to EACH pin (with the body of the resistor as close to the pin as practical), then twist the legs together, and solder input to that. signal in now goes to the twisted legs of the resistors, through them to the tube...

Pin 5 and 6 are the grids of the 19J6 tubes, in the 12AU7 version the grids are pin 2 and 7. For my next 12AU7 build I want to implement two grid stoppers as outlined above. What value should they be? Still 1K each?

 

[c12mech]

Quote:

c12mech and wiisus, what tubes did you build with? Adding tube led's might be a nice solution.

I used 17EW8 tubes.  No tube LED's for me.  I just don't care for the way they look.  I like the way the tubes look by themselves.  So far since I hooked up the new PSU it is working great.

 

[wiisus]

I used 12AU7. 

I'm going to be adding LEDs soon.

 

[nikongod]

 
Quote:

 
Pin 5 and 6 are the grids of the 19J6 tubes, in the 12AU7 version the grids are pin 2 and 7. For my next 12AU7 build I want to implement two grid stoppers as outlined above. What value should they be? Still 1K each?

The best answer is: the smallest value/least resistance that does the job. 
1K is nice because it almost always works. I would get a bunch of values and try them out.

 

[Beftus]

Quote:

 

The best answer is: the smallest value/least resistance that does the job. 
1K is nice because it almost always works. I would get a bunch of values and try them out.

 

Cool, thanks! Gonna start with two 1K's since a single 1K works so well already. Too bad I don't have access to a scope to obtain the optimum value.

 

[revolink24]

Quote:

I found an NKK DPDT rotary at mouser.
 
http://www.mouser.com/search/ProductDetail.aspx?R=MRT23-A-ROvirtualkey63300000virtualkey633-MRT23-A-RO
 
As far as I can tell though it would only be suitable for selecting gain, not my ultimate rotary switch dream.
 
Can anyone point me to a rotary switch that can do this? (pardon the poor illustration)
 

 
EDIT: Would something like this work? http://www.mouser.com/ProductDetail/NKK-Switches/MRF206-RO/?qs=sGAEpiMZZMvNbjZ2WlReYmt/ckRDMbNxDxWhl99ESfc%3d

In addition to this, I was hoping someone could point me to some heatshrink and wire suitable for a p2p build of the SSMH, since this will be my first P2P build. Mouser part numbers would be great.

 

[hellomoto]

 
Quote:

Originally posted by Beftus

Take your DMM, set it to measure conductivity or resistance. Touch the center pin with one probe then the probe contact pins of the power jack. When your DMM beeps (conductivity) or reads zero ohms (resistance) then you've found the corresponding contact pin. The center pin is positive, the sleeve is negative.

Hello,
 
The center pin is the biggest pin, who makes an "L" right? When I put one probe on this one, and the other on each of the two other pins, it tells me "1", used in resistivity, so no conductivity I think? It tells me 0 when i put the probes on the contact pin, so conductivity, right?
 
When I put the plug in the power jack, I haven't any conductivity between any of the pins
 
Is this normal?
 
On the site of P.Millet it shows on the picture how to solder it, (the pins are in the same disposition, and i also use a blank PCB board for ground) so can I solder it like on the picture?
 
Thanks

 

[ArtemF]

First of all, do NOT measure the resistance when the system is powered.
You can fry your multimeter.
 
Second, I'd suggested to use multimeter in voltage measuring mode to know for sure
where is "+" and "-". Naturally, this measurement should be performed when the PSU works.
Regardless of the internal stuff in the plug you'll have to find two pins with +48V across
them. The one the red lead of your multimeter is connected to is the "+", the other one is  "-".
That's it.

 

[hellomoto]

Thanks ArtemF, it works perfectly
 
I would like to know how to solder the Jack Output. I didn't pay attention and bought a PCB one, so I have 6 pins, two for each of plus, minus ang ground, and I recognized which was which, but how should i solder the pins on the wires?
http://fr.mouser.com/Search/ProductDetail.aspx?R=NMJ6HCD2virtualkey56810000virtualkey550-22302
 
For the pot, I have the same problem, I don't know which wire goes were, but It is the same as the one of Pete Millet on his website, so I think I just have to solder the wires like in the picture.
http://fr.mouser.com/Search/ProductDetail.aspx?R=RV122F-20-15F-A50Kvirtualkey14860000virtualkey313-1240F-50K

Thanks
 
Antoine