[Amatsu]

I just finished my case but I have a question. The potentiometer doesn't quite stay still due to the case being very wide, can I use some kind of glue to help fix it into the wood case? Maybe some other method instead of glue?
By the way, what would be the best material to use as a ground plate? Copper? Aluminium? Thanks.

 

[redsevn]

Quote:

I just finished my case but I have a question. The potentiometer doesn't quite stay still due to the case being very wide, can I use some kind of glue to help fix it into the wood case? Maybe some other method instead of glue?
By the way, what would be the best material to use as a ground plate? Copper? Aluminium? Thanks.

 
What do you mean by the case being "very wide"? Like the hole the potentiometer sits in is too wide for the shaft? To secure the pot you generally want to just screw it in tight enough (but not too tight to warp anything). Glue would work, too, I guess...
 
Most people use copper, because it's low resistance (I think).

 

[sandeepk]

Hopefully not too much of a threadjack but wondering if anyone knows of online stores selling NOS 19J6 tubes. Just started listening to my SSMH but I'm worried that the tubes are running on their last legs

 

[Fred_fred2004]

There's a few on ebay at the moment
 
cheers
FRED

 

[livewire]

Quote:

Hopefully not too much of a threadjack but wondering if anyone knows of online stores selling NOS 19J6 tubes. Just started listening to my SSMH but I'm worried that the tubes are running on their last legs

 
Not a threadjack at all, well within the subject matter discussed here.

Fred offers sage advice. Ebay is indeed your friend.
The days of cheap 19J6 tubes are over.
Expect to pay about $20 each for NOS tubes.
Heh, it wasnt too long ago that one could pick them up for $1 to $3 each, I did.
All of the online tube sellers have been cleaned out with the advent of the MSSH amp.
Happy hunting and here's hoping you dont get stuck with a couple of duds.<<crosses fingers>>

 

 

[sandeepk]

Quote:

Quote:

Hopefully not too much of a threadjack but wondering if anyone knows of online stores selling NOS 19J6 tubes. Just started listening to my SSMH but I'm worried that the tubes are running on their last legs

 
Not a threadjack at all, well within the subject matter discussed here.

Fred offers sage advice. Ebay is indeed your friend.
The days of cheap 19J6 tubes are over.
Expect to pay about $20 each for NOS tubes.
Heh, it wasnt too long ago that one could pick them up for $1 to $3 each, I did.
All of the online tube sellers have been cleaned out with the advent of the MSSH amp.
Happy hunting and here's hoping you dont get stuck with a couple of duds.<<crosses fingers>>

 

Thanks for the help! I'll keep a lookout for a potential deal and in the meanwhile hold out hope that my current tubes keep chugging along...

 

[Amatsu]

Try vacuumtubes, that's where I bought my 17ew8 tubes, the 19J6 are listed as 10$ each: http://www.vacuumtubes.net/Prices%2012A%20to%2029LE3.htm

 

[Amatsu]

Just finished my first try at building it, but when I turn the amp on, it starts making a constant high-pitched noise, it comes from the amp, there's nothing plugged yet. Any ideas? 
I'll probably start from scratch some other day because it's a little messy with lots of cables. Is there any way I can check what's good and what's bad with a multimeter/tester? I also did a quick test to see if there was sound but there's nothing as I suspected, although when I turned it off, the headphones did make a static sound. I didn't do any more tests because I'm worried about that high-pitched sound.
Thanks. I can't upload pics right now sorry.

 

[the_equalizer]

Your amp is most probably oscillating; this could be due to faulty wiring or to all the feedback (due to stray capacitance and electromagnetic fields) that messy wiring can cause.
 
I don't know if it helps but... from what I've read, a frequent cause for oscillation in the SSMH is to connect R3 and R9 to the MOSFET gate pin with a 'long' wire. This two resistors should be soldered directly to the pin as their purpose is precisely to discourage oscilation.
 
Good luck with your build and post pics when it's done !
 
Cheers!

 

[Amatsu]

Hey thanks Equalizer. Those resistors are soldered directly on the mosfets unfortunetly. I'm probably going to desolder everything and start again because I can't even close the case, there's too much wiring.
By the way, can I use 220uF 16v on the C3 and C5? I forgot to order those two 470uF, I figured it would be okay for a temporary solution, but I don't know.
 
Oh and just to be safe, I have to ask about the pins on the DC Jack and Switch, I have these two:
http://www.conrad.com/Panel-jack-2.5-mm.htm?websale7=conrad-int&pi=738204
http://www.conrad.com/ROCKER-SWT.-SPST,-ROUND-STECK-4,8-SW/SW.htm?websale7=conrad-int&pi=703040
 
I'm not completly sure which pin on the DC Jack is the ground, I assume it's the longer one? And on the switch, does it matter which pin is 1 and 2 on the schematic? Thanks again.

 

[the_equalizer]

 
Quote:

Hey thanks Equalizer. Those resistors are soldered directly on the mosfets unfortunetly. I'm probably going to desolder everything and start again because I can't even close the case, there's too much wiring.
By the way, can I use 220uF 16v on the C3 and C5? I forgot to order those two 470uF, I figured it would be okay for a temporary solution, but I don't know.
 
Oh and just to be safe, I have to ask about the pins on the DC Jack and Switch, I have these two:
http://www.conrad.com/Panel-jack-2.5-mm.htm?websale7=conrad-int&pi=738204
http://www.conrad.com/ROCKER-SWT.-SPST,-ROUND-STECK-4,8-SW/SW.htm?websale7=conrad-int&pi=703040
 
I'm not completly sure which pin on the DC Jack is the ground, I assume it's the longer one? And on the switch, does it matter which pin is 1 and 2 on the schematic? Thanks again.

16 volts is too low for those caps, I think. If everything is OK they'll never see more than ~12 volts; but that's a somewhat big if... a miswiring, a shorted MOSFET...  and BAM!!
 
In my opinion the best way to identify pins in jacks is to use a DMM and measure continuity between the different tabs and pins.
 
No, in a 1 pole 1 throw switch (that is, a switch with only two pins) it does not matter which pin is 1 and which is 2.
 
Cheers!

 

[Speedway]

Hey All
I'd like to try this amp as my first tube build.  Like everyone else, I can't source the 19J6's, so I want to go with the 12SR7 's. I've spent several days reading this thread but have not found an updated schematic with the value changes and BOM for the build.
Could someone help me out please?
Thx

 

[Ikarios]

Quote:

Hey All
I'd like to try this amp as my first tube build.  Like everyone else, I can't source the 19J6's, so I want to go with the 12SR7 's. I've spent several days reading this thread but have not found an updated schematic with the value changes and BOM for the build.
Could someone help me out please?
Thx

I don't think anyone has posted one. Unless you have a good reason to do a 12SR7 build, why don't you do the 17EW8 or 12AU7 mod? The tubes are just as easy to source and only a tad more expensive.

 

[Speedway]

Aflac
The only reason I was going with the 12SR7 is because I had bookmarked that post. My eyes must have been crossed when the 17EW8 was tried.
Anyway, I will search that tube in the thread to see what has to be changed in the circuit, unless it is a direct swap using the original BOM....
Thx

 

[Ikarios]

Quote:

Aflac
The only reason I was going with the 12SR7 is because I had bookmarked that post. My eyes must have been crossed when the 17EW8 was tried.
Anyway, I will search that tube in the thread to see what has to be changed in the circuit, unless it is a direct swap using the original BOM....
Thx

Yes, IIRC the 12AU7 mod is just a change to a couple of resistors. I used the original PCB BOM of the 19J6 kit build when I put together my 12AU7. Since you have to build point-to-point anyway it should be helpful to go through the schematic and double-check all values of capacitors and resistors on your BOM. It's also helpful to label what components are what if you're using Mouser or Digikey to put together your BOM.
 
The 17EW8 can also be used in the same circuit. I believe the_equalizer came up with the 17EW8 mod first, then detailed the 12AU7, then another user reported that the 17EW8 works great as a drop-in replacement in the 12AU7 version. You should probably search the thread to make sure, but I'm pretty sure this is how it went.