[dsavitsk]

Did you try swapping tubes and/or cables to see if the working side moves? The most likely reason is a bad solder joint -- look them all over carefully.

 

[tomb]

Maybe I'm wrong, but I was thinking that when he said "mono," he meant both channels were working, but he's not getting stereo.
 
I'm not saying that's impossible, but pretty close to it with the Torpedo.  This is usually caused by messing up the input wiring or on the volume pot: switching a signal wire for ground, for instance.  This is impossible with the Torpedo, though, because not only the volume pot is PCB-based, but so are the RCA jacks.  There are solid traces in the PCB in-between.
 
Can you supply us with a clear photo of your assembled PCB?  There are some extra pads that are not used and I'm wondering if maybe you soldered something into them?  (This might happen at the headphone jack, for instance.)  Just a guess, but it doesn't make much sense.
 
On the other hand, my assumption of your problem may be completely wrong.  In which case, please refer to dsavitsk's advice above.

 

[SomeGuy82]

Hey guys. Tried switching both the tubes and the cables. Same problem. I noticed that when I push the head phone jack half way into the input, both sides play but it's still mono. I've attached the pictures of the build below. Any ideas? I guess I may have to reheat all the wiring this weekend to be sure. Thanks a lot for your help! Really appreciate it!

 

[Punnisher]

It's common for headphone jacks to play mono in both channels when partially inserted. This happens when the tip and ring come in contact with the right channel at the same time.

 

[SomeGuy82]

It's common for headphone jacks to play mono in both channels when partially inserted. This happens when the tip and ring come in contact with the right channel at the same time.

Fair enough. But when I push the jack all the way in, sound cuts out on the left channel.

 

[tomb]

Well, you supplied excellent photos!  However, I can't see from any of them what might be wrong.  If the sound really cuts out on one channel, then dsavitsk's post is the best.  (He interpreted it correctly whether you described it that way or not.

 )
 
So, your left channel is not working.  That's discouraging, but you have a great resource - the other channel.  You can start with power off to see if you have an open circuit between any of the parts (measure for zero resistance between parts on the Left side (From the front of the PCB with the volume pot and headphone jack, the Left channel is on the Left side.)  You can reference measurements from the right side to see if they're the same.
 
Similarly, you can do this with the power on (VERY CAREFULLY) by measuring Ground to PL and PR.  If those are the same (not zero), then turn the amp off again and re-measure the parts and compare them between the two channels (resistance).  Check to see if there's not an open circuit somewhere, for instance, at the parafeed caps, C11 & C12.
 
Let us know what you find.

 

[OJNeg]

Interesting thought. The plan had been to use the same PT and OPTs. But I can definitely see your point. If we end up redesigning, that is not a bad option -- I use those for breadboarding all the time. The existing heater reg is an LDO, so we could actually go the other way and drop the voltage a little with likely the same effect.
Looks like a good tube and worth considering. Thanks. For now, the T2 has a totally different topology.

Interesting. I was halfway hoping the Torpedo 2 would use better (?) scaled up OPTs. Or maybe even roll-able ones for those of us with autistic tendencies?
 
Any hints on the different topology?

 

[tomb]

Hey guys. Tried switching both the tubes and the cables. Same problem. I noticed that when I push the head phone jack half way into the input, both sides play but it's still mono. I've attached the pictures of the build below. Any ideas? I guess I may have to reheat all the wiring this weekend to be sure. Thanks a lot for your help! Really appreciate it!

 
 

  Well, you supplied excellent photos!  However, I can't see from any of them what might be wrong.  If the sound really cuts out on one channel, then dsavitsk's post is the best.  (He interpreted it correctly whether you described it that way or not.

 )
 
So, your left channel is not working.  That's discouraging, but you have a great resource - the other channel.  You can start with power off to see if you have an open circuit between any of the parts (measure for zero resistance between parts on the Left side (From the front of the PCB with the volume pot and headphone jack, the Left channel is on the Left side.)  You can reference measurements from the right side to see if they're the same.
 
Similarly, you can do this with the power on (VERY CAREFULLY) by measuring Ground to PL and PR.  If those are the same (not zero), then turn the amp off again and re-measure the parts and compare them between the two channels (resistance).  Check to see if there's not an open circuit somewhere, for instance, at the parafeed caps, C11 & C12.
 
Let us know what you find.

 
Any luck?

 

[dpump]

Pictures of the bottom of the pcb might show something if you haven't figured it out yet.

 

[FishHead]

I thought I would give some impressions between two caps I have used in the T1 (as we now have multiple devs). My original build used the Mundorf EVO Aluminum Oil 4.7 450VDC cap. Most of my listening was done using the 6J6 tube. I did listen to the E90s but found them to "digital" for my taste. Moving on now, I have replaced the Mundorf with the Clarity Cap ESA 4.7 3% 630 V. While my sonic signature memory is imperfect at best and mildly delusional at worst, I find the Clarity Caps are a richer sound than the Mundorfs while using the 6J6 tubes. I will be spending some time with the 6J6s and have yet to roll the E90s through the T1. PM me if you would like to try the Mundorf's out. Bottom line is that I like the Clarity Caps more than the Mundorfs. You may have a different impression.

 

[tomb]

Beezar Labs testing the Torpedo II:
 

 
When I can't stand looking at the scope anymore or smelling the solder iron, this is on the other wall:
 

 

[Avro_Arrow]

  Beezar Labs testing the Torpedo II:

 
 

 
When I can't stand looking at the scope anymore or smelling the solder iron, this is on the other wall:

 
 

 
Nice collection of YoYos!
 

 

[tomb]

 

  Beezar Labs testing the Torpedo II:

 
 

 
When I can't stand looking at the scope anymore or smelling the solder iron, this is on the other wall:

 
 

 
Nice collection of YoYos!
 

Kind of fitting, isn't it?

 

[FishHead]

Kind of reminds me of following our build thread. Are you as proficient with that wall as you are with ours?

 

[tomb]

Kind of reminds me of following our build thread. Are you as proficient with that wall as you are with ours?

Not really (assuming I am proficient with either one.

).  I barely know how to bind and can do very little of the new tricks.  New top-flight machined, anodized, ball-bearing yo-yo's will not return to your hand unless you perform a "bind."  Most of what's on that wall are Duncan Freehands, but I have a few new ones - both plastic and aluminum.  Of course, the Freehand is still made in a number of iterations.  This is a great site that quickly shows the extent of the current state-of-the-art with yo-yo's (the yo-yo reviews and tutorials, especially):
http://www.highspeedyoyo.com/ (not a commercial site).
 
But I digress ...  Torpedo II tests continue.  We have some issues, but I have to defer to Dsavitsk on the conclusions and improvements.  I'm no scope jockey, by a long shot.