[lithium1085]

No offense taken....I am realistic about my abilities and it is better to be safe than sorry. I have seen the built versions on Beezar and I was wondering is it possible to order a custom build?
Basically is it possible to upgrade the capacitors? 
Do you think 250 mW power is enough for the new generation of planars, which are supposedly more efficient?

 

[tdubl07]

 
You've replaced so many parts to no effect, I kind of agree with Dsavitsk: the fact that you didn't notice it until you trimmed the pot shaft may just be a coincidence.  Or, the stress of trimming the shaft may have knocked something loose.
 
Again, I'm sorry you're going through this, but I would tend to focus on other things besides replacing the parts at this point.  Check all of your resistors - see if you can measure good resistance values by measuring from adjacent pads/traces, not the leads directly.  This can confirm good connections or not.  Also, you might take a close look at the tube sockets - especially on the left side.  I would've said this was a tube thing, but you said you switched them and it stayed in the left channel.  If that's the case, then maybe there's something wrong with the socket on that side and only allows intermittent connectivity with one or more of the pins.
 
Just some guesses ...

Hey guys, got a chance today to a least check resistance values from the left tube socket to adjacent pads and resistors. All tube socket measurements check out at 0hms to adjacent pads and all resistor values check out as well. All continuity checks for left side are good as well. Just learned how to check transistors, so checked all of them, both channels and all test identical to the opposite channel on adjacent pads. So I think all the transistors are ok. At this point, the only thing I can think of doing since all checks lead me to believe everything is fine per specs, is to reflow the entire board and cross my fingers. If that doesn't do it, I'll have to just start replacing stuff one by one. I'm wondering if it's possible to have a noisy resistor that measures good still. That's my next hunch. I can't veify resistance on R10 and R11 since they're grounded. Looked over the entire board with a magnifying glass just to double check my soldering and all looks well.....can't hurt to reflow anyway. The hunt continues....

 

[tomb]

  No offense taken....I am realistic about my abilities and it is better to be safe than sorry. I have seen the built versions on Beezar and I was wondering is it possible to order a custom build?
Basically is it possible to upgrade the capacitors? 
Do you think 250 mW power is enough for the new generation of planars, which are supposedly more efficient?

Yes, custom builds are possible ... except that a parafeed capacitor is basically the only upgrade that's readily available.  It's simple enough to substitute another type/brand of capacitor into an already built Torpedo, though.  And yes - I can do that for you, too.
 
I can't speak about the new generation of planars, except to say that if they're similar to a K701 (normally considered among the hardest to drive dynamics), then it should do fine.

 

[tdubl07]

I think I've found the problem guys!!! I reflowed the whole board and that didn't fix it. So I left the case open and took a pencil and used the eraser to start tapping on things. Got to D10 the front led (which was lit) tapped on it, and got a loud pop...and along with the pop the hiss would appear! Just desoldered the old led from d10 and replaced it. I'm hopeful that was the problem. I can not believe that an led could light up and still be "bad" in the circuit for it's intended purpose. I should have used the eraser trick much earlier.
Time to rock out 

 

 

[tdubl07]

  No offense taken....I am realistic about my abilities and it is better to be safe than sorry. I have seen the built versions on Beezar and I was wondering is it possible to order a custom build?
Basically is it possible to upgrade the capacitors? 
Do you think 250 mW power is enough for the new generation of planars, which are supposedly more efficient?

Hey man, just thought I'd throw this in. Listening to my HE-400's right now with this amp and it's drives them just fine. And that's with my phone straight to the amp. With a dac, it's even better in terms of power output since the dac puts out a stronger line signal than a phone. I think I like my dt990 pro's better with this amp but that's just preference, nothing more. As has been said before but if the phones you're looking at are terribly innefficient I think you should look elsewhere. Plenty of juice though for my dt 990 pro's and he-400's. 

 

[tdubl07]

Well guys, she's fixed! I can't believe a working led (lit up) could cause all of my problems. Glad to have this thing dialed in now. Thanks for everyone's help

 

[Punnisher]

I'm glad to see it worked out for you. I feel your pain, because I wouldn't ever want to be without a working Torpedo.

 

[lithium1085]

Thanks for the input everyone. I guess I will scrounge up some cash in the next few months and get tomb's completely built version. I am not planning on driving something much more inefficient than the HE-400, so the power output is perfect.

 

[dsavitsk]

No offense taken....I am realistic about my abilities and it is better to be safe than sorry. I have seen the built versions on Beezar and I was wondering is it possible to order a custom build?
Basically is it possible to upgrade the capacitors? 
Do you think 250 mW power is enough for the new generation of planars, which are supposedly more efficient?

I actually don't think it is too difficult as a first build if you know something about electricity, and if you have someone who knows how to solder sit next to you and guide you through the process. Indeed, for anyone for whom this is his first high voltage process, that is probably a good idea.

As to the parafeed caps, I would not worry too much about it. Better caps might make a small difference, but I think you'll be surprised about the sound quality in stock form. Most top of the line commercial equipment uses similar quality parts.

 

[lithium1085]

I actually don't think it is too difficult as a first build if you know something about electricity, and if you have someone who knows how to solder sit next to you and guide you through the process. Indeed, for anyone for whom this is his first high voltage process, that is probably a good idea.

As to the parafeed caps, I would not worry too much about it. Better caps might make a small difference, but I think you'll be surprised about the sound quality in stock form. Most top of the line commercial equipment uses similar quality parts.

Thank you for your input. I am guessing I will buy this in a few months, so maybe I can try to learn how to solder by then.

 

[AnalogSavior]

Hi all,
 
I'm pretty new to DIY with only a little bit of guitar pickup rewiring  under my belt, but after reading the article on parafeed amps on the ecp diy site, I'm curious to build one.  I don't have a background in electronics, so I don't understand everything going on, but I learned quite a bit from it and my math for the hypotheticals provided all added up.  I'm curious to try new things amp wise, so this seemed like the perfect project for me.
 
I really don't have anyone with experience to help me along, but do you think that with some patience and care a relative noob like myself could tackle this project?
 
Also, I read the Headfonia article on the Torpedo, and it mentions a small transformer hum.  It wont play a role in whether I take on the project or not, but I'm curious if this is a common thing and if it is easily resolved.  The Zener Diode tweak mentions that it can reduce hum, and I'm just curious as to what to expect.
 
Thanks!
 
EDIT: After reading the tweaks and beezar pages again, it looks like the zener mod and choke replacing R2 are standard.

 

[tomb]

  Hi all,
 
I'm pretty new to DIY with only a little bit of guitar pickup rewiring  under my belt, but after reading the article on parafeed amps on the ecp diy site, I'm curious to build one.  I don't have a background in electronics, so I don't understand everything going on, but I learned quite a bit from it and my math for the hypotheticals provided all added up.  I'm curious to try new things amp wise, so this seemed like the perfect project for me.
 
I really don't have anyone with experience to help me along, but do you think that with some patience and care a relative noob like myself could tackle this project?
 
Also, I read the Headfonia article on the Torpedo, and it mentions a small transformer hum.  It wont play a role in whether I take on the project or not, but I'm curious if this is a common thing and if it is easily resolved.  The Zener Diode tweak mentions that it can reduce hum, and I'm just curious as to what to expect.
 
Thanks!
 
EDIT: After reading the tweaks and beezar pages again, it looks like the zener mod and choke replacing R2 are standard.

There were really four tweaks that solved the hum problem:

• Use of the choke
• Zener diode tweak
• Replacing the heater supply schottky rectifiers with general purpose diodes.
• Installing snubber caps on the diodes in #3 above.

 
The last two were the latest and solved the hum issue from all reports. 

 

[tomb]

We're now shipping with a V1.02 PCB that Dsavitsk designed.  Changes are as follows:

• Trace moved under the PCB that was impinging on one of the standoffs
• Allowance for zener tweak with normal through-hole mounting.
• SMD pads on the bottom of the PCB for snubber caps on the heater rectifier (general purpose diodes).

 
Of course, because it's NEW ... that means it sounds better.  Just kidding.

 

 

[ChrisX]

  We're now shipping with a V1.02 PCB that Dsavitsk designed.  Changes are as follows:
[...]SMD pads on the bottom of the PCB for snubber caps on the heater rectifier (general purpose diodes).

 
I just picked up my kit from customs on Friday ... and have already the new PCB included.

 
So which SMD caps do you recommend?

 

[AnalogSavior]

 
There were really four tweaks that solved the hum problem:

• Use of the choke
• Zener diode tweak
• Replacing the heater supply schottky rectifiers with general purpose diodes.
• Installing snubber caps on the diodes in #3 above.

 
The last two were the latest and solved the hum issue from all reports. 

 

  We're now shipping with a V1.02 PCB that Dsavitsk designed.  Changes are as follows:

• Trace moved under the PCB that was impinging on one of the standoffs
• Allowance for zener tweak with normal through-hole mounting.
• SMD pads on the bottom of the PCB for snubber caps on the heater rectifier (general purpose diodes).

 

 
Wow, thanks for the great information.  A few more questions if you don't mind.  How many of these tweaks are included in a complete kit (I'm pretty sure I read the Zener diode and a Hammond choke are part of it)?  Regarding the scope of the project, aside from the SMD pads for the snubber caps, is the rest of the project through hole?
 
This seems like an exciting project for me, but I may need to tackle a smaller one or two (maybe a CMoy or Mini3) before I take it on, just to feel a little more comfortable.