Nomnomnom
New Head-Fier
- Joined
- Mar 31, 2012
- Posts
- 33
- Likes
- 0
Okay while I've been lurking for years on head-fi now this is my first post so please be gentle lol.
I recently assembled a MOSFET MAX kit from glassjaraudio (excellent kit by the way) along with some boutique parts from Beezar and partsconnexion. I followed all of the tips on diyforums.org pertaining to orientation of the parts and initial setup of the trim pots. When I put power to it (supplied Triad walwart w/ 24VAC@1000ma output) I got nothing. No LED, zilch, nadda. Now I shot an email out to TomB on Easter Sunday not expecting a reply but I'll be damned if I didn't have an email from him shortly after. He shot me a couple of ideas to look for and much to my dismay, my fuse was blown. I moved the power supply over to the "no fuse" pads, plugged her in and BAM! LEDs shining bright so I began the biasing procedure.
For whatever reason I could not get the power supply voltage over 25 volts so I decided to move on to the MOSFET and tube bias. I got the MOSFETS right about where I wanted them and decided to double check the power supply. Well, I had my DMM set to read mA and I'm not sure if that's what cause the following or not but figured I'd mention it. I put one lead in the GND test point and put the other in the V+ and POOF! A tiny spark and a little bit of smoke came out.
Now, Tom brought up a good point before I even started biasing. I emailed him when the MAX powered up but failed to check my email again until I had made a tiny S.O.S. smoke signal. Had I checked it I would have noticed that he emailed me back concerned because something had to have popped the fuse in the first place. So hindsight being 20/20 what I did today was reflowed, cleaned and attempted to power up the board again. Also from his suggestion I went to my local Rat Shack in search of the polyfuse located at PF1 (I got some interesting yet blank looks from the sales clerk there).
After doing a little more research however, it looks like a polyfuse doesn't pop? I'm far from an electronic engineer but from what I read it seems as though this is a part that is made to shut down and then reconnect once the current gets back to a specified level. So basically this is what I'm trying to achieve with this post. I hate bugging Tom with email after email. I felt terrible that he even replied to me on Easter Sunday but as far as I'm concerned that speaks volumes about him as a person and is extremely commendable. So what I figured I'd try before ordering every single part in the power supply (that LM317 looks like it would be a PITA to replace) is post my woes here to the community.
I have a bunch of fairly decent pictures taken from multiple angles throughout the build so with that being said, I have no clue how to post them and I don't want to be "that guy" who posts these MEGA SIZED PICS that take 6 minutes to view on a broadband connection.
Once again I've been lurking on here for quite some time. I saw the rise and fall of Bilavideo (SR60 thread lol), noticed the way the DIY community was and now I'm calling on all of you with infinitely more knowledge than myself on this subject. HELP ME lol.
Oh, one more thing, I almost sacrificed my modded T50RPs by hooking them up while messing around with it and got a good 8 seconds of AMAZING MUSIC! And that was through a UDAC2 as a source. I have a grubDAC that's sitting on my desk itching to be built and put in a good home and I believe this is the place for it to go.
Thank you all in advance,
-Chris
Oh and as a side note for anybody who, like I was, is unaware of certain aspects of this DIY community... When I had a question about my shipment from glassjaraudio I called the customer service number and Jeff answered. When I had questions about my order from Beezar I emailed the customer service address and Tom replied. In all honesty this freaked me out a little bit because I thought that these two places were multiple employee businesses but I'll be damned if they're not one man operations so for those of you reading this who are not in the know; these guys are freakin awesome and are bending over backwards for this community. I have had nothing but good luck talking to these men and highly recommend them and their expertise in anyone venturing into this "hobby(obsession?)"...
I recently assembled a MOSFET MAX kit from glassjaraudio (excellent kit by the way) along with some boutique parts from Beezar and partsconnexion. I followed all of the tips on diyforums.org pertaining to orientation of the parts and initial setup of the trim pots. When I put power to it (supplied Triad walwart w/ 24VAC@1000ma output) I got nothing. No LED, zilch, nadda. Now I shot an email out to TomB on Easter Sunday not expecting a reply but I'll be damned if I didn't have an email from him shortly after. He shot me a couple of ideas to look for and much to my dismay, my fuse was blown. I moved the power supply over to the "no fuse" pads, plugged her in and BAM! LEDs shining bright so I began the biasing procedure.
For whatever reason I could not get the power supply voltage over 25 volts so I decided to move on to the MOSFET and tube bias. I got the MOSFETS right about where I wanted them and decided to double check the power supply. Well, I had my DMM set to read mA and I'm not sure if that's what cause the following or not but figured I'd mention it. I put one lead in the GND test point and put the other in the V+ and POOF! A tiny spark and a little bit of smoke came out.
Now, Tom brought up a good point before I even started biasing. I emailed him when the MAX powered up but failed to check my email again until I had made a tiny S.O.S. smoke signal. Had I checked it I would have noticed that he emailed me back concerned because something had to have popped the fuse in the first place. So hindsight being 20/20 what I did today was reflowed, cleaned and attempted to power up the board again. Also from his suggestion I went to my local Rat Shack in search of the polyfuse located at PF1 (I got some interesting yet blank looks from the sales clerk there).
After doing a little more research however, it looks like a polyfuse doesn't pop? I'm far from an electronic engineer but from what I read it seems as though this is a part that is made to shut down and then reconnect once the current gets back to a specified level. So basically this is what I'm trying to achieve with this post. I hate bugging Tom with email after email. I felt terrible that he even replied to me on Easter Sunday but as far as I'm concerned that speaks volumes about him as a person and is extremely commendable. So what I figured I'd try before ordering every single part in the power supply (that LM317 looks like it would be a PITA to replace) is post my woes here to the community.
I have a bunch of fairly decent pictures taken from multiple angles throughout the build so with that being said, I have no clue how to post them and I don't want to be "that guy" who posts these MEGA SIZED PICS that take 6 minutes to view on a broadband connection.
Once again I've been lurking on here for quite some time. I saw the rise and fall of Bilavideo (SR60 thread lol), noticed the way the DIY community was and now I'm calling on all of you with infinitely more knowledge than myself on this subject. HELP ME lol.
Oh, one more thing, I almost sacrificed my modded T50RPs by hooking them up while messing around with it and got a good 8 seconds of AMAZING MUSIC! And that was through a UDAC2 as a source. I have a grubDAC that's sitting on my desk itching to be built and put in a good home and I believe this is the place for it to go.
Thank you all in advance,
-Chris
Oh and as a side note for anybody who, like I was, is unaware of certain aspects of this DIY community... When I had a question about my shipment from glassjaraudio I called the customer service number and Jeff answered. When I had questions about my order from Beezar I emailed the customer service address and Tom replied. In all honesty this freaked me out a little bit because I thought that these two places were multiple employee businesses but I'll be damned if they're not one man operations so for those of you reading this who are not in the know; these guys are freakin awesome and are bending over backwards for this community. I have had nothing but good luck talking to these men and highly recommend them and their expertise in anyone venturing into this "hobby(obsession?)"...