[scompton]

I put no thought into the layout like that, at least consciously. I probably did unconsciously. Not because I'm a lefty, I'm not, but because of the way my listening area is set up, both at home and work, the only place for my equipment is to the right of my computer. At home, it's a long reach to the volume knob on my NAD 3155.

It's going to work after I get back from vacation next week. The reach isn't as bad, but the way I picture fitting it in with my other equipment, it'll be sideways on a pile of other equipment.

It's going to replace a portable amp at work. Now all I need for my work setup is a preamp.

 

[TimJo]

Quote:

Originally Posted by scompton /img/forum/go_quote.gif Well I got mine working again. Both mosfets were fried. I also put heat shrink on any lead that I thought might short.

Glad to see that you got your amp up and running. Looks good!

I think it is a good idea to add the heatshrink. With the point-to-point wiring, it easy to get a short if things are a bit tight in the case.

 

[scompton]

Quote:

Originally Posted by TimJo /img/forum/go_quote.gif Glad to see that you got your amp up and running. Looks good! I think it is a good idea to add the heatshrink. With the point-to-point wiring, it easy to get a short if things are a bit tight in the case.

If I did it again, I'd also cut the leads shorter. The leads for all of the caps are uncut. The resistor leads are all about as long as you can make them without undoing the tape.

 

[adamus]

will i get away with 240k resistors for r2, r4 etc. thats all i have in the parts bag.

 

[Chipp]

Well, I went ahead and build the second (left) half of amp today completely ignoring how I built the first section and going solely by the schematic. It ended up looking the same and, unfortunately, functioning the same as well. I tried my "tester" Hytron and RCA tubes first, but when they didn't work I dropped one of my matched Sylvania's into the "new" side and still got nothing. Tested both mosfets with the DMM and they are functioning correctly. I also dropped a 1/4" to 1/8" adapter into the 1/4" socket just to see if that would change things. No dice.

 

[rds]

Chipp - post some high res pictures of the wiring

 

[Chipp]

Quote:

Originally Posted by rds /img/forum/go_quote.gif Chipp - post some high res pictures of the wiring

Sure - just a minute.

 

[Chipp]

Picasa Web Albums - Chipp - Millett Starv...

You should be able to zoom in quite a ways if the default is not large enough. Thanks for taking a look.

EDIT: After triple-checking things, it appears I left out 2 of the 2K ohm resistors. However, looking at the schematic, Pete and Nate's builds, and my build I am confused as to where they go. I used 5 2kohm resistors - one between the power switch and C6 (I'm certain it's R13) one between pin 7 on each tube socket and ground (R5 and R11) and one in each channel leading from the 4th terminal post back to the third post (which is grounded). I do not know whether those resistors are R3/R9 or R6/R12. In the pictures Pete and Nate posted I only can count 5 resistors, in the places I currently have them. Looking at the PCB prototype, there clearly are 7 (as on the schematic and BOM). I'm more than just a little confused as to what is going on here.

 

[rds]

See pin 1 of the Mosfets in the schematic. There's not a great angle to see this in your pictures, but it appears pin 1 of the IRF510s is connected together - that's not good.

 

[Chipp]

The mosfet's are correctly wired - each line from pin 1 returns to it's respective lug on the terminal strips, each pin 2 returns to 48v at the power switch, and each pin 3 returns to it's respective pin 3 on the tube sockets. I understand how it would be hard to discern exactly where a wire went in the mess, especially since I didn't color-code.

 

[m0b1liz3]

Quote:

Originally Posted by scompton /img/forum/go_quote.gif I put no thought into the layout like that, at least consciously. I probably did unconsciously. Not because I'm a lefty, I'm not, but because of the way my listening area is set up, both at home and work, the only place for my equipment is to the right of my computer. At home, it's a long reach to the volume knob on my NAD 3155. It's going to work after I get back from vacation next week. The reach isn't as bad, but the way I picture fitting it in with my other equipment, it'll be sideways on a pile of other equipment. It's going to replace a portable amp at work. Now all I need for my work setup is a preamp.

Why not just wire up the Millet SS to have pre outs with a resistor in line and a switch to go from HP amp to pre?

 

[rds]

Quote:

it appears I left out 2 of the 2K ohm resistors.

There should be a 2k resistor on each pin 1. You didn't mention those, so I figure those are the two you left out.

 

[rds]

Quote:

Why not just wire up the Millet SS to have pre outs with a resistor in line and a switch to go from HP amp to pre?

Trying to get someone to do your leg work for you?

 

[Chipp]

Quote:

Originally Posted by rds /img/forum/go_quote.gif There should be a 2k resistor on each pin 1. You didn't mention those, so I figure those are the two you left out.

Well I'll be darned.... Indeed I did.

Sorry if thats what you were trying to get across earlier, I thought you were saying that it looked like I bridged pin 1 on the mosfets together.

Update: Well, those resistors weren't whats keeping the tubes from firing.

 

[adamus]

anyone on using 240k resistors? or shall i pop to the electronics shop and buy some 220k?