pabbi1
Cavalli Audio Spiritual Advisor
- Joined
- Jan 12, 2004
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I've gotten as far as tubes... just a couple of projects to finish up first.
On the BOM you forgot to put the 10 Ohm 2W resistors for R22/R23
On the BOM for the caps at C1/C2 the "value" and "description" are different. Should I use 1uF/63V or 1uF/100V?
I know the LEDs have a negative and positive lead, but the board doesn't indicate polarity. Does orientation matter on this amp?
In your picture of the populated PCB it looks like you have some kind of jumper installed at JP1. I didn't see a JP1 on the BOM...what is that part and is it necessary?
The wirewound resistor I'm using at R5 is the recommended part in the BOM ( 71-CW005220R0JE73 ). I ordered two of these (one backup) from Mouser and the package is labeled correctly but I'm wondering if they put the wrong resistors in the package. The following text is printed on the resistor:
DALE
CW-5
220 Ohm 5%
6.5W
M1016
MEXICO
The part that confuses me is the "6.5W". Is this normal? I am looking at the data sheet for those resistors ( http://www.vishay.com/docs/30215/cw.pdf ) and I can see a CW-5 under "historical model" and then the corresponding data shows a Characteristic U of 5.0 and a Characteristic V of 6.5...I'm guessing that explains the confusion and there's nothing to worry about? This is my first build so I'm being extra cautious so nothing blows up on me.
Once I find out the answers to these concerns I'll put in a second Mouser order and hopefully the amp will be done next week! I'll probably do some of the chassis work tomorrow.
Mine's populated but I'm waiting on some particular ceramic tube sockets from Hong Kong. It looks like Pete used some plastic / phenolic sockets that are relatively straight without side protrusions for mounting to a chassis in order to make use of the relatively small 1/4" standoffs. Once those sockets come in I can finish the drilling of the chassis and get it off to the powdercoater along with the Edcor Bells.
N3rdling, The 10ohm resistors were missing on the BOM as you noticed, I mentioned it on DIYAudio but forgot to post it here. You don't have anything to worry about with the resistor. The BOM calls for a 5W and you have a higher spec'd 6.5W, no worries. The orientation of the LEDs is shown on the schematic.
Thanks for the help guys. Everything soldered into place. Now I just need to get those 10 Ohm resistors and the tube sockets/diodes are in the mail right now. Just double checking but I won't need to drill different holes than what is shown on the guide if I'm using these sockets right? http://www.partsconnexion.com/product9597.html Also, what knobs did you guys settle on?
Doh, I bet it was tough to get those tube sockets flipped around, 8 pins to desolder. I probably would have cut my losses, snipped the pins and desoldered them individually.
I'm pretty much finished drilling out the hammond chassis on mine, just have to run it over to the powdercoater. I ended up using the allied sockets that Pete used.