Hi All,
Firstly I just want to say thanks in advance to anyone who reads through this and can offer any advice. Hopefully it's all simple stuff - as I'm still new to all this and really just following the instructions and keeping my fingers crossed. So far though I've been enjoying my FPIII, Seduction & Crack. Now with these puppies (paramounts in 300b configuration) I have a full tube system which is a dream come true, really - I've never had one of those before! So, if any one can help me see this to fruition - help a boy achieve a dream - it is highly appreciated. Here goes, in order from least to most pressing (or not, you tell me):
1. The parts checklist called for 10 LEDS, which were all included, though I only used 8 in the build. You can be sure I double- perused the instructions (including the 2A3 specific portions) before firing up the amps but only came up with the need to use 8 (4 on each of the shunt reg active load PCboards). Comments? Did I miss something?
2. When I power on the amps in my system (connected to speakers and the above mentioned BH components) in about 15-20 seconds or so, there is a quick, high pitched "zip" sound through the speakers. This happens even before I turn any other components on (i.e. the amps are the only electronics powered up) - it's definitely coming from the Paramounts. Is this sound normal? If not, has anyone experienced this? If it is a problem, is there a way to get rid of it?
3. Both amps also make some of their own noise (from the amps themselves, not out of the speakers). It's not loud, you have to have the room quiet and put your ear up to them, but they do sound like they're running. None of my other BH stuff makes a noise that I can distinguish while it's on.
4. I should mention that I haven't done the "hum balance" adjustment yet (the last step of the instructions) not sure what the deal is but maybe my meter doesn't do AC millivolts (?!) is that crazy? I didn't get ANY reading off of speaker terminals. Can that be indicative of a different problem. I don't really know what the hum balance is doing - just reducing amount of noise floor coming off the speaker terminals? There is some noise floor coming through the speakers when only the amps (no other components are on) - though it's not very much and definitely not interfering with enjoying the music. I do plan on doing this hum balance step, I've just go to borrow my buddy's MM - should be able to this weekend (assuming there is an issue with my MM.
5. For me, the potentially most pressing issue: One of the amps has a "hot" smell when it is turned on. Though this smell has been lessening (I've been listening to the amps since this past Sunday), I believe, if I do listen for more than an hour, I can still really notice it around the equipment stand in the living room. I've tried having the amp on for that length of time with no signal running through it and then compare it to starting up the cold amp and starting music after just a couple minutes, and I *think* the smell is stronger while music is playing.
It is not a burning smell but it smells like hot plastic and kind of smells like plastic just shortly prior to when it starts burning. I've had my nose all over the underside and cannot pinpoint it. However, this one amp ( from here on I'll call it the stinky one) is definitely running hotter than the other one. I tried swapping each tube, and even the positions on the rack shelf (one is over the other on my shelf and I thought maybe it was heating up too much because the one underneath it was cooking it - though the issue always stayed with the amp no matter where it was placed or which tubes were in it. I have not measured the temp, but the difference between the two is noticeable to the touch. I believe that the extra heat on the stinky unit can be coming from the 25w resistors. Seems like that area of the chassis plate is the hottest and it is noticeably hotter to the touch than the non-stinky one. e.g. Once they have been running for an hour or so I can put my finger on the head of a mounting screw for the 25w resistor of the non stinky one and need to take my finger away after 3 seconds. On the stinky unit, I can only make it just to 2 seconds with my finger on the same mounting screw. Of course, I've also carefully checked the underside to see if anything was rubbing/touching up against anything else but to avail. I also double checked the mica washers to make sure they were not cracked and that the 25w resistors are isolated from the chassis plate. All advice is greatly appreciated.
I'm going to post my resistances and voltages for reference. They were mostly just fine. I'll post just the ones that were pushing 15% difference from the manual to make it easier to digest. Any others are available by request, no problem:
RESISTANCES
TERMINAL # SHOULD BE UNIT 1 UNIT 2
9 124k 148k 148k
12 5.6M or INF 6.6M 6.7M
14 9.2M or INF 13.3M 13.3M
19 128k 148k 148k
VOLTAGES
TERMINAL # SHOULD BE UNIT 1 UNIT 2
A3 "close to zero" zero zero (is it bad these are not slightly higher than zero?
6v RED 3.1VAC 2.8VAC 2.8VAC
6v BLACK 3.1VAC 2.8VAC 2.8VAC
KREG BSIDE 6.3 7.9 8.0
OB 200 180 179
It occurs to me now that I'm not sure which of these is the stinky one, though for the voltages, since they're so close to being the same and one doesn't smell and one does I don't think that would be helpful info.
Thanks again.
Mike