Yes, I found that getting my tungsol 12ax7's into the tube sockets to be really difficult - they didn't want to fit at all at first. I ended up using some kind of rounded tool to work around the edges of the tube sockets to expand them slightly - I just had to do this enough so that I was confident that the tubes had made a good connection on all pins.

I will, eventually. I guess I'm not one of the cool kids yet. I looked all over the net for pictures of heater wiring when I was building my amp, and while I found many examples of both ways, Nik's pictures and a few others done next to the chassis swayed me. If I had to do it over, I'd probably do it up in the air, as it'd be a bit easier.


I've been wondering about this. Nik's pictures have the heater wires AND the lead dress both against the chassis, right up next to each other. All I can say for certain is that my amp sounds REALLY nice the way I did it. And it's been great to have this forum to learn all this cool stuff about amp building from - and I really need to check out ampgarage also!

Excellent! Looks great!

Heater wires up in the air, fender style. Interesting.

You've got the ground switch wired up to do something - ? I seem to remember something from another thread.

I've noticed an odd thing along these lines. It's been noted many times that the deep switch on these amps are wired backwards - switch has to be down to engage the deep boost. So when I built mine, I took care to invert the wiring so the switch would work the "right" way.

What has confused me a bit is that at first, it seemed as if my deep boost was still backwards - apparently it works in conjunction with the bass knob. I've found that if the bass knob is above about 3 or 4, the deep boost when flipped up (on my amp) seems to cut the bass slightly, or have almost no effect. At the moment I have the bass knob on 2, and the deep switch works as expected.

I wonder if anyone else has noticed this? It's not a big deal for me - I don't really feel a need for a deep boost anyway, so have been leaving mine off most of the time anyway.

I agree. I'm still getting to know my bluesmaster, but the settings that I seem to be gravitating towards are the same as yours. I even have the treble up at about 7, but that might be to compensate for my lousy speakers.

Something doesn't sound right. My amp is a HRM bluesmaster, but I believe it is supposed to work the same way as yours. The master volume knob in the power amp section controls the overall clean channel volume, whether or not the pab button (the green one) is pressed. When the red button is pressed, the level knob in the overdrive section becomes the moster volume. The green button should work in both sections. Check the switches on the back of the amp - they should both be set to the pedal side for the footswitch to work correctly.

You've got tone knobs - use them! They're not there for decoration. No-one's said to leave them at 12 o'clock - just to use that as a starting point. On my bluesmaster, which I'm still breaking in, I currently have the treble knob at 6 1/2, the middle knob on 4, and the bass knob on 3. My 4x10 cab with some kind of generic speakers is kind of dark sounding, so these settings get things in the ballpark for me.

That is gorgeous!

Well yes, but that doesn't give me the right to get my nose in technical matters like this. Especially if I get one small detail like this wrong! I may have built one fully functional guitar amp, but I'm not nearly on the same playing field as some folks here who have been messing with these things for years.

However, if you visit the modular synth forums, I'll be more than happy to help you troubleshoot your DIY synth problems - that's my actual area of (some) expertise! 

You're absolutely correct, I had misread the email I recently got from Nik about this very thing.

I should probably stay out of technical discussions about these amps - they're not really my area of expertise.

Thomas - it's the one between the 3.15v wires, marked 0.

The presence knob is a very subtle effect, as Gregg mentions. And it's almost impossible to wire incorrectly, so I'd assume it's working. I hear more differences with mine if I use a clean, chimey fendery setting in the clean channel, but again, it's only small differences - I just set mine in the middle.

You'll probably want to check the settings on the internal tone settings before worrying about how the external tone knobs are working - at least with my BM kit the trimmers came pre-set in a strange wonky setting that had the same effect as what you're reporting. Set the trimmers to the settings that are in the users manual first, and then go from there.

Ha! Yup, that would do it.

Beautiful guitar! I never really took to those Loyd Frose tailpieces, although I had one on the HM strat, and it worked ok on that one.

Discharge all your caps before messing with the amp. Double check the values of the 3 resistors between the bias pot and the bias test points. Double check the wiring on the bias pot. And triple check the wiring on the psu. If you're not sure about any of this stuff ask Nik.

FWIW my amp hits 35 mv with the pot right in the center of it's travel.

<cowardly lion voice> Ain't it the truth... ain't it the truth</cowardly lion voice>

That early PRS alone would probably pay my daughter's college tuition. It was a really early specimen - serial number 4 or something like that - there were earlier handmade ones, but this was literally one of the first of their mass produced ones. I bought the first one in Nashville I think. Dickie Betts played it for a few hours on a trip I made back to the store for some setup work, and ended up buying one later.