Project: Carlsbro PA 60 Head

As mentioned previously Mr. Foxen of Ampstack has given me a Carlsbro PA 60 to work on.



From what I can tell from info-mining the internet this is a early-mid 70s model, probably a late Mk II. All other Mk IIs I've seen pictures of are point-to-point wired whereas this is on PCB, but I cannot find any reference to a Mk III so kind of assuming that at some point during the Mk II being in production it was changed to PCB construction.)

I have done initial solder refreshing and resistor testing. During the course of this testing I learned that sometimes resistors in circuit test at a lower ohmage than they are rated for and that by popping one end out of the board you can make sure they're sound. One of the resistors is duff (cheapo non-original, natch) plus the HT fuse has blown so that needs replacing. There was also a bodged in power cable which I've now removed.





Next I'm going to clean up the valve sockets, pots, input jack, etc. and after that is powering up with no valves to check voltages.

Finally here is a bit of random human interest stuff. The amp was apparently built by Trev and tested by people who as far as I know exist only as initials.

Things are afoot...

So, it appears to be all go here at Atomic Tangerine.

Not only am I soon to take on my second non-personal guitar upgrade, but I've taken on a project from Mr. Foxen.

The guitar upgrade is a simple electronics and pickups replacement for a dude who wants a bit more punch and versatility from his Epiphone SG. Pickups will come from IronGear.

The project from Mr. Foxen is a Carlsbro PA 60. Basically a 60 watt all valve amp head originally intended for PA use. Pretty much a win-win situation as I get to do more learning and Foxen gets more of his to-do pile finished.

Peavey Road Master - It's Alive!!

I have finally fixed my Peavey Road Master. Following the diagnosis a while back I have got the resistors that I needed, and replaced them (along with putting smaller LEDs in the front panel so they don't catch so easily.










And Eric the Destroyer is back in action! After all that it was a couple of duff resistors. Less than 50p's worth of parts. Feel kind of silly that it's taken this long to sort a simple problem, but I am quite new at this, plus I get the good feelings that go with having sorted the issue.

Doubleplusgood is that I can take Eric to band practice next weekend.

Stratocopy

Well, it's certainly been a bit of a day here at Atomic Tangerine. Having had a terrible night's sleep I overslept enough that I missed most of the overtime I'd volunteered for, enough that it simply wasn't worth going in. Fail. So following shower, exercise and breakfast I decided to get going on that Stratcopy I'm working on for a friend.

I downloaded a generic wiring diagram from StewMac, and set to work. I won't bore you with all the details but I ended up with a pretty neat wiring job.


Yuh huh, I'm pretty happy with that.

So neck the pickups go in, the neck and middle from the Strat body I got from Mr. Foxen, and the bridge was originally the neck pickup in my old Jag-Stang, so the guitar has a 6.0k bridge pickup as opposed to 5.2k.

Aaaaanyway, I wire up the jack, ground the bridge and set to work using my trusty old Peavey Envoy 110 and a tuning fork (it's much easier to test pickups this way as it means not having to remove brand new strings if you need to do more work), and what I found was a little surprising. Position 1 on the switch was giving me the neck pickup, position two was the neck and bridge combined, and the rest of the switch positions were giving nothing but silence.

So I look at the diagram and check the switch and realise that the wiring on the diagram needs a different switch, so I get yet another diagram and set about desoldering and re-wiring.

And this time it works. Which pleases me.

Now I need to re-string it and set it up left-handed as J injured his hand a while ago and is finding it easier to play left-handed now.

ETA: Oh yeah, and none of the knobs I have will go on the CTS* shafts so I need to get new knobs.

*Yeah, the eletronics are waaay better than needs to be in this guitar, but when there's only about a fiver difference between the generic electronics and the good stuff you might as well just get the good stuff.

Harley Benton GA5 head - Power up and begin troubleshooting

So, with the chassis back in the box (probably unneccessary, but I did it anyway) I took the amp upstairs, plugged it into my 4x12, switched it on and... nothing. Not a jot. Not even a hiss or hum.

I know it's not a problem with the speaker cable or cab, as I tested them using my Peavey Road Master head just now and they work fine. So what other possible issues could there be?

I don't think it's the EL84 (power amp valve) as that was glowing quite happily when I looked in the back of the head. No idea if the 12AX7 was glowing as it's in a metal tube thing so obviously I can't see it. Next power-on test will be chassis out, valves uncovered so I can see them both. In the mean time I'm going to have a closer look at all the connections within the amp and double double check that nothing's loose or broken. Also going to bodge some means of keeping that in-line fuse thingy closed in case that's a problem.