JapanAxe

I'm still having some issues with this amp on the fuse front. When I switch out of standby, the T2A mains fuse often blows but not the T500mA HT fuse. On one occasion the mains fuse blew some minutes after switch-on, I suspect because it had been weakened. With just the rectifier valve fitted, I tried a (temporary) T4A mains fuse - now when I switch the warmed-up amp out of standby, the mains fuse doesn't blow, but if I do the same thing with the 6L6 valves also installed, the 6.3V pilot dims momentarily but again the mains fuse remains intact. I suspect the problem may be related to one or both of the following: Inrush current to the first filter cap; Sudden flow of current caused by the heater CT being 'elevated' to the output valve cathodes. Any ideas folks?

In one of my previous bands I first used a Boss Multi FX, later a board of 3 individual pedals. It was fun but not really necessary, and these days I just use a tuner pedal. I never find myself thinking, ‘I wish I had X pedal for this bit.’ I do still try my bass through pedals for fun at home from time to time though.

PM’d

You can still get them new but you’re looking at nearly £900.

Although I have used Reaper for the last few years, I don’t have an axe to grind about which DAW you should use. I moved to Reaper from a hardware solution (Akai DPS16) and I’ve got used to using it, but if you’re using a particular DAW and it works for you, you may be better off sticking with it rather than taking on the challenge of learning a different one.

No I still like a mid boost for phatness!

Can’t help with this but you have made me nostalgic for my PF-50T!

Mmmm… warm edges!

Never mind the knobs, count the sockets!

Anyone tried turning those knobs?!

I played with the same band again last night, again on lead guitar. I had my amp firing at a lower volume from the side of the stage as a monitor. It was also DI’d into the PA, which worked well. That’s good - looks like I can carry on without going ampless! The bass player had just bought an Aguilar Tone Hammer preamp pedal but tbh it was hard to know whether this improved his bass sound over the simple DI pedal I had seen him with previously. Obviously it gave him a lot more control over his EQ. I am considering a bass EQ/DI pedal build… EDIT: ...for poos and giggles.

The RCD plug is JoJo with 2 sockets which is very handy but I’ve never seen another one like it. Just make sure you get a double pole one - switches off both live an neutral when triggered. The ring main tester is a Rapitest but there are plenty of inexpensive alternatives available.

I always carry an RCD plug and a ring main tester. I rarely have to use the RCD now as most venues have them at the stage socket or on the consumer unit. The ring main tester has occasionally shown up a missing earth connection, the last 2 times being on an outdoor stage and at a rehearsal studio.

I’ve picked up some dep gigs with a rock’n’roll band, some on guitar, some on bass. The existing players (and deps) all go through the PA, with results ranging from ok to godawful. I have okayed it with the BL to bring a small amp, so for bass I will use my BF One 10 and a small head, but I should probably be prepared for situations where I have to go direct to the PA. I’m quite taken with the EBS Microbass 2, not least because I love the EQ in my EBS head, and currently weighing up the pros and cons of versions 2 and 3. However, my best recent recorded bass sounds have been achieved by plugging straight into my interface (Focusrite Scarlett 6i6). Also, as noted in another thread, this is currently a DI/EQ bargain.

We have a name! I considered various one-syllable words starting with a 'bee' sound, before settling on something... Spanish. My previous build was a Champ-inspired circuit in a 1x12 combo from a deceased Line 6 Spider, which I dubbed the Araña Muerta - Spanish for Dead Spider. So this one is the ABEJA 15. 'Abeja' is Spanish for 'bee'. I sorted the troublesome treble pot with a blast of switch cleaner. I might still try cooling the bias down a bit - it really does get rather hot above the 6L6s!

The pilot light has a white cover, but it's not the best photo. Nice suggestion though!

Hmmm… A strong contender!

The T2A fuses arrived today and the amp is now working just as it should, without blowing fuses. It draws around 0.35A (88W) from the mains when it has settled down, which is not unusual given how delightfully inefficient valve amps are - my Princeton Reverb draws 0.24A (61W). The steel bird cage gets quite hot above the valves, but my PF-50T did the same. I'm calling that a win. I just need a name now - any suggestions?

I’ve had a Selmer T’n’B 50 and an Ampeg PF-50T. The Ampeg had much more usable volume than the Selmer.

This afternoon I sat down to find what might have caused both fuses to blow when coming out of Standby. My first hypothesis was a (near-)dead short from the HT to ground downstream of the HT fuse. I examined all the cabinet fixings but none would have contacted any conductors, and there were no signs of arcing there or elsewhere. I then checked both 6L6 valves on my Orange Valve Tester and they were fine. Next I worked through all the components ancillary to those valves, and again found no problem. I measured resistances on all the transformer windings, so nothing has burned out there, and there was no short to earth from the first HT node. I went away and sat down with the schematic, which was when I realised my error. Based on previous builds, I had fitted a a fast blow (F) 500mA fuse in the HT line. However the schematic calls for a slow-blow or timed (T) fuse. I expect this is because the first filter cap is a fairly chunky 47uF, which the HT rail briefly sees as close to a dead short when coming out of Standby - briefly, but long enough to blow an F-rated fuse. For 240V operation the mains fuse should be a T2A (slow blow again) but I didn't have any slow blow 2A so I had fitted an (unmarked) Medium fuse, which had duly blown in response to the inrush current. I have now fitted a T500mA HT fuse, and ordered a supply of T2A fuses. Once they arrive I will try again, initially with the dim bulb current limiter. In the meantime, if you suffer from insomnia you can read all about glass fuses here.