JapanAxe

Well I found this video comparing a 1963 B15N and a 1971 B15S. They both sound great but they are running through different cabs:

Cheers chaps. My last PP amp build was the Trainwreck Rocket, which is a stripped-down AC30 top boost and uses a long tailed pair PI.

I looked at the SB12 schematic (see below). The preamp uses 12AX7s but I fancy doing a build with octal preamp valves. Just out of interest, is there a name for that phase inverter arrangement?

Yes, the only place I see the old metal ones is on restorations by Uncle Doug on YouTube!

Quite right, like many people I just say 6L6 when I mean 6L6GC.

For whatever reason my bass tastes rarely seem to coincide with yours @Cat Burrito but that all changed when I saw that Burns!

I think this is what they call the nuclear option!

HB2U! I’m lagging behind you by 4 years...

I mainly play finger style these days and I always surprise myself when I switch to pick playing, whatever the amp and cab.

Hang on Mike, this is not going to be a build thread! I'm just hitting on the BC hive mind for thoughts on the different B15 versions, ideally with some idea of what the sonic differences are e.g. 'feel' of grid bias vs cathode bias. I already found the CtG page and downloaded the build docs. Thanks for the tip about Trinity Amps - just downloaded their stuff too. This is now giving me even more options, whereas I want to settle on a simple 1-channel build with Volume, Treble, Bass (and maybe a bright switch). So @Chimike where's your build thread!? Yes I have a capacitor discharge probe and a dummy load (both DIY of course).

My AVO is in fact digital! I also have an old moving coil multimeter which is handy at times. I’ll probably pick up a ‘scope at some point and will then realise what I’ve been missing... I intend to build a wooden head sleeve to make a good size match to my One 10. In the bottom 1/3 of that will sit a U- or C-section aluminium chassis which can be ordered to size from Modulus Amps. The final form factor will be similar to a Demeter head:

It’s a valid question @BassmanPaul I come from a science background (physics) and have been doing electronics as a hobby for over 40 years. I got into valve amp builds with a 5E3 kit 4 or 5 years ago. During lockdown I rebuilt a previous 5E3 Micro build and scratch-built clones of the Trainwreck Rocket amp and Fender 6G15 outboard reverb. I have a good quality Megger AVO, a variac with accurate voltage and current read-outs, and of course a dim bulb tester. I don’t have an oscilloscope but haven’t found that to be a drawback thus far. I hope that sets your mind at rest! In other news I have discovered that the Ceriatone Aunt Peg appears to be a cheeky copy of Ampeg’s Heritage B15.

I have been severely bitten by the valve amp-building bug during lockdown(s) and among the projects in contemplation is something closely based on an Ampeg B15. I have the schematics of the various versions, and a layout for the single-channel Ceriatone Aunt Peg, which provides the options of cathode bias (1964) or grid bias (1966). I am in the process of converting the layout into a schematic. The versions I have been looking at are: B15N (1962) - cathode biased; B15NC (1964) - almost identical to the 1962 (different rectifier valve and screen resistors); B15N (1968) - grid biased, tone stack moved to after second gain stage; and B15NF (1968) - as B15N but with ultra-Hi and Ultra-Lo switches I will be building this as a single-channel single-input head. It will be run through a Barefaced One 10, which sounded gorgeous with the PF50T that I used to own. I think I'm right in saying that the cathode biased and grid biased versions put out 25W and 30W respectively. I have yet to decide whether I want to include Hi/Lo switches or different bias options. Are there any B15 connoisseurs out there that can fill me in on the pros and cons of the various versions?

Subscribed! Long-time Zappa fan here.

I had an item for sale on another forum and a guy in Slovakia expressed an interest. There was no land/sea delivery available so I gave him a price based on Express Air delivery, which he went for. The item was picked up from my home Tuesday lunchtime and delivered to his apartment in Bratislava before 10am the next day!

I’m pretty sorted for basses, amps and cabs, and I don’t go much on fx pedals for bass. However I traded my Ampeg PF50T on here to buy an EBS Class AB head (also on here), and I’m now preparing to build a head based on a B15. Ceriatone published a layout for their ‘Aunt Peg’ (ahem!) so I’m going to draw out the circuit from that and see how it compares to the various iterations of the B15. I have a couple of guitar amp builds in mind too. Otherwise it’s going to be small tweaks to my existing kit e.g. rounds instead of flats on my Dingwall PZ5.

That's a win all round then!

Is that electronically same as the Little B@st@rd?